Subjects -> AGRICULTURE (Total: 963 journals)
    - AGRICULTURAL ECONOMICS (93 journals)
    - AGRICULTURE (662 journals)
    - CROP PRODUCTION AND SOIL (120 journals)
    - POULTRY AND LIVESTOCK (58 journals)

AGRICULTURE (662 journals)            First | 1 2 3 4     

Showing 201 - 263 of 263 Journals sorted by number of followers
Biodiversity     Hybrid Journal   (Followers: 28)
Agriculture & Food Security     Open Access   (Followers: 22)
Future of Food : Journal on Food, Agriculture and Society     Open Access   (Followers: 21)
Nature Plants     Full-text available via subscription   (Followers: 17)
African Journal of Food, Agriculture, Nutrition and Development     Open Access   (Followers: 17)
Advances in Agriculture     Open Access   (Followers: 16)
Agricultural History Review     Full-text available via subscription   (Followers: 15)
Indian Journal of Agricultural Sciences     Open Access   (Followers: 12)
Advances in Life Science and Technology     Open Access   (Followers: 11)
Biological Agriculture & Horticulture : An International Journal for Sustainable Production Systems     Partially Free   (Followers: 11)
Journal of Land and Rural Studies     Hybrid Journal   (Followers: 11)
Agriculture and Food Sciences Research     Open Access   (Followers: 10)
Agricultural Research     Hybrid Journal   (Followers: 10)
Indian Horticulture     Full-text available via subscription   (Followers: 9)
Culture, Agriculture, Food and Environment     Hybrid Journal   (Followers: 8)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (Followers: 7)
Aceh International Journal of Science and Technology     Open Access   (Followers: 7)
International Journal of Agriculture and Forestry     Open Access   (Followers: 7)
New Journal of Botany     Hybrid Journal   (Followers: 6)
Invertebrate Reproduction & Development     Hybrid Journal   (Followers: 6)
Journal of Agriculture and Sustainability     Open Access   (Followers: 6)
Journal of Agriculture and Social Research (JASR)     Open Access   (Followers: 6)
American Journal of Rural Development     Open Access   (Followers: 6)
Journal of Agriculture, Forestry and the Social Sciences     Full-text available via subscription   (Followers: 6)
Journal of Advances in Agriculture     Open Access   (Followers: 5)
Acta Scientiarum. Animal Sciences     Open Access   (Followers: 5)
EvoDevo     Open Access   (Followers: 5)
Italian Journal of Agronomy     Open Access   (Followers: 4)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
Studies in Australian Garden History     Full-text available via subscription   (Followers: 4)
Journal of Agricultural Science     Open Access   (Followers: 4)
Journal of Agriculture and Rural Development in the Tropics and Subtropics     Open Access   (Followers: 4)
Tanzania Journal of Agricultural Sciences     Open Access   (Followers: 4)
Journal of Modern Agriculture     Open Access   (Followers: 4)
EU Agrarian Law     Open Access   (Followers: 4)
Journal of Agricultural Extension and Rural Development     Open Access   (Followers: 4)
Acta Agrobotanica     Open Access   (Followers: 4)
Food and Energy Security     Open Access   (Followers: 4)
Journal of the Ghana Science Association     Full-text available via subscription   (Followers: 3)
Journal of Agriculture and Natural Resources Sciences     Open Access   (Followers: 3)
Journal of Science and Technology (Ghana)     Open Access   (Followers: 3)
Biocatalysis and Agricultural Biotechnology     Hybrid Journal   (Followers: 3)
Revista Verde de Agroecologia e Desenvolvimento Sustentável     Open Access   (Followers: 3)
Sustainable Agriculture Research     Open Access   (Followers: 3)
International Journal of Agricultural Research, Innovation and Technology     Open Access   (Followers: 3)
International Journal of Applied Agriculture and Apiculture Research     Open Access   (Followers: 3)
Agra Europe     Full-text available via subscription   (Followers: 3)
Journal of Essential Oil Research     Hybrid Journal   (Followers: 3)
Diatom Research     Hybrid Journal   (Followers: 3)
Acta Universitatis Sapientiae, Alimentaria     Open Access   (Followers: 3)
Journal of Food Security     Open Access   (Followers: 3)
Journal of Agricultural Chemistry and Environment     Open Access   (Followers: 3)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 3)
Rural China     Hybrid Journal   (Followers: 2)
Revista Cubana de Ciencia Agrícola     Open Access   (Followers: 2)
Rivista di Studi sulla Sostenibilità     Full-text available via subscription   (Followers: 2)
Nigerian Food Journal     Full-text available via subscription   (Followers: 2)
Tropical Agricultural Research     Open Access   (Followers: 2)
International Journal of Agricultural Management and Development     Open Access   (Followers: 2)
Tropical Agricultural Research and Extension     Open Access   (Followers: 2)
New Zealand Journal of Agricultural Research     Hybrid Journal   (Followers: 2)
International Journal for Parasitology : Parasites and Wildlife     Open Access   (Followers: 2)
Journal of Apicultural Science     Open Access   (Followers: 2)
Ciencia forestal en México     Open Access   (Followers: 2)
Agricultura Tropica et Subtropica     Open Access   (Followers: 2)
Journal of Biology, Agriculture and Healthcare     Open Access   (Followers: 2)
Journal of Sustainable Society     Open Access   (Followers: 2)
Journal of Agricultural Extension     Open Access   (Followers: 2)
Journal of Agriculture and Food Sciences     Full-text available via subscription   (Followers: 2)
Journal of Agricultural Engineering     Open Access   (Followers: 2)
Huria : Journal of the Open University of Tanzania     Full-text available via subscription   (Followers: 2)
Agro-Science     Full-text available via subscription   (Followers: 2)
Rural Sustainability Research     Open Access   (Followers: 2)
Ghana Journal of Agricultural Science     Full-text available via subscription   (Followers: 2)
Journal of Agricultural Studies     Open Access   (Followers: 1)
Berkala Ilmiah Pertanian     Open Access   (Followers: 1)
Journal of Natural Sciences Research     Open Access   (Followers: 1)
Agricultural Commodities     Full-text available via subscription   (Followers: 1)
Progressive Agriculture     Open Access   (Followers: 1)
COCOS : The Journal of the Coconut Research Institute of Sri Lanka     Open Access   (Followers: 1)
Jurnal Veteriner     Open Access   (Followers: 1)
Nigerian Journal of Technological Research     Full-text available via subscription   (Followers: 1)
Science, Technology and Arts Research Journal     Open Access   (Followers: 1)
Revista Brasileira de Higiene e Sanidade Animal     Open Access   (Followers: 1)
Wartazoa. Indonesian Bulletin of Animal and Veterinary Sciences     Open Access   (Followers: 1)
Archivos de Zootecnia     Open Access   (Followers: 1)
Folia Horticulturae     Open Access   (Followers: 1)
Acta Technologica Agriculturae     Open Access   (Followers: 1)
International Journal of Agricultural Extension     Open Access   (Followers: 1)
Frontiers in Science     Open Access   (Followers: 1)
Emirates Journal of Food and Agriculture     Open Access   (Followers: 1)
Research in Agriculture, Livestock and Fisheries     Open Access   (Followers: 1)
Journal of Agricultural Engineering     Full-text available via subscription   (Followers: 1)
Buletin Peternakan : Bulletin of Animal Science     Open Access   (Followers: 1)
RIA. Revista de Investigaciones Agropecuarias     Open Access   (Followers: 1)
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access   (Followers: 1)
Journal of Degraded and Mining Lands Management     Open Access   (Followers: 1)
Global Approaches to Extension Practice : A Journal of Agricultural Extension     Full-text available via subscription   (Followers: 1)
Plant Knowledge Journal     Open Access   (Followers: 1)
Iranian Journal of Applied Animal Science     Open Access   (Followers: 1)
Agrociencia Uruguay     Open Access   (Followers: 1)
Chemical and Biological Technologies for Agriculture     Open Access   (Followers: 1)
International Journal of Recycling of Organic Waste in Agriculture     Open Access   (Followers: 1)
Journal of Science Foundation     Open Access   (Followers: 1)
Annals of Agricultural Sciences     Open Access   (Followers: 1)
Avances en Investigacion Agropecuaria     Open Access   (Followers: 1)
International Journal of Sustainable Agricultural Management and Informatics     Hybrid Journal   (Followers: 1)
Bangladesh Journal of Agricultural Research     Open Access   (Followers: 1)
Journal of Agricultural Sciences     Open Access   (Followers: 1)
Jurnal Ilmu dan Kesehatan Hewan (Veterinary Science and Medicine Journal)     Open Access   (Followers: 1)
Innovare Journal of Agricultural Science     Open Access   (Followers: 1)
Arquivos do Instituto Biológico     Open Access   (Followers: 1)
Social and Natural Sciences Journal     Open Access  
Jurnal Agroteknologi     Open Access  
Perspectivas Rurales Nueva Época     Open Access  
Organic Farming     Open Access  
Research Ideas and Outcomes     Open Access  
Jurnal Udayana Mengabdi     Open Access  
Landtechnik : Agricultural Engineering     Open Access  
International Letters of Natural Sciences     Open Access  
International Journal of Agriculture System     Open Access  
Heliyon     Open Access  
Ciência e Técnica Vitivinícola     Open Access  
Oilseeds and fats, Crops and Lipids     Open Access  
Annals of Silvicultural Research     Open Access  
Pastura : Journal Of Tropical Forage Science     Open Access  
Journal of Citrus Pathology     Open Access  
Revista Iberoamericana de las Ciencias Biológicas y Agropecuarias     Open Access  
Kansas Agricultural Experiment Station Research Reports     Open Access  
International Journal of Secondary Metabolite     Open Access  
Scientia Agropecuaria     Open Access  
Pelita Perkebunan (Coffee and Cocoa Research Journal)     Open Access  
Revista de Agricultura Neotropical     Open Access  
Cogent Food & Agriculture     Open Access  
Fave : Sección ciencias agrarias     Open Access  
Revista de Ciências Agrárias     Open Access  
Review of Agrarian Studies     Open Access  
Nigerian Journal of Biotechnology     Open Access  
Nigeria Agricultural Journal     Full-text available via subscription  
Annales des Sciences Agronomiques     Full-text available via subscription  
Journal of the Bangladesh Agricultural University     Open Access  
Journal of Buffalo Science     Hybrid Journal  
Revista de Ciências Agroveterinárias     Open Access  
Tropical Grasslands - Forrajes Tropicales     Open Access  
Research in Plant Sciences     Open Access  
World Journal of Agricultural Research     Open Access  
Universal Journal of Agricultural Research     Open Access  
Research & Reviews : Journal of Agriculture Science and Technology     Full-text available via subscription  
Revue Marocaine des Sciences Agronomiques et Vétérinaires     Open Access  
Nativa     Open Access  
SAARC Journal of Agriculture     Open Access  
West African Journal of Applied Ecology     Open Access  
Journal of Agricultural Research and Development     Full-text available via subscription  
Journal de la Recherche Scientifique de l'Universite de Lome     Full-text available via subscription  
Global Journal of Agricultural Sciences     Full-text available via subscription  
Agrosearch     Open Access  
Agronomie Africaine     Full-text available via subscription  
Professional Agricultural Workers Journal     Open Access  
Interciencia     Open Access  
Nepal Journal of Science and Technology     Open Access  
Journal of the Saudi Society of Agricultural Sciences     Open Access  
Information Processing in Agriculture     Open Access  
Sabaragamuwa University Journal     Open Access  
Ceiba     Open Access  
Research in Sierra Leone Studies : Weave     Open Access  
The Agriculturists     Open Access  
La Calera     Open Access  
Selçuk Tarım ve Gıda Bilimleri Dergisi     Open Access  
Revista de la Universidad del Zulia     Open Access  
Journal of Arid Land     Hybrid Journal  
Rangifer     Open Access  
Encuentro     Open Access  
Journal Of Agrobiotechnology     Open Access  
Coffee Science     Open Access  
Bangladesh Journal of Scientific Research     Open Access  
Landbohistorisk Tidsskrift     Open Access  
Biotecnología en el Sector Agropecuario y Agroindustrial     Open Access  
Walailak Journal of Science and Technology     Open Access  
Universidad y Ciencia     Open Access  
Tropical and Subtropical Agroecosystems     Open Access  
Terra Latinoamericana     Open Access  
Revista Iberoamericana de Tecnologia Postcosecha     Open Access  
Revista Brasileira de Ciências Agrárias     Open Access  
Multiciencias     Open Access  
Ensaios e Ciência : Ciências Biológicas, Agrárias e da Saúde     Open Access  
Bioagro     Open Access  
Agroalimentaria     Open Access  
Revista Mexicana de Ciencias Agrícolas     Open Access  
Revista U.D.C.A Actualidad & Divulgación Científica     Open Access  
Revista Ciencias Técnicas Agropecuarias     Open Access  
Revista Chapingo. Serie horticultura     Open Access  
Pastos y Forrajes     Open Access  
Fitosanidad     Open Access  
Cultivos Tropicales     Open Access  
Cuadernos de Desarrollo Rural     Open Access  
Ciencia e Investigación Agraria     Open Access  
Agronomía Mesoamericana     Open Access  
Agronomía Costarricense     Open Access  
Agrociencia     Open Access  
Agrivita : Journal of Agricultural Science     Open Access  

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Journal Prestige (SJR): 2.062
Citation Impact (citeScore): 3
Number of Followers: 5  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2041-9139
Published by Springer-Verlag Homepage  [2467 journals]
  • Adenylate cyclase A amplification and functional diversification during
           Polyspondylium pallidum development

    • Abstract: Background In Dictyostelium discoideum (Ddis), adenylate cyclase A (ACA) critically generates the cAMP oscillations that coordinate aggregation and morphogenesis. Unlike group 4 species like Ddis, other groups do not use extracellular cAMP to aggregate. However, deletion of cAMP receptors (cARs) or extracellular phosphodiesterase (PdsA) in Polyspondylium pallidum (Ppal, group 2) blocks fruiting body formation, suggesting that cAMP oscillations ancestrally control post-aggregative morphogenesis. In group 2, the acaA gene underwent several duplications. We deleted the three Ppal aca genes to identify roles for either gene and tested whether Ppal shows transient cAMP-induced cAMP accumulation, which underpins oscillatory cAMP signalling. Results In contrast to Ddis, pre-aggregative Ppal cells did not produce a pulse of cAMP upon stimulation with the cAR agonist 2′H-cAMP, but acquired this ability after aggregation. Deletion of Ppal aca1, aca2 and aca3 yielded different phenotypes. aca1ˉ cells showed relatively thin stalks, aca2ˉ showed delayed secondary sorogen formation and aca3ˉ formed less aggregation centers. The aca1ˉaca2ˉ and aca1ˉaca3ˉ mutants combined individual defects, while aca2ˉaca3ˉ and aca1ˉaca3ˉaca2ˉ additionally showed > 24 h delay in aggregation, with only few aggregates with fragmenting streams being formed. The fragments developed into small fruiting bodies with stalk and spore cells. Aggregation was restored in aca2ˉaca3ˉ and aca1ˉaca3ˉaca2ˉ by 2.5 mM 8Br-cAMP, a membrane-permeant activator of cAMP-dependent protein kinase (PKA). Like Ddis, Ppal sorogens also express the adenylate cyclases ACR and ACG. We found that prior to aggregation, Ddis acaˉ/ACG cells produced a pulse of cAMP upon stimulation with 2′H-cAMP, indicating that cAMP oscillations may not be dependent on ACA alone. Conclusions The three Ppal replicates of acaA perform different roles in stalk morphogenesis, secondary branch formation and aggregation, but act together to enable development by activating PKA. While even an aca1ˉaca3ˉaca2ˉ mutant still forms (some) fruiting bodies, suggesting little need for ACA-induced cAMP oscillations in this process, we found that ACG also mediated transient cAMP-induced cAMP accumulation. It, therefore, remains likely that post-aggregative Ppal morphogenesis is organized by cAMP oscillations, favouring a previously proposed model, where cAR-regulated cAMP hydrolysis rather than its synthesis dominates oscillatory behaviour.
      PubDate: 2022-10-19
  • Brachiopod and mollusc biomineralisation is a conserved process that was
           lost in the phoronid–bryozoan stem lineage

    • Abstract: Background Brachiopods and molluscs are lophotrochozoans with hard external shells which are often believed to have evolved convergently. While palaeontological data indicate that both groups are descended from biomineralising Cambrian ancestors, the closest relatives of brachiopods, phoronids and bryozoans, are mineralised to a much lower extent and are comparatively poorly represented in the Palaeozoic fossil record. Although brachiopod and mollusc shells are structurally analogous, genomic and proteomic evidence indicates that their formation involves a complement of conserved, orthologous genes. Here, we study a set of genes comprised of 3 homeodomain transcription factors, one signalling molecule and 6 structural proteins which are implicated in mollusc and brachiopod shell formation, search for their orthologs in transcriptomes or genomes of brachiopods, phoronids and bryozoans, and present expression patterns of 8 of the genes in postmetamorphic juveniles of the rhynchonelliform brachiopod T. transversa. Results Transcriptome and genome searches for the 10 target genes in the brachiopods Terebratalia transversa, Lingula anatina, Novocrania anomala, the bryozoans Bugula neritina and Membranipora membranacea, and the phoronids Phoronis australis and Phoronopsis harmeri resulted in the recovery of orthologs of the majority of the genes in all taxa. While the full complement of genes was present in all brachiopods with a single exception in L. anatina, a bloc of four genes could consistently not be retrieved from bryozoans and phoronids. The genes engrailed, distal-less, ferritin, perlucin, sp1 and sp2 were shown to be expressed in the biomineralising mantle margin of T. transversa juveniles. Conclusions The gene expression patterns we recovered indicate that while mineralised shells in brachiopods and molluscs are structurally analogous, their formation builds on a homologous process that involves a conserved complement of orthologous genes. Losses of some of the genes related to biomineralisation in bryozoans and phoronids indicate that loss of the capacity to form mineralised structures occurred already in the phoronid–bryozoan stem group and supports the idea that mineralised skeletons evolved secondarily in some of the bryozoan subclades.
      PubDate: 2022-09-19
      DOI: 10.1186/s13227-022-00202-8
  • Daphnia as a versatile model system in ecology and evolution

    • Abstract: Abstract Water fleas of the genus Daphnia have been a model system for hundreds of years and is among the best studied ecological model organisms to date. Daphnia are planktonic crustaceans with a cyclic parthenogenetic life-cycle. They have a nearly worldwide distribution, inhabiting standing fresh- and brackish water bodies, from small temporary pools to large lakes. Their predominantly asexual reproduction allows for the study of phenotypes excluding genetic variation, enabling us to separate genetic from non-genetic effects. Daphnia are often used in studies related to ecotoxicology, predator-induced defence, host–parasite interactions, phenotypic plasticity and, increasingly, in evolutionary genomics. The most commonly studied species are Daphnia magna and D. pulex, for which a rapidly increasing number of genetic and genomic tools are available. Here, I review current research topics, where the Daphnia model system plays a critical role.
      PubDate: 2022-08-08
      DOI: 10.1186/s13227-022-00199-0
  • Characterizing Hox genes in mayflies (Ephemeroptera), with Hexagenia
           limbata as a new mayfly model

    • Abstract: Background Hox genes are key regulators of appendage development in the insect body plan. The body plan of mayfly (Ephemeroptera) nymphs differs due to the presence of abdominal appendages called gills. Despite mayflies’ phylogenetic position in Paleoptera and novel morphology amongst insects, little is known of their developmental genetics, such as the appendage-regulating Hox genes. To address this issue we present an annotated, early instar transcriptome and embryonic expression profiles for Antennapedia, Ultrabithorax, and Abdominal A proteins in the mayfly Hexagenia limbata, identify putative Hox protein sequences in the mayflies H. limbata, Cloeon dipterum, and Ephemera danica, and describe the genomic organization of the Hox gene cluster in E. danica. Results Transcriptomic sequencing of early instar H. limbata nymphs yielded a high-quality assembly of 83,795 contigs, of which 22,975 were annotated against Folsomia candida, Nilaparvata lugens, Zootermopsis nevadensis and UniRef90 protein databases. Homeodomain protein phylogeny and peptide annotations identified coding sequences for eight of the ten canonical Hox genes (excluding zerknüllt/Hox3 and fushi tarazu) in H. limbata and C. dipterum, and all ten in E. danica. Mayfly Hox protein sequences and embryonic expression patterns of Antp, Ubx, and Abd-A appear highly conserved with those seen in other non-holometabolan insects. Similarly, the genomic organization of the Hox cluster in E. danica resembles that seen in most insects. Conclusions We present evidence that mayfly Hox peptide sequences and the embryonic expression patterns for Antp, Ubx, and Abd-A are extensively conserved with other insects, as is organization of the mayfly Hox gene cluster. The protein data suggest mayfly Antp, Ubx, and Abd-A play appendage promoting and repressing roles during embryogenesis in the thorax and abdomen, respectively, as in other insects. The identified expression of eight Hox genes, including Ubx and abd-A, in early instar nymphs further indicates a post-embryonic role, possibly in gill development. These data provide a basis for H. limbata as a complementary Ephemeridae model to the growing repertoire of mayfly model species and molecular techniques.
      PubDate: 2022-07-27
      DOI: 10.1186/s13227-022-00200-w
  • The red flour beetle T. castaneum: elaborate genetic toolkit and unbiased
           large scale RNAi screening to study insect biology and evolution

    • Abstract: Abstract The red flour beetle Tribolium castaneum has emerged as an important insect model system for a variety of topics. With respect to studying gene function, it is second only to the vinegar fly D. melanogaster. The RNAi response in T. castaneum is exceptionally strong and systemic, and it appears to target all cell types and processes. Uniquely for emerging model organisms, T. castaneum offers the opportunity of performing time- and cost-efficient large-scale RNAi screening, based on commercially available dsRNAs targeting all genes, which are simply injected into the body cavity. Well established transgenic and genome editing approaches are met by ease of husbandry and a relatively short generation time. Consequently, a number of transgenic tools like UAS/Gal4, Cre/Lox, imaging lines and enhancer trap lines are already available. T. castaneum has been a genetic experimental system for decades and now has become a workhorse for molecular and reverse genetics as well as in vivo imaging. Many aspects of development and general biology are more insect-typical in this beetle compared to D. melanogaster. Thus, studying beetle orthologs of well-described fly genes has allowed macro-evolutionary comparisons in developmental processes such as axis formation, body segmentation, and appendage, head and brain development. Transgenic approaches have opened new ways for in vivo imaging. Moreover, this emerging model system is the first choice for research on processes that are not represented in the fly, or are difficult to study there, e.g. extraembryonic tissues, cryptonephridial organs, stink gland function, or dsRNA-based pesticides.
      PubDate: 2022-07-19
      DOI: 10.1186/s13227-022-00201-9
  • Comparisons of cell proliferation and cell death from tornaria larva to
           juvenile worm in the hemichordate Schizocardium californicum

    • Abstract: Background There are a wide range of developmental strategies in animal phyla, but most insights into adult body plan formation come from direct-developing species. For indirect-developing species, there are distinct larval and adult body plans that are linked together by metamorphosis. Some outstanding questions in the development of indirect-developing organisms include the extent to which larval tissue undergoes cell death during the process of metamorphosis and when and where the tissue that will give rise to the adult originates. How do the processes of cell division and cell death redesign the body plans of indirect developers' In this study, we present patterns of cell proliferation and cell death during larval body plan development, metamorphosis, and adult body plan formation, in the hemichordate Schizocardium californium (Cameron and Perez in Zootaxa 3569:79–88, 2012) to answer these questions. Results We identified distinct patterns of cell proliferation between larval and adult body plan formation of S. californicum. We found that some adult tissues proliferate during the late larval phase prior to the start of overt metamorphosis. In addition, using an irradiation and transcriptomic approach, we describe a genetic signature of proliferative cells that is shared across the life history states, as well as markers that are unique to larval or juvenile states. Finally, we observed that cell death is minimal in larval stages but begins with the onset of metamorphosis. Conclusions Cell proliferation during the development of S. californicum has distinct patterns in the formation of larval and adult body plans. However, cell death is very limited in larvae and begins during the onset of metamorphosis and into early juvenile development in specific domains. The populations of cells that proliferated and gave rise to the larvae and juveniles have a genetic signature that suggested a heterogeneous pool of proliferative progenitors, rather than a set-aside population of pluripotent cells. Taken together, we propose that the gradual morphological transformation of S. californicum is mirrored at the cellular level and may be more representative of the development strategies that characterize metamorphosis in many metazoan animals.
      PubDate: 2022-06-06
      DOI: 10.1186/s13227-022-00198-1
  • Distal-less and spalt are distal organisers of pierid wing patterns

    • Abstract: Abstract Two genes, Distal-less (Dll) and spalt (sal), are known to be involved in establishing nymphalid butterfly wing patterns. They function in several ways: in the differentiation of the eyespot’s central signalling cells, or foci; in the differentiation of the surrounding black disc; in overall scale melanisation (Dll); and in elaborating marginal patterns, such as parafocal elements. However, little is known about the functions of these genes in the development of wing patterns in other butterfly families. Here, we study the expression and function of Dll and sal in the development of spots and other melanic wing patterns of the Indian cabbage white, Pieris canidia, a pierid butterfly. In P. canidia, both Dll and Sal proteins are expressed in the scale-building cells at the wing tips, in chevron patterns along the pupal wing margins, and in areas of future scale melanisation. Additionally, Sal alone is expressed in the future black spots. CRISPR knockouts of Dll and sal showed that each gene is required for the development of melanic wing pattern elements, and repressing pteridine granule formation, in the areas where they are expressed. We conclude that both genes likely play ancestral roles in organising distal butterfly wing patterns, across pierid and nymphalid butterflies, but are unlikely to be differentiating signalling centres in pierids black spots. The genetic and developmental mechanisms that set up the location of spots and eyespots are likely distinct in each lineage.
      PubDate: 2022-06-03
      DOI: 10.1186/s13227-022-00197-2
  • Phloem wedges in Malpighiaceae: origin, structure, diversification, and
           systematic relevance

    • Abstract: Background Phloem wedges furrowing the wood are one of the most notorious, widespread types of cambial variants in Angiosperms. Many lianas in Malpighiaceae show these variations in the arrangement of the secondary tissues. Here we explore their ontogeny, structure, and evolution in Malpighiaceae, where phloem wedges appeared multiple times, showing how they have contributed to the anatomical diversification of the family. Using a broad sampling with 143 species from 50 genera, covering all major lineages in Malpighiaceae, we crossed data from ontogeny, stem anatomy, and phylogenetic comparative methods to determine ontogenetic trajectories, final anatomical architectures, and evolution within the most recent phylogeny for the family. Results Phloem wedges appeared exclusively in lianas and disappeared in shrub lineages nested within liana lineages. At the onset of development, the vascular cambium is regular, producing secondary tissues homogeneously across its girth, but soon, portions of the cambium in between the leaf insertions switch their activity producing less wood and more phloem, initially generating phloem arcs, which progress into phloem wedges. In the formation of these wedges, two ontogenetic trajectories were found, one that maintains the continuity of the cambium, and another where the cambium gets dissected. Phloem wedges frequently remain as the main cambial variant in several lineages, while in others there are additional steps toward more complex cambial variants, such as fissured stems, or included phloem wedges, the latter a novel type of interxylary phloem first described for the family. Conclusions Phloem wedges evolved exclusively in lianas, with two different ontogenies explaining the 10 independent origins of phloem wedges in Malpighiaceae. The presence of phloem wedges has favored the evolution of even more complex cambial variants such as fissured stems and interxylary phloem.
      PubDate: 2022-04-28
      DOI: 10.1186/s13227-022-00196-3
  • Fleshy or dry: transcriptome analyses reveal the genetic mechanisms
           underlying bract development in Ephedra

    • Abstract: Background Gnetales have a key phylogenetic position in the evolution of seed plants. Among the Gnetales, there is an extraordinary morphological diversity of seeds, the genus Ephedra, in particular, exhibits fleshy, coriaceous or winged (dry) seeds. Despite this striking diversity, its underlying genetic mechanisms remain poorly understood due to the limited studies in gymnosperms. Expanding the genomic and developmental data from gymnosperms contributes to a better understanding of seed evolution and development. Results We performed transcriptome analyses on different plant tissues of two Ephedra species with different seed morphologies. Anatomical observations in early developing ovules, show that differences in the seed morphologies are established early in their development. The transcriptomic analyses in dry-seeded Ephedra californica and fleshy-seeded Ephedra antisyphilitica, allowed us to identify the major differences between the differentially expressed genes in these species. We detected several genes known to be involved in fruit ripening as upregulated in the fleshy seed of Ephedra antisyphilitica. Conclusions This study allowed us to determine the differentially expressed genes involved in seed development of two Ephedra species. Furthermore, the results of this study of seeds with the enigmatic morphology in Ephedra californica and Ephedra antisyphilitica, allowed us to corroborate the hypothesis which suggest that the extra envelopes covering the seeds of Gnetales are not genetically similar to integument. Our results highlight the importance of carrying out studies on less explored species such as gymnosperms, to gain a better understanding of the evolutionary history of plants.
      PubDate: 2022-04-27
      DOI: 10.1186/s13227-022-00195-4
  • The diversity and evolution of electric organs in Neotropical knifefishes

    • Abstract: Abstract The Gymnotiformes, also known as the South American or Neotropical knifefishes, include the strongly electric Electrophorus electricus and many other weakly electric species. These fish possess specialised electric organs that are able to release electric discharges into the water, for electrolocation and communication, and sometimes for predation and defence. All Gymnotiform species possess a myogenic electric organ (mEO) derived from the muscle tissue, and members of the Apteronotidae family uniquely possess a neurogenic electric organ (nEOs) derived from the nervous tissue. A mEO may consist of ‘Type A’ electrocytes that develop within the tail muscle (for example, in Apteronotus leptorhynchus), or ‘Type B’ electrocytes that develop below the tail muscle (for example, in Brachyhypopomus gauderio). In this review, we discuss the diversity in the anatomy, electric discharge and development of electric organs found in different Gymnotiform species, as well as the ecological and environmental factors that have likely contributed to this diversity. We then describe various hypotheses regarding the evolution of electric organs, and discuss the potential evolutionary origin of the nEO: a pair of nerve cords that are located on either side of the aorta in B. gauderio, and which may have expanded and developed into a nEO in the Apteronotidae family during its evolution from a common ancestral species. Finally, we compare potential Gymnotiform phylogenies and their supporting evidence.
      PubDate: 2022-04-01
      DOI: 10.1186/s13227-022-00194-5
  • Fossils and plant evolution: structural fingerprints and modularity in the
           evo-devo paradigm

    • Abstract: Abstract Fossils constitute the principal repository of data that allow for independent tests of hypotheses of biological evolution derived from observations of the extant biota. Traditionally, transformational series of structure, consisting of sequences of fossils of the same lineage through time, have been employed to reconstruct and interpret morphological evolution. More recently, a move toward an updated paradigm was fueled by the deliberate integration of developmental thinking in the inclusion of fossils in reconstruction of morphological evolution. The vehicle for this is provided by structural fingerprints—recognizable morphological and anatomical structures generated by (and reflective of) the deployment of specific genes and regulatory pathways during development. Furthermore, because the regulation of plant development is both modular and hierarchical in nature, combining structural fingerprints recognized in the fossil record with our understanding of the developmental regulation of those structures produces a powerful tool for understanding plant evolution. This is particularly true when the systematic distribution of specific developmental regulatory mechanisms and modules is viewed within an evolutionary (paleo-evo-devo) framework. Here, we discuss several advances in understanding the processes and patterns of evolution, achieved by tracking structural fingerprints with their underlying regulatory modules across lineages, living and fossil: the role of polar auxin regulation in the cellular patterning of secondary xylem and the parallel evolution of arborescence in lycophytes and seed plants; the morphology and life history of early polysporangiophytes and tracheophytes; the role of modularity in the parallel evolution of leaves in euphyllophytes; leaf meristematic activity and the parallel evolution of venation patterns among euphyllophytes; mosaic deployment of regulatory modules and the diverse modes of secondary growth of euphyllophytes; modularity and hierarchy in developmental regulation and the evolution of equisetalean reproductive morphology. More generally, inclusion of plant fossils in the evo-devo paradigm has informed discussions on the evolution of growth patterns and growth responses, sporophyte body plans and their homology, sequences of character evolution, and the evolution of reproductive systems.
      PubDate: 2022-03-02
      DOI: 10.1186/s13227-022-00192-7
  • Heterochrony and repurposing in the evolution of gymnosperm seed dispersal

    • Abstract: Background Plant dispersal units, or diaspores, allow the colonization of new environments expanding geographic range and promoting gene flow. Two broad categories of diaspores found in seed plants are dry and fleshy, associated with abiotic and biotic dispersal agents, respectively. Anatomy and developmental genetics of fleshy angiosperm fruits is advanced in contrast to the knowledge gap for analogous fleshy structures in gymnosperm diaspores. Improved understanding of the structural basis of modified accessory organs that aid in seed dispersal will enable future work on the underlying genetics, contributing to hypotheses on the origin of angiosperm fruits. To generate a structural framework for the development and evolution of gymnosperm fleshy diaspores, we studied the anatomy and histochemistry of Ephedra (Gnetales) seed cone bracts, the modified leaves surrounding the reproductive organs. We took an ontogenetic approach, comparing and contrasting the anatomy and histology of fleshy and papery-winged seed cone bracts, and their respective pollen cone bracts and leaves in four species from the South American clade. Results Seed bract fleshiness in Ephedra derives from mucilage accumulated in chlorenchyma cells, also found in the reduced young leaves before they reach their mature, dry stage. Cellulosic fibers, an infrequent cell type in gymnosperms, were found in Ephedra, where they presumably function as a source of supplementary apoplastic water in fleshy seed cone bracts. Papery-winged bract development more closely resembles that of leaves, with chlorenchyma mucilage cells turning into tanniniferous cells early on, and hyaline margins further extending into “wings”. Conclusions We propose an evolutionary developmental model whereby fleshy and papery-winged bracts develop from an early-stage anatomy shared with leaves that differs at the pollination stage. The ancestral fleshy bract state may represent a novel differentiation program built upon young leaf anatomy, while the derived dry, papery-winged state is likely built upon an existing differentiation pattern found in mature vegetative leaves. This model for the evolution of cone bract morphology in South American Ephedra hence involves a novel differentiation program repurposed from leaves combined with changes in the timing of leaf differentiation, or heterochrony, that can further be tested in other gymnosperms with fleshy diaspores.
      PubDate: 2022-02-16
      DOI: 10.1186/s13227-022-00191-8
  • Correction to: Delayed differentiation of epidermal cells walls can
           underlie pedomorphosis in plants: the case of pedomorphic petals in the
           hummingbird-pollinated Caiophora hibiscifolia (Loasaceae, subfam.
           Loasoideae) species

    • PubDate: 2022-02-15
      DOI: 10.1186/s13227-022-00193-6
  • Duplication and expression patterns of CYCLOIDEA-like genes in

    • Abstract: Background CYCLOIDEA (CYC)-like transcription factors pattern floral symmetry in most angiosperms. In core eudicots, two duplications led to three clades of CYC-like genes: CYC1, CYC2, and CYC3, with orthologs of the CYC2 clade restricting expression dorsally in bilaterally symmetrical flowers. Limited data from CYC3 suggest that they also play a role in flower symmetry in some asterids. We examine the evolution of these genes in Campanulaceae, a group that contains broad transitions between radial and bilateral floral symmetry and 180° resupination (turning upside-down by twisting pedicle). Results We identify here all three paralogous CYC-like clades across Campanulaceae. Similar to other core eudicots, we show that CamCYC2 duplicated near the time of the divergence of the bilaterally symmetrical and resupinate Lobelioideae. However, in non-resupinate, bilaterally symmetrical Cyphioideae, CamCYC2 appears to have been lost and CamCYC3 duplicated, suggesting a novel genetic basis for bilateral symmetry in Cyphioideae. We additionally, utilized qRT-PCR to examine the correlation between CYC-like gene expression and shifts in flower morphology in four species of Lobelioideae. As expected, CamCYC2 gene expression was dorsoventrally restricted in bilateral symmetrical flowers. However, because Lobelioideae have resupinate flowers, both CamCYC2A and CamCYC2B are highly expressed in the finally positioned ventral petal lobes, corresponding to the adaxial side of the flower relative to meristem orientation. Conclusions Our sequences across Campanulaceae of all three of these paralogous groups suggests that radially symmetrical Campanuloideae duplicated CYC1, Lobelioideae duplicated CYC2 and lost CYC3 early in their divergence, and that Cyphioideae lost CYC2 and duplicated CYC3. This suggests a dynamic pattern of duplication and loss of major floral patterning genes in this group and highlights the first case of a loss of CYC2 in a bilaterally symmetrical group. We illustrate here that CYC expression is conserved along the dorsoventral axis of the flower even as it turns upside-down, suggesting that at least late CYC expression is not regulated by extrinsic factors such as gravity. We additionally show that while the pattern of dorsoventral expression of each paralog remains the same, CamCYC2A is more dominant in species with shorter relative finally positioned dorsal lobes, and CamCYC2B is more dominant in species with long dorsal lobes.
      PubDate: 2022-02-06
      DOI: 10.1186/s13227-021-00189-8
  • A CYC–RAD–DIV–DRIF interaction likely pre-dates the origin of floral
           monosymmetry in Lamiales

    • Abstract: Background An outstanding question in evolutionary biology is how genetic interactions defining novel traits evolve. They may evolve either by de novo assembly of previously non-interacting genes or by en bloc co-option of interactions from other functions. We tested these hypotheses in the context of a novel phenotype—Lamiales flower monosymmetry—defined by a developmental program that relies on regulatory interaction among CYCLOIDEA, RADIALIS, DIVARICATA, and DRIF gene products. In Antirrhinum majus (snapdragon), representing Lamiales, we tested whether components of this program likely function beyond their previously known role in petal and stamen development. In Solanum lycopersicum (tomato), representing Solanales which diverged from Lamiales before the origin of Lamiales floral monosymmetry, we additionally tested for regulatory interactions in this program. Results We found that RADIALIS, DIVARICATA, and DRIF are expressed in snapdragon ovaries and developing fruit, similar to their homologs during tomato fruit development. In addition, we found that a tomato CYCLOIDEA ortholog positively regulates a tomato RADIALIS ortholog. Conclusion Our results provide preliminary support to the hypothesis that the developmental program defining floral monosymmetry in Lamiales was co-opted en bloc from a function in carpel development. This expands our understanding of novel trait evolution facilitated by co-option of existing regulatory interactions.
      PubDate: 2022-01-29
      DOI: 10.1186/s13227-021-00187-w
  • Linking the evolution of development of stem vascular system in
           Nyctaginaceae and its correlation to habit and species diversification

    • Abstract: Background Alternative patterns of secondary growth in stems of Nyctaginaceae is present in all growth habits of the family and have been known for a long time. However, the interpretation of types of cambial variants have been controversial, given that different authors have given them different developmental interpretations. The different growth habits coupled with an enormous stem anatomical diversity offers the unique opportunity to investigate the evolution of complex developments, to address how these anatomies shifted within habits, and how the acquisition of novel cambial variants and habit transitions impacted the diversification of the family. Methods We integrated developmental data with a phylogenetic framework to investigate the diversity and evolution of stem anatomy in Nyctaginaceae using phylogenetic comparative methods, reconstructing ancestral states, and examining whether anatomical shifts correspond to species diversification rate shifts in the family. Results Two types of cambial variants, interxylary phloem and successive cambia, were recorded in Nyctaginaceae, which result from four different ontogenies. These ontogenetic trajectories depart from two distinct primary vascular structures (regular or polycyclic eustele) yet, they contain shared developmental stages which generate stem morphologies with deconstructed boundaries of morphological categories (continuum morphology). Unlike our a priori hypotheses, interxylary phloem is reconstructed as the ancestral character for the family, with three ontogenies characterized as successive cambia evolving in few taxa. Cambial variants are not contingent on habits, and their transitions are independent from species diversification. Conclusions Our findings suggest that multiple developmental mechanisms, such as heterochrony and heterotopy, generate the transitions between interxylary phloem and successive cambia. Intermediate between these two extremes are present in Nyctaginaceae, suggesting a continuum morphology across the family as a generator of anatomical diversity.
      PubDate: 2022-01-29
      DOI: 10.1186/s13227-021-00190-1
  • Evolution and expression of LEAFY genes in ferns and lycophytes

    • Abstract: Background The LEAFY (LFY) transcription factors are present in algae and across land plants. The available expression and functional data of these genes in embryophytes suggest that LFY genes control a plethora of processes including the first zygotic cell division in bryophytes, shoot cell divisions of the gametophyte and sporophyte in ferns, cone differentiation in gymnosperms and floral meristem identity in flowering plants. However, their putative plesiomorphic role in plant reproductive transition in vascular plants remains untested. Results We perform Maximum Likelihood (ML) phylogenetic analyses for the LFY gene lineage in embryophytes with expanded sampling in lycophytes and ferns. We recover the previously identified seed plant duplication that results in LEAFY and NEEDLY paralogs. In addition, we recover multiple species-specific duplications in ferns and lycophytes and large-scale duplications possibly correlated with the occurrence of whole genome duplication (WGD) events in Equisetales and Salviniales. To test putative roles in diverse ferns and lycophytes we perform LFY expression analyses in Adiantum raddianum, Equisetum giganteum and Selaginella moellendorffii. Our results show that LFY genes are active in vegetative and reproductive tissues, with higher expression in early fertile developmental stages and during sporangia differentiation. Conclusions Our data point to previously unrecognized roles of LFY genes in sporangia differentiation in lycophytes and ferns and suggests that functions linked to reproductive structure development are not exclusive to seed plant LFY homologs.
      PubDate: 2022-01-08
      DOI: 10.1186/s13227-021-00188-9
  • Delayed differentiation of epidermal cells walls can underlie
           pedomorphosis in plants: the case of pedomorphic petals in the
           hummingbird-pollinated Caiophora hibiscifolia (Loasaceae, subfam.
           Loasoideae) species

    • Abstract: Background Understanding the relationship between macroevolutionary diversity and variation in organism development is an important goal of evolutionary biology. Variation in the morphology of several plant and animal lineages is attributed to pedomorphosis, a case of heterochrony, where an ancestral juvenile shape is retained in an adult descendant. Pedomorphosis facilitated morphological adaptation in different plant lineages, but its cellular and molecular basis needs further exploration. Plant development differs from animal development in that cells are enclosed by cell walls and do not migrate. Moreover, in many plant lineages, the differentiated epidermis of leaves, and leaf-derived structures, such as petals, limits organ growth. We, therefore, proposed that pedomorphosis in leaves, and in leaf-derived structures, results from delayed differentiation of epidermal cells with respect to reproductive maturity. This idea was explored for petal evolution, given the importance of corolla morphology for angiosperm reproductive success. Results By comparing cell morphology and transcriptional profiles between 5 mm flower buds and mature flowers of an entomophile and an ornitophile Loasoideae species (a lineage that experienced transitions from bee- to hummingbird-pollination), we show that evolution of pedomorphic petals of the ornithophile species likely involved delayed differentiation of epidermal cells with respect to flower maturity. We also found that developmental mechanisms other than pedomorphosis might have contributed to evolution of corolla morphology. Conclusions Our results highlight a need for considering alternatives to the flower-centric perspective when studying the origin of variation in flower morphology, as this can be generated by developmental processes that are also shared with leaves. Graphical
      PubDate: 2022-01-03
      DOI: 10.1186/s13227-021-00186-x
  • Case not closed: the mystery of the origin of the carpel

    • Abstract: Abstract The carpel is a fascinating structure that plays a critical role in flowering plant reproduction and contributed greatly to the evolutionary success and diversification of flowering plants. The remarkable feature of the carpel is that it is a closed structure that envelopes the ovules and after fertilization develops into the fruit which protects, helps disperse, and supports seed development into a new plant. Nearly all plant-based foods are either derived from a flowering plant or are a direct product of the carpel. Given its importance it’s no surprise that plant and evolutionary biologists have been trying to explain the origin of the carpel for a long time. Before carpel evolution seeds were produced on open leaf-like structures that are exposed to the environment. When the carpel evolved in the stem lineage of flowering plants, seeds became protected within its closed structure. The evolutionary transition from that open precursor to the closed carpel remains one of the greatest mysteries of plant evolution. In recent years, we have begun to complete a picture of what the first carpels might have looked like. On the other hand, there are still many gaps in our understanding of what the precursor of the carpel looked like and what changes to its developmental mechanisms allowed for this evolutionary transition. This review aims to present an overview of existing theories of carpel evolution with a particular emphasis on those that account for the structures that preceded the carpel and/or present testable developmental hypotheses. In the second part insights from the development and evolution of diverse plant organs are gathered to build a developmental hypothesis for the evolutionary transition from a hypothesized laminar open structure to the closed structure of the carpel.
      PubDate: 2021-12-15
      DOI: 10.1186/s13227-021-00184-z
  • Whole body regeneration and developmental competition in two botryllid

    • Abstract: Background Botryllid ascidians are a group of marine invertebrate chordates that are colonial and grow by repeated rounds of asexual reproduction to form a colony of individual bodies, called zooids, linked by a common vascular network. Two distinct processes are responsible for zooid regeneration. In the first, called blastogenesis, new zooids arise from a region of multipotent epithelium from a pre-existing zooid. In the second, called whole body regeneration (WBR), mobile cells in the vasculature coalesce and are the source of the new zooid. In some botryllid species, blastogenesis and WBR occur concurrently, while in others, blastogenesis is used exclusively for growth, while WBR only occurs following injury or exiting periods of dormancy. In species such as Botrylloides diegensis, injury induced WBR is triggered by the surgical isolation of a small piece of vasculature. However, Botryllus schlosseri has unique requirements that must be met for successful injury induced WBR. Our goal was to understand why there would be different requirements between these two species. Results While WBR in B. diegensis was robust, we found that in B. schlosseri, new zooid growth following injury is unlikely due to circulatory cells, but instead a result of ectopic development of tissues leftover from the blastogenic process. These tissues could be whole, damaged, or partially resorbed developing zooids, and we defined the minimal amount of vascular biomass to support ectopic regeneration. We did find a common theme between the two species: a competitive process exists which results in only a single zooid reaching maturity following injury. We utilized this phenomenon and found that competition is reversible and mediated by circulating factors and/or cells. Conclusions We propose that WBR does not occur in B. schlosseri and that the unique requirements defined in other studies only serve to increase the chances of ectopic development. This is likely a response to injury as we have discovered a vascular-based reversible competitive mechanism which ensures that only a single zooid completes development. This competition has been described in other species, but the unique response of B. schlosseri to injury provides a new model to study resource allocation and competition within an individual.
      PubDate: 2021-12-15
      DOI: 10.1186/s13227-021-00185-y
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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