EvodevoPub Date : 2025-05-16DOI: 10.1186/s13227-025-00243-9
Jacob F Warner, Ryan Besemer, Alicia Schickle, Erin Borbee, Isabella V Changsut, Koty Sharp, Leslie S Babonis
{"title":"Microinjection, gene knockdown, and CRISPR-mediated gene knock-in in the hard coral, Astrangia poculata.","authors":"Jacob F Warner, Ryan Besemer, Alicia Schickle, Erin Borbee, Isabella V Changsut, Koty Sharp, Leslie S Babonis","doi":"10.1186/s13227-025-00243-9","DOIUrl":"10.1186/s13227-025-00243-9","url":null,"abstract":"<p><p>Cnidarians have become valuable models for understanding many aspects of developmental biology including the evolution of body plan diversity, novel cell type specification, and regeneration. Most of our understanding of gene function during early development in cnidarians comes from a small number of experimental systems including Hydra and the sea anemone, Nematostella vectensis. Few molecular tools have been developed for use in hard corals, limiting our understanding of this diverse and ecologically important clade. Here, we report the development of a suite of tools for manipulating and analyzing gene expression during early development in the northern star coral, Astrangia poculata. We present methods for gene knockdown using short hairpin RNAs, gene overexpression using exogenous mRNAs, and endogenous gene tagging using CRISPR-mediated gene knock-in. Combined with the fact that spawning can be induced in the laboratory, during the reproductive window, these tools make A. poculata a tractable experimental system for investigative studies of coral development. Further application of these tools will enable functional analyses of embryonic patterning and morphogenesis across Anthozoa and open new frontiers in coral biology research.</p>","PeriodicalId":49076,"journal":{"name":"Evodevo","volume":"16 1","pages":"6"},"PeriodicalIF":4.1,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12085026/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144086906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EvodevoPub Date : 2025-05-03DOI: 10.1186/s13227-025-00242-w
Oleg Simakov, Günter P Wagner
{"title":"The application of irreversible genomic states to define and trace ancient cell type homologies.","authors":"Oleg Simakov, Günter P Wagner","doi":"10.1186/s13227-025-00242-w","DOIUrl":"https://doi.org/10.1186/s13227-025-00242-w","url":null,"abstract":"<p><p>Homology, or relationship among characters by common descent, has been notoriously difficult to assess for many morphological features, and cell types in particular. The ontogenetic origin of morphological traits means that the only physically inherited information is encoded in the genomes. However, the complexity of the underlying gene regulatory network and often miniscule changes that can impact gene expression, make it practically impossible to postulate a clear demarcation line for what molecular signature should \"define\" a homologous cell type between two deeply branching animals. In this Hypothesis article, we propose the use of the recently characterized irreversible genomic states, that occur after chromosomal and sub-chromosomal mixing of genes and regulatory elements, to dissect regulatory signatures of each cell type into irreversible and reversible configurations. While many of such states will be non-functional, some may permanently impact gene expression in a given cell type. Our proposal is that such evolutionarily irreversible, and thus synapomorphic, functional genomic states can constitute a criterion for the timing of the origin of deep evolutionary cell type homologies. Our proposal thus aims to close the gap between the clearly defined homology of the individual genomic characters and their genomic states to the homology at the phenotypic level through the identification of the underlying evolutionarily irreversible and regulatory linked states.</p>","PeriodicalId":49076,"journal":{"name":"Evodevo","volume":"16 1","pages":"5"},"PeriodicalIF":4.1,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12049793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143992269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EvodevoPub Date : 2025-04-25DOI: 10.1186/s13227-025-00240-y
Isaac A Hinne, Hailee R Ciccotti, Jakub Wudarski, Michael N Pham, Arvind Sharma, Molly M McVicar, Benjamin Faustino, Andrew B Nuss, Prashant P Sharma, Monika Gulia-Nuss
{"title":"Early embryonic development in the tick Ixodes scapularis suggests syncytial organization and cellularization before blastoderm formation.","authors":"Isaac A Hinne, Hailee R Ciccotti, Jakub Wudarski, Michael N Pham, Arvind Sharma, Molly M McVicar, Benjamin Faustino, Andrew B Nuss, Prashant P Sharma, Monika Gulia-Nuss","doi":"10.1186/s13227-025-00240-y","DOIUrl":"https://doi.org/10.1186/s13227-025-00240-y","url":null,"abstract":"<p><p>Ixodes ticks are the most important vectors of arthropod-borne diseases in the United States, Canada, and Europe. Ixodes scapularis is the major vector that transmits the causative agent of Lyme disease in the eastern United States and can transmit up to six additional pathogens. In recent years, many advances have been made in building the toolkit for I. scapularis research, including genomic resources, transcriptomes, and forward and reverse genetics techniques. However, an understanding of the early embryonic development of this species is still lacking. In this study, we attempted to fill this knowledge gap and to further the efforts of functional genomics tools development. We developed a staging system consisting of 16 (0-15) stages describing unique morphologies and used wheat germ agglutinin staining and fluorescent dye injections to confirm cell membrane formation. These results provide an opportunity to identify an ideal time window for tick transgenics and deepen our understanding of the events during embryo development.</p>","PeriodicalId":49076,"journal":{"name":"Evodevo","volume":"16 1","pages":"4"},"PeriodicalIF":4.1,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12032745/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144041555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EvodevoPub Date : 2025-03-22DOI: 10.1186/s13227-025-00239-5
Zhenhua Zhang, Yao Liu, Na Liang, Zhenpeng Yu, Luoying Deme, Duo Xu, Jia Liu, Wenhua Ren, Shixia Xu, Guang Yang
{"title":"Functional evidence supports the potential role of Tbx4-HLEA in the hindlimb degeneration of cetaceans.","authors":"Zhenhua Zhang, Yao Liu, Na Liang, Zhenpeng Yu, Luoying Deme, Duo Xu, Jia Liu, Wenhua Ren, Shixia Xu, Guang Yang","doi":"10.1186/s13227-025-00239-5","DOIUrl":"10.1186/s13227-025-00239-5","url":null,"abstract":"<p><p>The evolution of limb morphology plays an important role in animal adaptation to different ecological niches. To fully adapt to aquatic life, cetaceans underwent hindlimb degeneration and forelimb transformed into flipper; however, the molecular mechanisms underlying the limb changes in cetaceans remain unclear. We previous study had shown that the Tbx4 hindlimb enhancer A (Tbx4-HLEA) in cetaceans exhibited specific deletions and nucleotide substitutions, with significantly reduced regulatory activity. To further investigate whether cetacean HLEA has a potential impact on hindlimb development in vivo, a knock-in mouse model was generated by knocking in the homologous cetacean HLEA in the present study. Phenotypic analysis showed a significant reduction in hindlimb bud development in homozygous knock-in mice at embryonic day (E)10.5; however, the phenotypic difference was rescued after E11.5. Transcriptomic and epigenetic analyses indicated that the cetacean HLEA acts as an enhancer in the mouse embryos and significantly reduces the transcriptional expression levels of Tbx4 at E10.5, supporting that downregulation of cetaceans HLEA regulatory activity reduces the expression of Tbx4. Additionally, both the number of activated non-coding elements and chromatin accessibility near Tbx4 were increased in homozygous knock-in mice at E11.5. The functional redundancy of enhancers compensated for the functional defect of cetacean HLEA, rescuing the expression level of Tbx4, and may account for the phenotype restoration after E11.5. In conclusion, our study suggested that the evolution of cetacean HLEA may be an important link with relevant molecular mechanism for the hindlimb degeneration.</p>","PeriodicalId":49076,"journal":{"name":"Evodevo","volume":"16 1","pages":"3"},"PeriodicalIF":4.1,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11929173/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143694198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EvodevoPub Date : 2025-03-08DOI: 10.1186/s13227-025-00238-6
Evgenia A Propistsova, Guilherme Gainett, Ariel D Chipman, Prashant P Sharma, Efrat Gavish-Regev
{"title":"Shedding light on the embryogenesis and eye development of the troglophile cave spider Tegenaria pagana C. L. Koch, 1840 (Araneae: Agelenidae).","authors":"Evgenia A Propistsova, Guilherme Gainett, Ariel D Chipman, Prashant P Sharma, Efrat Gavish-Regev","doi":"10.1186/s13227-025-00238-6","DOIUrl":"10.1186/s13227-025-00238-6","url":null,"abstract":"<p><strong>Background: </strong>Relatively little is known about the diversity of embryonic development across lineages of spiders, even though the study of embryonic development is a primary step in evo-devo studies and essential for understanding phenotypic evolution. Practically nothing is known about embryogenesis in cave-dwelling spiders, animals which play an important role in cave ecosystems and may have remarkable adaptations to aphotic habitats such as loss of eyes.</p><p><strong>Results: </strong>Here, we describe embryogenesis and study the expression patterns of several genes of the Retinal Determination Network (RDN) in the troglophile (species that have pre-adaptations to life in caves, and can complete their life cycle in caves, as well as in epigean habitats) eye-bearing funnel-web spider species Tegenaria pagana C. L. Koch, 1840, using fluorescent staining and confocal microscopy. We discuss the characteristic features of T. pagana embryogenesis and key RDN genes. Although in many respects the embryonic development of different species of entelegyne spiders is similar, we found differences in the rate of development, and the details of the opisthosoma, respiratory system, and brain morphogenesis in comparison with established spider model species. Our data supports the hypothesis of a conserved role of sine oculis gene in the eye formation of arachnids.</p><p><strong>Conclusions: </strong>Given the recent discovery of congeneric cave species with different degrees of eye reduction throughout Israel, these data sets provide a foundational point of comparison for studying eye reduction and eye loss events in the spider genus Tegenaria.</p>","PeriodicalId":49076,"journal":{"name":"Evodevo","volume":"16 1","pages":"2"},"PeriodicalIF":4.1,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11889846/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143587645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EvodevoPub Date : 2025-02-14DOI: 10.1186/s13227-025-00237-7
Sally P Leys, Lauren Grombacher, Daniel Field, Glen R D Elliott, Vanessa R Ho, Amanda S Kahn, Pamela J Reid, Ana Riesgo, Emilio Lanna, Yuriy Bobkov, Joseph F Ryan, April L Horton
{"title":"A morphological cell atlas of the freshwater sponge Ephydatia muelleri with key insights from targeted single-cell transcriptomes.","authors":"Sally P Leys, Lauren Grombacher, Daniel Field, Glen R D Elliott, Vanessa R Ho, Amanda S Kahn, Pamela J Reid, Ana Riesgo, Emilio Lanna, Yuriy Bobkov, Joseph F Ryan, April L Horton","doi":"10.1186/s13227-025-00237-7","DOIUrl":"10.1186/s13227-025-00237-7","url":null,"abstract":"<p><p>How animal cell types, tissues, and regional body plans arose is a fundamental question in EvoDevo. Many current efforts attempt to link genetic information to the morphology of cells, tissues and regionalization of animal body plans using single-cell sequencing of cell populations. However, a lack of in-depth understanding of the morphology of non-bilaterian animals remains a considerable block to understanding the transitions between bilaterian and non-bilaterian cells and tissues. Sponges (Porifera), one of the earliest diverging animal phyla, pose a particular challenge to this endeavour, because their body plans lack mouths, gut, conventional muscle and nervous systems. With a goal to help bridge this gap, we have studied the morphology, behaviour and transcriptomics of cells and tissue types of an easily accessible and well-studied species of freshwater sponge, Ephydatia muelleri. New features described here include: a polarized external epithelium, a new contractile sieve cell that forms the entry to incurrent canals, motile cilia on apopyle cells at the exit of choanocyte chambers, and non-motile cilia on cells in excurrent canals and oscula. Imaging cells in vivo shows distinct behavioural characteristics of motile cells in the mesohyl. Transcriptomic phenotypes of three cell types (cystencytes, choanocytes and archaeocytes) captured live indicate that cell-type transcriptomes are distinct. Importantly, individual archaeocytes show a range of transcriptomic phenotypes which is supported by the distinct expression of different genes by subsets of this cell type. In contrast, all five choanocyte cells sampled live revealed highly uniform transcriptomes with significantly fewer genes expressed than in other cell types. Our study shows that sponges have tissues whose morphology and cell diversity are both functionally complex, but which together enable the sponge, like other metazoans, to sense and respond to stimuli.</p>","PeriodicalId":49076,"journal":{"name":"Evodevo","volume":"16 1","pages":"1"},"PeriodicalIF":4.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11827373/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143426515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EvodevoPub Date : 2024-12-27DOI: 10.1186/s13227-024-00233-3
Emily P McFarland, Karen D Crow
{"title":"The evolution of cephalic fins in manta rays and their relatives: functional evidence for initiation of domain splitting and modulation of the Wnt signaling pathway in the pectoral fin AER of the little skate.","authors":"Emily P McFarland, Karen D Crow","doi":"10.1186/s13227-024-00233-3","DOIUrl":"10.1186/s13227-024-00233-3","url":null,"abstract":"<p><strong>Background: </strong>Batoids possess a unique body plan associated with a benthic lifestyle that includes dorsoventral compression and anteriorly expanded pectoral fins that fuse to the rostrum. The family Myliobatidae, including manta rays and their relatives, exhibit further modifications associated with invasion of the pelagic environment, and the evolution of underwater flight. Notably, the pectoral fins are split into two domains with independent functions that are optimized for feeding and oscillatory locomotion. Paired fin outgrowth is maintained during development by Wnt3, while domain splitting is accomplished by expression of the Wnt antagonist Dkk1, which is differentially expressed in the developing anterior pectoral fins of myliobatids, where cephalic fins separate from pectoral fins. We examine the evolution of this unique feature in the cownose ray (Rhinoptera bonasus), a member of the genus that is sister to Mobula.</p><p><strong>Results: </strong>Here, we provide functional evidence that DKK1 is sufficient to initiate pectoral fin domain splitting. Agarose beads soaked in DKK1 protein were implanted in the pectoral fins of little skate (Leucoraja erinacea) embryos resulting in AER interruption. This disruption arrests fin ray outgrowth, resembling the myliobatid phenotype. In addition, fins that received DKK1 beads exhibit interruption of Axin2 expression, a downstream target of β-catenin-dependent Wnt signaling and a known AER marker. We demonstrate that Msx1 and Lhx2 are also associated with fin expansion at the AER. These results provide functional evidence for the underlying genetic pathway associated with the evolution of a novel paired fin/limb modification in manta rays and their relatives. We introduce the gas/brake pedal model for paired fin remodeling at the AER, which may have been co-opted from domain splitting in pelvic fins of cartilaginous fishes 370 million years earlier.</p><p><strong>Conclusions: </strong>The pectoral fins of manta rays and their relatives represent a dramatic remodel of the ancestral batoid body plan. The premiere feature of this remodel is the cephalic fins, which evolved via domain splitting of the anterior pectoral fins through inhibition of fin ray outgrowth. Here, we functionally validate the role of Dkk1 in the evolution of this phenotype. We find that introduction of ectopic DKK1 is sufficient to recapitulate the myliobatid pectoral fin phenotype in an outgroup lacking cephalic fins via AER interruption and fin ray truncation. Additional gene expression data obtained via in situ hybridization suggests that cephalic fin development may have evolved as a co-option of the pathway specifying claspers as modifications to the pelvic fins, the only other known example of domain splitting in vertebrate appendages.</p>","PeriodicalId":49076,"journal":{"name":"Evodevo","volume":"15 1","pages":"17"},"PeriodicalIF":4.1,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11681717/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142899618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EvodevoPub Date : 2024-12-27DOI: 10.1186/s13227-024-00236-0
Dominik Lotz, Le Han Rössner, Katrin Ehlers, Doudou Kong, Clemens Rössner, Oliver Rupp, Annette Becker
{"title":"Conservation of the dehiscence zone gene regulatory network in dicots and the role of the SEEDSTICK ortholog of California poppy (Eschscholzia californica) in fruit development.","authors":"Dominik Lotz, Le Han Rössner, Katrin Ehlers, Doudou Kong, Clemens Rössner, Oliver Rupp, Annette Becker","doi":"10.1186/s13227-024-00236-0","DOIUrl":"10.1186/s13227-024-00236-0","url":null,"abstract":"<p><strong>Background: </strong>Fruits, with their diverse shapes, colors, and flavors, represent a fascinating aspect of plant evolution and have played a significant role in human history and nutrition. Understanding the origins and evolutionary pathways of fruits offers valuable insights into plant diversity, ecological relationships, and the development of agricultural systems. Arabidopsis thaliana (Brassicaceae, core eudicot) and Eschscholzia californica (California poppy, Papaveraceae, sister group to core eudicots) both develop dry dehiscent fruits, with two valves separating explosively from the replum-like region upon maturation. This led to the hypothesis, that homologous gene regulatory networks direct fruit development and dehiscence in both species.</p><p><strong>Results: </strong>Transcriptome analysis of separately collected valve and replum-like tissue of California poppy yielded the SEEDSTICK (STK) ortholog as candidate for dehiscence zone regulation. Expression analysis of STK orthologs from dry dehiscing fruits of legumes (Vicia faba, Glycine max and Pisum sativum) shows their involvement in fruit development. Functional analysis using Virus-Induced Gene Silencing (VIGS) showed premature rupture of fruits and clarified the roles of EscaSTK: an evolutionary conserved role in seed filling and seed coat development, and a novel role in restricting cell divisions in the inner cell layer of the valve.</p><p><strong>Conclusion: </strong>Our analysis shows that the gene regulatory network described in Arabidopsis is significantly different in other dicots, even if their fruits form a dehiscence zone at the valve margins. The ortholog of STK, known to be involved in ovule development and seed abscission in Arabidopsis, was recruited to a network regulating fruit wall proliferation in California poppy. There, EscaSTK allows fruit maturation without premature capsule rupture, highlighting the importance of proper endocarp development for successful seed dispersal.</p>","PeriodicalId":49076,"journal":{"name":"Evodevo","volume":"15 1","pages":"16"},"PeriodicalIF":4.1,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11673373/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142899593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EvodevoPub Date : 2024-11-13DOI: 10.1186/s13227-024-00235-1
Marc A Mapalo, Mandy Game, Frank W Smith, Javier Ortega-Hernández
{"title":"Expression of distal limb patterning genes in Hypsibius exemplaris indicate regionalization and suggest distal identity of tardigrade legs.","authors":"Marc A Mapalo, Mandy Game, Frank W Smith, Javier Ortega-Hernández","doi":"10.1186/s13227-024-00235-1","DOIUrl":"10.1186/s13227-024-00235-1","url":null,"abstract":"<p><strong>Background: </strong>Panarthropods, a major group of invertebrate animals comprised of arthropods, onychophorans, and tardigrades, are the only limb-bearing members of Ecdysozoa. The complexity and versatility of panarthropod paired limbs has prompted great interest in their development to better understand the formation of these structures and the genes involved in this process. However, studies of limb patterning and development are overwhelmingly focused on arthropods, followed by select work on onychophorans but almost entirely lacking for tardigrades. This model organism bias is inherently limited and precludes a comparative analysis of how panarthropod legs originated, have evolved, and the likely limb patterning genes present in the earliest panarthropod ancestors. In this study, we investigated tardigrade homologs of seven arthropod distal limb patterning genes (apterous, aristaless, BarH1, clawless, Lim1, rotund, and spineless) to better characterize tardigrade limb development in a comparative context.</p><p><strong>Results: </strong>We detected homologs of all seven genes in the eutardigrade Hypsibius exemplaris and heterotardigrade Echiniscoides cf. sigismundi suggesting their conservation in both tardigrade lineages. Hybridization chain reaction experiments in H. exemplaris reveal a regionalized expression pattern for the genes aristaless, BarH1, clawless, rotund and spineless.</p><p><strong>Conclusion: </strong>The observed regionalized expression of the distal limb patterning genes in H. exemplaris might reflect the external morphological features of tardigrade legs, such as the distal claws, sensory organs in the proximal region, and specific muscle attachment sites. The comparison between the expression of these limb patterning genes in H. exemplaris relative to other panarthropods suggests their conserved role in the last common panarthropod ancestor, such as establishing the distal limb end and the distribution of sensory structures. Our results support the hypothesis that tardigrade legs are homologous to the distal region of other panarthropod limbs, as suggested by previous work on the expression of leg gap genes in H. exemplaris.</p>","PeriodicalId":49076,"journal":{"name":"Evodevo","volume":"15 1","pages":"15"},"PeriodicalIF":4.1,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11562647/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142631110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EvodevoPub Date : 2024-10-26DOI: 10.1186/s13227-024-00234-2
Ariel Bar-Lev Viterbo, Judith R Wexler, Orel Mayost Lev-Ari, Ariel D Chipman
{"title":"Early embryonic development of the German cockroach Blattella germanica.","authors":"Ariel Bar-Lev Viterbo, Judith R Wexler, Orel Mayost Lev-Ari, Ariel D Chipman","doi":"10.1186/s13227-024-00234-2","DOIUrl":"10.1186/s13227-024-00234-2","url":null,"abstract":"<p><strong>Background: </strong>Early embryogenesis is characterized by dramatic cell proliferation and movement. In most insects, early embryogenesis includes a phase called the uniform blastoderm, during which cells evenly cover the entirety of the egg. However, the embryo of the German cockroach, Blattella germanica, like those of many insects within the super order Polyneoptera, does not have a uniform blastoderm; instead, its first cells condense rapidly at the site of a future germband. We investigated early development in this species in order to understand how early gene expression is or is not conserved in these insect embryos with distinct early cell behaviors.</p><p><strong>Results: </strong>We present a detailed time series of nuclear division and distribution from fertilization through germband formation and report patterns of expression for the early patterning genes hunchback, caudal, and twist in order to understand early polarization and mesoderm formation. We show a detailed time course of the spatial expression of two genes involved in the segmentation cascade, hedgehog and even-skipped, and demonstrate two distinct dynamics of the segmentation process.</p><p><strong>Conclusions: </strong>Despite dramatic differences in cell distribution between the blastoderms of many Polyneopteran insects and those of more well-studied developmental models, expression patterns of early patterning genes are mostly similar. Genes associated with axis determination in other insects are activated relatively late and are probably not maternally deposited. The two phases of segmentation-simultaneous and sequential-might indicate a broadly conserved mode of morphological differentiation. The developmental time course we present here should be of value for further investigation into the causes of this distinct blastoderm type.</p>","PeriodicalId":49076,"journal":{"name":"Evodevo","volume":"15 1","pages":"14"},"PeriodicalIF":4.1,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11520056/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142511331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}