1
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Liang Y, Carrillo-Baltodano AM, Martín-Durán JM. Emerging trends in the study of spiralian larvae. Evol Dev 2024; 26:e12459. [PMID: 37787615 DOI: 10.1111/ede.12459] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 09/11/2023] [Accepted: 09/13/2023] [Indexed: 10/04/2023]
Abstract
Many animals undergo indirect development, where their embryogenesis produces an intermediate life stage, or larva, that is often free-living and later metamorphoses into an adult. As their adult counterparts, larvae can have unique and diverse morphologies and occupy various ecological niches. Given their broad phylogenetic distribution, larvae have been central to hypotheses about animal evolution. However, the evolution of these intermediate forms and the developmental mechanisms diversifying animal life cycles are still debated. This review focuses on Spiralia, a large and diverse clade of bilaterally symmetrical animals with a fascinating array of larval forms, most notably the archetypical trochophore larva. We explore how classic research and modern advances have improved our understanding of spiralian larvae, their development, and evolution. Specifically, we examine three morphological features of spiralian larvae: the anterior neural system, the ciliary bands, and the posterior hyposphere. The combination of molecular and developmental evidence with modern high-throughput techniques, such as comparative genomics, single-cell transcriptomics, and epigenomics, is a promising strategy that will lead to new testable hypotheses about the mechanisms behind the evolution of larvae and life cycles in Spiralia and animals in general. We predict that the increasing number of available genomes for Spiralia and the optimization of genome-wide and single-cell approaches will unlock the study of many emerging spiralian taxa, transforming our views of the evolution of this animal group and their larvae.
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Affiliation(s)
- Yan Liang
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | | | - José M Martín-Durán
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
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2
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Huan P, Liu B. The gastropod Lottia peitaihoensis as a model to study the body patterning of trochophore larvae. Evol Dev 2024; 26:e12456. [PMID: 37667429 DOI: 10.1111/ede.12456] [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: 04/13/2023] [Revised: 07/03/2023] [Accepted: 08/18/2023] [Indexed: 09/06/2023]
Abstract
The body patterning of trochophore larvae is important for understanding spiralian evolution and the origin of the bilateral body plan. However, considerable variations are observed among spiralian lineages, which have adopted varied strategies to develop trochophore larvae or even omit a trochophore stage. Some spiralians, such as patellogastropod mollusks, are suggested to exhibit ancestral traits by producing equal-cleaving fertilized eggs and possessing "typical" trochophore larvae. In recent years, we developed a potential model system using the patellogastropod Lottia peitaihoensis (= Lottia goshimai). Here, we introduce how the species were selected and establish sources and techniques, including gene knockdown, ectopic gene expression, and genome editing. Investigations on this species reveal essential aspects of trochophore body patterning, including organizer signaling, molecular and cellular processes connecting the various developmental functions of the organizer, the specification and behaviors of the endomesoderm and ectomesoderm, and the characteristic dorsoventral decoupling of Hox expression. These findings enrich the knowledge of trochophore body patterning and have important implications regarding the evolution of spiralians as well as bilateral body plans.
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Affiliation(s)
- Pin Huan
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Baozhong Liu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
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3
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Ramos AP, Szalapak A, Ferme LC, Modes CD. From cells to form: A roadmap to study shape emergence in vivo. Biophys J 2023; 122:3587-3599. [PMID: 37243338 PMCID: PMC10541488 DOI: 10.1016/j.bpj.2023.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 04/25/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
Organogenesis arises from the collective arrangement of cells into progressively 3D-shaped tissue. The acquisition of a correctly shaped organ is then the result of a complex interplay between molecular cues, responsible for differentiation and patterning, and the mechanical properties of the system, which generate the necessary forces that drive correct shape emergence. Nowadays, technological advances in the fields of microscopy, molecular biology, and computer science are making it possible to see and record such complex interactions in incredible, unforeseen detail within the global context of the developing embryo. A quantitative and interdisciplinary perspective of developmental biology becomes then necessary for a comprehensive understanding of morphogenesis. Here, we provide a roadmap to quantify the events that lead to morphogenesis from imaging to image analysis, quantification, and modeling, focusing on the discrete cellular and tissue shape changes, as well as their mechanical properties.
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Affiliation(s)
| | - Alicja Szalapak
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany; Center for Systems Biology Dresden, Dresden, Germany
| | | | - Carl D Modes
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany; Center for Systems Biology Dresden, Dresden, Germany; Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany
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4
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Sun D, Huan P, Liu B. Early mesodermal development in the patellogastropod Lottia goshimai. Evol Appl 2023; 16:250-261. [PMID: 36793691 PMCID: PMC9923484 DOI: 10.1111/eva.13373] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 11/04/2022] Open
Abstract
Mesodermal development is essential to explore the interlineage variations in the development of spiralians. Compared with model mollusks such as Tritia and Crepidula, knowledge about the mesodermal development of other molluscan lineages is limited. Here, we investigated early mesodermal development in the patellogastropod Lottia goshimai, which shows equal cleavage and has a trochophore larva. The endomesoderm derived from the 4d blastomere, that is, the mesodermal bandlets, was situated dorsally and showed a characteristic morphology. Investigations of the potential mesodermal patterning genes revealed that twist1 and snail1 were expressed in a proportion of these endomesodermal tissues, while all of the five genes we investigated (twist1, twist2, snail1, snail2, and mox) were expressed in ventrally located ectomesodermal tissues. Relatively dynamic snail2 expression suggests additional roles in various internalization processes. By tracing snail2 expression in early gastrulae, the 3a211 and 3b211 blastomeres were suggested to be the precursors of the ectomesoderm, which elongated to become internalized before division. These results help to understand the variations in the mesodermal development of different spiralians and explore the different mechanisms by which ectomesodermal cells are internalized, which has important evolutionary implications.
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Affiliation(s)
- Dehui Sun
- CAS and Shandong Province Key Laboratory of Experimental Marine BiologyInstitute of OceanologyChinese Academy of SciencesQingdaoChina
- University of Chinese Academy of SciencesBeijingChina
| | - Pin Huan
- CAS and Shandong Province Key Laboratory of Experimental Marine BiologyInstitute of OceanologyChinese Academy of SciencesQingdaoChina
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao)QingdaoChina
| | - Baozhong Liu
- CAS and Shandong Province Key Laboratory of Experimental Marine BiologyInstitute of OceanologyChinese Academy of SciencesQingdaoChina
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao)QingdaoChina
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5
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Batzel GO, Moreno BK, Lopez LS, Nguyen CK, Livingston BT, Joester D, Lyons DC. Proteomic and Transcriptomic Analyses in the Slipper Snail Crepidula
fornicata Uncover Shell Matrix Genes Expressed During Adult and Larval Biomineralization. Integr Org Biol 2022; 4:obac023. [PMID: 35968217 PMCID: PMC9365450 DOI: 10.1093/iob/obac023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 05/18/2022] [Indexed: 11/12/2022] Open
Abstract
The gastropod shell is a composite composed of minerals and shell matrix proteins (SMPs). SMPs have been identified by proteomics in many molluscs, but few have been studied in detail. Open questions include (1) what gene regulatory networks regulate SMP expression, (2) what roles individual SMPs play in biomineralization, and (3) how the complement of SMPs changes over development. These questions are best addressed in a species in which gene perturbation studies are available; one such species is the slipper snail, Crepidula fornicata. Here, SEM and pXRD analysis demonstrated that the adult shell of C. fornicata exhibits crossed lamellar microstructure and is composed of aragonite. Using high-throughput proteomics we identified 185 SMPs occluded within the adult shell. Over half of the proteins in the shell proteome have known biomineralization domains, while at least 10% have no homologs in public databases. Differential gene expression analysis identified 20 SMP genes that are up-regulated in the shell-producing mantle tissue. Over half of these 20 SMPs are expressed during development with two, CfSMP1 and CfSMP2, expressed exclusively in the shell gland. Together, the description of the shell microstructure and a list of SMPs now sets the stage for studying the consequences of SMP gene knockdowns in molluscs.
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Affiliation(s)
- G O Batzel
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography , UCSD, La Jolla, CA 92037, USA
| | - B K Moreno
- Department of Materials Science and Engineering, Northwestern University , Evanston, IL 60208, USA
| | - L S Lopez
- Department of Biological Sciences, California State University , Long Beach, CA 90802, USA
| | - C K Nguyen
- Department of Biological Sciences, California State University , Long Beach, CA 90802, USA
| | - B T Livingston
- Department of Biological Sciences, California State University , Long Beach, CA 90802, USA
| | - D Joester
- Department of Materials Science and Engineering, Northwestern University , Evanston, IL 60208, USA
| | - D C Lyons
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography , UCSD, La Jolla, CA 92037, USA
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6
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Slipper snail tales: How Crepidula fornicata and Crepidula atrasolea became model molluscs. Curr Top Dev Biol 2022; 147:375-399. [PMID: 35337456 DOI: 10.1016/bs.ctdb.2021.12.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Despite the great abundance and diversity of molluscs, only a few have attained "model research organism" status. One of those species is the slipper snail Crepidula fornicata. Its embryos were first used for classical lineage tracing studies in the late 19th century, and over a 100 years later they were "re-discovered" by our labs and used for modern fate mapping, gene perturbation, in vivo imaging, transcriptomics, and the first application of CRISPR/Cas9-mediated genome editing among the Spiralia/Lophotrochozoa. Simultaneously, other labs made extensive examinations of taxonomy, phylogeny, ecology, life-history, mode of development, larval feeding behavior, and responses to the environment in members of the family Calyptraeidae, which includes the genus Crepidula. Recently, we developed tools, resources, and husbandry protocols for another, direct-developing species, Crepidula atrasolea. This species is an ideal "lab rat" among molluscs. Together these species will be valuable for probing the cellular and molecular mechanisms underlying molluscan biology and evolution.
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7
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Tan S, Huan P, Liu B. Molluscan dorsal-ventral patterning relying on BMP2/4 and Chordin provides insights into spiralian development and evolution. Mol Biol Evol 2021; 39:6424002. [PMID: 34751376 PMCID: PMC8789067 DOI: 10.1093/molbev/msab322] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although a conserved mechanism relying on BMP2/4 and Chordin is suggested for animal dorsal–ventral (DV) patterning, this mechanism has not been reported in spiralians, one of the three major clades of bilaterians. Studies on limited spiralian representatives have suggested markedly diverse DV patterning mechanisms, a considerable number of which no longer deploy BMP signaling. Here, we showed that BMP2/4 and Chordin regulate DV patterning in the mollusk Lottia goshimai, which was predicted in spiralians but not previously reported. In the context of the diverse reports in spiralians, it conversely represents a relatively unusual case. We showed that BMP2/4 and Chordin coordinate to mediate signaling from the D-quadrant organizer to induce the DV axis, and Chordin relays the symmetry-breaking information from the organizer. Further investigations on L. goshimai embryos with impaired DV patterning suggested roles of BMP signaling in regulating the behavior of the blastopore and the organization of the nervous system. These findings provide insights into the evolution of animal DV patterning and the unique development mode of spiralians driven by the D-quadrant organizer.
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Affiliation(s)
- Sujian Tan
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266000, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Pin Huan
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266000, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Baozhong Liu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266000, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
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8
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Wu L, Lambert JD. A serpin is required for ectomesoderm, a hallmark of spiralian development. Dev Biol 2021; 469:172-181. [PMID: 33148394 DOI: 10.1016/j.ydbio.2020.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 11/28/2022]
Abstract
Among animals, diploblasts contain two germ layers, endoderm and ectoderm, while triploblasts have a distinct third germ layer called the mesoderm. Spiralians are a group of triploblast animals that have highly conserved development: they share the distinctive spiralian cleavage pattern as well as a unique source of mesoderm, the ectomesoderm. This population of mesoderm is distinct from endomesoderm and is considered a hallmark of spiralian development, but the regulatory network that drives its development is unknown. Here we identified ectomesoderm-specific genes in the mollusc Tritia (aka Ilyanassa) obsoleta through differential gene expression analyses comparing control and ectomesoderm-ablated embryos, followed by in situ hybridization of identified transcripts. We identified a Tritia serpin gene (ToSerpin1) that appears to be specifically expressed in the ectomesoderm of the posterior and head. Ablation of the 3a and 3b cells, which make most of the ectomesoderm, abolishes ToSerpin1 expression, consistent with its expression in these cells. Morpholino knockdown of ToSerpin1 causes ectomesoderm defects, most prominently in the muscle system of the larval head. This is the first gene identified that is specifically implicated in spiralian ectomesoderm development.
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Affiliation(s)
- Longjun Wu
- Department of Biology, University of Rochester, Rochester, NY, 14627, USA.
| | - J David Lambert
- Department of Biology, University of Rochester, Rochester, NY, 14627, USA.
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9
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Abstract
The freshwater snail Lymnaea stagnalis has a long research history, but only relatively recently has it emerged as an attractive model organism to study molecular mechanisms in the areas of developmental biology and translational medicine such as learning/memory and neurodegenerative diseases. The species has the advantage of being a hermaphrodite and can both cross- and self-mate, which greatly facilitates genetic approaches. The establishment of body-handedness, or chiromorphogenesis, is a major topic of study, since chirality is evident in the shell coiling. Chirality is maternally inherited, and only recently a gene-editing approach identified the actin-related gene Lsdia1 as the key handedness determinant. This short article reviews the natural habitat, life cycle, major research questions and interests, and experimental approaches.
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Affiliation(s)
- Reiko Kuroda
- Frontier Research Institute, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi, 487-8501, Japan.
| | - Masanori Abe
- Frontier Research Institute, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi, 487-8501, Japan
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10
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Lyons DC, Perry KJ, Batzel G, Henry JQ. BMP signaling plays a role in anterior-neural/head development, but not organizer activity, in the gastropod Crepidula fornicata. Dev Biol 2020; 463:135-157. [PMID: 32389712 PMCID: PMC7444637 DOI: 10.1016/j.ydbio.2020.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 02/06/2023]
Abstract
BMP signaling is involved in many aspects of metazoan development, with two of the most conserved functions being to pattern the dorsal-ventral axis and to specify neural versus epidermal fates. An active area of research within developmental biology asks how BMP signaling was modified over evolution to build disparate body plans. Animals belonging to the superclade Spiralia/Lophotrochozoa are excellent experimental subjects for studying the evolution of BMP signaling because a highly conserved, stereotyped early cleavage program precedes the emergence of distinct body plans. In this study we examine the role of BMP signaling in one representative, the slipper snail Crepidula fornicata. We find that mRNAs encoding BMP pathway components (including the BMP ligand decapentaplegic, and BMP antagonists chordin and noggin-like proteins) are not asymmetrically localized along the dorsal-ventral axis in the early embryo, as they are in other species. Furthermore, when BMP signaling is perturbed by adding ectopic recombinant BMP4 protein, or by treating embryos with the selective Activin receptor-like kinase-2 (ALK-2) inhibitor Dorsomorphin Homolog 1 (DMH1), we observe no obvious effects on dorsal-ventral patterning within the posterior (post-trochal) region of the embryo. Instead, we see effects on head development and the balance between neural and epidermal fates specifically within the anterior, pre-trochal tissue derived from the 1q1 lineage. Our experiments define a window of BMP signaling sensitivity that ends at approximately 44-48 hours post fertilization, which occurs well after organizer activity has ended and after the dorsal-ventral axis has been determined. When embryos were exposed to BMP4 protein during this window, we observed morphogenetic defects leading to the separation of the anterior, 1q lineage from the rest of the embryo. The 1q-derived organoid remained largely undifferentiated and was radialized, while the post-trochal portion of the embryo developed relatively normally and exhibited clear signs of dorsal-ventral patterning. When embryos were exposed to DMH1 during the same time interval, we observed defects in the head, including protrusion of the apical plate, enlarged cerebral ganglia and ectopic ocelli, but otherwise the larvae appeared normal. No defects in shell development were noted following DMH1 treatments. The varied roles of BMP signaling in the development of several other spiralians have recently been examined. We discuss our results in this context, and highlight the diversity of developmental mechanisms within spiral-cleaving animals.
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Affiliation(s)
- Deirdre C Lyons
- Scripps Institution of Oceanography, U.C. San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
| | - Kimberly J Perry
- University of Illinois, Department of Cell & Developmental Biology, 601 S. Goodwin Ave., Urbana, IL, 61801, USA
| | - Grant Batzel
- Scripps Institution of Oceanography, U.C. San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Jonathan Q Henry
- University of Illinois, Department of Cell & Developmental Biology, 601 S. Goodwin Ave., Urbana, IL, 61801, USA.
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11
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Abstract
Snails, earthworms and flatworms are remarkably different animals, but they all exhibit a very similar mode of early embryogenesis: spiral cleavage. This is one of the most widespread developmental programs in animals, probably ancestral to almost half of the animal phyla, and therefore its study is essential for understanding animal development and evolution. However, our knowledge of spiral cleavage is still in its infancy. Recent technical and conceptual advances, such as the establishment of genome editing and improved phylogenetic resolution, are paving the way for a fresher and deeper look into this fascinating early cleavage mode.
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Affiliation(s)
- José M Martín-Durán
- Queen Mary, University of London, School of Biological and Chemical Sciences, Mile End Road, E1 4NS London, UK
| | - Ferdinand Marlétaz
- Molecular Genetics Unit, Okinawa Institute of Science & Technology, 1919-1, Tancha, Onna 904-0495, Japan
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12
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Dorsoventral decoupling of Hox gene expression underpins the diversification of molluscs. Proc Natl Acad Sci U S A 2019; 117:503-512. [PMID: 31871200 DOI: 10.1073/pnas.1907328117] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
In contrast to the Hox genes in arthropods and vertebrates, those in molluscs show diverse expression patterns with differences reported among lineages. Here, we investigate 2 phylogenetically distant molluscs, a gastropod and a polyplacophoran, and show that the Hox expression in both species can be divided into 2 categories. The Hox expression in the ventral ectoderm generally shows a canonical staggered pattern comparable to the patterns of other bilaterians and likely contributes to ventral patterning, such as neurogenesis. The other category of Hox expression on the dorsal side is strongly correlated with shell formation and exhibits lineage-specific characteristics in each class of mollusc. This generalized model of decoupled dorsoventral Hox expression is compatible with known Hox expression data from other molluscan lineages and may represent a key characteristic of molluscan Hox expression. These results support the concept of widespread staggered Hox expression in Mollusca and reveal aspects that may be related to the evolutionary diversification of molluscs. We propose that dorsoventral decoupling of Hox expression allowed lineage-specific dorsal and ventral patterning, which may have facilitated the evolution of diverse body plans in different molluscan lineages.
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13
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Martín-Durán JM, Hejnol A. A developmental perspective on the evolution of the nervous system. Dev Biol 2019; 475:181-192. [PMID: 31610146 DOI: 10.1016/j.ydbio.2019.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 06/02/2018] [Accepted: 10/04/2019] [Indexed: 12/20/2022]
Abstract
The evolution of nervous systems in animals has always fascinated biologists, and thus multiple evolutionary scenarios have been proposed to explain the appearance of neurons and complex neuronal centers. However, the absence of a robust phylogenetic framework for animal interrelationships, the lack of a mechanistic understanding of development, and a recapitulative view of animal ontogeny have traditionally limited these scenarios. Only recently, the integration of advanced molecular and morphological studies in a broad range of animals has allowed to trace the evolution of developmental and neuronal characters on a better-resolved animal phylogeny. This has falsified most traditional scenarios for nervous system evolution, paving the way for the emergence of new testable hypotheses. Here we summarize recent progress in studies of nervous system development in major animal lineages and formulate some of the arising questions. In particular, we focus on how lineage analyses of nervous system development and a comparative study of the expression of neural-related genes has influenced our understanding of the evolution of an elaborated central nervous system in Bilateria. We argue that a phylogeny-guided study of neural development combining thorough descriptive and functional analyses is key to establish more robust scenarios for the origin and evolution of animal nervous systems.
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Affiliation(s)
- José M Martín-Durán
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thørmohlensgate 55, 5006, Bergen, Norway; School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, E1 4NS, London, UK.
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thørmohlensgate 55, 5006, Bergen, Norway.
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14
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Pechenik JA, Levy M, Allen JD. Instant Ocean Versus Natural Seawater: Impacts on Aspects of Reproduction and Development in Three Marine Invertebrates. THE BIOLOGICAL BULLETIN 2019; 237:16-25. [PMID: 31441700 DOI: 10.1086/705134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Marine invertebrate larvae have often been reared in artificial rather than natural seawater, either for convenience or to avoid potentially confounding effects of unknown contaminants. This study sought to determine the impact of artificial seawater on various aspects of development for three marine invertebrate species. We examined the impact of Instant Ocean on growth, survival, and fecundity of the deposit-feeding polychaete Capitella teleta at 2 salinities: 24 and 34 ppt; the impact on survival, growth rate, and time to metamorphic competence for the slipper limpet Crepidula fornicata; and the impact on larval growth for the sea star Asterias forbesi. Juveniles of C. teleta survived better in natural seawater than in Instant Ocean at both salinities but at the higher salinity grew more quickly in Instant Ocean; fecundity was not significantly affected by the type of seawater used at either salinity. Using Instant Ocean in place of natural seawater had no pronounced impact on the survival of C. fornicata larvae or on how long it took them to become competent to metamorphose; however, larvae grew somewhat more quickly in Instant Ocean than in natural seawater for the first 4 days of development, but by day 7 they were about 4.5% larger if they had been reared in seawater. The type of seawater used affected the growth of A. forbesi larvae, with larvae growing significantly more slowly in Instant Ocean than in natural seawater, no matter how growth was measured. In conclusion, our results suggest that although Instant Ocean may be a reasonable substitute for natural seawater for work with some species, using it may affect experimental outcomes in some aspects of work with other species.
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15
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Namigai† EKO, Shimeld SM. Live Imaging of Cleavage Variability and Vesicle Flow Dynamics in Dextral and Sinistral Spiralian Embryos. Zoolog Sci 2019; 36:5-16. [DOI: 10.2108/zs180088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 09/13/2018] [Indexed: 11/17/2022]
Affiliation(s)
- Erica K. O. Namigai†
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, U. K
| | - Sebastian M. Shimeld
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, U. K
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16
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Teso V, Penchaszadeh PE. Development of the gastropod Trochita pileus (Calyptraeidae) in the sub-Antarctic Southwestern Atlantic. Polar Biol 2018. [DOI: 10.1007/s00300-018-2412-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Osborne CC, Perry KJ, Shankland M, Henry JQ. Ectomesoderm and epithelial-mesenchymal transition-related genes in spiralian development. Dev Dyn 2018; 247:1097-1120. [PMID: 30133032 DOI: 10.1002/dvdy.24667] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Spiralians (e.g., annelids, molluscs, and flatworms) possess two sources of mesoderm. One is from endodermal precursors (endomesoderm), which is considered to be the ancestral source in metazoans. The second is from ectoderm (ectomesoderm) and may represent a novel cell type in the Spiralia. In the mollusc Crepidula fornicata, ectomesoderm is derived from micromere daughters within the A and B cell quadrants. Their progeny lie along the anterolateral edges of the blastopore. There they undergo epithelial-mesenchymal transition (EMT), become rounded and undergo delamination/ingression. Subsequently, they assume the mesenchymal phenotype, and migrate beneath the surface ectoderm to differentiate various cell types, including muscles and pigment cells. RESULTS We examined expression of several genes whose homologs are known to regulate Type 1 EMT in other metazoans. Most of these genes were expressed within spiralian ectomesoderm during EMT. CONCLUSIONS We propose that spiralian ectomesoderm, which exhibits analogous cellular behaviors to other populations of mesenchymal cells, may be controlled by the same genes that drive EMT in other metazoans. Perhaps these genes comprise a conserved metazoan EMT gene regulatory network (GRN). This study represents the first step in elucidating the GRN controlling the development of a novel spiralian cell type (ectomesoderm). Developmental Dynamics 247:1097-1120, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- C Cornelia Osborne
- University of Illinois, Department of Cell and Developmental Biology, Urbana, Illinois
| | - Kimberly J Perry
- University of Illinois, Department of Cell and Developmental Biology, Urbana, Illinois
| | - Marty Shankland
- University of Illinois, Department of Cell and Developmental Biology, Urbana, Illinois
| | - Jonathan Q Henry
- University of Illinois, Department of Cell and Developmental Biology, Urbana, Illinois
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Evolution of the bilaterian mouth and anus. Nat Ecol Evol 2018; 2:1358-1376. [PMID: 30135501 DOI: 10.1038/s41559-018-0641-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 06/26/2018] [Accepted: 07/11/2018] [Indexed: 12/17/2022]
Abstract
It is widely held that the bilaterian tubular gut with mouth and anus evolved from a simple gut with one major gastric opening. However, there is no consensus on how this happened. Did the single gastric opening evolve into a mouth, with the anus forming elsewhere in the body (protostomy), or did it evolve into an anus, with the mouth forming elsewhere (deuterostomy), or did it evolve into both mouth and anus (amphistomy)? These questions are addressed by the comparison of developmental fates of the blastopore, the opening of the embryonic gut, in diverse animals that live today. Here we review comparative data on the identity and fate of blastoporal tissue, investigate how the formation of the through-gut relates to the major body axes, and discuss to what extent evolutionary scenarios are consistent with these data. Available evidence indicates that stem bilaterians had a slit-like gastric opening that was partially closed in subsequent evolution, leaving open the anus and most likely also the mouth, which would favour amphistomy. We discuss remaining difficulties, and outline directions for future research.
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Nielsen C. Origin of the trochophora larva. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180042. [PMID: 30109065 PMCID: PMC6083724 DOI: 10.1098/rsos.180042] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/21/2018] [Indexed: 06/08/2023]
Abstract
The trochophora larva, which is so well known from the marine plankton, is central to our understanding of the evolution of a large branch of the bilaterians. Two theories for this larval type have been prevalent, the trochaea theory and the theory proposed by Ivanova-Kazas. The embryology, or more precisely the cell-lineage, of these larvae seems to be central for our understanding of their origin, but important details have been missing. According to the trochaea theory, a circumblastoporal ring of blastomeres differentiates to follow the convoluted shape of the conspicuous ciliary bands of the larvae, with prototroch and metatroch around the mouth, forming a filtering system, and telotroch around the anus. According to the Ivanova-Kazas theory, the blastomeres with the ciliary bands develop through specialization of rings of cells of the general ciliation in a lecithotrophic larva. Now, a new cell-lineage study of the gastropod Crepidula has shown that the ring of cells at the edge of the blastopore develops into the band of cells carrying prototroch and metatroch, characteristic of the trochophora. This gives strong support to the trochaea theory.
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Lorente-Sorolla J, Truchado-Garcia M, Perry KJ, Henry JQ, Grande C. Molecular, phylogenetic and developmental analyses of Sall proteins in bilaterians. EvoDevo 2018; 9:9. [PMID: 29644029 PMCID: PMC5892016 DOI: 10.1186/s13227-018-0096-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 03/17/2018] [Indexed: 11/10/2022] Open
Abstract
Background Sall (Spalt-like) proteins are zinc-finger transcription factors involved in a number of biological processes. They have only been studied in a few model organisms, such as Drosophila melanogaster, Caenorhabditis elegans, Schmidtea mediterranea and some vertebrates. Further taxon sampling is critical to understand the evolution and diversification of this protein and its functional roles in animals. Results Using genome and transcriptome mining, we confirmed the presence of sall genes in a range of additional animal taxa, for which their presence had not yet been described. We show that sall genes are broadly conserved across the Bilateria, and likely appeared in the bilaterian stem lineage. Our analysis of the protein domains shows that the characteristic arrangement of the multiple zinc-finger domains is conserved in bilaterians and may represent the ancient arrangement of this family of transcription factors. We also show the existence of a previously unknown zinc-finger domain. In situ hybridization was used to describe the gene expression patterns in embryonic and larval stages in two species of snails: Crepidula fornicata and Lottia gigantea. In L. gigantea, sall presents maternal expression, although later on the expression is restricted to the A and B quadrants during gastrulation and larval stage. In C. fornicata, sall has no maternal expression and it is expressed mainly in the A, C and D quadrants during blastula stages and in an asymmetric fashion during the larval stage. Discussion Our results suggest that the bilaterian common ancestor had a Sall protein with at least six zinc-finger domains. The evolution of Sall proteins in bilaterians might have occurred mostly as a result of the loss of protein domains and gene duplications leading to diversification. The new evidence complements previous studies in highlighting an important role of Sall proteins in bilaterian development. Our results show maternal expression of sall in the snail L. gigantea, but not C. fornicata. The asymmetric expression shown in the ectoderm of the trochophore larva of snails is probably related to shell/mantle development. The observed sall expression in cephalic tissue in snails and some other bilaterians suggests a possible ancestral role of sall in neural development in bilaterians.
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Affiliation(s)
- José Lorente-Sorolla
- 1Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,2Present Address: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Marta Truchado-Garcia
- 1Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,2Present Address: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Kimberly J Perry
- 3Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL 61801 USA
| | - Jonathan Q Henry
- 3Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL 61801 USA
| | - Cristina Grande
- 1Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,2Present Address: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain.,4Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Darwin, 1; Cantoblanco, 28049 Madrid, Spain
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Lyons DC, Perry KJ, Henry JQ. Morphogenesis along the animal-vegetal axis: fates of primary quartet micromere daughters in the gastropod Crepidula fornicata. BMC Evol Biol 2017; 17:217. [PMID: 28915788 PMCID: PMC5603038 DOI: 10.1186/s12862-017-1057-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/29/2017] [Indexed: 11/30/2022] Open
Abstract
Background The Spiralia are a large, morphologically diverse group of protostomes (e.g. molluscs, annelids, nemerteans) that share a homologous mode of early development called spiral cleavage. One of the most highly-conserved features of spiralian development is the contribution of the primary quartet cells, 1a-1d, to the anterior region of the embryo (including the brain, eyes, and the anterior ciliary band, called the prototroch). Yet, very few studies have analyzed the ultimate fates of primary quartet sub-lineages, or examined the morphogenetic events that take place in the anterior region of the embryo. Results This study focuses on the caenogastropod slipper snail, Crepidula fornicata, a model for molluscan developmental biology. Through direct lineage tracing of primary quartet daughter cells, and examination of these cells during gastrulation and organogenesis stages, we uncovered behaviors never described before in a spiralian. For the first time, we show that the 1a2-1d2 cells do not contribute to the prototroch (as they do in other species) and are ultimately lost before hatching. During gastrulation and anterior-posterior axial elongation stages, these cells cleavage-arrest and spread dramatically, contributing to a thin provisional epidermis on the dorsal side of the embryo. This spreading is coupled with the displacement of the animal pole, and other pretrochal cells, closer to the ventrally-positioned mouth, and the vegetal pole. Conclusions This is the first study to document the behavior and fate of primary quartet sub-lineages among molluscs. We speculate that the function of 1a2-1d2 cells (in addition to two cells derived from 1d12, and the 2b lineage) is to serve as a provisional epithelium that allows for anterior displacement of the other progeny of the primary quartet towards the anterior-ventral side of the embryo. These data support a new and novel mechanism for axial bending, distinct from canonical models in which axial bending is suggested to be driven primarily by differential proliferation of posterior dorsal cells. These data suggest also that examining sub-lineages in other spiralians will reveal greater variation than previously assumed.
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Affiliation(s)
- Deirdre C Lyons
- Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093, USA.
| | - Kimberly J Perry
- Department of Cell & Developmental Biology, University of Illinois, 601 S. Goodwin Ave, Urbana, IL, 61801, USA
| | - Jonathan Q Henry
- Department of Cell & Developmental Biology, University of Illinois, 601 S. Goodwin Ave, Urbana, IL, 61801, USA.
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22
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Lesoway MP, Collin R, Abouheif E. Early Activation of MAPK and Apoptosis in Nutritive Embryos of Calyptraeid Gastropods. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2017; 328:449-461. [DOI: 10.1002/jez.b.22745] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 03/09/2017] [Accepted: 04/05/2017] [Indexed: 01/04/2023]
Affiliation(s)
- Maryna P. Lesoway
- Department of Biology McGill University Montreal Quebec Canada
- Smithsonian Tropical Research Institute Balboa Ancón Panamá
| | - Rachel Collin
- Smithsonian Tropical Research Institute Balboa Ancón Panamá
| | - Ehab Abouheif
- Department of Biology McGill University Montreal Quebec Canada
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Vellutini BC, Martín-Durán JM, Hejnol A. Cleavage modification did not alter blastomere fates during bryozoan evolution. BMC Biol 2017; 15:33. [PMID: 28454545 PMCID: PMC5408385 DOI: 10.1186/s12915-017-0371-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 04/04/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Stereotypic cleavage patterns play a crucial role in cell fate determination by precisely positioning early embryonic blastomeres. Although misplaced cell divisions can alter blastomere fates and cause embryonic defects, cleavage patterns have been modified several times during animal evolution. However, it remains unclear how evolutionary changes in cleavage impact the specification of blastomere fates. Here, we analyze the transition from spiral cleavage - a stereotypic pattern remarkably conserved in many protostomes - to a biradial cleavage pattern, which occurred during the evolution of bryozoans. RESULTS Using 3D-live imaging time-lapse microscopy (4D-microscopy), we characterize the cell lineage, MAPK signaling, and the expression of 16 developmental genes in the bryozoan Membranipora membranacea. We found that the molecular identity and the fates of early bryozoan blastomeres are similar to the putative homologous blastomeres in spiral-cleaving embryos. CONCLUSIONS Our work suggests that bryozoans have retained traits of spiral development, such as the early embryonic fate map, despite the evolution of a novel cleavage geometry. These findings provide additional support that stereotypic cleavage patterns can be modified during evolution without major changes to the molecular identity and fate of embryonic blastomeres.
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Affiliation(s)
- Bruno C Vellutini
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5006, Bergen, Norway
| | - José M Martín-Durán
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5006, Bergen, Norway
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5006, Bergen, Norway.
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Abstract
Comparative data on the developing gastropod foregut suggest that this multicomponent feeding complex consists of two developmental modules. Modularity is revealed by delayed development of the buccal cavity and radular sac (“ventral module”) relative to the dorsal food channel (“dorsal module”) in gastropods with feeding larvae compared with those that may have never had a feeding larval stage. If nonfeeding larvae like those of extant patellogastropods and vetigastropods are ancestral for gastropods, then the uncoupling and heterochronic offset of dorsal and ventral foregut modules allowed the post-metamorphic dorsal food channel to be co-opted as a simple but functional esophagus for feeding larvae. Furthermore, by reducing energy cost per ovum, the heterochronic offset may have given mothers the evolutionary option of increasing fecundity or investing in protective egg encapsulation material. A second developmental innovation was spatial separation of the dorsal and ventral foregut modules, as illustrated by distal foregut development in buccinid neogastropods and venom gland development in cone snails. Spatial uncoupling may have enhanced the evolvability of gastropod foreguts by allowing phenotypic variants of ventral module components to be selected within post-metamorphic ecological settings, without needing to be first tested for compatibility with larval feeding. Finally, we describe a case in which foregut modularity has helped facilitate a highly derived life history in which encapsulated embryos ingest nurse eggs.
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Affiliation(s)
- Louise R. Page
- Department of Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, BC V8W 2Y2, Canada
- Department of Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, BC V8W 2Y2, Canada
| | - Brenda Hookham
- Department of Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, BC V8W 2Y2, Canada
- Department of Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, BC V8W 2Y2, Canada
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25
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The importance of evo-devo to an integrated understanding of molluscan biomineralisation. J Struct Biol 2016; 196:67-74. [DOI: 10.1016/j.jsb.2016.01.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/10/2016] [Accepted: 01/11/2016] [Indexed: 01/05/2023]
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26
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Henry JQ, Lyons DC. Molluscan models: Crepidula fornicata. Curr Opin Genet Dev 2016; 39:138-148. [PMID: 27526387 DOI: 10.1016/j.gde.2016.05.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 05/16/2016] [Accepted: 05/30/2016] [Indexed: 12/11/2022]
Abstract
Gastropod snails in the genus Crepidula have emerged as model systems for studying a metazoan super clade, the Spiralia. Recent work on one species in particular, Crepidula fornicata, has produced high-resolution cell lineage fate maps, details of morphogenetic events during gastrulation, key insights into the molecular underpinnings of early development, and the first demonstration of CRISPR/Cas9 genome editing in the Spiralia. Furthermore, invasive species of Crepidula are a significant ecological threat, while one of these, C. fornicata, is also being harvested for food. This review highlights progress towards developing these animals as models for evolutionary, developmental, and ecological studies. Such studies have contributed greatly to our understanding of biology in a major clade of bilaterians. This information may also help us to control and cultivate these snails.
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Affiliation(s)
- Jonathan Q Henry
- University of Illinois, Department of Cell & Developmental Biology, 601 South Goodwin Avenue, Urbana, IL 61801, United States.
| | - Deirdre C Lyons
- University of California, San Diego, Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093, United States.
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Perry KJ, Lyons DC, Truchado-Garcia M, Fischer AHL, Helfrich LW, Johansson KB, Diamond JC, Grande C, Henry JQ. Deployment of regulatory genes during gastrulation and germ layer specification in a model spiralian mollusc Crepidula. Dev Dyn 2016. [PMID: 26197970 DOI: 10.1002/dvdy.24308] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND During gastrulation, endoderm and mesoderm are specified from a bipotential precursor (endomesoderm) that is argued to be homologous across bilaterians. Spiralians also generate mesoderm from ectodermal precursors (ectomesoderm), which arises near the blastopore. While a conserved gene regulatory network controls specification of endomesoderm in deuterostomes and ecdysozoans, little is known about genes controlling specification or behavior of either source of spiralian mesoderm or the digestive tract. RESULTS Using the mollusc Crepidula, we examined conserved regulatory factors and compared their expression to fate maps to score expression in the germ layers, blastopore lip, and digestive tract. Many genes were expressed in both ecto- and endomesoderm, but only five were expressed in ectomesoderm exclusively. The latter may contribute to epithelial-to-mesenchymal transition seen in ectomesoderm. CONCLUSIONS We present the first comparison of genes expressed during spiralian gastrulation in the context of high-resolution fate maps. We found variation of genes expressed in the blastopore lip, mouth, and cells that will form the anus. Shared expression of many genes in both mesodermal sources suggests that components of the conserved endomesoderm program were either co-opted for ectomesoderm formation or that ecto- and endomesoderm are derived from a common mesodermal precursor that became subdivided into distinct domains during evolution.
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Affiliation(s)
- Kimberly J Perry
- University of Illinois, Department of Cell and Developmental Biology, Urbana, Illinois
| | | | - Marta Truchado-Garcia
- Departamento de Biología Molecular and Centro de Biología Molecular, "Severo Ochoa" (CSIC, Universidad Autónoma de Madrid), Madrid, Spain
| | - Antje H L Fischer
- Department of Metabolic Biochemistry, Ludwig-Maximilians-University, Munich, Germany.,Marine Biological Laboratory, Woods Hole, Massachusetts
| | | | - Kimberly B Johansson
- Marine Biological Laboratory, Woods Hole, Massachusetts.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts
| | | | - Cristina Grande
- Departamento de Biología Molecular and Centro de Biología Molecular, "Severo Ochoa" (CSIC, Universidad Autónoma de Madrid), Madrid, Spain
| | - Jonathan Q Henry
- University of Illinois, Department of Cell and Developmental Biology, Urbana, Illinois
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Kurita Y, Hashimoto N, Wada H. Evolution of the molluscan body plan: the case of the anterior adductor muscle of bivalves. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12812] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yoshihisa Kurita
- Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba 305-8572 Japan
| | - Naoki Hashimoto
- Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba 305-8572 Japan
| | - Hiroshi Wada
- Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba 305-8572 Japan
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Mohri M, Hashimoto N, Wada H. Lineage tracing of the bivalve shell field with special interest in the descendants of the 2d blastomere. Biol Lett 2016; 12:20151055. [PMID: 26932681 DOI: 10.1098/rsbl.2015.1055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
By evolving bilaterally separated shell plates, bivalves acquired a unique body plan in which their soft tissues are completely protected by hard shell plates. In this unique body plan, mobility between the separated shell plates is provided by novel structures such as a ligament and adductor muscles. As a first step towards understanding how the bivalve body plan was established, we investigated the development of the separated shell plates and ligament. Over 100 years ago, it was hypothesized that the development of separated shell plates is tightly linked with the unique cell cleavage (division) pattern of bivalves during development, wherein each bilateral daughter cell of the 2d descendant 2d(1121) develops into one of the bilateral shell fields. In this study, we tested this hypothesis by tracing the cell lineages of the Japanese purple mussel Septifer virgatus. Although the shell fields were found to be exclusively derived from the bilateral descendant cells of 2d: 2d(11211) and 2d(11212), the descendants of these cells were not restricted to shell fields alone, nor were they confined to the left or right side of the shell field based on their lineage. Our study demonstrated that ligament cells are also derived from 2d(11211) and 2d(11212), indicating that the ligament cells emerged as a subpopulation of shell field cells. This also suggests that the establishment of the novel developmental system for the ligament cells was critical for the evolution of the unique body plan of bivalves.
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Affiliation(s)
- Masakuni Mohri
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
| | - Naoki Hashimoto
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
| | - Hiroshi Wada
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
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