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Minařík M, Modrell MS, Gillis JA, Campbell AS, Fuller I, Lyne R, Micklem G, Gela D, Pšenička M, Baker CVH. Identification of multiple transcription factor genes potentially involved in the development of electrosensory versus mechanosensory lateral line organs. Front Cell Dev Biol 2024; 12:1327924. [PMID: 38562141 PMCID: PMC10982350 DOI: 10.3389/fcell.2024.1327924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 02/19/2024] [Indexed: 04/04/2024] Open
Abstract
In electroreceptive jawed vertebrates, embryonic lateral line placodes give rise to electrosensory ampullary organs as well as mechanosensory neuromasts. Previous reports of shared gene expression suggest that conserved mechanisms underlie electroreceptor and mechanosensory hair cell development and that electroreceptors evolved as a transcriptionally related "sister cell type" to hair cells. We previously identified only one transcription factor gene, Neurod4, as ampullary organ-restricted in the developing lateral line system of a chondrostean ray-finned fish, the Mississippi paddlefish (Polyodon spathula). The other 16 transcription factor genes we previously validated in paddlefish were expressed in both ampullary organs and neuromasts. Here, we used our published lateral line organ-enriched gene-set (arising from differential bulk RNA-seq in late-larval paddlefish), together with a candidate gene approach, to identify 25 transcription factor genes expressed in the developing lateral line system of a more experimentally tractable chondrostean, the sterlet (Acipenser ruthenus, a small sturgeon), and/or that of paddlefish. Thirteen are expressed in both ampullary organs and neuromasts, consistent with conservation of molecular mechanisms. Seven are electrosensory-restricted on the head (Irx5, Irx3, Insm1, Sp5, Satb2, Mafa and Rorc), and five are the first-reported mechanosensory-restricted transcription factor genes (Foxg1, Sox8, Isl1, Hmx2 and Rorb). However, as previously reported, Sox8 is expressed in ampullary organs as well as neuromasts in a catshark (Scyliorhinus canicula), suggesting the existence of lineage-specific differences between cartilaginous and ray-finned fishes. Overall, our results support the hypothesis that ampullary organs and neuromasts develop via largely conserved transcriptional mechanisms, and identify multiple transcription factors potentially involved in the formation of electrosensory versus mechanosensory lateral line organs.
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Affiliation(s)
- Martin Minařík
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Melinda S. Modrell
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - J. Andrew Gillis
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Alexander S. Campbell
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Isobel Fuller
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Rachel Lyne
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Gos Micklem
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - David Gela
- Faculty of Fisheries and Protection of Waters, Research Institute of Fish Culture and Hydrobiology, University of South Bohemia in České Budějovice, Vodňany, Czechia
| | - Martin Pšenička
- Faculty of Fisheries and Protection of Waters, Research Institute of Fish Culture and Hydrobiology, University of South Bohemia in České Budějovice, Vodňany, Czechia
| | - Clare V. H. Baker
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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2
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Ermakova GV, Meyntser IV, Zaraisky AG, Bayramov AV. Loss of noggin1, a classic embryonic inducer gene, in elasmobranchs. Sci Rep 2024; 14:3805. [PMID: 38360907 PMCID: PMC10869764 DOI: 10.1038/s41598-024-54435-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 02/13/2024] [Indexed: 02/17/2024] Open
Abstract
Secreted proteins of the Noggin family serve as pivotal regulators of early development and cell differentiation in all multicellular animals, including vertebrates. Noggin1 was identified first among all Noggins. Moreover, it was described as the first known embryonic inducer specifically secreted by the Spemann organizer and capable of inducing a secondary body axis when expressed ectopically. In the classical default model of neural induction, Noggin1 is presented as an antagonist of BMP signalling, playing a role as a neural inducer. Additionally, Noggin1 is involved in the dorsalization of embryonic mesoderm and later controls the differentiation of various tissues, including muscles, bones, and neural crest derivatives. Hitherto, noggin1 was found in all studied vertebrates. Here, we report the loss of noggin1 in elasmobranchs (sharks, rays and skates), which is a unique case among vertebrates. noggin2 and noggin4 retained in this group and studied in the embryos of the grey bamboo shark Chiloscyllium griseum revealed similarities in expression patterns and functional properties with their orthologues described in other vertebrates. The loss of noggin1 in elasmobranchs may be associated with histological features of the formation of their unique internal cartilaginous skeleton, although additional research is required to establish functional connections between these events.
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Affiliation(s)
- Galina V Ermakova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
| | - Irina V Meyntser
- Moskvarium Center for Oceanography and Marine Biology, Moscow, 129223, Russia
| | - Andrey G Zaraisky
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia.
- Pirogov Russian National Research Medical University, Moscow, 117997, Russia.
| | - Andrey V Bayramov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia.
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3
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Rees JM, Palmer MA, Gillis JA. Fgf signalling is required for gill slit formation in the skate, Leucoraja erinacea. Dev Biol 2024; 506:85-94. [PMID: 38040078 PMCID: PMC11195640 DOI: 10.1016/j.ydbio.2023.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 11/03/2023] [Accepted: 11/24/2023] [Indexed: 12/03/2023]
Abstract
The gill slits of fishes develop from an iterative series of pharyngeal endodermal pouches that contact and fuse with surface ectoderm on either side of the embryonic head. We find in the skate (Leucoraja erinacea) that all gill slits form via a stereotypical sequence of epithelial interactions: 1) endodermal pouches approach overlying surface ectoderm, with 2) focal degradation of ectodermal basement membranes preceding endoderm-ectoderm contact; 3) endodermal pouches contact and intercalate with overlying surface ectoderm, and finally 4) perforation of a gill slit occurs by epithelial remodelling, without programmed cell death, at the site of endoderm-ectoderm intercalation. Skate embryos express Fgf8 and Fgf3 within developing pharyngeal epithelia during gill slit formation. When we inhibit Fgf signalling by treating skate embryos with the Fgf receptor inhibitor SU5402 we find that endodermal pouch formation, basement membrane degradation and endodermal-ectodermal intercalation are unaffected, but that epithelial remodelling and gill slit perforation fail to occur. These findings point to a role for Fgf signalling in epithelial remodelling during gill slit formation in the skate and, more broadly, to an ancestral role for Fgf signalling during pharyngeal pouch epithelial morphogenesis in vertebrate embryos.
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Affiliation(s)
- Jenaid M Rees
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Michael A Palmer
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, USA
| | - J Andrew Gillis
- Department of Zoology, University of Cambridge, Cambridge, UK; Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, USA.
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4
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Rees JM, Sleight VA, Clark SJ, Nakamura T, Gillis JA. Ectodermal Wnt signaling, cell fate determination, and polarity of the skate gill arch skeleton. eLife 2023; 12:79964. [PMID: 36940244 PMCID: PMC10027317 DOI: 10.7554/elife.79964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 03/03/2023] [Indexed: 03/21/2023] Open
Abstract
The gill skeleton of cartilaginous fishes (sharks, skates, rays, and holocephalans) exhibits a striking anterior-posterior polarity, with a series of fine appendages called branchial rays projecting from the posterior margin of the gill arch cartilages. We previously demonstrated in the skate (Leucoraja erinacea) that branchial rays derive from a posterior domain of pharyngeal arch mesenchyme that is responsive to Sonic hedgehog (Shh) signaling from a distal gill arch epithelial ridge (GAER) signaling centre. However, how branchial ray progenitors are specified exclusively within posterior gill arch mesenchyme is not known. Here, we show that genes encoding several Wnt ligands are expressed in the ectoderm immediately adjacent to the skate GAER, and that these Wnt signals are transduced largely in the anterior arch environment. Using pharmacological manipulation, we show that inhibition of Wnt signalling results in an anterior expansion of Shh signal transduction in developing skate gill arches, and in the formation of ectopic anterior branchial ray cartilages. Our findings demonstrate that ectodermal Wnt signalling contributes to gill arch skeletal polarity in skate by restricting Shh signal transduction and chondrogenesis to the posterior arch environment and highlights the importance of signalling interactions at embryonic tissue boundaries for cell fate determination in vertebrate pharyngeal arches.
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Affiliation(s)
- Jenaid M Rees
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Victoria A Sleight
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | | | - Tetsuya Nakamura
- Department of Genetics, Rutgers University, Piscataway, United States
| | - J Andrew Gillis
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, United States
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Hirschberger C, Gillis JA. The pseudobranch of jawed vertebrates is a mandibular arch-derived gill. Development 2022; 149:275947. [PMID: 35762641 PMCID: PMC9340550 DOI: 10.1242/dev.200184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 06/14/2022] [Indexed: 12/16/2022]
Abstract
The pseudobranch is a gill-like epithelial elaboration that sits behind the jaw of most fishes. This structure was classically regarded as a vestige of the ancestral gill arch-like condition of the gnathostome jaw. However, more recently, hypotheses of jaw evolution by transformation of a gill arch have been challenged, and the pseudobranch has alternatively been considered a specialised derivative of the second (hyoid) pharyngeal arch. Here, we demonstrate in the skate (Leucoraja erinacea) that the pseudobranch does, in fact, derive from the mandibular arch, and that it shares gene expression features and cell types with gills. We also show that the skate mandibular arch pseudobranch is supported by a spiracular cartilage that is patterned by a shh-expressing epithelial signalling centre. This closely parallels the condition seen in the gill arches, where cartilaginous appendages called branchial rays, which support the respiratory lamellae of the gills, are patterned by a shh-expressing gill arch epithelial ridge. Together with similar discoveries in zebrafish, our findings support serial homology of the pseudobranch and gills, and an ancestral origin of gill arch-like anatomical features from the gnathostome mandibular arch. Summary: The skate pseudobranch is a gill serial homologue and reveals the ancestral gill arch-like nature of the jawed vertebrate mandibular arch.
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Affiliation(s)
- Christine Hirschberger
- University of Cambridge 1 Department of Zoology , , Downing Street, Cambridge CB2 3EJ , UK
| | - J. Andrew Gillis
- University of Cambridge 1 Department of Zoology , , Downing Street, Cambridge CB2 3EJ , UK
- Marine Biological Laboratory 2 , 7 MBL Street, Woods Hole, MA 02543 , USA
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6
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Distinct proliferative and middle ear skeletal-patterning functions for SHH-expressing epithelia in the chick hyoid arch. Dev Biol 2022; 489:98-108. [PMID: 35714752 DOI: 10.1016/j.ydbio.2022.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 11/23/2022]
Abstract
During chick craniofacial development, the second (hyoid) pharyngeal arch expands to close the neck and gives rise to skeletal elements, including the columella of the middle ear (a homologue of the mammalian stapes). Sonic hedgehog (SHH) signalling has been implicated in hyoid arch expansion and columella formation, but spatial and temporal aspects of these signalling interactions within the hyoid arch remain poorly understood. Here, we show that SHH is initially expressed in the posterior endoderm of the hyoid arch, and that this domain subsequently splits into a distal domain at the site of arch expansion (the posterior epithelial margin, PEM), and a proximal domain that lines the foregut (the proximal hyoid epithelium, PHE). Pharmacological manipulations and heterotopic grafting experiments demonstrate that SHH signalling is required for hyoid arch expansion and skeletogenesis, and reveal distinct roles for the PEM and PHE in these processes. The PEM promotes mesenchymal cell proliferation during arch expansion but is not sufficient to repattern the columella. Conversely, the PHE promotes mesenchymal cell survival, and PHE grafts induce partial duplication of the columella. This work demonstrates crucial and distinct roles for endodermal SHH signalling in hyoid arch morphogenesis and patterning of the middle ear skeleton.
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7
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Redeployment of odontode gene regulatory network underlies dermal denticle formation and evolution in suckermouth armored catfish. Sci Rep 2022; 12:6172. [PMID: 35418659 PMCID: PMC9007992 DOI: 10.1038/s41598-022-10222-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 04/05/2022] [Indexed: 11/21/2022] Open
Abstract
Odontodes, i.e., teeth and tooth-like structures, consist of a pulp cavity and dentin covered by a mineralized cap. These structures first appeared on the outer surface of vertebrate ancestors and were repeatedly lost and gained across vertebrate clades; yet, the underlying genetic mechanisms and trajectories of this recurrent evolution remain long-standing mysteries. Here, we established suckermouth armored catfish (Ancistrus sp.; Loricariidae), which have reacquired dermal odontodes (dermal denticles) all over most of their body surface, as an experimental model animal amenable to genetic manipulation for studying odontode development. Our histological analysis showed that suckermouth armored catfish develop dermal denticles through the previously defined odontode developmental stages. De novo transcriptomic profiling identified the conserved odontode genetic regulatory network (oGRN) as well as expression of paired like homeodomain 2 (pitx2), previously known as an early regulator of oGRN in teeth but not in other dermal odontodes, in developing dermal denticles. The early onset of pitx2 expression in cranial dermal denticle placodes implies its function as one of the inducing factors of the cranial dermal denticles. By comprehensively identifying the genetic program for dermal odontode development in suckermouth armored catfish, this work illuminates how dermal odontodes might have evolved and diverged in distinct teleost lineages via redeployment of oGRN.
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Schmidt P, Leman E, Lagadec R, Schubert M, Mazan S, Reshef R. Evolutionary Transition in the Regulation of Vertebrate Pronephros Development: A New Role for Retinoic Acid. Cells 2022; 11:cells11081304. [PMID: 35455988 PMCID: PMC9026449 DOI: 10.3390/cells11081304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/29/2022] [Accepted: 04/01/2022] [Indexed: 11/25/2022] Open
Abstract
The anterior-posterior (AP) axis in chordates is regulated by a conserved set of genes and signaling pathways, including Hox genes and retinoic acid (RA), which play well-characterized roles in the organization of the chordate body plan. The intermediate mesoderm (IM), which gives rise to all vertebrate kidneys, is an example of a tissue that differentiates sequentially along this axis. Yet, the conservation of the spatiotemporal regulation of the IM across vertebrates remains poorly understood. In this study, we used a comparative developmental approach focusing on non-conventional model organisms, a chondrichthyan (catshark), a cyclostome (lamprey), and a cephalochordate (amphioxus), to assess the involvement of RA in the regulation of chordate and vertebrate pronephros formation. We report that the anterior expression boundary of early pronephric markers (Pax2 and Lim1), positioned at the level of somite 6 in amniotes, is conserved in the catshark and the lamprey. Furthermore, RA, driving the expression of Hox4 genes like in amniotes, regulates the anterior pronephros boundary in the catshark. We find no evidence for the involvement of this regulatory hierarchy in the AP positioning of the lamprey pronephros and the amphioxus pronephros homolog, Hatschek’s nephridium. This suggests that despite the conservation of Pax2 and Lim1 expressions in chordate pronephros homologs, the responsiveness of the IM, and hence of pronephric genes, to RA- and Hox-dependent regulation is a gnathostome novelty.
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Affiliation(s)
- Pascal Schmidt
- Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel; (P.S.); (E.L.)
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France;
| | - Eva Leman
- Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel; (P.S.); (E.L.)
| | - Ronan Lagadec
- CNRS, Sorbonne Université, UMR7232-Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, 66650 Banyuls-sur-Mer, France; (R.L.); (S.M.)
| | - Michael Schubert
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France;
| | - Sylvie Mazan
- CNRS, Sorbonne Université, UMR7232-Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, 66650 Banyuls-sur-Mer, France; (R.L.); (S.M.)
| | - Ram Reshef
- Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel; (P.S.); (E.L.)
- Correspondence:
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Mayeur H, Lanoizelet M, Quillien A, Menuet A, Michel L, Martin KJ, Dejean S, Blader P, Mazan S, Lagadec R. When Bigger Is Better: 3D RNA Profiling of the Developing Head in the Catshark Scyliorhinus canicula. Front Cell Dev Biol 2021; 9:744982. [PMID: 34746140 PMCID: PMC8569936 DOI: 10.3389/fcell.2021.744982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/28/2021] [Indexed: 11/13/2022] Open
Abstract
We report the adaptation of RNA tomography, a technique allowing spatially resolved, genome-wide expression profiling, to a species occupying a key phylogenetic position in gnathostomes, the catshark Scyliorhinus canicula. We focused analysis on head explants at an embryonic stage, shortly following neural tube closure and of interest for a number of developmental processes, including early brain patterning, placode specification or the establishment of epithalamic asymmetry. As described in the zebrafish, we have sequenced RNAs extracted from serial sections along transverse, horizontal and sagittal planes, mapped the data onto a gene reference taking advantage of the high continuity genome recently released in the catshark, and projected read counts onto a digital model of the head obtained by confocal microscopy. This results in the generation of a genome-wide 3D atlas, containing expression data for most protein-coding genes in a digital model of the embryonic head. The digital profiles obtained for candidate forebrain regional markers along antero-posterior, dorso-ventral and left-right axes reproduce those obtained by in situ hybridization (ISH), with expected relative organizations. We also use spatial autocorrelation and correlation as measures to analyze these data and show that they provide adequate statistical tools to extract novel expression information from the model. These data and tools allow exhaustive searches of genes exhibiting any predefined expression characteristic, such a restriction to a territory of interest, thus providing a reference for comparative analyses across gnathostomes. This methodology appears best suited to species endowed with large embryo or organ sizes and opens novel perspectives to a wide range of evo-devo model organisms, traditionally counter-selected on size criterion.
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Affiliation(s)
- Hélène Mayeur
- CNRS, Sorbonne Université, UMR 7232-Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Banyuls sur Mer, France
| | - Maxence Lanoizelet
- CNRS, Sorbonne Université, UMR 7232-Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Banyuls sur Mer, France
| | - Aurélie Quillien
- Molecular, Cellular and Developmental Biology (MCD UMR 5077), Centre de Biologie Intégrative (CBI, FR 3743), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Arnaud Menuet
- UMR 7355, Experimental and Molecular Immunology and Neurogenetics, CNRS and University of Orléans, Orléans, France
| | - Léo Michel
- CNRS, Sorbonne Université, UMR 7232-Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Banyuls sur Mer, France
| | - Kyle John Martin
- United Kingdom Research and Innovation, Biotechnology and Biological Sciences Research Council, Swindon, United Kingdom
| | - Sébastien Dejean
- Institut de Mathématiques de Toulouse, Université de Toulouse, CNRS, UPS, UMR 5219, Toulouse, France
| | - Patrick Blader
- Molecular, Cellular and Developmental Biology (MCD UMR 5077), Centre de Biologie Intégrative (CBI, FR 3743), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Sylvie Mazan
- CNRS, Sorbonne Université, UMR 7232-Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Banyuls sur Mer, France
| | - Ronan Lagadec
- CNRS, Sorbonne Université, UMR 7232-Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Banyuls sur Mer, France
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Hirschberger C, Sleight VA, Criswell KE, Clark SJ, Gillis JA. Conserved and unique transcriptional features of pharyngeal arches in the skate (Leucoraja erinacea) and evolution of the jaw. Mol Biol Evol 2021; 38:4187-4204. [PMID: 33905525 PMCID: PMC8476176 DOI: 10.1093/molbev/msab123] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The origin of the jaw is a long-standing problem in vertebrate evolutionary biology. Classical hypotheses of serial homology propose that the upper and lower jaw evolved through modifications of dorsal and ventral gill arch skeletal elements, respectively. If the jaw and gill arches are derived members of a primitive branchial series, we predict that they would share common developmental patterning mechanisms. Using candidate and RNAseq/differential gene expression analyses, we find broad conservation of dorsoventral (DV) patterning mechanisms within the developing mandibular, hyoid, and gill arches of a cartilaginous fish, the skate (Leucoraja erinacea). Shared features include expression of genes encoding members of the ventralizing BMP and endothelin signaling pathways and their effectors, the joint markers nkx3.2 and gdf5 and prochondrogenic transcription factor barx1, and the dorsal territory marker pou3f3. Additionally, we find that mesenchymal expression of eya1/six1 is an ancestral feature of the mandibular arch of jawed vertebrates, whereas differences in notch signaling distinguish the mandibular and gill arches in skate. Comparative transcriptomic analyses of mandibular and gill arch tissues reveal additional genes differentially expressed along the DV axis of the pharyngeal arches, including scamp5 as a novel marker of the dorsal mandibular arch, as well as distinct transcriptional features of mandibular and gill arch muscle progenitors and developing gill buds. Taken together, our findings reveal conserved patterning mechanisms in the pharyngeal arches of jawed vertebrates, consistent with serial homology of their skeletal derivatives, as well as unique transcriptional features that may underpin distinct jaw and gill arch morphologies.
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Affiliation(s)
| | - Victoria A Sleight
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, UK.,School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
| | | | | | - J Andrew Gillis
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, UK.,Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, USA
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11
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Sleight VA, Gillis JA. Embryonic origin and serial homology of gill arches and paired fins in the skate, Leucoraja erinacea. eLife 2020; 9:60635. [PMID: 33198887 PMCID: PMC7671686 DOI: 10.7554/elife.60635] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/17/2020] [Indexed: 12/11/2022] Open
Abstract
Paired fins are a defining feature of the jawed vertebrate body plan, but their evolutionary origin remains unresolved. Gegenbaur proposed that paired fins evolved as gill arch serial homologues, but this hypothesis is now widely discounted, owing largely to the presumed distinct embryonic origins of these structures from mesoderm and neural crest, respectively. Here, we use cell lineage tracing to test the embryonic origin of the pharyngeal and paired fin skeleton in the skate (Leucoraja erinacea). We find that while the jaw and hyoid arch skeleton derive from neural crest, and the pectoral fin skeleton from mesoderm, the gill arches are of dual origin, receiving contributions from both germ layers. We propose that gill arches and paired fins are serially homologous as derivatives of a continuous, dual-origin mesenchyme with common skeletogenic competence, and that this serial homology accounts for their parallel anatomical organization and shared responses to axial patterning signals.
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Affiliation(s)
- Victoria A Sleight
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Marine Biological Laboratory, Woods Hole, United Kingdom
| | - J Andrew Gillis
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Marine Biological Laboratory, Woods Hole, United Kingdom
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12
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Barske L, Fabian P, Hirschberger C, Jandzik D, Square T, Xu P, Nelson N, Yu HV, Medeiros DM, Gillis JA, Crump JG. Evolution of vertebrate gill covers via shifts in an ancient Pou3f3 enhancer. Proc Natl Acad Sci U S A 2020; 117:24876-24884. [PMID: 32958671 PMCID: PMC7547273 DOI: 10.1073/pnas.2011531117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Whereas the gill chambers of jawless vertebrates open directly into the environment, jawed vertebrates evolved skeletal appendages that drive oxygenated water unidirectionally over the gills. A major anatomical difference between the two jawed vertebrate lineages is the presence of a single large gill cover in bony fishes versus separate covers for each gill chamber in cartilaginous fishes. Here, we find that these divergent patterns correlate with the pharyngeal arch expression of Pou3f3 orthologs. We identify a deeply conserved Pou3f3 arch enhancer present in humans through sharks but undetectable in jawless fish. Minor differences between the bony and cartilaginous fish enhancers account for their restricted versus pan-arch expression patterns. In zebrafish, mutation of Pou3f3 or the conserved enhancer disrupts gill cover formation, whereas ectopic pan-arch Pou3f3b expression generates ectopic skeletal elements resembling the multimeric covers of cartilaginous fishes. Emergence of this Pou3f3 arch enhancer >430 Mya and subsequent modifications may thus have contributed to the acquisition and diversification of gill covers and respiratory strategies during gnathostome evolution.
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Affiliation(s)
- Lindsey Barske
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033;
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Peter Fabian
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | | | - David Jandzik
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309
- Department of Zoology, Comenius University in Bratislava, 84215 Bratislava, Slovakia
| | - Tyler Square
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Pengfei Xu
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | - Nellie Nelson
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | - Haoze Vincent Yu
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | - Daniel M Medeiros
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309
| | - J Andrew Gillis
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, United Kingdom
- Marine Biological Laboratory, Woods Hole, MA 02543
| | - J Gage Crump
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033;
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13
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Musa SM, Ripley DM, Moritz T, Shiels HA. Ocean warming and hypoxia affect embryonic growth, fitness and survival of small-spotted catsharks, Scyliorhinus canicula. JOURNAL OF FISH BIOLOGY 2020; 97:257-264. [PMID: 32383486 DOI: 10.1111/jfb.14370] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 04/26/2020] [Accepted: 05/03/2020] [Indexed: 06/11/2023]
Abstract
Elasmobranchs are key to a healthy marine ecosystem but are under threat from human activities, such as destructive fisheries and shark finning. Embryos of oviparous elasmobranchs may be further challenged during development by rising temperatures and falling dissolved oxygen concentrations in their intertidal environment. However, the impact of climate change on survival and growth of oviparous elasmobranchs is still poorly understood. Here, we investigate the effects of temperature and hypoxia on the growth and survival of small-spotted catshark (Scyliorhinus canicula) embryos by incubating eggs in normoxia 15°C, normoxia 20°C, hypoxia 15°C, or hypoxia 20°C. Incubation under the elevated temperature increased the embryonic growth rate, yolk consumption rate and Fulton's condition factor at hatching, whilst decreasing the total length and body mass of newly hatched sharks. Under low oxygen conditions (50% air saturation) the survival rate of S. canicula embryos dropped significantly and the temperature-induced increase in Fulton's condition factor was reversed. Together, these data demonstrate both the individual and compound effects of elevated temperature and hypoxia on the survival and growth during early ontogeny of a ubiquitous, coastal elasmobranch, S. canicula.
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Affiliation(s)
- Syafiq M Musa
- Faculty of Biology, Medicine and Health, The University of Manchester, 3.15d Core Technology Facility, Manchester, UK
- Marine Science Programme, Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Daniel M Ripley
- Faculty of Biology, Medicine and Health, The University of Manchester, 3.15d Core Technology Facility, Manchester, UK
| | - Timo Moritz
- Deutsches Meeresmuseum, Stralsund, Germany
- Institute for Zoology and Evolutionary Research, Friedrich-Schiller University of Jena, Jena, Germany
| | - Holly A Shiels
- Faculty of Biology, Medicine and Health, The University of Manchester, 3.15d Core Technology Facility, Manchester, UK
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14
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Marconi A, Hancock-Ronemus A, Gillis JA. Adult chondrogenesis and spontaneous cartilage repair in the skate, Leucoraja erinacea. eLife 2020; 9:e53414. [PMID: 32393435 PMCID: PMC7217701 DOI: 10.7554/elife.53414] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 04/21/2020] [Indexed: 12/13/2022] Open
Abstract
Mammalian articular cartilage is an avascular tissue with poor capacity for spontaneous repair. Here, we show that embryonic development of cartilage in the skate (Leucoraja erinacea) mirrors that of mammals, with developing chondrocytes co-expressing genes encoding the transcription factors Sox5, Sox6 and Sox9. However, in skate, transcriptional features of developing cartilage persist into adulthood, both in peripheral chondrocytes and in cells of the fibrous perichondrium that ensheaths the skeleton. Using pulse-chase label retention experiments and multiplexed in situ hybridization, we identify a population of cycling Sox5/6/9+ perichondral progenitor cells that generate new cartilage during adult growth, and we show that persistence of chondrogenesis in adult skates correlates with ability to spontaneously repair cartilage injuries. Skates therefore offer a unique model for adult chondrogenesis and cartilage repair and may serve as inspiration for novel cell-based therapies for skeletal pathologies, such as osteoarthritis.
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Affiliation(s)
| | - Amy Hancock-Ronemus
- Charles River LaboratoriesWilmington, MassachusettsUnited States
- Marine Biological LaboratoryWoods Hole, MassachusettsUnited States
| | - J Andrew Gillis
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Marine Biological LaboratoryWoods Hole, MassachusettsUnited States
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15
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Criswell KE, Gillis JA. Resegmentation is an ancestral feature of the gnathostome vertebral skeleton. eLife 2020; 9:51696. [PMID: 32091389 PMCID: PMC7064331 DOI: 10.7554/elife.51696] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 02/19/2020] [Indexed: 01/03/2023] Open
Abstract
The vertebral skeleton is a defining feature of vertebrate animals. However, the mode of vertebral segmentation varies considerably between major lineages. In tetrapods, adjacent somite halves recombine to form a single vertebra through the process of 'resegmentation'. In teleost fishes, there is considerable mixing between cells of the anterior and posterior somite halves, without clear resegmentation. To determine whether resegmentation is a tetrapod novelty, or an ancestral feature of jawed vertebrates, we tested the relationship between somites and vertebrae in a cartilaginous fish, the skate (Leucoraja erinacea). Using cell lineage tracing, we show that skate trunk vertebrae arise through tetrapod-like resegmentation, with anterior and posterior halves of each vertebra deriving from adjacent somites. We further show that tail vertebrae also arise through resegmentation, though with a duplication of the number of vertebrae per body segment. These findings resolve axial resegmentation as an ancestral feature of the jawed vertebrate body plan.
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Affiliation(s)
- Katharine E Criswell
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Marine Biological Laboratory, Woods Hole, United States
| | - J Andrew Gillis
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Marine Biological Laboratory, Woods Hole, United States
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16
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Gilly WF, Renken C, Rosenthal JJC, Kier WM. Specialization for rapid excitation in fast squid tentacle muscle involves action potentials absent in slow arm muscle. J Exp Biol 2020; 223:jeb218081. [PMID: 31900349 DOI: 10.1242/jeb.218081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 12/27/2019] [Indexed: 11/20/2022]
Abstract
An important aspect of the performance of many fast muscle fiber types is rapid excitation. Previous research on the cross-striated muscle fibers responsible for the rapid tentacle strike in squid has revealed the specializations responsible for high shortening velocity, but little is known about excitation of these fibers. Conventional whole-cell patch recordings were made from tentacle fibers and the slower obliquely striated muscle fibers of the arms. The fast-contracting tentacle fibers show an approximately 10-fold greater sodium conductance than that of the arm fibers and, unlike the arm fibers, the tentacle muscle fibers produce action potentials. In situ hybridization using an antisense probe to the voltage-dependent sodium channel present in this squid genus shows prominent expression of sodium channel mRNA in tentacle fibers but undetectable expression in arm fibers. Production of action potentials by tentacle muscle fibers and their absence in arm fibers is likely responsible for the previously reported greater twitch-tetanus ratio in the tentacle versus the arm fibers. During the rapid tentacle strike, a few closely spaced action potentials would result in maximal activation of transverse tentacle muscle. Activation of the slower transverse muscle fibers in the arms would require summation of excitatory postsynaptic potentials over a longer time, allowing the precise modulation of force required for supporting slower movements of the arms.
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Affiliation(s)
- William F Gilly
- Hopkins Marine Station of Stanford University, 120 Ocean View Boulevard, Pacific Grove, CA 93950, USA
| | - Corbin Renken
- The Eugene Bell Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | | | - William M Kier
- Department of Biology, CB# 3280 Coker Hall, University of North Carolina, Chapel Hill, NC 27599, USA
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17
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Ontogeny of the anuran urostyle and the developmental context of evolutionary novelty. Proc Natl Acad Sci U S A 2020; 117:3034-3044. [PMID: 31988131 PMCID: PMC7022158 DOI: 10.1073/pnas.1917506117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Fusion of caudal vertebrae has evolved multiple times independently: the pygostyle of birds, coccyx in apes and humans, ural plate of fish, and the urostyle of frogs. The anuran urostyle, however, is structurally and developmentally distinct because of the contribution of an ossifying hypochord. To date, the developmental mechanisms behind an ossifying hypochord have remained obscure. Here, we provide a detailed analysis of the development of this evolutionary innovative structure and of how neuromusculature, cell death, and proliferation paved their way to facilitate its formation. Finally, we propose that the ossifying hypochord plays a role in tail loss in anurans and reorganizing the dorsal aorta and thus is pivotal in the evolution of the anuran bauplan. Developmental novelties often underlie the evolutionary origins of key metazoan features. The anuran urostyle, which evolved nearly 200 MYA, is one such structure. It forms as the tail regresses during metamorphosis, when locomotion changes from an axial-driven mode in larvae to a limb-driven one in adult frogs. The urostyle comprises of a coccyx and a hypochord. The coccyx forms by fusion of caudal vertebrae and has evolved repeatedly across vertebrates. However, the contribution of an ossifying hypochord to the coccyx in anurans is unique among vertebrates and remains a developmental enigma. Here, we focus on the developmental changes that lead to the anuran urostyle, with an emphasis on understanding the ossifying hypochord. We find that the coccyx and hypochord have two different developmental histories: First, the development of the coccyx initiates before metamorphic climax whereas the ossifying hypochord undergoes rapid ossification and hypertrophy; second, thyroid hormone directly affects hypochord formation and appears to have a secondary effect on the coccygeal portion of the urostyle. The embryonic hypochord is known to play a significant role in the positioning of the dorsal aorta (DA), but the reason for hypochordal ossification remains obscure. Our results suggest that the ossifying hypochord plays a role in remodeling the DA in the newly forming adult body by partially occluding the DA in the tail. We propose that the ossifying hypochord-induced loss of the tail during metamorphosis has enabled the evolution of the unique anuran bauplan.
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18
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Rawlinson KA, Lapraz F, Ballister ER, Terasaki M, Rodgers J, McDowell RJ, Girstmair J, Criswell KE, Boldogkoi M, Simpson F, Goulding D, Cormie C, Hall B, Lucas RJ, Telford MJ. Extraocular, rod-like photoreceptors in a flatworm express xenopsin photopigment. eLife 2019; 8:45465. [PMID: 31635694 PMCID: PMC6805122 DOI: 10.7554/elife.45465] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 08/15/2019] [Indexed: 11/17/2022] Open
Abstract
Animals detect light using opsin photopigments. Xenopsin, a recently classified subtype of opsin, challenges our views on opsin and photoreceptor evolution. Originally thought to belong to the Gαi-coupled ciliary opsins, xenopsins are now understood to have diverged from ciliary opsins in pre-bilaterian times, but little is known about the cells that deploy these proteins, or if they form a photopigment and drive phototransduction. We characterized xenopsin in a flatworm, Maritigrella crozieri, and found it expressed in ciliary cells of eyes in the larva, and in extraocular cells around the brain in the adult. These extraocular cells house hundreds of cilia in an intra-cellular vacuole (phaosome). Functional assays in human cells show Maritigrella xenopsin drives phototransduction primarily by coupling to Gαi. These findings highlight similarities between xenopsin and c-opsin and reveal a novel type of opsin-expressing cell that, like jawed vertebrate rods, encloses the ciliary membrane within their own plasma membrane. Eyes are elaborate organs that many animals use to detect light and see, but light can also be sensed in other, simpler ways and for purposes other than seeing. All animals that perceive light rely on cells called photoreceptors, which come in two main types: ciliary or rhabdomeric. Sometimes, an organism has both types of photoreceptors, but one is typically more important than the other. For example, most vertebrates see using ciliary photoreceptors, while rhabdomeric photoreceptors underpin vision in invertebrates. Flatworms are invertebrates that have long been studied due to their ability to regenerate following injuries. These worms have rhabdomeric photoreceptors in their eyes, but they also have unusual cells outside their eyes that have cilia – slender protuberances from the cell body - and could potentially be light sensitive. One obvious way to test if a cell is a photoreceptor is to see if it produces any light-sensing proteins, such as opsins. Until recently it was thought that each type of photoreceptor produced a different opsin, which were therefore classified into rhabdomeric of ciliary opsins. However, recent work has identified a new type of opsin, called xenopsin, in the ciliary photoreceptors of the larvae of some marine invertebrates. To determine whether the cells outside the flatworm’s eye were ciliary photoreceptors, Rawlinson et al. examined the genetic code of 30 flatworm species looking for ciliary opsin and xenopsin genes. This search revealed that all the flatworm species studied contained the genetic sequence for xenopsin, but not for the ciliary opsin. Rawlinson et al. chose the tiger flatworm to perform further experiments. First, they showed that, in this species, xenopsin genes are active both in the eyes of larvae and in the unusual ciliary cells found outside the eyes of the adult. Next, they put the xenopsin from the tiger flatworm into human embryonic kidney cells, and found that when the protein is present these cells can respond to light. This demonstrates that the newly discovered xenopsin is light-sensitive, suggesting that the unusual ciliary cells found expressing this protein outside the eyes in flatworms are likely photoreceptive cells. It is unclear why flatworms have developed these unusual ciliary photoreceptor cells or what their purpose is outside the eye. Often, photoreceptor cells outside the eyes are used to align the ‘body clock’ with the day-night cycle. This can be a factor in healing, hinting perhaps that these newly found cells may have a role in flatworms’ ability to regenerate.
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Affiliation(s)
- Kate A Rawlinson
- Wellcome Sanger Institute, Hinxton, United Kingdom.,Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Marine Biological Laboratory, Woods Hole, United States
| | - Francois Lapraz
- Université Côte D'Azur, CNRS, Institut de Biologie Valrose, Nice, France
| | - Edward R Ballister
- New York University School of Medicine, New York, United States.,Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Mark Terasaki
- Marine Biological Laboratory, Woods Hole, United States.,University of Connecticut Health Center, Farmington, United States
| | - Jessica Rodgers
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Richard J McDowell
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Johannes Girstmair
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London, United Kingdom.,Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Katharine E Criswell
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Marine Biological Laboratory, Woods Hole, United States
| | - Miklos Boldogkoi
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Fraser Simpson
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | | | | | - Brian Hall
- Department of Biology, Dalhousie University, Halifax, Canada
| | - Robert J Lucas
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Maximilian J Telford
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
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19
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Asymmetric paralog evolution between the "cryptic" gene Bmp16 and its well-studied sister genes Bmp2 and Bmp4. Sci Rep 2019; 9:3136. [PMID: 30816280 PMCID: PMC6395752 DOI: 10.1038/s41598-019-40055-1] [Citation(s) in RCA: 210] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 02/07/2019] [Indexed: 12/05/2022] Open
Abstract
The vertebrate gene repertoire is characterized by “cryptic” genes whose identification has been hampered by their absence from the genomes of well-studied species. One example is the Bmp16 gene, a paralog of the developmental key genes Bmp2 and -4. We focus on the Bmp2/4/16 group of genes to study the evolutionary dynamics following gen(om)e duplications with special emphasis on the poorly studied Bmp16 gene. We reveal the presence of Bmp16 in chondrichthyans in addition to previously reported teleost fishes and reptiles. Using comprehensive, vertebrate-wide gene sampling, our phylogenetic analysis complemented with synteny analyses suggests that Bmp2, -4 and -16 are remnants of a gene quartet that originated during the two rounds of whole-genome duplication (2R-WGD) early in vertebrate evolution. We confirm that Bmp16 genes were lost independently in at least three lineages (mammals, archelosaurs and amphibians) and report that they have elevated rates of sequence evolution. This finding agrees with their more “flexible” deployment during development; while Bmp16 has limited embryonic expression domains in the cloudy catshark, it is broadly expressed in the green anole lizard. Our study illustrates the dynamics of gene family evolution by integrating insights from sequence diversification, gene repertoire changes, and shuffling of expression domains.
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20
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Baker CVH, Modrell MS. Insights into Electroreceptor Development and Evolution from Molecular Comparisons with Hair Cells. Integr Comp Biol 2019; 58:329-340. [PMID: 29846597 DOI: 10.1093/icb/icy037] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The vertebrate lateral line system comprises a mechanosensory division, with neuromasts containing hair cells that detect local water movement ("distant touch"); and an electrosensory division, with electrosensory organs that detect the weak, low-frequency electric fields surrounding other animals in water (primarily used for hunting). The entire lateral line system was lost in the amniote lineage with the transition to fully terrestrial life; the electrosensory division was lost independently in several lineages, including the ancestors of frogs and of teleost fishes. (Electroreception with different characteristics subsequently evolved independently within two teleost lineages.) Recent gene expression studies in a non-teleost actinopterygian fish suggest that electroreceptor ribbon synapses employ the same transmission mechanisms as hair cell ribbon synapses, and show that developing electrosensory organs express transcription factors essential for hair cell development, including Atoh1 and Pou4f3. Previous hypotheses for electroreceptor evolution suggest either that electroreceptors and hair cells evolved independently in the vertebrate ancestor from a common ciliated secondary cell, or that electroreceptors evolved from hair cells. The close developmental and putative physiological similarities implied by the gene expression data support the latter hypothesis, i.e., that electroreceptors evolved in the vertebrate ancestor as a "sister cell-type" to lateral line hair cells.
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Affiliation(s)
- Clare V H Baker
- Department of Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Downing Street, Cambridge CB2 3DY, UK
| | - Melinda S Modrell
- Department of Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Downing Street, Cambridge CB2 3DY, UK
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21
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Shark genomes provide insights into elasmobranch evolution and the origin of vertebrates. Nat Ecol Evol 2018; 2:1761-1771. [PMID: 30297745 DOI: 10.1038/s41559-018-0673-5] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 08/16/2018] [Indexed: 02/07/2023]
Abstract
Modern cartilaginous fishes are divided into elasmobranchs (sharks, rays and skates) and chimaeras, and the lack of established whole-genome sequences for the former has prevented our understanding of early vertebrate evolution and the unique phenotypes of elasmobranchs. Here we present de novo whole-genome assemblies of brownbanded bamboo shark and cloudy catshark and an improved assembly of the whale shark genome. These relatively large genomes (3.8-6.7 Gbp) contain sparse distributions of coding genes and regulatory elements and exhibit reduced molecular evolutionary rates. Our thorough genome annotation revealed Hox C genes previously hypothesized to have been lost, as well as distinct gene repertories of opsins and olfactory receptors that would be associated with adaptation to unique underwater niches. We also show the early establishment of the genetic machinery governing mammalian homoeostasis and reproduction at the jawed vertebrate ancestor. This study, supported by genomic, transcriptomic and epigenomic resources, provides a foundation for the comprehensive, molecular exploration of phenotypes unique to sharks and insights into the evolutionary origins of vertebrates.
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22
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Criswell KE, Coates MI, Gillis JA. Embryonic origin of the gnathostome vertebral skeleton. Proc Biol Sci 2018; 284:rspb.2017.2121. [PMID: 29167367 PMCID: PMC5719183 DOI: 10.1098/rspb.2017.2121] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 10/24/2017] [Indexed: 12/17/2022] Open
Abstract
The vertebral column is a key component of the jawed vertebrate (gnathostome) body plan, but the primitive embryonic origin of this skeleton remains unclear. In tetrapods, all vertebral components (neural arches, haemal arches and centra) derive from paraxial mesoderm (somites). However, in teleost fishes, vertebrae have a dual embryonic origin, with arches derived from somites, but centra formed, in part, by secretion of bone matrix from the notochord. Here, we test the embryonic origin of the vertebral skeleton in a cartilaginous fish (the skate, Leucoraja erinacea) which serves as an outgroup to tetrapods and teleosts. We demonstrate, by cell lineage tracing, that both arches and centra are somite-derived. We find no evidence of cellular or matrix contribution from the notochord to the skate vertebral skeleton. These findings indicate that the earliest gnathostome vertebral skeleton was exclusively of somitic origin, with a notochord contribution arising secondarily in teleosts.
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Affiliation(s)
- Katharine E Criswell
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA .,Department of Zoology, University of Cambridge, Cambridge, UK.,Marine Biological Laboratory, Woods Hole, MA, USA
| | - Michael I Coates
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA
| | - J Andrew Gillis
- Department of Zoology, University of Cambridge, Cambridge, UK.,Marine Biological Laboratory, Woods Hole, MA, USA
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23
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Trunk neural crest origin of dermal denticles in a cartilaginous fish. Proc Natl Acad Sci U S A 2017; 114:13200-13205. [PMID: 29158384 DOI: 10.1073/pnas.1713827114] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cartilaginous fishes (e.g., sharks and skates) possess a postcranial dermal skeleton consisting of tooth-like "denticles" embedded within their skin. As with teeth, the principal skeletal tissue of dermal denticles is dentine. In the head, cranial neural crest cells give rise to the dentine-producing cells (odontoblasts) of teeth. However, trunk neural crest cells are generally regarded as nonskeletogenic, and so the embryonic origin of trunk denticle odontoblasts remains unresolved. Here, we use expression of FoxD3 to pinpoint the specification and emigration of trunk neural crest cells in embryos of a cartilaginous fish, the little skate (Leucoraja erinacea). Using cell lineage tracing, we further demonstrate that trunk neural crest cells do, in fact, give rise to odontoblasts of trunk dermal denticles. These findings expand the repertoire of vertebrate trunk neural crest cell fates during normal development, highlight the likely primitive skeletogenic potential of this cell population, and point to a neural crest origin of dentine throughout the ancestral vertebrate dermal skeleton.
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24
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Modrell MS, Lyne M, Carr AR, Zakon HH, Buckley D, Campbell AS, Davis MC, Micklem G, Baker CV. Insights into electrosensory organ development, physiology and evolution from a lateral line-enriched transcriptome. eLife 2017; 6. [PMID: 28346141 PMCID: PMC5429088 DOI: 10.7554/elife.24197] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/23/2017] [Indexed: 01/22/2023] Open
Abstract
The anamniote lateral line system, comprising mechanosensory neuromasts and electrosensory ampullary organs, is a useful model for investigating the developmental and evolutionary diversification of different organs and cell types. Zebrafish neuromast development is increasingly well understood, but neither zebrafish nor Xenopus is electroreceptive and our molecular understanding of ampullary organ development is rudimentary. We have used RNA-seq to generate a lateral line-enriched gene-set from late-larval paddlefish (Polyodon spathula). Validation of a subset reveals expression in developing ampullary organs of transcription factor genes critical for hair cell development, and genes essential for glutamate release at hair cell ribbon synapses, suggesting close developmental, physiological and evolutionary links between non-teleost electroreceptors and hair cells. We identify an ampullary organ-specific proneural transcription factor, and candidates for the voltage-sensing L-type Cav channel and rectifying Kv channel predicted from skate (cartilaginous fish) ampullary organ electrophysiology. Overall, our results illuminate ampullary organ development, physiology and evolution.
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Affiliation(s)
- Melinda S Modrell
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Mike Lyne
- Cambridge Systems Biology Centre, University of Cambridge, Cambridge, United Kingdom.,Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Adrian R Carr
- Cambridge Systems Biology Centre, University of Cambridge, Cambridge, United Kingdom.,Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Harold H Zakon
- Department of Neuroscience, The University of Texas at Austin, Austin, United States.,Department of Integrative Biology, The University of Texas at Austin, Austin, United States
| | - David Buckley
- Departmento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales-MNCN-CSIC, Madrid, Spain.,Department of Natural Sciences, Saint Louis University - Madrid Campus, Madrid, Spain
| | - Alexander S Campbell
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Marcus C Davis
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, United States
| | - Gos Micklem
- Cambridge Systems Biology Centre, University of Cambridge, Cambridge, United Kingdom.,Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Clare Vh Baker
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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25
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Gillis JA, Hall BK. A shared role for sonic hedgehog signalling in patterning chondrichthyan gill arch appendages and tetrapod limbs. Development 2016; 143:1313-7. [PMID: 27095494 DOI: 10.1242/dev.133884] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 02/22/2016] [Indexed: 11/20/2022]
Abstract
Chondrichthyans (sharks, skates, rays and holocephalans) possess paired appendages that project laterally from their gill arches, known as branchial rays. This led Carl Gegenbaur to propose that paired fins (and hence tetrapod limbs) originally evolved via transformation of gill arches. Tetrapod limbs are patterned by asonic hedgehog(Shh)-expressing signalling centre known as the zone of polarising activity, which establishes the anteroposterior axis of the limb bud and maintains proliferative expansion of limb endoskeletal progenitors. Here, we use loss-of-function, label-retention and fate-mapping approaches in the little skate to demonstrate that Shh secretion from a signalling centre in the developing gill arches establishes gill arch anteroposterior polarity and maintains the proliferative expansion of branchial ray endoskeletal progenitor cells. These findings highlight striking parallels in the axial patterning mechanisms employed by chondrichthyan branchial rays and paired fins/limbs, and provide mechanistic insight into the anatomical foundation of Gegenbaur's gill arch hypothesis.
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Affiliation(s)
- J Andrew Gillis
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA
| | - Brian K Hall
- Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, Canada B3H 4R2
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26
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Miller SR, Perera SN, Benito C, Stott SRW, Baker CVH. Evidence for a Notch1-mediated transition during olfactory ensheathing cell development. J Anat 2016; 229:369-83. [PMID: 27271278 PMCID: PMC4974551 DOI: 10.1111/joa.12494] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2016] [Indexed: 01/19/2023] Open
Abstract
Olfactory ensheathing cells (OECs) are a unique glial population found in both the peripheral and central nervous system: they ensheath bundles of unmyelinated olfactory axons from their peripheral origin in the olfactory epithelium to their central synaptic targets in the glomerular layer of the olfactory bulb. Like all other peripheral glia (Schwann cells, satellite glia, enteric glia), OECs are derived from the embryonic neural crest. However, in contrast to Schwann cells, whose development has been extensively characterised, relatively little is known about their normal development in vivo. In the Schwann cell lineage, the transition from multipotent Schwann cell precursor to immature Schwann cell is promoted by canonical Notch signalling. Here, in situ hybridisation and immunohistochemistry data from chicken, mouse and human embryos are presented that suggest a canonical Notch-mediated transition also occurs during OEC development.
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Affiliation(s)
- Sophie R. Miller
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUK
- Present address: DanStemUniversity of Copenhagen3B BlegdamsvejDK‐2200Copenhagen NDenmark
| | - Surangi N. Perera
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUK
| | - Cristina Benito
- Department of Cell and Developmental BiologyUniversity College LondonLondonUK
| | - Simon R. W. Stott
- John van Geest Centre for Brain RepairUniversity of CambridgeCambridgeUK
| | - Clare V. H. Baker
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUK
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27
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Abstract
The diversification of paired appendages has been a major factor in the evolutionary radiation of vertebrates. Despite its importance, an understanding of the origin of paired appendages has remained elusive. To address this problem, we focused on T-box transcription factor 5 (Tbx5), a gene indispensable for pectoral appendage initiation and development. Comparison of gene expression in jawless and jawed vertebrates reveals that the Tbx5 expression in jawed vertebrates is derived in having an expression domain that extends caudal to the heart and gills. Chromatin profiling, phylogenetic footprinting, and functional assays enabled the identification of a Tbx5 fin enhancer associated with this apomorphic pattern of expression. Comparative functional analysis of reporter constructs reveals that this enhancer activity is evolutionarily conserved among jawed vertebrates and is able to rescue the finless phenotype of tbx5a mutant zebrafish. Taking paleontological evidence of early vertebrates into account, our results suggest that the gain of apomorphic patterns of Tbx5 expression and regulation likely contributed to the morphological transition from a finless to finned condition at the base of the vertebrate lineage.
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28
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Rasch LJ, Martin KJ, Cooper RL, Metscher BD, Underwood CJ, Fraser GJ. An ancient dental gene set governs development and continuous regeneration of teeth in sharks. Dev Biol 2016; 415:347-370. [PMID: 26845577 DOI: 10.1016/j.ydbio.2016.01.038] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/11/2016] [Accepted: 01/29/2016] [Indexed: 12/20/2022]
Abstract
The evolution of oral teeth is considered a major contributor to the overall success of jawed vertebrates. This is especially apparent in cartilaginous fishes including sharks and rays, which develop elaborate arrays of highly specialized teeth, organized in rows and retain the capacity for life-long regeneration. Perpetual regeneration of oral teeth has been either lost or highly reduced in many other lineages including important developmental model species, so cartilaginous fishes are uniquely suited for deep comparative analyses of tooth development and regeneration. Additionally, sharks and rays can offer crucial insights into the characters of the dentition in the ancestor of all jawed vertebrates. Despite this, tooth development and regeneration in chondrichthyans is poorly understood and remains virtually uncharacterized from a developmental genetic standpoint. Using the emerging chondrichthyan model, the catshark (Scyliorhinus spp.), we characterized the expression of genes homologous to those known to be expressed during stages of early dental competence, tooth initiation, morphogenesis, and regeneration in bony vertebrates. We have found that expression patterns of several genes from Hh, Wnt/β-catenin, Bmp and Fgf signalling pathways indicate deep conservation over ~450 million years of tooth development and regeneration. We describe how these genes participate in the initial emergence of the shark dentition and how they are redeployed during regeneration of successive tooth generations. We suggest that at the dawn of the vertebrate lineage, teeth (i) were most likely continuously regenerative structures, and (ii) utilised a core set of genes from members of key developmental signalling pathways that were instrumental in creating a dental legacy redeployed throughout vertebrate evolution. These data lay the foundation for further experimental investigations utilizing the unique regenerative capacity of chondrichthyan models to answer evolutionary, developmental, and regenerative biological questions that are impossible to explore in classical models.
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Affiliation(s)
- Liam J Rasch
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Kyle J Martin
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Rory L Cooper
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Brian D Metscher
- Department of Theoretical Biology, University of Vienna, Vienna A-1090, Austria
| | - Charlie J Underwood
- Department of Earth and Planetary Sciences, Birkbeck, University of London, London WC1E 7HX, United Kingdom
| | - Gareth J Fraser
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom.
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29
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Miyashita T. Fishing for jaws in early vertebrate evolution: a new hypothesis of mandibular confinement. Biol Rev Camb Philos Soc 2015; 91:611-57. [DOI: 10.1111/brv.12187] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 03/18/2015] [Accepted: 03/19/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Tetsuto Miyashita
- Department of Biological Sciences; University of Alberta; Edmonton Alberta T6G 2E9 Canada
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30
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Jandzik D, Garnett AT, Square TA, Cattell MV, Yu JK, Medeiros DM. Evolution of the new vertebrate head by co-option of an ancient chordate skeletal tissue. Nature 2014; 518:534-7. [PMID: 25487155 DOI: 10.1038/nature14000] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 10/24/2014] [Indexed: 02/01/2023]
Abstract
A defining feature of vertebrates (craniates) is a pronounced head that is supported and protected by a robust cellular endoskeleton. In the first vertebrates, this skeleton probably consisted of collagenous cellular cartilage, which forms the embryonic skeleton of all vertebrates and the adult skeleton of modern jawless and cartilaginous fish. In the head, most cellular cartilage is derived from a migratory cell population called the neural crest, which arises from the edges of the central nervous system. Because collagenous cellular cartilage and neural crest cells have not been described in invertebrates, the appearance of cellular cartilage derived from neural crest cells is considered a turning point in vertebrate evolution. Here we show that a tissue with many of the defining features of vertebrate cellular cartilage transiently forms in the larvae of the invertebrate chordate Branchiostoma floridae (Florida amphioxus). We also present evidence that during evolution, a key regulator of vertebrate cartilage development, SoxE, gained new cis-regulatory sequences that subsequently directed its novel expression in neural crest cells. Together, these results suggest that the origin of the vertebrate head skeleton did not depend on the evolution of a new skeletal tissue, as is commonly thought, but on the spread of this tissue throughout the head. We further propose that the evolution of cis-regulatory elements near an ancient regulator of cartilage differentiation was a major factor in the evolution of the vertebrate head skeleton.
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Affiliation(s)
- David Jandzik
- 1] Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309, USA [2] Department of Zoology, Comenius University, Bratislava 84215, Slovakia
| | - Aaron T Garnett
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309, USA
| | - Tyler A Square
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309, USA
| | - Maria V Cattell
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309, USA
| | - Jr-Kai Yu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Daniel M Medeiros
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309, USA
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31
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Selection and constraint underlie irreversibility of tooth loss in cypriniform fishes. Proc Natl Acad Sci U S A 2014; 111:7707-12. [PMID: 24821783 DOI: 10.1073/pnas.1321171111] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The apparent irreversibility of the loss of complex traits in evolution (Dollo's Law) has been explained either by constraints on generating the lost traits or the complexity of selection required for their return. Distinguishing between these explanations is challenging, however, and little is known about the specific nature of potential constraints. We investigated the mechanisms underlying the irreversibility of trait loss using reduction of dentition in cypriniform fishes, a lineage that includes the zebrafish (Danio rerio) as a model. Teeth were lost from the mouth and upper pharynx in this group at least 50 million y ago and retained only in the lower pharynx. We identified regional loss of expression of the Ectodysplasin (Eda) signaling ligand as a likely cause of dentition reduction. In addition, we found that overexpression of this gene in the zebrafish is sufficient to restore teeth to the upper pharynx but not to the mouth. Because both regions are competent to respond to Eda signaling with transcriptional output, the likely constraint on the reappearance of oral teeth is the alteration of multiple genetic pathways required for tooth development. The upper pharyngeal teeth are fully formed, but do not exhibit the ancestral relationship to other pharyngeal structures, suggesting that they would not be favored by selection. Our results illustrate an underlying commonality between constraint and selection as explanations for the irreversibility of trait loss; multiple genetic changes would be required to restore teeth themselves to the oral region and optimally functioning ones to the upper pharynx.
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32
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Steventon B, Mayor R, Streit A. Neural crest and placode interaction during the development of the cranial sensory system. Dev Biol 2014; 389:28-38. [PMID: 24491819 PMCID: PMC4439187 DOI: 10.1016/j.ydbio.2014.01.021] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 01/19/2014] [Accepted: 01/25/2014] [Indexed: 01/13/2023]
Abstract
In the vertebrate head, the peripheral components of the sensory nervous system are derived from two embryonic cell populations, the neural crest and cranial sensory placodes. Both arise in close proximity to each other at the border of the neural plate: neural crest precursors abut the future central nervous system, while placodes originate in a common preplacodal region slightly more lateral. During head morphogenesis, complex events organise these precursors into functional sensory structures, raising the question of how their development is coordinated. Here we review the evidence that neural crest and placode cells remain in close proximity throughout their development and interact repeatedly in a reciprocal manner. We also review recent controversies about the relative contribution of the neural crest and placodes to the otic and olfactory systems. We propose that a sequence of mutual interactions between the neural crest and placodes drives the coordinated morphogenesis that generates functional sensory systems within the head.
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Affiliation(s)
- Ben Steventon
- Department of Developmental and Stem Cell Biology, Insitut Pasteur, France
| | - Roberto Mayor
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Andrea Streit
- Department of Craniofacial Development and Stem Cell Biology, King׳s College London, London, UK.
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33
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Modrell MS, Hockman D, Uy B, Buckley D, Sauka-Spengler T, Bronner ME, Baker CVH. A fate-map for cranial sensory ganglia in the sea lamprey. Dev Biol 2014; 385:405-16. [PMID: 24513489 PMCID: PMC3928997 DOI: 10.1016/j.ydbio.2013.10.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 10/17/2013] [Accepted: 10/21/2013] [Indexed: 11/30/2022]
Abstract
Cranial neurogenic placodes and the neural crest make essential contributions to key adult characteristics of all vertebrates, including the paired peripheral sense organs and craniofacial skeleton. Neurogenic placode development has been extensively characterized in representative jawed vertebrates (gnathostomes) but not in jawless fishes (agnathans). Here, we use in vivo lineage tracing with DiI, together with neuronal differentiation markers, to establish the first detailed fate-map for placode-derived sensory neurons in a jawless fish, the sea lamprey Petromyzon marinus, and to confirm that neural crest cells in the lamprey contribute to the cranial sensory ganglia. We also show that a pan-Pax3/7 antibody labels ophthalmic trigeminal (opV, profundal) placode-derived but not maxillomandibular trigeminal (mmV) placode-derived neurons, mirroring the expression of gnathostome Pax3 and suggesting that Pax3 (and its single Pax3/7 lamprey ortholog) is a pan-vertebrate marker for opV placode-derived neurons. Unexpectedly, however, our data reveal that mmV neuron precursors are located in two separate domains at neurula stages, with opV neuron precursors sandwiched between them. The different branches of the mmV nerve are not comparable between lampreys and gnatho-stomes, and spatial segregation of mmV neuron precursor territories may be a derived feature of lampreys. Nevertheless, maxillary and mandibular neurons are spatially segregated within gnathostome mmV ganglia, suggesting that a more detailed investigation of gnathostome mmV placode development would be worthwhile. Overall, however, our results highlight the conservation of cranial peripheral sensory nervous system development across vertebrates, yielding insight into ancestral vertebrate traits. The first detailed fate-map for placode-derived sensory neurons in a jawless fish. Pax3 is a pan-vertebrate marker for ophthalmic trigeminal placode-derived neurons. Maxillomandibular trigeminal neuron precursors are located in two separate domains. Confirmation that lamprey neural crest cells contribute to cranial sensory ganglia. Results overall highlight conservation of cranial sensory nervous system development.
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34
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Juarez M, Reyes M, Coleman T, Rotenstein L, Sao S, Martinez D, Jones M, Mackelprang R, De Bellard ME. Characterization of the trunk neural crest in the bamboo shark, Chiloscyllium punctatum. J Comp Neurol 2014; 521:3303-20. [PMID: 23640803 DOI: 10.1002/cne.23351] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 04/15/2013] [Accepted: 04/25/2013] [Indexed: 12/12/2022]
Abstract
The neural crest is a population of mesenchymal cells that after migrating from the neural tube gives rise to structure and cell types: the jaw, part of the peripheral ganglia, and melanocytes. Although much is known about neural crest development in jawed vertebrates, a clear picture of trunk neural crest development for elasmobranchs is yet to be developed. Here we present a detailed study of trunk neural crest development in the bamboo shark, Chiloscyllium punctatum. Vital labeling with dioctadecyl tetramethylindocarbocyanine perchlorate (DiI) and in situ hybridization using cloned Sox8 and Sox9 probes demonstrated that trunk neural crest cells follow a pattern similar to the migratory paths already described in zebrafish and amphibians. We found shark trunk neural crest along the rostral side of the somites, the ventromedial pathway, the branchial arches, the gut, the sensory ganglia, and the nerves. Interestingly, C. punctatum Sox8 and Sox9 sequences aligned with vertebrate SoxE genes, but appeared to be more ancient than the corresponding vertebrate paralogs. The expression of these two SoxE genes in trunk neural crest cells, especially Sox9, matched the Sox10 migratory patterns observed in teleosts. Also of interest, we observed DiI cells and Sox9 labeling along the lateral line, suggesting that in C. punctatum, glial cells in the lateral line are likely of neural crest origin. Although this has been observed in other vertebrates, we are the first to show that the pattern is present in cartilaginous fishes. These findings demonstrate that trunk neural crest cell development in C. punctatum follows the same highly conserved migratory pattern observed in jawed vertebrates.
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Affiliation(s)
- Marilyn Juarez
- Biology Department, California State University Northridge, Northridge, California 91330, USA
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35
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Piotrowski T, Baker CVH. The development of lateral line placodes: taking a broader view. Dev Biol 2014; 389:68-81. [PMID: 24582732 DOI: 10.1016/j.ydbio.2014.02.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 02/11/2014] [Accepted: 02/12/2014] [Indexed: 10/25/2022]
Abstract
The lateral line system of anamniote vertebrates enables the detection of local water movement and weak bioelectric fields. Ancestrally, it comprises neuromasts - small sense organs containing mechanosensory hair cells - distributed in characteristic lines over the head and trunk, flanked on the head by fields of electroreceptive ampullary organs, innervated by afferent neurons projecting respectively to the medial and dorsal octavolateral nuclei in the hindbrain. Given the independent loss of the electrosensory system in multiple lineages, the development and evolution of the mechanosensory and electrosensory components of the lateral line must be dissociable. Nevertheless, the entire system arises from a series of cranial lateral line placodes, which exhibit two modes of sensory organ formation: elongation to form sensory ridges that fragment (with neuromasts differentiating in the center of the ridge, and ampullary organs on the flanks), or migration as collectives of cells, depositing sense organs in their wake. Intensive study of the migrating posterior lateral line placode in zebrafish has yielded a wealth of information concerning the molecular control of migration and neuromast formation in this migrating placode, in this cypriniform teleost species. However, our mechanistic understanding of neuromast and ampullary organ formation by elongating lateral line placodes, and even of other zebrafish lateral line placodes, is sparse or non-existent. Here, we attempt to highlight the diversity of lateral line development and the limits of the current research focus on the zebrafish posterior lateral line placode. We hope this will stimulate a broader approach to this fascinating sensory system.
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Affiliation(s)
- Tatjana Piotrowski
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO 64110, USA.
| | - Clare V H Baker
- Department of Physiology, Development and Neuroscience, University of Cambridge CB2 3DY, UK
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36
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Baker CVH, Modrell MS, Gillis JA. The evolution and development of vertebrate lateral line electroreceptors. ACTA ACUST UNITED AC 2014; 216:2515-22. [PMID: 23761476 DOI: 10.1242/jeb.082362] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Electroreception is an ancient vertebrate sense with a fascinating evolutionary history involving multiple losses as well as independent evolution at least twice within teleosts. We review the phylogenetic distribution of electroreception and the morphology and innervation of electroreceptors in different vertebrate groups. We summarise recent work from our laboratory that has confirmed the homology of ampullary electroreceptors in non-teleost jawed vertebrates by showing, in conjunction with previously published work, that these are derived embryonically from lateral line placodes. Finally, we review hypotheses to explain the distribution of electroreception within teleosts, including the hypothesis that teleost ampullary and tuberous electroreceptors evolved via the modification of mechanosensory hair cells in lateral line neuromasts. We conclude that further experimental work on teleost electroreceptor development is needed to test such hypotheses.
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Affiliation(s)
- Clare V H Baker
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
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37
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Quintana-Urzainqui I, Rodríguez-Moldes I, Candal E. Developmental, tract-tracing and immunohistochemical study of the peripheral olfactory system in a basal vertebrate: insights on Pax6 neurons migrating along the olfactory nerve. Brain Struct Funct 2014; 219:85-104. [PMID: 23224251 PMCID: PMC3889696 DOI: 10.1007/s00429-012-0486-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 11/16/2012] [Indexed: 11/02/2022]
Abstract
The olfactory system represents an excellent model for studying different aspects of the development of the nervous system ranging from neurogenesis to mechanisms of axon growth and guidance. Important findings in this field come from comparative studies. We have analyzed key events in the development of the olfactory system of the shark Scyliorhinus canicula by combining immunohistochemical and tract-tracing methods. We describe for the first time in a cartilaginous fish an early population of pioneer HuC/D-immunoreactive (ir) neurons that seemed to delaminate from the olfactory pit epithelium and migrate toward the telencephalon before the olfactory nerve was identifiable. A distinct, transient cell population, namely the migratory mass, courses later on in apposition to the developing olfactory nerve. It contains olfactory ensheathing glial (GFAP-ir) cells and HuC/D-ir neurons, some of which course toward an extrabulbar region. We also demonstrate that Pax6-ir cells coursing along the developing olfactory pathways in S. canicula are young migrating (HuC/D and DCX-ir) neurons of the migratory mass that do not form part of the terminal nerve pathway. Evidences that these Pax6 neurons originate in the olfactory epithelium are also reported. As Pax6 neurons in the olfactory epithelium show characteristics of olfactory receptor neurons, and migrating Pax6-ir neurons formed transient corridors along the course of olfactory axons at the entrance of the olfactory bulb, we propose that these neurons could play a role as guideposts for axons of olfactory receptor neurons growing toward the olfactory bulb.
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Affiliation(s)
- Idoia Quintana-Urzainqui
- Departamento de Biología Celular y Ecología, Edificio CIBUS Campus Vida, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Isabel Rodríguez-Moldes
- Departamento de Biología Celular y Ecología, Edificio CIBUS Campus Vida, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Eva Candal
- Departamento de Biología Celular y Ecología, Edificio CIBUS Campus Vida, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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38
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Higashiyama H, Kuratani S. On the maxillary nerve. J Morphol 2013; 275:17-38. [DOI: 10.1002/jmor.20193] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 08/06/2013] [Accepted: 08/08/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Hiroki Higashiyama
- Department of Biology; Graduate School of Science; Kobe University; Kobe 657-8501 Japan
- Laboratory for Evolutionary Morphology; RIKEN Center for Developmental Biology; Kobe 650-0047 Japan
| | - Shigeru Kuratani
- Laboratory for Evolutionary Morphology; RIKEN Center for Developmental Biology; Kobe 650-0047 Japan
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39
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Carlson BA, Gallant JR. From sequence to spike to spark: evo-devo-neuroethology of electric communication in mormyrid fishes. J Neurogenet 2013; 27:106-29. [PMID: 23802152 DOI: 10.3109/01677063.2013.799670] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mormyrid fishes communicate using pulses of electricity, conveying information about their identity, behavioral state, and location. They have long been used as neuroethological model systems because they are uniquely suited to identifying cellular mechanisms for behavior. They are also remarkably diverse, and they have recently emerged as a model system for studying how communication systems may influence the process of speciation. These two lines of inquiry have now converged, generating insights into the neural basis of evolutionary change in behavior, as well as the influence of sensory and motor systems on behavioral diversification and speciation. Here, we review the mechanisms of electric signal generation, reception, and analysis and relate these to our current understanding of the evolution and development of electromotor and electrosensory systems. We highlight the enormous potential of mormyrids for studying evolutionary developmental mechanisms of behavioral diversification, and make the case for developing genomic and transcriptomic resources. A complete mormyrid genome sequence would enable studies that extend our understanding of mormyrid behavior to the molecular level by linking morphological and physiological mechanisms to their genetic basis. Applied in a comparative framework, genomic resources would facilitate analysis of evolutionary processes underlying mormyrid diversification, reveal the genetic basis of species differences in behavior, and illuminate the origins of a novel vertebrate sensory and motor system. Genomic approaches to studying the evo-devo-neuroethology of mormyrid communication represent a deeply integrative approach to understanding the evolution, function, development, and mechanisms of behavior.
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Affiliation(s)
- Bruce A Carlson
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri 63130-4899, USA.
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40
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Gillis JA, Modrell MS, Baker CVH. Developmental evidence for serial homology of the vertebrate jaw and gill arch skeleton. Nat Commun 2013; 4:1436. [PMID: 23385581 PMCID: PMC3600657 DOI: 10.1038/ncomms2429] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 01/02/2013] [Indexed: 12/02/2022] Open
Abstract
Gegenbaur’s classical hypothesis of jaw-gill arch serial homology is widely cited, but remains unsupported by either paleontological evidence (e.g. a series of fossils reflecting the stepwise transformation of a gill arch into a jaw) or developmental genetic data (e.g. shared molecular mechanisms underlying segment identity in the mandibular, hyoid and gill arch endoskeletons). Here we show that nested expression of Dlx genes – the “Dlx code” that specifies upper and lower jaw identity in mammals and teleosts – is a primitive feature of the mandibular, hyoid and gill arches of jawed vertebrates. Using fate-mapping techniques, we demonstrate that the principal dorsal and ventral endoskeletal segments of the jaw, hyoid and gill arches of the skate Leucoraja erinacea derive from molecularly equivalent mesenchymal domains of combinatorial Dlx gene expression. Our data suggest that vertebrate jaw, hyoid and gill arch cartilages are serially homologous, and were primitively patterned dorsoventrally by a common Dlx blueprint.
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Affiliation(s)
- J Andrew Gillis
- Department of Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Downing Street, Cambridge CB2 3DY, UK.
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Compagnucci C, Debiais-Thibaud M, Coolen M, Fish J, Griffin JN, Bertocchini F, Minoux M, Rijli FM, Borday-Birraux V, Casane D, Mazan S, Depew MJ. Pattern and polarity in the development and evolution of the gnathostome jaw: both conservation and heterotopy in the branchial arches of the shark, Scyliorhinus canicula. Dev Biol 2013; 377:428-48. [PMID: 23473983 DOI: 10.1016/j.ydbio.2013.02.022] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Revised: 01/26/2013] [Accepted: 02/18/2013] [Indexed: 10/27/2022]
Abstract
The acquisition of jaws constitutes a landmark event in vertebrate evolution, one that in large part potentiated their success and diversification. Jaw development and patterning involves an intricate spatiotemporal series of reciprocal inductive and responsive interactions between the cephalic epithelia and the cranial neural crest (CNC) and cephalic mesodermal mesenchyme. The coordinated regulation of these interactions is critical for both the ontogenetic registration of the jaws and the evolutionary elaboration of variable jaw morphologies and designs. Current models of jaw development and evolution have been built on molecular and cellular evidence gathered mostly in amniotes such as mice, chicks and humans, and augmented by a much smaller body of work on the zebrafish. These have been partnered by essential work attempting to understand the origins of jaws that has focused on the jawless lamprey. Chondrichthyans (cartilaginous fish) are the most distant group to amniotes within extant gnathostomes, and comprise the crucial clade uniting amniotes and agnathans; yet despite their critical phylogenetic position, evidence of the molecular and cellular underpinnings of jaw development in chondrichthyans is still lacking. Recent advances in genome and molecular developmental biology of the lesser spotted dogfish shark, Scyliorhinus canicula, make it ideal for the molecular study of chondrichthyan jaw development. Here, following the 'Hinge and Caps' model of jaw development, we have investigated evidence of heterotopic (relative changes in position) and heterochronic (relative changes in timing) shifts in gene expression, relative to amniotes, in the jaw primordia of S. canicula embryos. We demonstrate the presence of clear proximo-distal polarity in gene expression patterns in the shark embryo, thus establishing a baseline molecular baüplan for branchial arch-derived jaw development and further validating the utility of the 'Hinge and Caps' model in comparative studies of jaw development and evolution. Moreover, we correlate gene expression patterns with the absence of a lambdoidal junction (formed where the maxillary first arch meets the frontonasal processes) in chondrichthyans, further highlighting the importance of this region for the development and evolution of jaw structure in advanced gnathostomes.
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Affiliation(s)
- Claudia Compagnucci
- Department of Craniofacial Development, King's College London, Floor 27, Guy's Hospital, London Bridge, London SE1 9RT, UK
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Modrell MS, Baker CVH. Evolution of electrosensory ampullary organs: conservation of Eya4 expression during lateral line development in jawed vertebrates. Evol Dev 2013; 14:277-85. [PMID: 23017075 DOI: 10.1111/j.1525-142x.2012.00544.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The lateral line system of fishes and amphibians comprises two ancient sensory systems: mechanoreception and electroreception. Electroreception is found in all major vertebrate groups (i.e. jawless fishes, cartilaginous fishes, and bony fishes); however, it was lost in several groups including anuran amphibians (frogs) and amniotes (reptiles, birds, and mammals), as well as in the lineage leading to the neopterygian clade of bony fishes (bowfins, gars, and teleosts). Electroreception is mediated by modified "hair cells," which are collected in ampullary organs that flank lines of mechanosensory hair cell containing neuromasts. In the axolotl (a urodele amphibian), grafting and ablation studies have shown a lateral line placode origin for both mechanosensory neuromasts and electrosensory ampullary organs (and the neurons that innervate them). However, little is known at the molecular level about the development of the amphibian lateral line system in general and electrosensory ampullary organs in particular. Previously, we identified Eya4 as a marker for lateral line (and otic) placodes, neuromasts, and ampullary organs in a shark (a cartilaginous fish) and a paddlefish (a basal ray-finned fish). Here, we show that Eya4 is similarly expressed during otic and lateral line placode development in the axolotl (a representative of the lobe-finned fish clade). Furthermore, Eya4 expression is specifically restricted to hair cells in both neuromasts and ampullary organs, as identified by coexpression with the calcium-buffering protein Parvalbumin3. As well as identifying new molecular markers for amphibian mechanosensory and electrosensory hair cells, these data demonstrate that Eya4 is a conserved marker for lateral line placodes and their derivatives in all jawed vertebrates.
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Affiliation(s)
- Melinda S Modrell
- Department of Physiology, Development and Neuroscience, University of Cambridge, UK
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Adachi N, Takechi M, Hirai T, Kuratani S. Development of the head and trunk mesoderm in the dogfish, Scyliorhinus torazame: II. Comparison of gene expression between the head mesoderm and somites with reference to the origin of the vertebrate head. Evol Dev 2013; 14:257-76. [PMID: 23017074 DOI: 10.1111/j.1525-142x.2012.00543.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The vertebrate mesoderm differs distinctly between the head and trunk, and the evolutionary origin of the head mesoderm remains enigmatic. Although the presence of somite-like segmentation in the head mesoderm of model animals is generally denied at molecular developmental levels, the appearance of head cavities in elasmobranch embryos has not been explained, and the possibility that they may represent vestigial head somites once present in an amphioxus-like ancestor has not been ruled out entirely. To examine whether the head cavities in the shark embryo exhibit any molecular signatures reminiscent of trunk somites, we isolated several developmentally key genes, including Pax1, Pax3, Pax7, Pax9, Myf5, Sonic hedgehog, and Patched2, which are involved in myogenic and chondrogenic differentiation in somites, and Pitx2, Tbx1, and Engrailed2, which are related to the patterning of the head mesoderm, from an elasmobranch species, Scyliorhinus torazame. Observation of the expression patterns of these genes revealed that most were expressed in patterns that resembled those found in amniote embryos. In addition, the head cavities did not exhibit an overt similarity to somites; that is, the similarity was no greater than that of the unsegmented head mesoderm in other vertebrates. Moreover, the shark head mesoderm showed an amniote-like somatic/visceral distinction according to the expression of Pitx2, Tbx1, and Engrailed2. We conclude that the head cavities do not represent a manifestation of ancestral head somites; rather, they are more likely to represent a derived trait obtained in the lineage of gnathostomes.
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Affiliation(s)
- Noritaka Adachi
- Laboratory for Evolutionary Morphology, RIKEN Center for Developmental Biology, Kobe, Japan
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44
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Adachi N, Kuratani S. Development of head and trunk mesoderm in the dogfish, Scyliorhinus torazame: I. Embryology and morphology of the head cavities and related structures. Evol Dev 2013; 14:234-56. [PMID: 23017073 DOI: 10.1111/j.1525-142x.2012.00542.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Vertebrate head segmentation has attracted the attention of comparative and evolutionary morphologists for centuries, given its importance for understanding the developmental body plan of vertebrates and its evolutionary origin. In particular, the segmentation of the mesoderm is central to the problem. The shark embryo has provided a canonical morphological scheme of the head, with its epithelialized coelomic cavities (head cavities), which have often been regarded as head somites. To understand the evolutionary significance of the head cavities, the embryonic development of the mesoderm was investigated at the morphological and histological levels in the shark, Scyliorhinus torazame. Unlike somites and some enterocoelic mesodermal components in other vertebrates, the head cavities in S. torazame appeared as irregular cyst(s) in the originally unsegmented mesenchymal head mesoderm, and not via segmentation of an undivided coelom. The mandibular cavity appeared first in the paraxial part of the mandibular mesoderm, followed by the hyoid cavity, and the premandibular cavity was the last to form. The prechordal plate was recognized as a rhomboid roof of the preoral gut, continuous with the rostral notochord, and was divided anteroposteriorly into two parts by the growth of the hypothalamic primordium. Of those, the posterior part was likely to differentiate into the premandibular cavity, and the anterior part disappeared later. The head cavities and somites in the trunk exhibited significant differences, in terms of histological appearance and timing of differentiation. The mandibular cavity developed a rostral process secondarily; its homology to the anterior cavity reported in some elasmobranch embryos is discussed.
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Affiliation(s)
- Noritaka Adachi
- Laboratory for Evolutionary Morphology, RIKEN Center for Developmental Biology, Kobe, Japan
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Manousaki T, Feiner N, Begemann G, Meyer A, Kuraku S. Co-orthology of Pax4 and Pax6 to the fly eyeless gene: molecular phylogenetic, comparative genomic, and embryological analyses. Evol Dev 2013; 13:448-59. [PMID: 23016906 DOI: 10.1111/j.1525-142x.2011.00502.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The functional equivalence of Pax6/eyeless genes across distantly related animal phyla has been one of central findings on which evo-devo studies is based. In this study, we show that Pax4, in addition to Pax6, is a vertebrate ortholog of the fly eyeless gene (and its duplicate, twin of eyeless [toy] gene, unique to Insecta). Molecular phylogenetic trees published to date placed the Pax4 gene outside the Pax6/eyeless subgroup as if the Pax4 gene originated from a gene duplication before the origin of bilaterians. However, Pax4 genes had only been reported for mammals. Our molecular phylogenetic analysis, including previously unidentified teleost fish pax4 genes, equally supported two scenarios: one with the Pax4-Pax6 duplication early in vertebrate evolution and the other with this duplication before the bilaterian radiation. We then investigated gene compositions in the genomic regions containing Pax4 and Pax6, and identified (1) conserved synteny between these two regions, suggesting that the Pax4-Pax6 split was caused by a large-scale duplication and (2) its timing within early vertebrate evolution based on the duplication timing of the members of neighboring gene families. Our results are consistent with the so-called two-round genome duplications in early vertebrates. Overall, the Pax6/eyeless ortholog is merely part of a 2:2 orthology relationship between vertebrates (with Pax4 and Pax6) and the fly (with eyeless and toy). In this context, evolution of transcriptional regulation associated with the Pax4-Pax6 split is also discussed in light of the zebrafish pax4 expression pattern that is analyzed here for the first time.
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Affiliation(s)
- Tereza Manousaki
- Laboratory for Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78464, Konstanz, Germany
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Rhinn M, Miyoshi K, Watanabe A, Kawaguchi M, Ito F, Kuratani S, Baker CV, Murakami Y, Rijli FM. Evolutionary divergence of trigeminal nerve somatotopy in amniotes. J Comp Neurol 2013; 521:1378-94. [DOI: 10.1002/cne.23236] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 07/24/2012] [Accepted: 10/02/2012] [Indexed: 11/10/2022]
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The amniote paratympanic organ develops from a previously undiscovered sensory placode. Nat Commun 2013; 3:1041. [PMID: 22948823 PMCID: PMC3518548 DOI: 10.1038/ncomms2036] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 07/31/2012] [Indexed: 11/25/2022] Open
Abstract
The paratympanic organ (PTO), a mechanosensory hair cell-containing pouch in the amniote middle ear, was first described 100 years ago yet its origins remain unresolved. Homology with the anamniote spiracular organ is supported by association with homologous skeletal elements and similar central targets of afferent neurons, suggesting it might be a remnant of the water-dependent lateral line system, otherwise lost during the amniote transition to terrestrial life. However, this is incompatible with studies suggesting it arises from the first epibranchial (geniculate) placode. Here we show that a previously undiscovered Sox2-positive placode, immediately dorsal to the geniculate placode, forms the PTO and its afferent neurons, which are molecularly and morphologically distinct from geniculate neurons. These data remove the only obstacle to accepting the homology of the PTO and spiracular organ. We hypothesise that the PTO/spiracular organ represents an ancient head ectoderm module, developmentally and evolutionarily independent of both lateral line and epibranchial placodes.
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SONG W, SONG JK. Development of the lateral line system in juvenile Siberian sturgeon ( Acipenser baerii). Zool Res 2013; 33:261-70. [DOI: 10.3724/sp.j.1141.2012.03261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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49
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Morphological Diversity, Development, and Evolution of the Mechanosensory Lateral Line System. SPRINGER HANDBOOK OF AUDITORY RESEARCH 2013. [DOI: 10.1007/2506_2013_12] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Ferreiro-Galve S, Candal E, Rodríguez-Moldes I. Dynamic expression of Pax6 in the shark olfactory system: evidence for the presence of Pax6 cells along the olfactory nerve pathway. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2012; 318:79-90. [PMID: 22532471 DOI: 10.1002/jezb.21444] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pax6 is involved in the control of neuronal specification, migration, and differentiation in the olfactory epithelium and in the generation of different interneuron subtypes in the olfactory bulb. Whether these roles are conserved during evolution is not known. Cartilaginous fish are extremely useful models for assessing the ancestral condition of brain organization because of their phylogenetic position. To shed light on the evolution of development of the olfactory system in vertebrates and on the involvement of Pax6 in this process, we analyzed by in situ hybridization and immunohistochemistry the expression pattern of Pax6 in the developing olfactory system in a basal vertebrate, the lesser spotted dogfish Scyliorhinus canicula. This small shark is becoming an important fish model in studies of vertebrate development. We report Pax6 expression in cells of the olfactory epithelium and olfactory bulb, and present the first evidence in vertebrates of strings of Pax6-expressing cells extending along the developing olfactory nerve. The results indicate the olfactory epithelium as the origin of these cells. These data are compatible with a role for Pax6 in the development of the olfactory epithelium and fibers, and provide a basis for future investigations into the mechanisms that regulate development of the olfactory system throughout evolution.
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Affiliation(s)
- Susana Ferreiro-Galve
- Department of Cell Biology and Ecology, University of Santiago de Compostela, Compostela, Spain
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