Developmental Dynamics最新文献

{"title":"Elongation of the developing spinal cord is driven by Oct4-type transcription factor-mediated regulation of retinoic acid signaling in zebrafish embryos","authors":"Tatsuya Yuikawa,&nbsp;Takehisa Sato,&nbsp;Masaaki Ikeda,&nbsp;Momo Tsuruoka,&nbsp;Kaede Yasuda,&nbsp;Yuto Sato,&nbsp;Kouhei Nasu,&nbsp;Kyo Yamasu","doi":"10.1002/dvdy.666","DOIUrl":"10.1002/dvdy.666","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Elongation of the spinal cord is dependent on neural development from neuromesodermal progenitors in the tail bud. We previously showed the involvement of the <i>Oct4</i>-type gene, <i>pou5f3</i>, in this process in zebrafish mainly by dominant-interference gene induction, but, to compensate for the limitation of this transgene approach, mutant analysis was indispensable. <i>pou5f</i>3 involvement in the signaling pathways was another unsolved question.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We examined the phenotypes of <i>pou5f3</i> mutants and the effects of Pou5f3 activation by the tamoxifen-ERT2 system in the posterior neural tube, together confirming the involvement of <i>pou5f3</i>. The reporter assays using P19 cells implicated tail bud-related transcription factors in <i>pou5f3</i> expression. Regulation of tail bud development by retinoic acid (RA) signaling was confirmed by treatment of embryos with RA and the synthesis inhibitor, and in vitro reporter assays further showed that RA signaling regulated <i>pou5f3</i> expression. Importantly, the expression of the RA degradation enzyme gene, <i>cyp26a1</i>, was down-regulated in embryos with disrupted <i>pou5f3</i> activity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The involvement of <i>pou5f3</i> in spinal cord extension was supported by using mutants and the gain-of-function approach. Our findings further suggest that <i>pou5f3</i> regulates the RA level, contributing to neurogenesis in the posterior neural tube.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11247,"journal":{"name":"Developmental Dynamics","volume":"253 4","pages":"404-422"},"PeriodicalIF":2.5,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dvdy.666","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41233235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impaired breakdown of Herwig's epithelial root sheath disturbs tooth root development","authors":"Ju-Kyung Jeong,&nbsp;Tak-Heun Kim,&nbsp;Hwajung Choi,&nbsp;Eui-Sic Cho","doi":"10.1002/dvdy.667","DOIUrl":"10.1002/dvdy.667","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Wnt/β-catenin signaling plays a variety of roles in both the dental epithelium and mesenchyme at most stages of tooth development. In this study, we verified the roles of Hertwig's epithelial root sheath (HERS) breakdown in tooth root development. This breakdown results in formation of epithelial cell rests of Malassez (ERM).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Following induction of β-catenin stabilization in the epithelium of developing tooth at the moment of HERS breakdown, HERS failed to break down for ERM formation. HERS with stabilized β-catenin was altered into a multicellular layer enveloping elongated root dentin with higher expression of junctional proteins such as Zo-1 and E-cadherin. Importantly, this impairment of HERS breakdown led to arrest of further root elongation. In addition, the portion of root dentin enveloped by the undissociated HERS remained in a hypomineralized state. The odontoblasts showed ectopically higher expression of pyrophosphate regulators including Ank and Npp1, whereas Tnap expression was unchanged.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our data suggest that Wnt/β-catenin signaling is decreased in HERS for ERM formation during root development. Furthermore, ERM formation is important for further elongation and dentin mineralization of the tooth roots. These findings may provide new insight to understand the contribution of ERM to root formation.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11247,"journal":{"name":"Developmental Dynamics","volume":"253 4","pages":"423-434"},"PeriodicalIF":2.5,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dvdy.667","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41233236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Loss of function of male-specific lethal 3 (Msl3) does not affect spermatogenesis in rodents","authors":"T. A. Mitchell,&nbsp;J. M. Lin,&nbsp;S. M. Hicks,&nbsp;J. R. James,&nbsp;P. Rangan,&nbsp;P. E. Forni","doi":"10.1002/dvdy.669","DOIUrl":"10.1002/dvdy.669","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Male-specific lethal 3 (Msl3) is a member of the chromatin-associated male-specific lethal MSL complex, which is responsible for the transcriptional upregulation of genes on the X chromosome in males of <i>Drosophila</i>. Although the dosage complex operates differently in mammals, the Msl3 gene is conserved from flies to humans. Msl3 is required for meiotic entry during <i>Drosophila</i> oogenesis. Recent reports indicate that also in primates, Msl3 is expressed in undifferentiated germline cells before meiotic entry. However, if Msl3 plays a role in the meiotic entry of mammals has yet to be explored.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>To understand, if Msl3a plays a role in the meiotic entry of mammals, we used mouse spermatogenesis as a study model. Analyses of single-cell RNA-seq data revealed that, in mice, Msl3 is mostly expressed in meiotic cells. To test the role of Msl3 in meiosis, we used a male germline-specific Stra8-iCre driver and a newly generated Msl3^flox conditional knock-out mouse line. Msl3 conditional loss-of-function in spermatogonia did not cause spermatogenesis defects or changes in the expression of genes related to meiosis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our data suggest that, in mice, Msl3 exhibits delayed expression compared to <i>Drosophila</i> and primates, and loss-of-function mutations disrupting the chromodomain of Msl3 alone do not impede meiotic entry in rodents.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11247,"journal":{"name":"Developmental Dynamics","volume":"253 5","pages":"453-466"},"PeriodicalIF":2.5,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41233237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Darwin, Haeckel, and the “Mikluskan gas organ theory”","authors":"Ingmar Werneburg,&nbsp;Uwe Hoßfeld,&nbsp;Georgy S. Levit","doi":"10.1002/dvdy.661","DOIUrl":"10.1002/dvdy.661","url":null,"abstract":"<p>A previously unknown reference to the Russian ethnologist, biologist, and traveler Nikolai N. Miklucho-Maclay (1846–1888) was discovered in correspondence between Charles Darwin (1809–1882) and Ernst Haeckel (1834–1919). This reference has remained unknown to science, even to Miklucho-Maclay's biographers, probably because Darwin used the Russian nickname “Mikluska” when alluding to this young scientist. Here, we briefly outline the story behind the short discussion between Darwin and his German counterpart Haeckel, and highlight its importance for the history of science. Miklucho-Maclay's discovery of a putative swim bladder anlage in sharks, published in 1867, was discussed in four letters between the great biologists. Whereas, Haeckel showed enthusiasm for the finding because it supported (his view on) evolutionary theory, Darwin was less interested, which highlights the conceptual differences between the two authorities. We discuss the scientific treatment of Miklucho-Maclay's observation in the literature and discuss the homology, origin, and destiny of gas organs—swim bladders and lungs—in vertebrate evolution, from an ontogenetic point of view. We show that the conclusions reached by Miklucho-Maclay and Haeckel were rather exaggerated, although they gave rise to fundamental insights, and we illustrate how tree-thinking may lead to differences in the conceptualization of evolutionary change.</p>","PeriodicalId":11247,"journal":{"name":"Developmental Dynamics","volume":"253 4","pages":"370-389"},"PeriodicalIF":2.5,"publicationDate":"2023-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dvdy.661","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41194426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct diffusion of anti-Müllerian hormone from both the cranial and caudal regions of the testis during early gonadal development in mice","authors":"Shiori Kato,&nbsp;Toshifumi Yokoyama,&nbsp;Nobusuke Okunishi,&nbsp;Hiroto Narita,&nbsp;Taisei Fujikawa,&nbsp;Yusuke Kirizuki,&nbsp;Youhei Mantani,&nbsp;Takanori Miki,&nbsp;Nobuhiko Hoshi","doi":"10.1002/dvdy.662","DOIUrl":"10.1002/dvdy.662","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>The Müllerian duct (MD), the primordium of the female reproductive tract, is also formed in males during the early stage of development, then regresses due to the anti-Müllerian hormone (AMH) secreted from the testes. However, the detailed diffusion pathway of AMH remains unclear. We herein investigated the mechanism by which AMH reaches the middle region of the MD using an organ culture system.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Injection of recombinant human AMH into the testis around the start of MD regression induced diffuse immunoreactivity in the mesonephros near the injection site. When the testis and mesonephros were cultured separately, the diameters of both cranial and middle MDs were significantly increased compared to the control. In the testis–mesonephros complex cultured by inhibiting the diffusion of AMH through the cranial region, the cranial MD diameter was significantly increased compared to the control, and there was no difference in middle MD diameter.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These results indicate that AMH, which infiltrates from the testis through the cranial region at physiological concentrations, induces regression of the cranial MD at the start of MD regression. They also indicate that AMH infiltrating through the caudal regions induces regression of the middle MD.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11247,"journal":{"name":"Developmental Dynamics","volume":"253 3","pages":"296-311"},"PeriodicalIF":2.5,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41123860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial highlights","authors":"Paul A. Trainor","doi":"10.1002/dvdy.664","DOIUrl":"10.1002/dvdy.664","url":null,"abstract":"&lt;p&gt;Every organism is a model organism for understanding development, evolution, disease, and regeneration, and we have only begun to scratch the surface of the interdisciplinary genetic, molecular, cellular, and developmental mechanisms that regulate these biological processes. These “Highlights” denote exciting advances recently reported in &lt;i&gt;Developmental Dynamics&lt;/i&gt; that illustrate the complex dynamics of developmental biology.&lt;/p&gt;&lt;p&gt;&lt;b&gt;Cardiovascular Organogenesis.&lt;/b&gt; “Experimental Assessment of Cardiovascular Physiology in the Chick Embryo” by Vijayakumar Sukumaran, Onur Mutlu, Mohammad Murtaza, Rawia Alhalbouni, Benjamin Dubansky and Huseyin Yalcin; &lt;i&gt;DevDyn&lt;/i&gt; 252:10, pp. 1247-1268; https://doi.org/10.1002/dvdy.589. Cardiovascular disease is a major cause of mortality. As soon as heart begins contracting during embryogenesis, the hemodynamic forces of blood moving through the heart and vasculature, helps drive and shape drive cardiac morphogenesis, angiogenesis, and development of the cardiac conduction system. Historically, the chicken embryo has served as an important model for cardiovascular research. This review article discusses several technical approaches for studying chick embryo cardiovascular development and physiology such as doppler echocardiography, optical coherence tomography, micro-magnetic resonance imaging, micro-particle image velocimetry, and real-time pressure monitoring, alongside recent advances in the measurement of cardiac function.&lt;/p&gt;&lt;p&gt;&lt;b&gt;Hearing and Balance.&lt;/b&gt; “Fgf, Hh and pax2a differentially regulate expression of pax5 and pou3f3b in vestibular and auditory maculae in the zebrafish otic vesicle” by Amy Tan, Sydney Christensen, Allison Baker and Bruce Riley; &lt;i&gt;DevDyn&lt;/i&gt; 252:10, pp. 1269-1279; https://doi.org/10.1002/dvdy.599&lt;b&gt;.&lt;/b&gt; The vertebrate inner ear contains distinct sensory epithelia specialized for auditory or vestibular function. In zebrafish, utricular and saccular maculae alone mediate vestibular and auditory functions, respectively. Specification of utricular versus saccular maculae requires different levels of Fgf and Hh signaling, and alterations in combinatorial Fgf or Hh signaling elicit corresponding shifts in utricular vs. saccular development. However, pax2a maintains both fates downstream of these signaling pathways, and similarities in mouse embryos suggest this is indicative of a broadly conserved developmental mechanism.&lt;/p&gt;&lt;p&gt;&lt;b&gt;Craniofacial and Tooth Development.&lt;/b&gt; “Enam expression is regulated by Msx2” by Intan Ruspita, Pragnya Das, Keiko Miyoshi, Takafumi Noma, Malcolm Snead and Marianna Bei; &lt;i&gt;DevDyn&lt;/i&gt; 252:10, pp. 1292-1302; https://doi.org/10.1002/dvdy.598. Amelogenesis, the process of enamel formation, requires tight transcriptional control of secreted matrix proteins. Enamelin is one of the major proteins secreted by ameloblasts for propoper enamel formation. This study shows that expression of the &lt;i&gt;Enam&lt;/i&gt; gene, which encodes enamalin, is regulated by Msx2. An","PeriodicalId":11247,"journal":{"name":"Developmental Dynamics","volume":"252 10","pages":"1246"},"PeriodicalIF":2.5,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dvdy.664","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41132380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Primary cilia are critical for tracheoesophageal septation","authors":"Lindsey Avery Fitzsimons,&nbsp;Evangelia Tasouri,&nbsp;Marc August Willaredt,&nbsp;Daniel Stetson,&nbsp;Christian Gojak,&nbsp;Joachim Kirsch,&nbsp;Humphrey A. R. Gardner,&nbsp;Karin Gorgas,&nbsp;Kerry L. Tucker","doi":"10.1002/dvdy.660","DOIUrl":"10.1002/dvdy.660","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>Primary cilia play pivotal roles in the patterning and morphogenesis of a wide variety of organs during mammalian development. Here we examined murine foregut septation in the <i>cobblestone</i> mutant, a hypomorphic allele of the gene encoding the intraflagellar transport protein IFT88, a protein essential for normal cilia function.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We reveal a crucial role for primary cilia in foregut division, since their dramatic decrease in cilia in both the foregut endoderm and mesenchyme of mutant embryos resulted in a proximal tracheoesophageal septation defects and in the formation of distal tracheo(broncho)esophageal fistulae similar to the most common congenital tracheoesophageal malformations in humans. Interestingly, the dorsoventral patterning determining the dorsal digestive and the ventral respiratory endoderm remained intact, whereas Hedgehog signaling was aberrantly activated.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results demonstrate the <i>cobblestone</i> mutant to represent one of the very few mouse models that display both correct endodermal dorsoventral specification but defective compartmentalization of the proximal foregut. It stands exemplary for a tracheoesophageal ciliopathy, offering the possibility to elucidate the molecular mechanisms how primary cilia orchestrate the septation process. The plethora of malformations observed in the <i>cobblestone</i> embryo allow for a deeper insight into a putative link between primary cilia and human VATER/VACTERL syndromes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11247,"journal":{"name":"Developmental Dynamics","volume":"253 3","pages":"312-332"},"PeriodicalIF":2.5,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41130955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rspo1 and Rspo3 are required for sensory lineage neural crest formation in mouse embryos","authors":"Takuma Shinozuka,&nbsp;Motoko Aoki,&nbsp;Yudai Hatakeyama,&nbsp;Noriaki Sasai,&nbsp;Hitoshi Okamoto,&nbsp;Shinji Takada","doi":"10.1002/dvdy.659","DOIUrl":"10.1002/dvdy.659","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>R-spondins (Rspos) are secreted proteins that modulate Wnt/β-catenin signaling. At the early stages of spinal cord development, <i>Wnts (Wnt1, Wnt3a)</i> and <i>Rspos (Rspo1, Rspo3)</i> are co-expressed in the roof plate, suggesting that <i>Rspos</i> are involved in development of dorsal spinal cord and neural crest cells in cooperation with Wnt ligands.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Here, we found that <i>Rspo1</i> and <i>Rspo3</i>, as well as <i>Wnt1</i> and <i>Wnt3a</i>, maintained roof-plate-specific expression until late embryonic stages. <i>Rspo1-</i> and <i>Rspo3</i>-double-knock-out (dKO) embryos partially exhibited the phenotype of <i>Wnt1</i> and <i>Wnt3a</i> dKO embryos. While the number of <i>Ngn2</i>-positive sensory lineage neural crest cells is reduced in <i>Rspo</i>-dKO embryos, development of dorsal spinal cord, including its size and dorso-ventral patterning in early development, elongation of the roof plate, and proliferation of ependymal cells, proceeded normally. Consistent with these slight defects, Wnt/β-catenin signaling was not obviously changed in developing spinal cord of dKO embryos.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results show that <i>Rspo1</i> and <i>Rspo3</i> are dispensable for most developmental processes involving roof plate-derived Wnt ligands, except for specification of a subtype of neural crest cells. Thus, Rspos may modulate Wnt/β-catenin signaling in a context-dependent manner.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11247,"journal":{"name":"Developmental Dynamics","volume":"253 4","pages":"435-446"},"PeriodicalIF":2.5,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dvdy.659","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41095504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Embryonic development in the bonnethead (Sphyrna tiburo), a viviparous hammerhead shark","authors":"Steven R. Byrum,&nbsp;Bryan S. Frazier,&nbsp;R. Dean Grubbs,&nbsp;Gavin J. P. Naylor,&nbsp;Gareth J. Fraser","doi":"10.1002/dvdy.658","DOIUrl":"10.1002/dvdy.658","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>The hammerhead sharks (family Sphyrnidae) are an immediately recognizable group of sharks due to their unique head shape. Though there has long been an interest in hammerhead development, there are currently no explicit staging tables published for any members of the group. The bonnethead <i>Sphyrna tiburo</i> is the smallest member of Sphyrnidae and is abundant in estuarine and nearshore waters in the Gulf of Mexico and Western North Atlantic Ocean. Due to their relative abundance, close proximity to shore, and brief gestation period, it has been possible to collect and document multiple embryonic specimens at progressive stages of development.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We present the first comprehensive embryonic staging series for the Bonnethead, a viviparous hammerhead shark. Our stage series covers a period of development from stages that match the vertebrate phylotypic period, from Stage 23, through stages of morphological divergence to complete development at birth—Stage 35). Notably, we use a variety of techniques to document crucial stages that lead to their extreme craniofacial diversity, resulting in the formation of one of the most distinctive characters of any shark species, the cephalofoil or hammer-like head.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Documenting the development of hard-to-access vertebrates, like this viviparous shark species, offers important information about how new and diverse morphologies arise that otherwise may remain poorly studied. This work will serve as a platform for future comparative developmental research both within sharks and across the phylogeny of vertebrates, underpinning the extreme potential of craniofacial development and morphological diversity in vertebrate animals.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11247,"journal":{"name":"Developmental Dynamics","volume":"253 3","pages":"351-362"},"PeriodicalIF":2.5,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dvdy.658","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41115508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of the vertebra and fin skeleton in the lamprey and its implications for the homology of vertebrate vertebrae","authors":"Hirofumi Kariyayama,&nbsp;Natalia Gogoleva,&nbsp;Keishi Harada,&nbsp;Hiromasa Yokoyama,&nbsp;Hiroki Ono,&nbsp;Daichi G. Suzuki,&nbsp;Yuji Yamazaki,&nbsp;Hiroshi Wada","doi":"10.1002/dvdy.657","DOIUrl":"10.1002/dvdy.657","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Although vertebrae are the defining character of vertebrates, they are found only in rudimentary form in extant agnathans. In addition, the vertebrae of agnathans possess several unique features, such as elastin-like molecules as the main matrix component and late (post-metamorphosis) differentiation of lamprey vertebrae. In this study, by tracing the developmental process of vertebrae in lamprey, we examined the homology of vertebrae between lampreys and gnathostomes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found that the lamprey somite is first subdivided mediolaterally, with myotome cells differentiating medially and non-myotome cells emerging laterally. Subsequently, collagen-positive non-myotome cells surround the myotome. This pattern of somitogenesis is rather similar to that in amphioxi and sheds doubt on the presence of a sclerotome, in terms of mesenchyme cells induced by a signal from the notochord, in lamprey. Further tracing of non-myotome cell development revealed that fin cartilage develops in ammocoete larvae approximately 35 mm in body length. The development of the fin cartilage occurs much earlier than that of the vertebra whose development proceeds during metamorphosis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>We propose that the homology of vertebrae between agnathans and gnathostomes should be discussed carefully, because the developmental process of the lamprey vertebra is different from that of gnathostomes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11247,"journal":{"name":"Developmental Dynamics","volume":"253 3","pages":"283-295"},"PeriodicalIF":2.5,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41135274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}