1
|
Hydrocoel morphogenesis forming the pentaradial body plan in a sea cucumber, Apostichopus japonicus. Sci Rep 2022; 12:6025. [PMID: 35410352 PMCID: PMC9001670 DOI: 10.1038/s41598-022-09691-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 03/24/2022] [Indexed: 11/09/2022] Open
Abstract
Echinoderms constitute an animal phylum characterized by the pentaradial body plan. During the development from bilateral larvae to pentaradial adults, the formation of the multiple of five hydrocoel lobes, i.e., the buddings from the mesodermal coelom, is the firstly emerging pentameral character. The developmental mechanism underlying the hydrocoel-lobe formation should be revealed to understand the evolutionary process of this unique and highly derived body plan of echinoderms, although the morphogenetic mechanisms of hydrocoel lobes are largely uninvestigated. In this study, using the sea cucumber Apostichopus japonicus, in which hydrocoel is easily observable, the developmental process of hydrocoel lobes was described in detail, focusing on cell proliferation and rearrangement. Cell proliferation was not specifically distributed in the growing tips of the hydrocoel lobes, and inhibition of cell proliferation did not affect lobe formation. During lobe formation, the epithelium of the hydrocoel lobes was firstly thickened and then transformed into a simple epithelium, suggesting that tissue expansion via tissue remodeling contributes to the hydrocoel-lobe formation.
Collapse
|
2
|
Abstract
As analyses of developmental mechanisms extend to ever more species, it becomes important to understand not just what is conserved or altered during evolution, but why. Closely related species that exhibit extreme phenotypic divergence can be uniquely informative in this regard. A case in point is the sea urchin genus Heliocidaris, which contains species that recently evolved a life history involving nonfeeding larvae following nearly half a billion years of prior evolution with feeding larvae. The resulting shift in selective regimes produced rapid and surprisingly extensive changes in developmental mechanisms that are otherwise highly conserved among echinoderm species. The magnitude and extent of these changes challenges the notion that conservation of early development in echinoderms is largely due to internal constraints that prohibit modification and instead suggests that natural selection actively maintains stability of inherently malleable trait developmental mechanisms over immense time periods. Knowing how and why natural selection changed during the evolution of nonfeeding larvae can also reveal why developmental mechanisms do and do not change in particular ways.
Collapse
Affiliation(s)
- Gregory A Wray
- Department of Biology, Duke University, Durham, NC, United States.
| |
Collapse
|
3
|
Devens HR, Davidson PL, Deaker DJ, Smith KE, Wray GA, Byrne M. Ocean acidification induces distinct transcriptomic responses across life history stages of the sea urchin Heliocidaris erythrogramma. Mol Ecol 2020; 29:4618-4636. [PMID: 33002253 PMCID: PMC8994206 DOI: 10.1111/mec.15664] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/23/2020] [Accepted: 08/25/2020] [Indexed: 09/01/2023]
Abstract
Ocean acidification (OA) from seawater uptake of rising carbon dioxide emissions impairs development in marine invertebrates, particularly in calcifying species. Plasticity in gene expression is thought to mediate many of these physiological effects, but how these responses change across life history stages remains unclear. The abbreviated lecithotrophic development of the sea urchin Heliocidaris erythrogramma provides a valuable opportunity to analyse gene expression responses across a wide range of life history stages, including the benthic, post-metamorphic juvenile. We measured the transcriptional response to OA in H. erythrogramma at three stages of the life cycle (embryo, larva, and juvenile) in a controlled breeding design. The results reveal a broad range of strikingly stage-specific impacts of OA on transcription, including changes in the number and identity of affected genes; the magnitude, sign, and variance of their expression response; and the developmental trajectory of expression. The impact of OA on transcription was notably modest in relation to gene expression changes during unperturbed development and much smaller than genetic contributions from parentage. The latter result suggests that natural populations may provide an extensive genetic reservoir of resilience to OA. Taken together, these results highlight the complexity of the molecular response to OA, its substantial life history stage specificity, and the importance of contextualizing the transcriptional response to pH stress in light of normal development and standing genetic variation to better understand the capacity for marine invertebrates to adapt to OA.
Collapse
Affiliation(s)
| | | | - Dione J Deaker
- School of Life and Environmental Science, The University of Sydney, Sydney, NSW, Australia
| | - Kathryn E Smith
- The Laboratory, The Marine Biological Association, Plymouth, UK
| | - Gregory A Wray
- Department of Biology, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Maria Byrne
- School of Life and Environmental Science, The University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
4
|
Byrne M, Koop D, Morris VB, Chui J, Wray GA, Cisternas P. Expression of genes and proteins of the pax-six-eya-dach network in the metamorphic sea urchin: Insights into development of the enigmatic echinoderm body plan and sensory structures. Dev Dyn 2017; 247:239-249. [PMID: 28850769 DOI: 10.1002/dvdy.24584] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 07/25/2017] [Accepted: 07/31/2017] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Photoreception-associated genes of the Pax-Six-Eya-Dach network (PSEDN) are deployed for many roles in addition to photoreception development. In this first study of PSEDN genes during development of the pentameral body in sea urchins, we investigated their spatial expression in Heliocidaris erythrogramma. RESULTS Expression of PSEDN genes in the hydrocoele of early (Dach, Eya, Six1/2) and/or late (Pax6, Six3/6) larvae, and the five hydrocoele lobes, the first morphological expression of pentamery, supports a role in body plan development. Pax6, Six1/2, and Six3/6 were localized to the primary and/or secondary podia and putative sensory/neuronal cells. Six1/2 and Six3/6 were expressed in the neuropil region in the terminal disc of the podia. Dach was localized to spines. Sequential up-regulation of gene expression as new podia and spines formed was evident. Rhabdomeric opsin and pax6 protein were localized to cells in the primary podia and spines. CONCLUSIONS Our results support roles for PSEDN genes in development of the pentameral body plan, contributing to our understanding of how the most unusual body plan in the Bilateria may have evolved. Development of sensory cells within the Pax-Six expression field is consistent with the role of these genes in sensory cell development in diverse species. Developmental Dynamics 247:239-249, 2018. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Maria Byrne
- School of Medical Sciences, The University of Sydney, NSW, Australia.,School of Life and Environmental Sciences, The University of Sydney, NSW, Australia
| | - Demian Koop
- School of Medical Sciences, The University of Sydney, NSW, Australia
| | - Valerie B Morris
- School of Life and Environmental Sciences, The University of Sydney, NSW, Australia
| | - Juanita Chui
- School of Medical Sciences, The University of Sydney, NSW, Australia
| | - Gregory A Wray
- Department of Biology and Center for Genomic and Computational Biology, Duke University, Durham, North Carolina
| | - Paula Cisternas
- School of Medical Sciences, The University of Sydney, NSW, Australia
| |
Collapse
|
5
|
Mashanov VS, Zueva OR, García-Arrarás JE. Inhibition of cell proliferation does not slow down echinoderm neural regeneration. Front Zool 2017; 14:12. [PMID: 28250799 PMCID: PMC5324207 DOI: 10.1186/s12983-017-0196-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 02/07/2017] [Indexed: 01/14/2023] Open
Abstract
Background Regeneration of the damaged central nervous system is one of the most interesting post-embryonic developmental phenomena. Two distinct cellular events have been implicated in supplying regenerative neurogenesis with cellular material – generation of new cells through cell proliferation and recruitment of already existing cells through cell migration. The relative contribution and importance of these two mechanisms is often unknown. Methods Here, we use the regenerating radial nerve cord (RNC) of the echinoderm Holothuria glaberrima as a model of extensive post-traumatic neurogenesis in the deuterostome central nervous system. To uncouple the effects of cell proliferation from those of cell migration, we treated regenerating animals with aphidicolin, a specific inhibitor of S-phase DNA replication. To monitor the effect of aphidicolin on DNA synthesis, we used BrdU immunocytochemistry. The specific radial glial marker ERG1 was used to label the regenerating RNC. Cell migration was tracked with vital staining with the lipophilic dye DiI. Results Aphidicolin treatment resulted in a significant 2.1-fold decrease in cell proliferation. In spite of this, the regenerating RNC in the treated animals did not differ in histological architecture, size and cell number from its counterpart in the control vehicle-treated animals. DiI labeling showed extensive cell migration in the RNC. Some cells migrated from as far as 2 mm away from the injury plane to contribute to the neural outgrowth. Conclusions We suggest that inhibition of cell division in the regenerating RNC of H. glaberrima is compensated for by recruitment of cells, which migrate into the RNC outgrowth from deeper regions of the neuroepithelium. Neural regeneration in echinoderms is thus a highly regulative developmental phenomenon, in which the size of the cell pool can be controlled either by cell proliferation or cell migration, and the latter can neutralize perturbations in the former. Electronic supplementary material The online version of this article (doi:10.1186/s12983-017-0196-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Vladimir S Mashanov
- University of North Florida, 1 UNF Drive, Jacksonville, 32224 FL USA.,University of Puerto Rico, Rio Piedras, PO Box 70377, San Juan, 00936-8377 PR USA
| | - Olga R Zueva
- University of North Florida, 1 UNF Drive, Jacksonville, 32224 FL USA.,University of Puerto Rico, Rio Piedras, PO Box 70377, San Juan, 00936-8377 PR USA
| | | |
Collapse
|
6
|
Koop D, Cisternas P, Morris VB, Strbenac D, Yang JYH, Wray GA, Byrne M. Nodal and BMP expression during the transition to pentamery in the sea urchin Heliocidaris erythrogramma: insights into patterning the enigmatic echinoderm body plan. BMC DEVELOPMENTAL BIOLOGY 2017; 17:4. [PMID: 28193178 PMCID: PMC5307799 DOI: 10.1186/s12861-017-0145-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 01/26/2017] [Indexed: 12/27/2022]
Abstract
BACKGROUND The molecular mechanisms underlying the development of the unusual echinoderm pentameral body plan and their likeness to mechanisms underlying the development of the bilateral plans of other deuterostomes are of interest in tracing body plan evolution. In this first study of the spatial expression of genes associated with Nodal and BMP2/4 signalling during the transition to pentamery in sea urchins, we investigate Heliocidaris erythrogramma, a species that provides access to the developing adult rudiment within days of fertilization. RESULTS BMP2/4, and the putative downstream genes, Six1/2, Eya, Tbx2/3 and Msx were expressed in the earliest morphological manifestation of pentamery during development, the five hydrocoele lobes. The formation of the vestibular ectoderm, the specialized region overlying the left coelom that forms adult ectoderm, involved the expression of putative Nodal target genes Chordin, Gsc and BMP2/4 and putative BMP2/4 target genes Dlx, Msx and Tbx. The expression of Nodal, Lefty and Pitx2 in the right ectoderm, and Pitx2 in the right coelom, was as previously observed in other sea urchins. CONCLUSION That genes associated with Nodal and BMP2/4 signalling are expressed in the hydrocoele lobes, indicates that they have a role in the developmental transition to pentamery, contributing to our understanding of how the most unusual body plan in the Bilateria may have evolved. We suggest that the Nodal and BMP2/4 signalling cascades might have been duplicated or split during the evolution to pentamery.
Collapse
Affiliation(s)
- Demian Koop
- School of Medical Science and Bosch Institute, The University of Sydney, Sydney, NSW 2006 Australia
| | - Paula Cisternas
- School of Medical Science and Bosch Institute, The University of Sydney, Sydney, NSW 2006 Australia
| | - Valerie B. Morris
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006 Australia
| | - Dario Strbenac
- School of Mathematics and Statistics, The University of Sydney, Sydney, NSW 2006 Australia
| | - Jean Yee Hwa Yang
- School of Mathematics and Statistics, The University of Sydney, Sydney, NSW 2006 Australia
| | - Gregory A. Wray
- Department of Biology and Center for Genomic and Computational Biology, Duke University, Durham, NC 27708 USA
| | - Maria Byrne
- School of Medical Science and Bosch Institute, The University of Sydney, Sydney, NSW 2006 Australia
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006 Australia
| |
Collapse
|
7
|
Divergence of ectodermal and mesodermal gene regulatory network linkages in early development of sea urchins. Proc Natl Acad Sci U S A 2016; 113:E7202-E7211. [PMID: 27810959 DOI: 10.1073/pnas.1612820113] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Developmental gene regulatory networks (GRNs) are assemblages of gene regulatory interactions that direct ontogeny of animal body plans. Studies of GRNs operating in the early development of euechinoid sea urchins have revealed that little appreciable change has occurred since their divergence ∼90 million years ago (mya). These observations suggest that strong conservation of GRN architecture was maintained in early development of the sea urchin lineage. Testing whether this holds for all sea urchins necessitates comparative analyses of echinoid taxa that diverged deeper in geological time. Recent studies highlighted extensive divergence of skeletogenic mesoderm specification in the sister clade of euechinoids, the cidaroids, suggesting that comparative analyses of cidaroid GRN architecture may confer a greater understanding of the evolutionary dynamics of developmental GRNs. Here I report spatiotemporal patterning of 55 regulatory genes and perturbation analyses of key regulatory genes involved in euechinoid oral-aboral patterning of nonskeletogenic mesodermal and ectodermal domains in early development of the cidaroid Eucidaris tribuloides These results indicate that developmental GRNs directing mesodermal and ectodermal specification have undergone marked alterations since the divergence of cidaroids and euechinoids. Notably, statistical and clustering analyses of echinoid temporal gene expression datasets indicate that regulation of mesodermal genes has diverged more markedly than regulation of ectodermal genes. Although research on indirect-developing euechinoid sea urchins suggests strong conservation of GRN circuitry during early embryogenesis, this study indicates that since the divergence of cidaroids and euechinoids, developmental GRNs have undergone significant, cell type-biased alterations.
Collapse
|
8
|
Israel JW, Martik ML, Byrne M, Raff EC, Raff RA, McClay DR, Wray GA. Comparative Developmental Transcriptomics Reveals Rewiring of a Highly Conserved Gene Regulatory Network during a Major Life History Switch in the Sea Urchin Genus Heliocidaris. PLoS Biol 2016; 14:e1002391. [PMID: 26943850 PMCID: PMC4778923 DOI: 10.1371/journal.pbio.1002391] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 01/26/2016] [Indexed: 01/08/2023] Open
Abstract
The ecologically significant shift in developmental strategy from planktotrophic (feeding) to lecithotrophic (nonfeeding) development in the sea urchin genus Heliocidaris is one of the most comprehensively studied life history transitions in any animal. Although the evolution of lecithotrophy involved substantial changes to larval development and morphology, it is not known to what extent changes in gene expression underlie the developmental differences between species, nor do we understand how these changes evolved within the context of the well-defined gene regulatory network (GRN) underlying sea urchin development. To address these questions, we used RNA-seq to measure expression dynamics across development in three species: the lecithotroph Heliocidaris erythrogramma, the closely related planktotroph H. tuberculata, and an outgroup planktotroph Lytechinus variegatus. Using well-established statistical methods, we developed a novel framework for identifying, quantifying, and polarizing evolutionary changes in gene expression profiles across the transcriptome and within the GRN. We found that major changes in gene expression profiles were more numerous during the evolution of lecithotrophy than during the persistence of planktotrophy, and that genes with derived expression profiles in the lecithotroph displayed specific characteristics as a group that are consistent with the dramatically altered developmental program in this species. Compared to the transcriptome, changes in gene expression profiles within the GRN were even more pronounced in the lecithotroph. We found evidence for conservation and likely divergence of particular GRN regulatory interactions in the lecithotroph, as well as significant changes in the expression of genes with known roles in larval skeletogenesis. We further use coexpression analysis to identify genes of unknown function that may contribute to both conserved and derived developmental traits between species. Collectively, our results indicate that distinct evolutionary processes operate on gene expression during periods of life history conservation and periods of life history divergence, and that this contrast is even more pronounced within the GRN than across the transcriptome as a whole.
Collapse
Affiliation(s)
- Jennifer W. Israel
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Megan L. Martik
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Maria Byrne
- Schools of Medical and Biological Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Elizabeth C. Raff
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Rudolf A. Raff
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - David R. McClay
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Gregory A. Wray
- Department of Biology, Duke University, Durham, North Carolina, United States of America
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, United States of America
| |
Collapse
|
9
|
Byrne M, Koop D, Cisternas P, Strbenac D, Yang JYH, Wray GA. Transcriptomic analysis of Nodal- and BMP-associated genes during juvenile development of the sea urchin Heliocidaris erythrogramma. Mar Genomics 2015; 24 Pt 1:41-5. [DOI: 10.1016/j.margen.2015.05.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/30/2015] [Accepted: 05/30/2015] [Indexed: 10/23/2022]
|
10
|
Wygoda JA, Yang Y, Byrne M, Wray GA. Transcriptomic analysis of the highly derived radial body plan of a sea urchin. Genome Biol Evol 2015; 6:964-73. [PMID: 24696402 PMCID: PMC4007537 DOI: 10.1093/gbe/evu070] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
With their complex life cycle and highly derived body plan, echinoderms are unique among bilaterians. Although early development has been intensively studied, the molecular mechanisms underlying development of the adult echinoderm and its unusual radial body plan are largely unknown. To investigate the evolution of developmental changes in gene expression underlying radial body plan development and metamorphosis, we assembled a reference transcriptome de novo and used RNA-seq to measure gene expression profiles across larval, metamorphic, and postmetamorphic life cycle phases in the sea urchin Heliocidaris erythrogramma. Our results present a high-resolution view of gene expression dynamics during the complex transition from pre- to postmetamorphic development and suggest that distinct sets of regulatory and effector proteins are used during different life history phases. These analyses provide an important foundation for more detailed analyses of the evolution of the radial adult body of echinoderms.
Collapse
|
11
|
Binks RM, Prince J, Evans JP, Kennington WJ. MORE THAN BINDIN DIVERGENCE: REPRODUCTIVE ISOLATION BETWEEN SYMPATRIC SUBSPECIES OF A SEA URCHIN BY ASYNCHRONOUS SPAWNING. Evolution 2012; 66:3545-57. [DOI: 10.1111/j.1558-5646.2012.01700.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
12
|
Raff RA, Snoke Smith M. Chapter 7. Axis formation and the rapid evolutionary transformation of larval form. Curr Top Dev Biol 2009; 86:163-90. [PMID: 19361693 DOI: 10.1016/s0070-2153(09)01007-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Marine invertebrate embryos and larvae are diverse and can evolve rapidly, providing a link between early developmental and evolutionary mechanisms. We here discuss the role of evolutionary changes in axis formation, which is a crucial part of the patterning of marine embryos and larvae. We focus on sea urchin embryos, where axial features are well defined and subject to active current investigation. The genetic control of processes of formation of the three axial systems, animal-vegetal, dorsal-ventral, and left-right, is becoming established for species that undergo development via the feeding pluteus larva. These species represent the primitive condition among living sea urchins. We compare their developmental processes to the highly modified development of a species that has evolved a nonfeeding larva. This derived form has accelerated some elements of axis formation, and eliminated or modified others. Three features of embryonic/larval evolution stand out (1) evolution of developmental features occurs rapidly over geological time; (2) upstream gene regulatory systems of axis formation are conserved, whereas downstream features evolve rapidly; and (3) heterochronies play an important role.
Collapse
Affiliation(s)
- Rudolf A Raff
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | | |
Collapse
|