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Journal Cover Current Biology
  [SJR: 4.729]   [H-I: 258]   [218 followers]  Follow
    
   Full-text available via subscription Subscription journal
   ISSN (Print) 0960-9822
   Published by Elsevier Homepage  [3043 journals]
  • Exocrine Gland-Secreting Peptide 1 Is a Key Chemosensory Signal
           Responsible for the Bruce Effect in Mice
    • Abstract: Publication date: Available online 12 October 2017
      Source:Current Biology
      Author(s): Tatsuya Hattori, Takuya Osakada, Takuto Masaoka, Rumi Ooyama, Nao Horio, Kazutaka Mogi, Miho Nagasawa, Sachiko Haga-Yamanaka, Kazushige Touhara, Takefumi Kikusui
      The Bruce effect refers to pregnancy termination in recently pregnant female rodents upon exposure to unfamiliar males [1]. This event occurs in specific combinations of laboratory mouse strains via the vomeronasal system [2, 3]; however, the responsible chemosensory signals have not been fully identified. Here we demonstrate that the male pheromone exocrine gland-secreting peptide 1 (ESP1) is one of the key factors that causes pregnancy block. Female mice exhibited high pregnancy failure rates upon encountering males that secreted different levels of ESP1 compared to the mated male. The effect was not observed in mice that lacked the ESP1 receptor, V2Rp5, which is expressed in vomeronasal sensory neurons. Prolactin surges in the blood after mating, which are essential for maintaining luteal function, were suppressed by ESP1 exposure, suggesting that a neuroendocrine mechanism underlies ESP1-mediated pregnancy failure. The single peptide pheromone ESP1 conveys not only maleness to promote female receptivity but also the males’ characteristics to facilitate memorization of the mating partner.
      Teaser Hattori et al. reveal that the male mouse pheromone ESP1 is a signaling molecule responsible for the pregnancy block. The female mated with a male memorizes the amount of ESP1 from the partner as an individual signature. Differences in the amount of ESP1 inhibit prolactin release and induce pregnancy block.

      PubDate: 2017-10-14T11:15:26Z
       
  • The Cys-Arg/N-End Rule Pathway Is a General Sensor of Abiotic Stress in
           Flowering Plants
    • Abstract: Publication date: Available online 12 October 2017
      Source:Current Biology
      Author(s): Jorge Vicente, Guillermina M. Mendiondo, Mahsa Movahedi, Marta Peirats-Llobet, Yu-ting Juan, Yu-yen Shen, Charlene Dambire, Katherine Smart, Pedro L. Rodriguez, Yee-yung Charng, Julie E. Gray, Michael J. Holdsworth
      Abiotic stresses impact negatively on plant growth, profoundly affecting yield and quality of crops. Although much is known about plant responses, very little is understood at the molecular level about the initial sensing of environmental stress. In plants, hypoxia (low oxygen, which occurs during flooding) is directly sensed by the Cys-Arg/N-end rule pathway of ubiquitin-mediated proteolysis, through oxygen-dependent degradation of group VII Ethylene Response Factor transcription factors (ERFVIIs) via amino-terminal (Nt-) cysteine [1, 2]. Using Arabidopsis (Arabidopsis thaliana) and barley (Hordeum vulgare), we show that the pathway regulates plant responses to multiple abiotic stresses. In Arabidopsis, genetic analyses revealed that response to these stresses is controlled by N-end rule regulation of ERFVII function. Oxygen sensing via the Cys-Arg/N-end rule in higher eukaryotes is linked through a single mechanism to nitric oxide (NO) sensing [3, 4]. In plants, the major mechanism of NO synthesis is via NITRATE REDUCTASE (NR), an enzyme of nitrogen assimilation [5]. Here, we identify a negative relationship between NR activity and NO levels and stabilization of an artificial Nt-Cys substrate and ERFVII function in response to environmental changes. Furthermore, we show that ERFVIIs enhance abiotic stress responses via physical and genetic interactions with the chromatin-remodeling ATPase BRAHMA. We propose that plants sense multiple abiotic stresses through the Cys-Arg/N-end rule pathway either directly (via oxygen sensing) or indirectly (via NO sensing downstream of NR activity). This single mechanism can therefore integrate environment and response to enhance plant survival.
      Graphical abstract image Teaser Vicente et al. show that the Cys-Arg/N-end rule pathway is a general sensor of abiotic stress. N-end rule action on ERFVII transcription factor substrates controls stress tolerance, influenced by NITRATE REDUCTASE and interactions with chromatin remodeling ATPase BRAHMA. This mechanism integrates environment and response to enhance survival.

      PubDate: 2017-10-14T11:15:26Z
       
  • Nanoscale Visualization of Biomineral Formation in Coral Proto-Polyps
    • Abstract: Publication date: Available online 12 October 2017
      Source:Current Biology
      Author(s): Tali Mass, Jeana L. Drake, John M. Heddleston, Paul G. Falkowski
      Calcium carbonate platforms produced by reef-building stony corals over geologic time are pervasive features around the world [1]; however, the mechanism by which these organisms produce the mineral is poorly understood (see review by [2]). It is generally assumed that stony corals precipitate calcium carbonate extracellularly as aragonite in a calcifying medium between the calicoblastic ectoderm and pre-existing skeleton, separated from the overlying seawater [2]. The calicoblastic ectoderm produces extracellular matrix (ECM) proteins, secreted to the calcifying medium [3–6], which appear to provide the nucleation, alteration, elongation, and inhibition mechanisms of the biomineral [7] and remain occluded and preserved in the skeleton [8–10]. Here we show in cell cultures of the stony coral Stylophora pistillata that calcium is concentrated in intracellular pockets that are subsequently exported from the cell where a nucleation process leads to the formation of extracellular aragonite crystals. Analysis of the growing crystals by lattice light-sheet microscopy suggests that the crystals elongate from the cells’ surfaces outward.
      Teaser Using coral cell cultures, Mass et al. show that the stony coral biomineralization mechanism begins with intracellularly concentrated calcium, which is exported for extracellular crystal nucleation and growth. Aragonite crystals elongate outward from an extracellular protein matrix into the culture medium.

      PubDate: 2017-10-14T11:15:26Z
       
  • Mothers Consistently Alter Their Unique Vocal Fingerprints When
           Communicating with Infants
    • Abstract: Publication date: Available online 12 October 2017
      Source:Current Biology
      Author(s): Elise A. Piazza, Marius Cătălin Iordan, Casey Lew-Williams
      The voice is the most direct link we have to others’ minds, allowing us to communicate using a rich variety of speech cues [1, 2]. This link is particularly critical early in life as parents draw infants into the structure of their environment using infant-directed speech (IDS), a communicative code with unique pitch and rhythmic characteristics relative to adult-directed speech (ADS) [3, 4]. To begin breaking into language, infants must discern subtle statistical differences about people and voices in order to direct their attention toward the most relevant signals. Here, we uncover a new defining feature of IDS: mothers significantly alter statistical properties of vocal timbre when speaking to their infants. Timbre, the tone color or unique quality of a sound, is a spectral fingerprint that helps us instantly identify and classify sound sources, such as individual people and musical instruments [5–7]. We recorded 24 mothers’ naturalistic speech while they interacted with their infants and with adult experimenters in their native language. Half of the participants were English speakers, and half were not. Using a support vector machine classifier, we found that mothers consistently shifted their timbre between ADS and IDS. Importantly, this shift was similar across languages, suggesting that such alterations of timbre may be universal. These findings have theoretical implications for understanding how infants tune in to their local communicative environments. Moreover, our classification algorithm for identifying infant-directed timbre has direct translational implications for speech recognition technology.
      Teaser Piazza et al. report a novel feature of motherese. When communicating with their infants, mothers shift the summary statistics of their vocal spectra, thereby altering their unique timbre fingerprints. This shift generalizes across a wide variety of languages and thus may be a universal form of communication with infants.

      PubDate: 2017-10-14T11:15:26Z
       
  • 40,000-Year-Old Individual from Asia Provides Insight into Early
           Population Structure in Eurasia
    • Abstract: Publication date: Available online 12 October 2017
      Source:Current Biology
      Author(s): Melinda A. Yang, Xing Gao, Christoph Theunert, Haowen Tong, Ayinuer Aximu-Petri, Birgit Nickel, Montgomery Slatkin, Matthias Meyer, Svante Pääbo, Janet Kelso, Qiaomei Fu
      By at least 45,000 years before present, anatomically modern humans had spread across Eurasia [1–3], but it is not well known how diverse these early populations were and whether they contributed substantially to later people or represent early modern human expansions into Eurasia that left no surviving descendants today. Analyses of genome-wide data from several ancient individuals from Western Eurasia and Siberia have shown that some of these individuals have relationships to present-day Europeans [4, 5] while others did not contribute to present-day Eurasian populations [3, 6]. As contributions from Upper Paleolithic populations in Eastern Eurasia to present-day humans and their relationship to other early Eurasians is not clear, we generated genome-wide data from a 40,000-year-old individual from Tianyuan Cave, China, [1, 7] to study his relationship to ancient and present-day humans. We find that he is more related to present-day and ancient Asians than he is to Europeans, but he shares more alleles with a 35,000-year-old European individual than he shares with other ancient Europeans, indicating that the separation between early Europeans and early Asians was not a single population split. We also find that the Tianyuan individual shares more alleles with some Native American groups in South America than with Native Americans elsewhere, providing further support for population substructure in Asia [8] and suggesting that this persisted from 40,000 years ago until the colonization of the Americas. Our study of the Tianyuan individual highlights the complex migration and subdivision of early human populations in Eurasia.
      Graphical abstract image Teaser Yang et al. show that the genome of a 40 kya individual from Tianyuan cave near Beijing is more similar to Asians than to Europeans, past or present. His similarity to a 35 kya European and to individuals from some South American populations suggests a persistence of population structure in Asia that lasted until the colonization of the Americas.

      PubDate: 2017-10-14T11:15:26Z
       
  • Genetic Ancestry of Rapanui before and after European Contact
    • Abstract: Publication date: Available online 12 October 2017
      Source:Current Biology
      Author(s): Lars Fehren-Schmitz, Catrine L. Jarman, Kelly M. Harkins, Manfred Kayser, Brian N. Popp, Pontus Skoglund
      The origins and lifeways of the inhabitants of Rapa Nui (Easter Island), a remote island in the southeast Pacific Ocean, have been debated for generations. Archaeological evidence substantiates the widely accepted view that the island was first settled by people of Polynesian origin, as late as 1200 CE [1–4]. What remains controversial, however, is the nature of events in the island’s population history prior to the first historic contact with Europeans in 1722 CE. Purported contact between Rapa Nui and South America is particularly contentious, and recent studies have reported genetic evidence for Native American admixture in present-day indigenous inhabitants of Rapa Nui [5–8]. Statistical modeling has suggested that this genetic contribution might have occurred prior to European contact [6]. Here we directly test the hypothesis that the Native American admixture of the current Rapa Nui population predates the arrival of Europeans with a paleogenomic analysis of five individual samples excavated from Ahu Nau Nau, Anakena, dating to pre- and post-European contact, respectively. Complete mitochondrial genomes and low-coverage autosomal genomes show that the analyzed individuals fall within the genetic diversity of present-day and ancient Polynesians, and we can reject the hypothesis that any of these individuals had substantial Native American ancestry. Our data thus suggest that the Native American ancestry in contemporary Easter Islanders was not present on the island prior to European contact and may thus be due to events in more recent history.
      Teaser Fehren-Schmitz et al. sequence low-coverage genomes of three pre-European-contact and two post-European-contact individuals from Rapa Nui (Easter Island, Chile). They find that the pre-European-contact Rapanui individuals fall well into the genetic variability of prehistoric and modern Polynesian populations and show no admixture with Native Americans.

      PubDate: 2017-10-14T11:15:26Z
       
  • Disruption of Core Planar Cell Polarity Signaling Regulates Renal Tubule
           Morphogenesis but Is Not Cystogenic
    • Abstract: Publication date: Available online 12 October 2017
      Source:Current Biology
      Author(s): Koshi Kunimoto, Roy D. Bayly, Eszter K. Vladar, Tyson Vonderfecht, Anna-Rachel Gallagher, Jeffrey D. Axelrod
      Oriented cell division (OCD) and convergent extension (CE) shape developing renal tubules, and their disruption has been associated with polycystic kidney disease (PKD) genes, the majority of which encode proteins that localize to primary cilia. Core planar cell polarity (PCP) signaling controls OCD and CE in other contexts, leading to the hypothesis that disruption of PCP signaling interferes with CE and/or OCD to produce PKD. Nonetheless, the contribution of PCP to tubulogenesis and cystogenesis is uncertain, and two major questions remain unanswered. Specifically, the inference that mutation of PKD genes interferes with PCP signaling is untested, and the importance of PCP signaling for cystogenic PKD phenotypes has not been examined. We show that, during proliferative stages, PCP signaling polarizes renal tubules to control OCD. However, we find that, contrary to the prevailing model, PKD mutations do not disrupt PCP signaling but instead act independently and in parallel with PCP signaling to affect OCD. Indeed, PCP signaling that is normally downregulated once development is completed is retained in cystic adult kidneys. Disrupting PCP signaling results in inaccurate control of tubule diameter, a tightly regulated parameter with important physiological ramifications. However, we show that disruption of PCP signaling is not cystogenic. Our results suggest that regulating tubule diameter is a key function of PCP signaling but that loss of this control does not induce cysts.
      Graphical abstract image Teaser Although perturbation of oriented cell division is frequently associated with polycystic kidney disease, Kunimoto et al. show that blocking planar cell polarity (PCP) signaling is not cystogenic, nor is PCP disturbed in cysts induced by disruption of primary cilia. The commonly proposed model in which PCP regulates cystogenesis is thus incorrect.

      PubDate: 2017-10-14T11:15:26Z
       
  • Transcranial Direct Current Stimulation Facilitates Associative Learning
           and Alters Functional Connectivity in the Primate Brain
    • Abstract: Publication date: Available online 12 October 2017
      Source:Current Biology
      Author(s): Matthew R. Krause, Theodoros P. Zanos, Bennett A. Csorba, Praveen K. Pilly, Jaehoon Choe, Matthew E. Phillips, Abhishek Datta, Christopher C. Pack
      There has been growing interest in transcranial direct current stimulation (tDCS), a non-invasive technique purported to modulate neural activity via weak, externally applied electric fields. Although some promising preliminary data have been reported for applications ranging from stroke rehabilitation to cognitive enhancement, little is known about how tDCS affects the human brain, and some studies have concluded that it may have no effect at all. Here, we describe a macaque model of tDCS that allows us to simultaneously examine the effects of tDCS on brain activity and behavior. We find that applying tDCS to right prefrontal cortex improves monkeys’ performance on an associative learning task. While firing rates do not change within the targeted area, tDCS does induce large low-frequency oscillations in the underlying tissue. These oscillations alter functional connectivity, both locally and between distant brain areas, and these long-range changes correlate with tDCS’s effects on behavior. Together, these results are consistent with the idea that tDCS leads to widespread changes in brain activity and suggest that it may be a valuable method for cheaply and non-invasively altering functional connectivity in humans.
      Teaser Krause et al. test transcranial direct current stimulation (tDCS) in a realistic non-human primate model. Stimulation of prefrontal cortex (PFC) improved animals’ associative learning while altering coherence between PFC and sensory areas. Their data suggest that tDCS may act by altering long-range connectivity between PFC and other brain areas.

      PubDate: 2017-10-14T11:15:26Z
       
  • Alpha-Band Activity Reveals Spontaneous Representations of Spatial
           Position in Visual Working Memory
    • Abstract: Publication date: Available online 12 October 2017
      Source:Current Biology
      Author(s): Joshua J. Foster, Emma M. Bsales, Russell J. Jaffe, Edward Awh
      An emerging view suggests that spatial position is an integral component of working memory (WM), such that non-spatial features are bound to locations regardless of whether space is relevant [1, 2]. For instance, past work has shown that stimulus position is spontaneously remembered when non-spatial features are stored. Item recognition is enhanced when memoranda appear at the same location where they were encoded [3–5], and accessing non-spatial information elicits shifts of spatial attention to the original position of the stimulus [6, 7]. However, these findings do not establish that a persistent, active representation of stimulus position is maintained in WM because similar effects have also been documented following storage in long-term memory [8, 9]. Here we show that the spatial position of the memorandum is actively coded by persistent neural activity during a non-spatial WM task. We used a spatial encoding model in conjunction with electroencephalogram (EEG) measurements of oscillatory alpha-band (8–12 Hz) activity to track active representations of spatial position. The position of the stimulus varied trial to trial but was wholly irrelevant to the tasks. We nevertheless observed active neural representations of the original stimulus position that persisted throughout the retention interval. Further experiments established that these spatial representations are dependent on the volitional storage of non-spatial features rather than being a lingering effect of sensory energy or initial encoding demands. These findings provide strong evidence that online spatial representations are spontaneously maintained in WM—regardless of task relevance—during the storage of non-spatial features.
      Teaser Foster et al. show that human observers spontaneously maintain active neural representations of the spatial positions of memoranda held in visual working memory, even when space is wholly irrelevant to the task. These spatial representations are coded by oscillatory activity in the alpha band (8–12 Hz).

      PubDate: 2017-10-14T11:15:26Z
       
  • Genetic Discontinuity between the Maritime Archaic and Beothuk Populations
           in Newfoundland, Canada
    • Abstract: Publication date: Available online 12 October 2017
      Source:Current Biology
      Author(s): Ana T. Duggan, Alison J.T. Harris, Stephanie Marciniak, Ingeborg Marshall, Melanie Kuch, Andrew Kitchen, Gabriel Renaud, John Southon, Ben Fuller, Janet Young, Stuart Fiedel, G. Brian Golding, Vaughan Grimes, Hendrik Poinar
      Situated at the furthest northeastern edge of Canada, the island of Newfoundland (approximately 110,000 km2) and Labrador (approximately 295,000 km2) today constitute a province characterized by abundant natural resources but low population density. Both landmasses were covered by the Laurentide ice sheet during the Last Glacial Maximum (18,000 years before present [YBP]); after the glacier retreated, ice patches remained on the island until ca. 9,000 calibrated (cal) YBP [1]. Nevertheless, indigenous peoples, whose ancestors had trekked some 5,000 km from the west coast, arrived approximately 10,000 cal YBP in Labrador and ca. 6,000 cal YBP in Newfoundland [2, 3]. Differential features in material culture indicate at least three settlement episodes by distinct cultural groups, including the Maritime Archaic, Palaeoeskimo, and Beothuk. Newfoundland has remained home to indigenous peoples until present day with only one apparent hiatus (3,400–2,800 YBP). This record suggests abandonment, severe constriction, or local extinction followed by subsequent immigrations from single or multiple source populations, but the specific dynamics and the cultural and biological relationships, if any, among these successive peoples remain enigmatic [4]. By examining the mitochondrial genome diversity and isotopic ratios of 74 ancient remains in conjunction with the archaeological record, we have provided definitive evidence for the genetic discontinuity between the maternal lineages of these populations. This northeastern margin of North America appears to have been populated multiple times by distinct groups that did not share a recent common ancestry, but rather one much deeper in time at the entry point into the continent.
      Teaser Duggan et al. generate 74 whole mitochondrial genomes and stable-isotope data from three ancient aboriginal populations from coastal Eastern Canada, spanning eight millennia as well as European contact. The findings indicate a lack of genetic continuity between successive cultural groups and suggest complex dynamics of population and settlement.

      PubDate: 2017-10-14T11:15:26Z
       
  • Life’s islands under the sea
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Michael Gross
      Islands, with their effective but leaky isolation from the rest of the world, have helped evolution to produce some remarkable diversity, as Darwin noticed when he visited the Galápagos archipelago. Since then, the theory of island biogeography has enabled ecologists to understand the fate of species in similarly isolated locations on the continents and even under water. Michael Gross reports.
      Teaser Islands have helped evolution to produce some remarkable diversity, as Darwin noticed when he visited the Galápagos archipelago. Since then, the theory of island biogeography has enabled ecologists to understand the fate of species in similarly isolated locations on the continents and even under water.

      PubDate: 2017-10-14T11:15:26Z
       
  • Melissa Coleman
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Melissa Coleman
      Teaser An interview with neuroethologist Melissa Coleman.

      PubDate: 2017-10-14T11:15:26Z
       
  • Russia’s new Lysenkoism
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Edouard I. Kolchinsky, Ulrich Kutschera, Uwe Hossfeld, Georgy S. Levit
      During the late 1940s and 1950s, a pseudo-scientific concept based on Marxist-Leninist ideology became internationally known as ‘Lysenkoism’. Lysenkoism was a neo-Lamarckian idea, claiming that in crop plants, such as wheat, environmental influences are heritable via all cells of the organism. Lysenkoism was applied to agriculture during the Stalin era with disastrous consequences. Despite the triumphs of modern genetics, and the disproval of Lysenkoism, recent years have seen a ‘re-thinking’ of this doctrine in Russia. This disturbing pro-Lysenko movement, which is accompanied by a growing sympathy for Stalin, claims to have its scientific roots in modern epigenetics, specifically the heritability of variation by mechanisms other than changes in DNA sequence. Based on recent research on the model plant Arabidopsis thaliana, its is clear that Lysenkoism has nothing to do with heritable ‘epigenetic’ modifications. Biologists should defend science against ideological and political interferences.
      Teaser Kolchinsky et al. investigate the current resurgent interest in Soviet geneticist Trofim Lysenko and relate it to recent advances in epigenetics.

      PubDate: 2017-10-14T11:15:26Z
       
  • Transvection
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Takashi Fukaya, Michael Levine
      Teaser Fukaya and Levine explain the basic features of the genetic phenomenon of transvection, a special class of genetic complementation of mutant alleles on homologous chromosomes.

      PubDate: 2017-10-14T11:15:26Z
       
  • Bee cognition
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Lars Chittka
      Maeterlinck did not mean to suggest that honeybees rival humans in intelligence — rather he saw in the bee a qualitatively different form of intelligence, tailored to the challenges of a profoundly different kind of society and lifestyle. Insects are strange “aliens from inner space”, with sensory and cognitive worlds wholly different from our own. The 19th century discovery that ants can detect ultraviolet light triggered a golden age in the exploration of the diversity of sensory systems of insects (and indeed other animals), identifying such abilities as magnetic compasses, electrosensitivity, polarization vision, and peculiar locations for sense organs such as the infrared sensors on the abdomens of some beetles or photoreceptors on the genitalia of some butterflies. Could insect minds be equally strange and diverse'
      Teaser A Primer by Lars Chittka on bee cognition, explaining how, despite as insects having relatively small brains, bees have a remarkably diverse behavioural repertoire and cognitive flexibility.

      PubDate: 2017-10-14T11:15:26Z
       
  • A combined 3D-SIM/SMLM approach allows centriole proteins to be localized
           with a precision of ∼4–5 nm
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Lisa Gartenmann, Alan Wainman, Maryam Qurashi, Rainer Kaufmann, Sebastian Schubert, Jordan W. Raff, Ian M. Dobbie
      Centrioles are small barrel-shaped structures that form centrosomes and cilia [1]. Centrioles assemble around a central cartwheel comprising the Sas-6 and Ana2/STIL proteins. The amino termini of nine Sas-6 dimers form a central hub of ∼12 nm radius from which nine dimer spokes radiate, placing the Sas-6 carboxyl termini at the outer edge of the ∼60 nm radius cartwheel [2]. Several centriole proteins are distributed in a toroid around the cartwheel, and super-resolution light microscopy studies have measured the average radii of these ∼100–200 nm radius toroids with a ‘precision’ — or standard deviation (s.d. or 1σ) — of ±∼10–40 nm. The organization of Ana2/STIL within the cartwheel, however, has not been resolvable. Here, we develop methods to calculate the average toroidal radius of centriolar proteins in the ∼20–60 nm range with a s.d. of just ±∼4–5 nm, revealing that the amino and carboxyl termini of Ana2 are located in the outer cartwheel region.
      Teaser Centrioles are small structures that assemble around a central cartwheel comprising Sas-6, Ana2/STIL and Sas-4. The cartwheel cannot be resolved by conventional light microscopy. Here, Gartenmann et al. resolve the relative positions of the Sas-6, Ana2 and Sas-4 termini within the cartwheel using combined SIM/SMLM super-resolution microscopy.

      PubDate: 2017-10-14T11:15:26Z
       
  • Dawn illumination prepares desert cyanobacteria for dehydration
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Nadav Oren, Hagai Raanan, Omer Murik, Nir Keren, Aaron Kaplan
      Desert biological soil crusts (BSC), among the harshest environments on Earth, are formed by the adhesion of soil particles to polysaccharides excreted mainly by filamentous cyanobacteria (see [1] and references therein). These species are the main primary producers in this habitat where they cope with various stressors including frequent hydration–dehydration cycles. Water is mainly provided as early-morning dew, followed by dehydration with rising temperatures and declining relative humidity. Earlier studies focused on community structure and cyanobacterial activities in various BSCs [1,2]. They identified genes present in dehydration-tolerant, but not -sensitive cyanobacteria [3], and suggested that abiotic conditions during natural dehydration (Figure 1A) are critical for the recovery upon rewetting. Inability of Leptolyngbya ohadii, which is abundant in the BSC examined here, to recover after rapid desiccation (Figure 1B) [4] suggested that the cells must prepare themselves toward forthcoming dehydration, but the nature of the signal involved was unknown. We show here that the rising dawn illumination, perceived by photo-sensors, serves as the signal inciting BSC-inhabiting cyanobacteria to prepare for forthcoming dehydration. L. ohadii filaments were exposed to simulated natural conditions from the morning of October 14th 2009, using our environmental chamber that enables accurate reproduction of BSC environment [4] (Supplemental Figure S1A). Samples were withdrawn at specific time points (Figure 1A), followed by RNA extraction and global transcript profiling (accession PRJNA391854). Four hours of dehydration led to up-regulation of 567 genes and down-regulation of 1597 (by more than 2-fold). Since BSC-inhabiting organisms have not been used as genetic models, the functions of 3258 (43.5% of the 7487 L. ohadii genes [3]) are unknown. Nevertheless, a pronounced rise in transcript levels of genes involved in carbon metabolism, transport, osmolyte production, energy dissipation and other cellular activities was observed. On the other hand, a declining transcript abundance for genes involved in light harvesting, photosynthetic metabolism, protein biosynthesis, cell division and other pathways was detected. The analysis unraveled clear distinctions between early- and late-responding genes. Supplemental Table S1 lists the 40 strongest differentially expressed genes verified by RT-qPCR and used in further analyses.
      Teaser Oren et al. show that dawn illumination is used by desert soil cyanobacteria to prepare for dehydration.

      PubDate: 2017-10-14T11:15:26Z
       
  • Northern pygmy right whales highlight Quaternary marine mammal interchange
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Cheng-Hsiu Tsai, Alberto Collareta, Erich M.G. Fitzgerald, Felix G. Marx, Naoki Kohno, Mark Bosselaers, Gianni Insacco, Agatino Reitano, Rita Catanzariti, Masayuki Oishi, Giovanni Bianucci
      The pygmy right whale, Caperea marginata, is the most enigmatic living whale. Little is known about its ecology and behaviour, but unusual specialisations of visual pigments [1], mitochondrial tRNAs [2], and postcranial anatomy [3] suggest a lifestyle different from that of other extant whales. Geographically, Caperea represents the only major baleen whale lineage entirely restricted to the Southern Ocean. Caperea-like fossils, the oldest of which date to the Late Miocene, are exceedingly rare and likewise limited to the Southern Hemisphere [4], despite a more substantial history of fossil sampling north of the equator. Two new Pleistocene fossils now provide unexpected evidence of a brief and relatively recent period in geological history when Caperea occurred in the Northern Hemisphere (Figure 1A,B).
      Teaser During the Pleistocene, glacial cooling allowed marine mammals to cross the tropics and disperse across both hemispheres, Here, Tsai et al. report fossil findings suggesting that pygmy right whales, Caperea marginata, occurred in the Northern Hemisphere during this era.

      PubDate: 2017-10-14T11:15:26Z
       
  • Sleep Origins: Restful Jellyfish Are Sleeping Jellyfish
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): John A. Lesku, Linh M.T. Ly
      What is the ‘simplest’ animal that sleeps' When did sleep first evolve' Do all animals sleep' Tantalizing hints to answers come from new research showing that jellyfish, one of the earliest evolving groups of animals, have a sleep-like restful state.
      Teaser What is the ‘simplest’ animal that sleeps' When did sleep first evolve' Do all animals sleep' Tantalizing hints to answers come from new research showing that jellyfish, one of the earliest evolving groups of animals, have a sleep-like restful state.

      PubDate: 2017-10-14T11:15:26Z
       
  • Plant Biology: Unravelling the Transient Physiological Role for PHO1 in
           the Seed
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Laurent Nussaume
      During seed development, an important transfer of nutrients occurs between the seed coat and the embryo. A new study reveals that, for inorganic phosphate (Pi), this function is transiently performed by PHO1, a protein associated previously with Pi loading into the xylem.
      Teaser During seed development, an important transfer of nutrients occurs between the seed coat and the embryo. A new study reveals that, for inorganic phosphate (Pi) this function is transiently performed by PHO1, a protein associated previously with Pi loading into the xylem.

      PubDate: 2017-10-14T11:15:26Z
       
  • Evolution: A Parthenogenetic Nematode Shows How Animals Become Sexless
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Erich M. Schwarz
      Most animals have male and female sexes, implying that sex is ancient and beneficial; yet some have survived for millions of years without sex. The genome of the parthenogenetic nematode Diploscapter pachys gives clues as to how ‘ancient asexual’ animals can exist.
      Teaser Most animals have male and female sexes, implying that sex is ancient and beneficial; yet some have survived for millions of years without sex. The genome of the parthenogenetic nematode Diploscapter pachys gives clues as to how ‘ancient asexual’ animals can exist.

      PubDate: 2017-10-14T11:15:26Z
       
  • Retrotransposons: Stowaways in the Primordial Germline
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Erin S. Kelleher
      In order to succeed, retrotransposon transcripts must identify the subset of nuclei that will be transmitted to offspring. A new study reveals that the primordial germline is a hideout for retrotransposon transcripts, providing early access to future gametes.
      Teaser In order to succeed, retrotransposon transcripts must identify the subset of nuclei that will be transmitted to offspring. A new study reveals that the primordial germline is a hideout for retrotransposon transcripts: providing early access to future gametes.

      PubDate: 2017-10-14T11:15:26Z
       
  • Plant Biology: Rethinking Structure–Function Relationships in Guard
           Cells
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Graham Dow
      Recent findings highlight the role of polar reinforcement in guard cell function, which simultaneously improves our understanding of stomatal mechanics and questions our long-standing beliefs about structurally important factors.
      Teaser Recent findings highlight the role of polar reinforcement in guard cell function, which simultaneously improves our understanding of stomatal mechanics and questions our long-standing beliefs about structurally important factors.

      PubDate: 2017-10-14T11:15:26Z
       
  • Muscle Development: Nucleating Microtubules at the Nuclear Envelope
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Daniel A. Starr
      Microtubule-organizing centers move from centrosomes to the nuclear envelope during muscle development. The KASH protein Nesprin-1α recruits pericentriolar material to the surface of myotube nuclei, where it nucleates microtubules to ensure even spacing of nuclei within the developing myotube.
      Teaser Microtubule-organizing centers move from centrosomes to the nuclear envelope during muscle development. The KASH protein Nesprin-1α recruits pericentriolar material to the surface of myotube nuclei, where it nucleates microtubules to ensure even spacing of nuclei within the developing myotube.

      PubDate: 2017-10-14T11:15:26Z
       
  • Behavioural Ecology: Spiders Play the Imitation Game
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Tom N. Sherratt
      Examples of mimicry are widely celebrated because of the remarkable physical similarities they entail. A new study shows how an ant-mimicking spider uses behaviour to create the illusion of antennae, while walking in a manner resembling ants following pheromone trails.
      Teaser Examples of mimicry are widely celebrated because of the remarkable physical similarities they entail. A new study shows how an ant-mimicking spider uses behaviour to create the illusion of antennae, while walking in a manner resembling ants following pheromone trails.

      PubDate: 2017-10-14T11:15:26Z
       
  • Insect Vision: A Neuron that Anticipates an Object’s Path
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Mark A. Frye
      Dragonflies are superb aerial predators, plucking tiny insect prey from the sky. This ability depends on a visual system that has fascinated scientists for decades, and now one of its visual-target-detecting neurons has been shown to anticipate the image path of prey.
      Teaser Dragonflies are superb aerial predators, plucking tiny insect prey from the sky. This ability depends on a visual system that has fascinated scientists for decades, and now one of its visual-target-detecting neurons has been shown to anticipate the image path of prey.

      PubDate: 2017-10-14T11:15:26Z
       
  • Cell Biology: Capturing Formin’s Mechano-Inhibition
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Dimitrios Vavylonis, Brandon G. Horan
      Formins polymerize actin filaments for the cytokinetic contractile ring. Using in vitro reconstitution of fission yeast contractile ring precursor nodes containing formins and myosin, a new study shows that formin-mediated polymerization is strongly inhibited upon the capture and pulling of actin filaments by myosin, a result that has broad implications for cellular mechanosensing.
      Teaser Formins polymerize actin filaments for the cytokinetic contractile ring. In vitro reconstitution of fission yeast contractile ring precursor nodes containing formins and myosin shows that formin-mediated polymerization is strongly inhibited upon the capture and pulling of actin filaments by myosin, with broader implications for mechanosensing.

      PubDate: 2017-10-14T11:15:26Z
       
  • Embracing Uncertainty in Reconstructing Early Animal Evolution
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Nicole King, Antonis Rokas
      The origin of animals, one of the major transitions in evolution, remains mysterious. Many key aspects of animal evolution can be reconstructed by comparing living species within a robust phylogenetic framework. However, uncertainty remains regarding the evolutionary relationships between two ancient animal lineages — sponges and ctenophores — and the remaining animal phyla. Comparative morphology and some phylogenomic analyses support the view that sponges represent the sister lineage to the rest of the animals, while other phylogenomic analyses support ctenophores, a phylum of carnivorous, gelatinous marine organisms, as the sister lineage. Here, we explore why different studies yield different answers and discuss the implications of the two alternative hypotheses for understanding the origin of animals. Reconstruction of ancient evolutionary radiations is devilishly difficult and will likely require broader sampling of sponge and ctenophore genomes, improved analytical strategies and critical analyses of the phylogenetic distribution and molecular mechanisms underlying apparently conserved traits. Rather than staking out positions in favor of the ctenophores-sister or the sponges-sister hypothesis, we submit that research programs aimed at understanding the biology of the first animals should instead embrace the uncertainty surrounding early animal evolution in their experimental designs.
      Teaser King and Rokas investigate why it has been so hard to resolve the relationships among sponges, ctenophores and the rest of animal phyla and what this uncertainty means for the early evolution of animals in general.

      PubDate: 2017-10-14T11:15:26Z
       
  • PHO1 Exports Phosphate from the Chalazal Seed Coat to the Embryo in
           Developing Arabidopsis Seeds
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Evangelia Vogiatzaki, Célia Baroux, Ji-Yul Jung, Yves Poirier
      Seed production requires the transfer of nutrients from the maternal seed coat to the filial endosperm and embryo. Because seed coat and filial tissues are symplasmically isolated, nutrients arriving in the seed coat via the phloem must be exported to the apoplast before reaching the embryo. Proteins implicated in the transfer of inorganic phosphate (Pi) from the seed coat to the embryo are unknown despite seed P content being an important agronomic trait. Here we show that the Arabidopsis Pi exporters PHO1 and PHOH1 are expressed in the chalazal seed coat (CZSC) of developing seeds. PHO1 is additionally expressed in developing ovules. Phosphorus (P) content and Pi flux between the seed coat and embryo were analyzed in seeds from grafts between WT roots and scions from either pho1, phoh1, or the pho1 phoh1 double mutant. Whereas P content and distribution between the seed coat and embryo in fully mature dry seeds of these mutants are similar to the WT, at the mature green stage of seed development the seed coat of the pho1 and pho1 phoh1 mutants, but not of the phoh1 mutant, retains approximately 2-fold more P than its WT control. Expression of PHO1 under a CZSC-specific promoter complemented the seed P distribution phenotype of the pho1 phoh1 double mutant. CZSC-specific down-expression of PHO1 also recapitulated the seed P distribution phenotype of pho1. Together, these experiments show that PHO1 expression in the CZSC is important for the transfer of P from the seed coat to the embryo in developing seeds.
      Teaser Transfer of nutrients from the maternal seed coat to the filial embryo involves an apoplastic export step because these tissues are symplastically isolated. Vogiatzaki et al. demonstrate that the PHO1 phosphate exporter is expressed in the chalazal seed coat and contributes to the transfer of phosphate to the embryo in developing Arabidopsis seeds.

      PubDate: 2017-10-14T11:15:26Z
       
  • Drosophila Spatiotemporally Integrates Visual Signals to Control Saccades
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Jean-Michel Mongeau, Mark A. Frye
      Like many visually active animals, including humans, flies generate both smooth and rapid saccadic movements to stabilize their gaze. How rapid body saccades and smooth movement interact for simultaneous object pursuit and gaze stabilization is not understood. We directly observed these interactions in magnetically tethered Drosophila free to rotate about the yaw axis. A moving bar elicited sustained bouts of saccades following the bar, with surprisingly little smooth movement. By contrast, a moving panorama elicited robust smooth movement interspersed with occasional optomotor saccades. The amplitude, angular velocity, and torque transients of bar-fixation saccades were finely tuned to the speed of bar motion and were triggered by a threshold in the temporal integral of the bar error angle rather than its absolute retinal position error. Optomotor saccades were tuned to the dynamics of panoramic image motion and were triggered by a threshold in the integral of velocity over time. A hybrid control model based on integrated motion cues simulates saccade trigger and dynamics. We propose a novel algorithm for tuning fixation saccades in flies.
      Teaser Visual animals generate smooth and saccadic eye movements, which must interact to both stabilize gaze and track salient features. Mongeau and Frye examine magnetically tethered fruit flies and show that they temporally integrate visual cues to trigger and tune object-fixation saccades independently from smooth movement for ground stabilization.

      PubDate: 2017-10-14T11:15:26Z
       
  • BubR1 Promotes Bub3-Dependent APC/C Inhibition during Spindle Assembly
           Checkpoint Signaling
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Katharina Overlack, Tanja Bange, Florian Weissmann, Alex C. Faesen, Stefano Maffini, Ivana Primorac, Franziska Müller, Jan-Michael Peters, Andrea Musacchio
      The spindle assembly checkpoint (SAC) prevents premature sister chromatid separation during mitosis. Phosphorylation of unattached kinetochores by the Mps1 kinase promotes recruitment of SAC machinery that catalyzes assembly of the SAC effector mitotic checkpoint complex (MCC). The SAC protein Bub3 is a phospho-amino acid adaptor that forms structurally related stable complexes with functionally distinct paralogs named Bub1 and BubR1. A short motif (“loop”) of Bub1, but not the equivalent loop of BubR1, enhances binding of Bub3 to kinetochore phospho-targets. Here, we asked whether the BubR1 loop directs Bub3 to different phospho-targets. The BubR1 loop is essential for SAC function and cannot be removed or replaced with the Bub1 loop. BubR1 loop mutants bind Bub3 and are normally incorporated in MCC in vitro but have reduced ability to inhibit the MCC target anaphase-promoting complex (APC/C), suggesting that BubR1:Bub3 recognition and inhibition of APC/C requires phosphorylation. Thus, small sequence differences in Bub1 and BubR1 direct Bub3 to different phosphorylated targets in the SAC signaling cascade.
      Graphical abstract image Teaser In spindle assembly checkpoint (SAC) signaling, the phospho-amino acid adaptor Bub3 forms complexes with Bub1 and BubR1 paralogs. Whether Bub3-Bub1 and Bub3-BubR1 bind distinct targets has been unclear. Overlack et al. demonstrate that this is the case and identify a motif in BubR1 that directs Bub3 to the SAC target, the anaphase-promoting complex.

      PubDate: 2017-10-14T11:15:26Z
       
  • Genome Architecture and Evolution of a Unichromosomal Asexual Nematode
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Hélène Fradin, Karin Kiontke, Charles Zegar, Michelle Gutwein, Jessica Lucas, Mikhail Kovtun, David L. Corcoran, L. Ryan Baugh, David H.A. Fitch, Fabio Piano, Kristin C. Gunsalus
      Asexual reproduction in animals, though rare, is the main or exclusive mode of reproduction in some long-lived lineages. The longevity of asexual clades may be correlated with the maintenance of heterozygosity by mechanisms that rearrange genomes and reduce recombination. Asexual species thus provide an opportunity to gain insight into the relationship between molecular changes, genome architecture, and cellular processes. Here we report the genome sequence of the parthenogenetic nematode Diploscapter pachys with only one chromosome pair. We show that this unichromosomal architecture is shared by a long-lived clade of asexual nematodes closely related to the genetic model organism Caenorhabditis elegans. Analysis of the genome assembly reveals that the unitary chromosome arose through fusion of six ancestral chromosomes, with extensive rearrangement among neighboring regions. Typical nematode telomeres and telomeric protection-encoding genes are lacking. Most regions show significant heterozygosity; homozygosity is largely concentrated to one region and attributed to gene conversion. Cell-biological and molecular evidence is consistent with the absence of key features of meiosis I, including synapsis and recombination. We propose that D. pachys preserves heterozygosity and produces diploid embryos without fertilization through a truncated meiosis. As a prelude to functional studies, we demonstrate that D. pachys is amenable to experimental manipulation by RNA interference.
      Graphical abstract image Teaser By genome sequencing, Fradin et al. discover that the single chromosome in an asexual group of nematodes resulted from a fusion of six ancestral chromosomal domains. Due to the lack of recombination between alleles at most loci, high heterozygosity has evolved, providing one explanation for the unexpected longevity of this asexual lineage.

      PubDate: 2017-10-14T11:15:26Z
       
  • Spatial Auxin Signaling Controls Leaf Flattening in Arabidopsis
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Chunmei Guan, Binbin Wu, Ting Yu, Qingqing Wang, Naden T. Krogan, Xigang Liu, Yuling Jiao
      The flattening of leaves to form broad blades is an important adaptation that maximizes photosynthesis. However, the molecular mechanism underlying this process remains unclear. The WUSCHEL-RELATED HOMEOBOX (WOX) genes WOX1 and PRS are expressed in the leaf marginal domain to enable leaf flattening, but the nature of WOX expression establishment remains elusive. Here, we report that adaxial-expressed MONOPTEROS (MP) and abaxial-enriched auxin together act as positional cues for patterning the WOX domain. MP directly binds to the WOX1 and PRS promoters and activates their expression. Furthermore, redundant abaxial-enriched ARF repressors suppress WOX1 and PRS expression, also through direct binding. In particular, we show that ARF2 is redundantly required with ARF3 and ARF4 to maintain the abaxial identity. Taken together, these findings explain how adaxial-abaxial polarity patterns the mediolateral axis and subsequent lateral expansion of leaves.
      Graphical abstract image Teaser The flattening of leaves to form broad blades is an important adaptation. Guan et al. show that the adaxial-expressed MP, abaxial-enriched auxin, and abaxial-expressed ARF repressors together position WOX expression in the middle domain. This finding describes how adaxial-abaxial polarity patterns the mediolateral axis and thus leaf flattening.

      PubDate: 2017-10-14T11:15:26Z
       
  • The Jellyfish Cassiopea Exhibits a Sleep-like State
    • Abstract: Publication date: 9 October 2017
      Source:Current Biology, Volume 27, Issue 19
      Author(s): Ravi D. Nath, Claire N. Bedbrook, Michael J. Abrams, Ty Basinger, Justin S. Bois, David A. Prober, Paul W. Sternberg, Viviana Gradinaru, Lea Goentoro
      Do all animals sleep' Sleep has been observed in many vertebrates, and there is a growing body of evidence for sleep-like states in arthropods and nematodes [1–5]. Here we show that sleep is also present in Cnidaria [6–8], an earlier-branching metazoan lineage. Cnidaria and Ctenophora are the first metazoan phyla to evolve tissue-level organization and differentiated cell types, such as neurons and muscle [9–15]. In Cnidaria, neurons are organized into a non-centralized radially symmetric nerve net [11, 13, 15–17] that nevertheless shares fundamental properties with the vertebrate nervous system: action potentials, synaptic transmission, neuropeptides, and neurotransmitters [15–20]. It was reported that cnidarian soft corals [21] and box jellyfish [22, 23] exhibit periods of quiescence, a pre-requisite for sleep-like states, prompting us to ask whether sleep is present in Cnidaria. Within Cnidaria, the upside-down jellyfish Cassiopea spp. displays a quantifiable pulsing behavior, allowing us to perform long-term behavioral tracking. Monitoring of Cassiopea pulsing activity for consecutive days and nights revealed behavioral quiescence at night that is rapidly reversible, as well as a delayed response to stimulation in the quiescent state. When deprived of nighttime quiescence, Cassiopea exhibited decreased activity and reduced responsiveness to a sensory stimulus during the subsequent day, consistent with homeostatic regulation of the quiescent state. Together, these results indicate that Cassiopea has a sleep-like state, supporting the hypothesis that sleep arose early in the metazoan lineage, prior to the emergence of a centralized nervous system.
      Teaser Understanding the phylogenetic roots of behaviors sheds light on the evolutionary forces that shape them. Sleep has been observed in worms, flies, zebrafish, and mice. Nath et al. discover that jellyfish have a sleep-like state. This shifts the known root of sleep in the phylogenetic tree prior to the emergence of a centralized nervous system.

      PubDate: 2017-10-14T11:15:26Z
       
  • EHD Proteins Cooperate to Generate Caveolar Clusters and to Maintain
           Caveolae during Repeated Mechanical Stress
    • Abstract: Publication date: Available online 21 September 2017
      Source:Current Biology
      Author(s): Ivana Yeow, Gillian Howard, Jessica Chadwick, Carolina Mendoza-Topaz, Carsten G. Hansen, Benjamin J. Nichols, Elena Shvets
      Caveolae introduce flask-shaped convolutions into the plasma membrane and help to protect the plasma membrane from damage under stretch forces. The protein components that form the bulb of caveolae are increasingly well characterized, but less is known about the contribution of proteins that localize to the constricted neck. Here we make extensive use of multiple CRISPR/Cas9-generated gene knockout and knockin cell lines to investigate the role of Eps15 Homology Domain (EHD) proteins at the neck of caveolae. We show that EHD1, EHD2, and EHD4 are recruited to caveolae. Recruitment of the other EHDs increases markedly when EHD2, which has been previously detected at caveolae, is absent. Construction of knockout cell lines lacking EHDs 1, 2, and 4 confirms this apparent functional redundancy. Two striking sets of phenotypes are observed in EHD1,2,4 knockout cells: (1) the characteristic clustering of caveolae into higher-order assemblies is absent; and (2) when the EHD1,2,4 knockout cells are subjected to prolonged cycles of stretch forces, caveolae are destabilized and the plasma membrane is prone to rupture. Our data identify the first molecular components that act to cluster caveolae into a membrane ultrastructure with the potential to extend stretch-buffering capacity and support a revised model for the function of EHDs at the caveolar neck.
      Teaser Yeow et al. apply gene-editing approaches to show that members of the EHD protein family are recruited to plasma membrane invaginations termed caveolae. The EHD proteins act to promote clustering of caveolae into higher-order assemblies and also to protect the plasma membrane from rupture under stretch forces.

      PubDate: 2017-10-09T04:26:35Z
       
  • Stomatal Opening Involves Polar, Not Radial, Stiffening Of Guard Cells
    • Abstract: Publication date: Available online 21 September 2017
      Source:Current Biology
      Author(s): Ross Carter, Hugh Woolfenden, Alice Baillie, Sam Amsbury, Sarah Carroll, Eleanor Healicon, Spyros Sovatzoglou, Sioban Braybrook, Julie E. Gray, Jamie Hobbs, Richard J. Morris, Andrew J. Fleming
      It has long been accepted that differential radial thickening of guard cells plays an important role in the turgor-driven shape changes required for stomatal pore opening to occur [1–4]. This textbook description derives from an original interpretation of structure rather than measurement of mechanical properties. Here we show, using atomic force microscopy, that although mature guard cells display a radial gradient of stiffness, this is not present in immature guard cells, yet young stomata show a normal opening response. Finite element modeling supports the experimental observation that radial stiffening plays a very limited role in stomatal opening. In addition, our analysis reveals an unexpected stiffening of the polar regions of the stomata complexes, both in Arabidopsis and other plants, suggesting a widespread occurrence. Combined experimental data (analysis of guard cell wall epitopes and treatment of tissue with cell wall digesting enzymes, coupled with bioassay of guard cell function) plus modeling lead us to propose that polar stiffening reflects a mechanical, pectin-based pinning down of the guard cell ends, which restricts increase of stomatal complex length during opening. This is predicted to lead to an improved response sensitivity of stomatal aperture movement with respect to change of turgor pressure. Our results provide new insight into the mechanics of stomatal function, both negating an established view of the importance of radial thickening and providing evidence for a significant role for polar stiffening. Improved stomatal performance via altered cell-wall-mediated mechanics is likely to be of evolutionary and agronomic significance.
      Graphical abstract image Teaser Textbooks state that radial stiffening of guard cells is required for stomatal opening. Carter et al. show that this is not the case. They demonstrate that stomatal poles are stiffer than surrounding cells. A new “fix and flex” model is proposed in which polar stiffening leads to more efficient stomata, potentially allowing better water use by plants.

      PubDate: 2017-10-09T04:26:35Z
       
  • Single-Neuron Correlates of Conscious Perception in the Human Medial
           Temporal Lobe
    • Abstract: Publication date: Available online 21 September 2017
      Source:Current Biology
      Author(s): Thomas P. Reber, Jennifer Faber, Johannes Niediek, Jan Boström, Christian E. Elger, Florian Mormann
      The neuronal mechanisms giving rise to conscious perception remain largely elusive [1]. It is known that the strength of single-neuron activity correlates with conscious perception, especially in anterior regions of the ventral pathway in non-human primates [2–4] and in the human medial temporal lobe (MTL) [5, 6]. It is unclear, however, whether single-neuron correlates of conscious perception are characterized solely by the magnitude of neuronal responses, and whether the correlates of perception are equally prominent across different regions of the human MTL. While recording from 2,735 neurons in 21 neurosurgical patients during 40 experimental sessions, we created experimental conditions in which otherwise identical visual stimuli are sometimes seen and sometimes not detected at all by means of the attentional blink, i.e., the phenomenon that the second of two target stimuli in close succession often goes unnoticed to conscious perception [7]. Remarkably, responses to unseen versus seen stimuli were delayed and temporally more dispersed, in addition to being attenuated in firing rate. This finding suggests precise timing of neuronal responses as a novel candidate physiological marker of conscious perception. In addition, we found modulation of neuronal response timing and strength in response to seen versus unseen stimuli to increase along an anatomical gradient from the posterior to the anterior MTL. Our results thus map out the neuronal correlates of conscious perception in the human MTL both in time and in space.
      Teaser Reber et al. demonstrate that neurons in the human MTL also fire in response to unseen visual stimuli and that not only strength but also timing of neuronal responses indicates conscious perception.

      PubDate: 2017-10-09T04:26:35Z
       
  • Horizontal Transfer of a Synthetic Metabolic Pathway between Plant Species
    • Abstract: Publication date: Available online 21 September 2017
      Source:Current Biology
      Author(s): Yinghong Lu, Sandra Stegemann, Shreya Agrawal, Daniel Karcher, Stephanie Ruf, Ralph Bock
      Transgene expression from the plastid (chloroplast) genome provides unique advantages, including high levels of foreign protein accumulation, convenient transgene stacking in operons, and increased biosafety due to exclusion of plastids from pollen transmission [1, 2]. However, applications in biotechnology and synthetic biology are severely restricted by the very small number of plant species whose plastid genomes currently can be transformed [3, 4]. Here we report a simple method for the introduction of useful plastid transgenes into non-transformable species. The transgenes tested comprised a synthetic operon encoding three components of a biosynthetic pathway for producing the high-value ketocarotenoid astaxanthin in the plastids of the cigarette tobacco, Nicotiana tabacum. Transplastomic N. tabacum plants accumulated astaxanthin to up to 1% of the plants’ dry weight. We then used grafting, a procedure recently shown to facilitate horizontal genome transfer between plants [5–7], to let the transgenic chloroplast genome move across the graft junction from N. tabacum plants into plants of the nicotine-free tree species Nicotiana glauca. Transplastomic N. glauca trees expressing the synthetic pathway were recovered at high frequency, thus providing a straightforward method for extension of the transplastomic technology to new species.
      Teaser Using a synthetic biosynthetic pathway for the high-value pigment astaxanthin, Lu et al. demonstrate that biotechnologically useful chloroplast transgenes can be moved from a transformable species into a recalcitrant species by horizontal genome transfer.

      PubDate: 2017-10-09T04:26:35Z
       
  • Rates of Molecular Evolution Suggest Natural History of Life History
           Traits and a Post-K-Pg Nocturnal Bottleneck of Placentals
    • Abstract: Publication date: Available online 28 September 2017
      Source:Current Biology
      Author(s): Jiaqi Wu, Takahiro Yonezawa, Hirohisa Kishino
      Life history and behavioral traits are often difficult to discern from the fossil record, but evolutionary rates of genes and their changes over time can be inferred from extant genomic data. Under the neutral theory, molecular evolutionary rate is a product of mutation rate and the proportion of neutral mutations [1, 2]. Mutation rates may be shared across the genome, whereas proportions of neutral mutations vary among genes because functional constraints vary. By analyzing evolutionary rates of 1,185 genes in a phylogeny of 89 mammals, we extracted historical profiles of functional constraints on these rates in the form of gene-branch interactions. By applying a novel statistical approach to these profiles, we reconstructed the history of ten discrete traits related to activity, diet, and social behaviors. Our results indicate that the ancestor of placental mammals was solitary, seasonally breeding, insectivorous, and likely nocturnal. The results suggest placental diversification began 10–20 million years before the K-Pg boundary (66 million years ago), with some ancestors of extant placental mammals becoming diurnal and adapted to different diets. However, from the Paleocene to the Eocene-Oligocene transition (EOT, 33.9 mya), we detect a post-K-Pg nocturnal bottleneck where all ancestral lineages of extant placentals were nocturnal. Although diurnal placentals may have existed during the elevated global temperatures of the Paleocene-Eocene thermal maximum [3], we hypothesize that diurnal placentals were selectively extirpated during or after the global cooling of the EOT, whereas some nocturnal lineages survived due to preadaptations to cold environments [4].
      Teaser Using a novel rate-based method of reconstructing ancestral states, Wu et al. find that the ancestor of placental mammals was solitary, seasonally breeding, insectivorous, and likely nocturnal. All ancestral lineages of extant placentals were nocturnal from the Paleocene to the Eocene-Oligocene transition (EOT, 33.9 mya).

      PubDate: 2017-10-01T03:41:09Z
       
  • Reduced Laughter Contagion in Boys at Risk for Psychopathy
    • Abstract: Publication date: Available online 28 September 2017
      Source:Current Biology
      Author(s): Elizabeth O’Nions, César F. Lima, Sophie K. Scott, Ruth Roberts, Eamon J. McCrory, Essi Viding
      Humans are intrinsically social animals, forming enduring affiliative bonds [1]. However, a striking minority with psychopathic traits, who present with violent and antisocial behaviors, tend to value other people only insofar as they contribute to their own advancement [2, 3]. Extant research has addressed the neurocognitive processes associated with aggression in such individuals, but we know remarkably little about processes underlying their atypical social affiliation. This is surprising, given the importance of affiliation and bonding in promoting social order and reducing aggression [4, 5]. Human laughter engages brain areas that facilitate social reciprocity and emotional resonance, consistent with its established role in promoting affiliation and social cohesion [6–8]. We show that, compared with typically developing boys, those at risk for antisocial behavior in general (irrespective of their risk of psychopathy) display reduced neural response to laughter in the supplementary motor area, a premotor region thought to facilitate motor readiness to join in during social behavior [9–11]. Those at highest risk for developing psychopathy additionally show reduced neural responses to laughter in the anterior insula. This region is implicated in auditory-motor processing and in linking action tendencies with emotional experience and subjective feelings [10, 12, 13]. Furthermore, this same group reports reduced desire to join in with the laughter of others—a behavioral profile in part accounted for by the attenuated anterior insula response. These findings suggest that atypical processing of laughter could represent a novel mechanism that impoverishes social relationships and increases risk for psychopathy and antisocial behavior.
      Teaser Laughter promotes affiliation with others and engages brain areas that facilitate emotional resonance. O’Nions, Lima et al. report that boys at risk for psychopathy show decreased responsiveness to laughter across these brain areas. Research into positive emotions can contribute to our understanding of atypical social affiliation in psychopathy.

      PubDate: 2017-10-01T03:41:09Z
       
  • Area Prostriata in the Human Brain
    • Abstract: Publication date: Available online 28 September 2017
      Source:Current Biology
      Author(s): Kyriaki Mikellidou, Jan W. Kurzawski, Francesca Frijia, Domenico Montanaro, Vincenzo Greco, David C. Burr, Maria Concetta Morrone
      Area prostriata is a cortical area at the fundus of the calcarine sulcus, described anatomically in humans [1–5] and other primates [6–9]. It is lightly myelinated and lacks the clearly defined six-layer structure evident throughout the cerebral cortex, with a thinner layer 4 and thicker layer 2 [10], characteristic of limbic cortex [11]. In the marmoset and rhesus monkey, area prostriata has cortical connections with MT+ [12], the cingulate motor cortex [8], the auditory cortex [13], the orbitofrontal cortex, and the frontal polar cortices [14]. Here we use functional magnetic resonance together with a wide-field projection system to study its functional properties in humans. With population receptive field mapping [15], we show that area prostriata has a complete representation of the visual field, clearly distinct from the adjacent area V1. As in the marmoset, the caudal-dorsal border of human prostriata—abutting V1—represents the far peripheral visual field, with eccentricities decreasing toward its rostral boundary. Area prostriata responds strongly to very fast motion, greater than 500°/s. The functional properties of area prostriata suggest that it may serve to alert the brain quickly to fast visual events, particularly in the peripheral visual field.
      Teaser Mikellidou et al. describe functionally area prostriata in humans. Located at the fundus of the calcarine sulcus, it has an orderly representation of the contralateral visual field, evenly distributed receptive fields, and a preference for fast motion. Prostriata may be alerting the brain to rapidly appearing visual events, mainly in the periphery.

      PubDate: 2017-10-01T03:41:09Z
       
  • Modulation of Long-Range Connectivity Patterns via Frequency-Specific
           Stimulation of Human Cortex
    • Abstract: Publication date: Available online 28 September 2017
      Source:Current Biology
      Author(s): Christiane A. Weinrich, John-Stuart Brittain, Magdalena Nowak, Reza Salimi-Khorshidi, Peter Brown, Charlotte J. Stagg
      There is increasing interest in how the phase of local oscillatory activity within a brain area determines the long-range functional connectivity of that area. For example, increasing convergent evidence from a range of methodologies suggests that beta (20 Hz) oscillations may play a vital role in the function of the motor system [1–5]. The “communication through coherence” hypothesis posits that the precise phase of coherent oscillations in network nodes is a determinant of successful communication between them [6, 7]. Here we set out to determine whether oscillatory activity in the beta band serves to support this theory within the cortical motor network in vivo. We combined non-invasive transcranial alternating-current stimulation (tACS) [8–12] with resting-state functional MRI (fMRI) [13] to follow both changes in local activity and long-range connectivity, determined by inter-areal blood-oxygen-level-dependent (BOLD) signal correlation, as a proxy for communication in the human cortex. Twelve healthy subjects participated in three fMRI scans with 20 Hz, 5 Hz, or sham tACS applied separately on each scan. Transcranial magnetic stimulation (TMS) at beta frequency has previously been shown to increase local activity in the beta band [14] and to modulate long-range connectivity within the default mode network [15]. We demonstrated that beta-frequency tACS significantly changed the connectivity pattern of the stimulated primary motor cortex (M1), without changing overall local activity or network connectivity. This finding is supported by a simple phase-precession model, which demonstrates the plausibility of the results and provides emergent predictions that are consistent with our empirical findings. These findings therefore inform our understanding of how local oscillatory activity may underpin network connectivity.
      Teaser Weinrich et al. show that entraining the phase of oscillations in one brain region modulates the connectivity pattern of that region without altering the strength of its connectivity with any specific region. These data provide evidence for how disordered functional communication arises in conditions characterized by perturbation of oscillations.

      PubDate: 2017-10-01T03:41:09Z
       
  • Retrotransposons Mimic Germ Plasm Determinants to Promote
           Transgenerational Inheritance
    • Abstract: Publication date: Available online 28 September 2017
      Source:Current Biology
      Author(s): Bhavana Tiwari, Paula Kurtz, Amanda E. Jones, Annika Wylie, James F. Amatruda, Devi Prasad Boggupalli, Graydon B. Gonsalvez, John M. Abrams
      Retrotransposons are a pervasive class of mobile elements present in the genomes of virtually all forms of life [1, 2]. In metazoans, these are preferentially active in the germline, which, in turn, mounts defenses that restrain their activity [3, 4]. Here we report that certain classes of retrotransposons ensure transgenerational inheritance by invading presumptive germ cells before they are formed. Using sensitized Drosophila and zebrafish models, we found that diverse classes of retrotransposons migrate to the germ plasm, a specialized region of the oocyte that prefigures germ cells and specifies the germline of descendants in the fertilized egg. In Drosophila, we found evidence for a “stowaway” model, whereby Tahre retroelements traffic to the germ plasm by mimicking oskar RNAs and engaging the Staufen-dependent active transport machinery. Consistent with this, germ plasm determinants attracted retroelement RNAs even when these components were ectopically positioned in bipolar oocytes. Likewise, vertebrate retrotransposons similarly migrated to the germ plasm in zebrafish oocytes. Together, these results suggest that germ plasm targeting represents a fitness strategy adopted by some retrotransposons to ensure transgenerational propagation.
      Graphical abstract image Teaser Retrotransposons are mobile elements present in virtually all genomes. Tiwari et al. found that, as a fitness strategy, some types of retrotransposons migrate to the germ plasm, a structure that prefigures descendants in the developing oocyte.

      PubDate: 2017-10-01T03:41:09Z
       
  • Distinct Roles of Ventromedial versus Ventrolateral Striatal Medium Spiny
           Neurons in Reward-Oriented Behavior
    • Abstract: Publication date: Available online 28 September 2017
      Source:Current Biology
      Author(s): Iku Tsutsui-Kimura, Akiyo Natsubori, Marina Mori, Kenta Kobayashi, Michael R. Drew, Alban de Kerchove d’Exaerde, Masaru Mimura, Kenji F. Tanaka
      The ventral striatum (VS) is a key brain center regulating reward-oriented behavior [1–4]. The VS can be anatomically divided into medial (VMS) and lateral (VLS) portions based on cortical input patterns. The VMS receives inputs from medial pallium-originated limbic structures (e.g., the medial prefrontal cortex [mPFC]), and the VLS receives inputs from the lateral pallium-originated areas (e.g., the insula) [5, 6]. This anatomical feature led us to hypothesize a functional segregation within the VS in terms of the regulation of reward-oriented behavior. Here, we engineered a fiber photometry system [4] and monitored population-level Ca2+ activities of dopamine D2-receptor-expressing medium spiny neurons (D2-MSNs), one of the major cell types in the striatum, during a food-seeking discrimination task. We found that VLS D2-MSNs were activated at the time of cue presentation. In stark contrast, VMS D2-MSNs were inhibited at this time point. Optogenetic counteraction of those changes in the VLS and VMS impaired action initiation and increased responding toward non-rewarded cues, respectively. During lever-press reversal training, VMS inhibition at the time of cue presentation temporarily ceased and optogenetic activation of VMS D2-MSNs facilitated acquisition of the new contingency. These data indicate that the opposing inhibition and excitation in VMS and VLS are important for selecting and initiating a proper action in a reward-oriented behavior. We propose distinct subregional roles within the VS in the execution of successful reward-oriented behavior.
      Graphical abstract image Teaser Tsutsui-Kimura, Natsubori, et al. find opposing activity patterns of medium spiny neurons at the medial and lateral portions of the ventral striatum during reward-oriented behavior. Each activity mediates distinct function but cooperates with successful reward-oriented behavior, proposing a new functional dichotomy of the ventral striatum.

      PubDate: 2017-10-01T03:41:09Z
       
  • Steroid Hormone Ecdysone Signaling Specifies Mushroom Body Neuron
           Sequential Fate via Chinmo
    • Abstract: Publication date: Available online 28 September 2017
      Source:Current Biology
      Author(s): Giovanni Marchetti, Gaia Tavosanis
      The functional variety in neuronal composition of an adult brain is established during development. Recent studies proposed that interactions between genetic intrinsic programs and external cues are necessary to generate proper neural diversity [1]. However, the molecular mechanisms underlying this developmental process are still poorly understood. Three main subtypes of Drosophila mushroom body (MB) neurons are sequentially generated during development and provide a good example of developmental neural plasticity [2]. Our present data propose that the environmentally controlled steroid hormone ecdysone functions as a regulator of early-born MB neuron fate during larval-pupal transition. We found that the BTB-zinc finger factor Chinmo acts upstream of ecdysone signaling to promote a neuronal fate switch. Indeed, Chinmo regulates the expression of the ecdysone receptor B1 isoform to mediate the production of γ and α′β′ MB neurons. In addition, we provide genetic evidence for a regulatory negative feedback loop driving the α′β′ to αβ MB neuron transition in which ecdysone signaling in turn controls microRNA let-7 depression of Chinmo expression. Thus, our results uncover a novel interaction in the MB neural specification pathway for temporal control of neuronal identity by interplay between an extrinsic hormonal signal and an intrinsic transcription factor cascade.
      Teaser Marchetti and Tavosanis show that the environmentally controlled steroid hormone ecdysone functions as a regulator of MB neuronal fate transition via Chinmo. A regulatory negative feedback loop, in which ecdysone signaling controls microRNA let-7-dependent Chinmo depression, promotes an early-to-late MB neuronal fate shift.

      PubDate: 2017-10-01T03:41:09Z
       
  • Nesprin-1α-Dependent Microtubule Nucleation from the Nuclear Envelope via
           Akap450 Is Necessary for Nuclear Positioning in Muscle Cells
    • Abstract: Publication date: Available online 28 September 2017
      Source:Current Biology
      Author(s): Petra Gimpel, Yin Loon Lee, Radoslaw M. Sobota, Alessandra Calvi, Victoria Koullourou, Rutti Patel, Kamel Mamchaoui, François Nédélec, Sue Shackleton, Jan Schmoranzer, Brian Burke, Bruno Cadot, Edgar R. Gomes
      The nucleus is the main microtubule-organizing center (MTOC) in muscle cells due to the accumulation of centrosomal proteins and microtubule (MT) nucleation activity at the nuclear envelope (NE) [1–4]. The relocalization of centrosomal proteins, including Pericentrin, Pcm1, and γ-tubulin, depends on Nesprin-1, an outer nuclear membrane (ONM) protein that connects the nucleus to the cytoskeleton via its N-terminal region [5–7]. Nesprins are also involved in the recruitment of kinesin to the NE and play a role in nuclear positioning in skeletal muscle cells [8–12]. However, a function for MT nucleation from the NE in nuclear positioning has not been established. Using the proximity-dependent biotin identification (BioID) method [13, 14], we found several centrosomal proteins, including Akap450, Pcm1, and Pericentrin, whose association with Nesprin-1α is increased in differentiated myotubes. We show that Nesprin-1α recruits Akap450 to the NE independently of kinesin and that Akap450, but not other centrosomal proteins, is required for MT nucleation from the NE. Furthermore, we demonstrate that this mechanism is disrupted in congenital muscular dystrophy patient myotubes carrying a nonsense mutation within the SYNE1 gene (23560 G>T) encoding Nesprin-1 [15, 16]. Finally, using computer simulation and cell culture systems, we provide evidence for a role of MT nucleation from the NE on nuclear spreading in myotubes. Our data thus reveal a novel function for Nesprin-1α/Nesprin-1 in nuclear positioning through recruitment of Akap450-mediated MT nucleation activity to the NE.
      Graphical abstract image Teaser Gimpel et al. find that LINC complexes comprising Nesprin-1α and Sun1/2 are required for the recruitment of centrosomal proteins and Akap450-mediated microtubule nucleation activity to the myotube nuclear envelope. Absence of microtubule nucleation from the nucleus affects nuclear positioning in muscle cells in vitro and in computer simulations.

      PubDate: 2017-10-01T03:41:09Z
       
  • Actin Turnover in Lamellipodial Fragments
    • Abstract: Publication date: Available online 28 September 2017
      Source:Current Biology
      Author(s): Dikla Raz-Ben Aroush, Noa Ofer, Enas Abu-Shah, Jun Allard, Oleg Krichevsky, Alex Mogilner, Kinneret Keren
      Actin turnover is the central driving force underlying lamellipodial motility. The molecular components involved are largely known, and their properties have been studied extensively in vitro. However, a comprehensive picture of actin turnover in vivo is still missing. We focus on fragments from fish epithelial keratocytes, which are essentially stand-alone motile lamellipodia. The geometric simplicity of the fragments and the absence of additional actin structures allow us to characterize the spatiotemporal lamellipodial actin organization with unprecedented detail. We use fluorescence recovery after photobleaching, fluorescence correlation spectroscopy, and extraction experiments to show that about two-thirds of the lamellipodial actin diffuses in the cytoplasm with nearly uniform density, whereas the rest forms the treadmilling polymer network. Roughly a quarter of the diffusible actin pool is in filamentous form as diffusing oligomers, indicating that severing and debranching are important steps in the disassembly process generating oligomers as intermediates. The remaining diffusible actin concentration is orders of magnitude higher than the in vitro actin monomer concentration required to support the observed polymerization rates, implying that the majority of monomers are transiently kept in a non-polymerizable “reserve” pool. The actin network disassembles and reassembles throughout the lamellipodium within seconds, so the lamellipodial network turnover is local. The diffusible actin transport, on the other hand, is global: actin subunits typically diffuse across the entire lamellipodium before reassembling into the network. This combination of local network turnover and global transport of dissociated subunits through the cytoplasm makes actin transport robust yet rapidly adaptable and amenable to regulation.
      Graphical abstract image Teaser Raz-Ben Aroush et al. combine experimental measurements with mathematical modeling to quantitatively characterize actin turnover in lamellipodial fragments. Although the network assembles and disassembles locally, most of the actin subunits diffuse as monomers or short oligomers, moving across the entire lamellipodium before reassembling into the network.

      PubDate: 2017-10-01T03:41:09Z
       
  • Roots of Mediterranean civilisations
    • Abstract: Publication date: 25 September 2017
      Source:Current Biology, Volume 27, Issue 18
      Author(s): Michael Gross
      European culture traces its history back to the ancient Greek civilisations, while Christianity and Judaism have their roots in the populations on the eastern shore of the Mediterranean Sea. Genome studies of several Bronze Age individuals from each of these regions have now probed the genetic roots of early civilisations, revealing both migration and continuity in both cases. Michael Gross reports.
      Teaser European culture traces its history back to the ancient Greek civilisations, while Christianity and Judaism have their roots in the populations on the eastern shore of the Mediterranean Sea. Genome studies of several Bronze Age individuals from each of these regions have now probed the genetic roots of early civilisations, revealing both migration and continuity in both cases.

      PubDate: 2017-10-01T03:41:09Z
       
  • Maya Schuldiner
    • Abstract: Publication date: 25 September 2017
      Source:Current Biology, Volume 27, Issue 18
      Author(s): Maya Schuldiner
      Teaser Interview with Maya Schuldiner, who studies the cell biology of organelles at the Weizmann Institute in Israel.

      PubDate: 2017-10-01T03:41:09Z
       
  • Multilevel societies
    • Abstract: Publication date: 25 September 2017
      Source:Current Biology, Volume 27, Issue 18
      Author(s): Cyril C. Grueter, Xiaoguang Qi, Baoguo Li, Ming Li
      Teaser Grueter et al. introduce complex animal societies with different grouping levels

      PubDate: 2017-10-01T03:41:09Z
       
 
 
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