1
|
Bar-Lev Viterbo A, Wexler JR, Mayost Lev-Ari O, Chipman AD. Early embryonic development of the German cockroach Blattella germanica. EvoDevo 2024; 15:14. [PMID: 39462430 PMCID: PMC11520056 DOI: 10.1186/s13227-024-00234-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Accepted: 10/18/2024] [Indexed: 10/29/2024] Open
Abstract
BACKGROUND Early embryogenesis is characterized by dramatic cell proliferation and movement. In most insects, early embryogenesis includes a phase called the uniform blastoderm, during which cells evenly cover the entirety of the egg. However, the embryo of the German cockroach, Blattella germanica, like those of many insects within the super order Polyneoptera, does not have a uniform blastoderm; instead, its first cells condense rapidly at the site of a future germband. We investigated early development in this species in order to understand how early gene expression is or is not conserved in these insect embryos with distinct early cell behaviors. RESULTS We present a detailed time series of nuclear division and distribution from fertilization through germband formation and report patterns of expression for the early patterning genes hunchback, caudal, and twist in order to understand early polarization and mesoderm formation. We show a detailed time course of the spatial expression of two genes involved in the segmentation cascade, hedgehog and even-skipped, and demonstrate two distinct dynamics of the segmentation process. CONCLUSIONS Despite dramatic differences in cell distribution between the blastoderms of many Polyneopteran insects and those of more well-studied developmental models, expression patterns of early patterning genes are mostly similar. Genes associated with axis determination in other insects are activated relatively late and are probably not maternally deposited. The two phases of segmentation-simultaneous and sequential-might indicate a broadly conserved mode of morphological differentiation. The developmental time course we present here should be of value for further investigation into the causes of this distinct blastoderm type.
Collapse
Affiliation(s)
- Ariel Bar-Lev Viterbo
- The Department of Ecology, Evolution & Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, 91904, Jerusalem, Israel
| | - Judith R Wexler
- The Department of Ecology, Evolution & Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, 91904, Jerusalem, Israel
| | - Orel Mayost Lev-Ari
- The Department of Ecology, Evolution & Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, 91904, Jerusalem, Israel
| | - Ariel D Chipman
- The Department of Ecology, Evolution & Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, 91904, Jerusalem, Israel.
| |
Collapse
|
2
|
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: 0.5] [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.
Collapse
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
| |
Collapse
|
3
|
Andrikou C, Hejnol A. FGF signaling acts on different levels of mesoderm development within Spiralia. Development 2021; 148:264929. [PMID: 33999997 PMCID: PMC8180254 DOI: 10.1242/dev.196089] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 04/08/2021] [Indexed: 01/23/2023]
Abstract
FGF signaling is involved in mesoderm induction in members of deuterostomes (e.g. tunicates, hemichordates), but not in flies and nematodes, in which it has a role in mesoderm patterning and migration. However, we need comparable studies in other protostome taxa in order to decipher whether this mesoderm-inducing function of FGF extends beyond the lineage of deuterostomes. Here, we investigated the role of FGF signaling in mesoderm development in three species of lophophorates, a clade within the protostome group Spiralia. Our gene expression analyses show that the mesodermal molecular patterning is conserved between brachiopods and phoronids, but the spatial and temporal recruitment of transcription factors differs significantly. Moreover, the use of the inhibitor SU5402 demonstrates that FGF signaling is involved in different steps of mesoderm development, as well as in morphogenetic movements of gastrulation and axial elongation. Our findings suggest that the mesoderm-inducing role of FGF extends beyond the group of deuterostomes.
Collapse
Affiliation(s)
- Carmen Andrikou
- University of Bergen, Department of Biological Sciences, Thormøhlensgate 55, 5006 Bergen, Norway.,Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5006 Bergen, Norway
| | - Andreas Hejnol
- University of Bergen, Department of Biological Sciences, Thormøhlensgate 55, 5006 Bergen, Norway.,Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5006 Bergen, Norway
| |
Collapse
|
4
|
Evolution of Snail-mediated regulation of neural crest and placodes from an ancient role in bilaterian neurogenesis. Dev Biol 2019; 453:180-190. [PMID: 31211947 DOI: 10.1016/j.ydbio.2019.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 06/14/2019] [Accepted: 06/14/2019] [Indexed: 12/26/2022]
Abstract
A major challenge in vertebrate evolution is to identify the gene regulatory mechanisms that facilitated the origin of neural crest cells and placodes from ancestral precursors in invertebrates. Here, we show in lamprey, a primitively jawless vertebrate, that the transcription factor Snail is expressed simultaneously throughout the neural plate, neural plate border, and pre-placodal ectoderm in the early embryo and is then upregulated in the CNS throughout neurogenesis. Using CRISPR/Cas9-mediated genome editing, we demonstrate that Snail plays functional roles in all of these embryonic domains or their derivatives. We first show that Snail patterns the neural plate border by repressing lateral expansion of Pax3/7 and activating nMyc and ZicA. We also present evidence that Snail is essential for DlxB-mediated establishment of the pre-placodal ectoderm but is not required for SoxB1a expression during formation of the neural plate proper. At later stages, Snail regulates formation of neural crest-derived and placode-derived PNS neurons and controls CNS neural differentiation in part by promoting cell survival. Taken together with established functions of invertebrate Snail genes, we identify a pan-bilaterian mechanism that extends to jawless vertebrates for regulating neurogenesis that is dependent on Snail transcription factors. We propose that ancestral vertebrates deployed an evolutionarily conserved Snail expression domain in the CNS and PNS for neurogenesis and then acquired derived functions in neural crest and placode development by recruitment of regulatory genes downstream of neuroectodermal Snail activity. Our results suggest that Snail regulatory mechanisms in vertebrate novelties such as the neural crest and placodes may have emerged from neurogenic roles that originated early in bilaterian evolution.
Collapse
|
5
|
Hou X, Wei M, Li Q, Zhang T, Zhou D, Kong D, Xie Y, Qin Z, Zhang Z. Transcriptome Analysis of Larval Segment Formation and Secondary Loss in the Echiuran Worm Urechis unicinctus. Int J Mol Sci 2019; 20:E1806. [PMID: 31013695 PMCID: PMC6514800 DOI: 10.3390/ijms20081806] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/23/2019] [Accepted: 04/10/2019] [Indexed: 01/06/2023] Open
Abstract
The larval segment formation and secondary loss in echiurans is a special phenomenon, which is considered to be one of the important characteristics in the evolutionary relationship between the Echiura and Annelida. To better understand the molecular mechanism of this phenomenon, we revealed the larval transcriptome profile of the echiuran worm Urechis unicinctus using RNA-Seq technology. Twelve cDNA libraries of U. unicinctus larvae, late-trochophore (LT), early-segmentation larva (ES), segmentation larva (SL), and worm-shaped larva (WL) were constructed. Totally 243,381 unigenes were assembled with an average length of 1125 bp and N50 of 1836 bp, and 149,488 unigenes (61.42%) were annotated. We obtained 70,517 differentially expressed genes (DEGs) by pairwise comparison of the larval transcriptome data at different developmental stages and clustered them into 20 gene expression profiles using STEM software. Based on the typical profiles during the larval segment formation and secondary loss, eight signaling pathways were enriched, and five of which, mTOR, PI3K-AKT, TGF-β, MAPK, and Dorso-ventral axis formation signaling pathway, were proposed for the first time to be involved in the segment formation. Furthermore, we identified 119 unigenes related to the segment formation of annelids, arthropods, and chordates, in which 101 genes were identified in Drosophila and annelids. The function of most segment polarity gene homologs (hedgehog, wingless, engrailed, etc.) was conserved in echiurans, annelids, and arthropods based on their expression profiles, while the gap and pair-rule gene homologs were not. Finally, we verified that strong positive signals of Hedgehog were indeed located on the boundary of larval segments using immunofluorescence. Data in this study provide molecular evidence for the understanding of larval segment development in echiurans and may serve as a blueprint for segmented ancestors in future research.
Collapse
Affiliation(s)
- Xitan Hou
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
| | - Maokai Wei
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
| | - Qi Li
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
| | - Tingting Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
| | - Di Zhou
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
| | - Dexu Kong
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
| | - Yueyang Xie
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
| | - Zhenkui Qin
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
| | - Zhifeng Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
| |
Collapse
|
6
|
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: 1.9] [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.
Collapse
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
| |
Collapse
|
7
|
Kim JS, Kwak HJ, Medina Jiménez BI, Park SC, Xiao P, Weisblat DA, Cho SJ. Expression patterns of duplicated snail genes in the leech Helobdella. Dev Genes Evol 2017; 227:415-421. [PMID: 29188382 DOI: 10.1007/s00427-017-0598-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/23/2017] [Indexed: 01/28/2023]
Abstract
snail gene family members are zinc-finger transcription factors with key roles in morphogenesis. Involvement of snail family genes in mesoderm formation has been observed in insects and mammals. The snail genes are also involved in cell motility, neural differentiation, cell fate, survival decision, and left-right identity. The functions of snail genes have been studied primarily among ecdysozoans and deuterostomes, with relatively little work carried out in lophotrochozoans. In this study, we isolated two snail homologs (Hau-snail1 and Hau-snail2) from the leech Helobdella austinensis. We characterized the temporal and spatial expression patterns of these two genes by semi-quantitative RT-PCR and in situ hybridization. The expression of Hau-snail1 and Hau-snail2 correlates with ventral nerve cord (VNC) development, segmental mesoderm, and with a ring of cells that comes to lie at the base of the leech proboscis, respectively, showing similarity to the divergent expression of duplicated snail genes in polychaetes. Our results do not support the function of lophotrochozoan snail genes in mesoderm specification.
Collapse
Affiliation(s)
- Jin-Se Kim
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Hee-Jin Kwak
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Brenda Irene Medina Jiménez
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Soon Cheol Park
- Department of Life Sciences, Chung-Ang University, Seoul, 156-756, Republic of Korea
| | - Ping Xiao
- Department of Molecular and Cell Biology, 385 LSA, University of California, Berkeley, CA, USA
| | - David A Weisblat
- Department of Molecular and Cell Biology, 385 LSA, University of California, Berkeley, CA, USA.
| | - Sung-Jin Cho
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea.
- Department of Molecular and Cell Biology, 385 LSA, University of California, Berkeley, CA, USA.
| |
Collapse
|
8
|
Kim JS, Jiménez BIM, Kwak HJ, Park SC, Xiao P, Weisblat DA, Cho SJ. Spatiotemporal expression of a twist homolog in the leech Helobdella austinensis. Dev Genes Evol 2017; 227:245-252. [PMID: 28699036 DOI: 10.1007/s00427-017-0585-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 06/27/2017] [Indexed: 11/28/2022]
Abstract
Genes of the twist family encode bHLH transcription factors known to be involved in the regulation and differentiation of early mesoderm. Here, we report our characterization of Hau-twist, a twist homolog from the leech Helobdella austinensis, a tractable lophotrochozoan representative. Hau-twist was expressed in segmental founder cells of the mesodermal lineage, in subsets of cells within the mesodermal lineage of the germinal plate, in circumferential muscle fibers of a provisional integument during segmentation and organogenesis stages and on the ventral side of the developing proboscis. Thus, consistent with other systems, our results suggest that twist gene of the leech Helobdella might function in mesoderm differentiation.
Collapse
Affiliation(s)
- Jin-Se Kim
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Brenda Irene Medina Jiménez
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Hee-Jin Kwak
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Soon Cheol Park
- Department of Life Sciences, Chung-Ang University, Seoul, 156-756, Republic of Korea
| | - Ping Xiao
- Department of Molecular and Cell Biology, 385 LSA, University of California, Berkeley, CA, 94720-3200, USA
| | - David A Weisblat
- Department of Molecular and Cell Biology, 385 LSA, University of California, Berkeley, CA, 94720-3200, USA.
| | - Sung-Jin Cho
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea. .,Department of Molecular and Cell Biology, 385 LSA, University of California, Berkeley, CA, 94720-3200, USA.
| |
Collapse
|
9
|
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: 2.5] [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.
Collapse
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.
| |
Collapse
|
10
|
Tan J, Chen XJ, Shen CL, Zhang HX, Tang LY, Lu SY, Wu WT, Kuang Y, Fei J, Wang ZG. Lacking of palladin leads to multiple cellular events changes which contribute to NTD. Neural Dev 2017; 12:4. [PMID: 28340616 PMCID: PMC5366166 DOI: 10.1186/s13064-017-0081-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 03/03/2017] [Indexed: 11/23/2022] Open
Abstract
Background The actin cytoskeleton-associated protein palladin plays an important role in cell motility, morphogenesis and adhesion. In mice, Palladin deficient embryos are lethal before embryonic day (E) 15.5, and exhibit severe cranial neural tube and body wall closure defects. However, the mechanism how palladin regulates the process of cranial neural tube closure (NTC) remains unknown. Methods In this paper, we use gene knockout mouse to elucidate the function of palladin in the regulation of NTC process. Results We initially focuse on the expression pattern of palladin and found that in embryonic brain, palladin is predominantly expressed in the neural folds at E9.5. We further check the major cellular events in the neural epithelium that may contribute to NTC during the early embryogenesis. Palladin deficiency leads to a disturbance of cytoskeleton in the neural tube and the cultured neural progenitors. Furthermore, increased cell proliferation, decreased cell differentiation and diminished apical cell apoptosis of neural epithelium are found in palladin deficient embryos. Cell cycle of neural progenitors in Palladin-/- embryos is much shorter than that in wt ones. Cell adhesion shows a reduction in Palladin-/- neural tubes. Conclusions Palladin is expressed with proper spatio-temporal pattern in the neural folds. It plays a crucial role in regulating mouse cranial NTC by modulating cytoskeleton, proliferation, differentiation, apoptosis, and adhesion of neural epithelium. Our findings facilitate further study of the function of palladin and the underlying molecular mechanism involved in NTC. Electronic supplementary material The online version of this article (doi:10.1186/s13064-017-0081-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Juan Tan
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Building 17, No. 197, Ruijin 2nd Rd, Shanghai, 200025, China.,Model Organism Division, E-Institutes of Shanghai Universities, SJTUSM, Shanghai, 200025, China
| | - Xue-Jiao Chen
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Building 17, No. 197, Ruijin 2nd Rd, Shanghai, 200025, China.,Model Organism Division, E-Institutes of Shanghai Universities, SJTUSM, Shanghai, 200025, China
| | - Chun-Ling Shen
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Building 17, No. 197, Ruijin 2nd Rd, Shanghai, 200025, China
| | - Hong-Xin Zhang
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Building 17, No. 197, Ruijin 2nd Rd, Shanghai, 200025, China
| | - Ling-Yun Tang
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Building 17, No. 197, Ruijin 2nd Rd, Shanghai, 200025, China.,Model Organism Division, E-Institutes of Shanghai Universities, SJTUSM, Shanghai, 200025, China
| | - Shun-Yuan Lu
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Building 17, No. 197, Ruijin 2nd Rd, Shanghai, 200025, China
| | - Wen-Ting Wu
- Shanghai Research Center for Model Organisms, Shanghai, 201203, China
| | - Ying Kuang
- Shanghai Research Center for Model Organisms, Shanghai, 201203, China
| | - Jian Fei
- Shanghai Research Center for Model Organisms, Shanghai, 201203, China
| | - Zhu-Gang Wang
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Building 17, No. 197, Ruijin 2nd Rd, Shanghai, 200025, China. .,Model Organism Division, E-Institutes of Shanghai Universities, SJTUSM, Shanghai, 200025, China. .,Shanghai Research Center for Model Organisms, Shanghai, 201203, China.
| |
Collapse
|
11
|
Redl E, Scherholz M, Wollesen T, Todt C, Wanninger A. Cell Proliferation Pattern and Twist Expression in an Aplacophoran Mollusk Argue Against Segmented Ancestry of Mollusca. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2016; 326:422-436. [PMID: 27966274 PMCID: PMC5299467 DOI: 10.1002/jez.b.22714] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 10/28/2016] [Accepted: 11/02/2016] [Indexed: 01/12/2023]
Abstract
The study of aplacophoran mollusks (i.e., Solenogastres or Neomeniomorpha and Caudofoveata or Chaetodermomorpha) has traditionally been regarded as crucial for reconstructing the morphology of the last common ancestor of the Mollusca. Since their proposed close relatives, the Polyplacophora, show a distinct seriality in certain organ systems, the aplacophorans are also in the focus of attention with regard to the question of a potential segmented ancestry of mollusks. To contribute to this question, we investigated cell proliferation patterns and the expression of the twist ortholog during larval development in solenogasters. In advanced to late larvae, during the outgrowth of the trunk, a pair of longitudinal bands of proliferating cells is found subepithelially in a lateral to ventrolateral position. These bands elongate during subsequent development as the trunk grows longer. Likewise, expression of twist occurs in two laterally positioned, subepithelial longitudinal stripes in advanced larvae. Both, the pattern of proliferating cells and the expression domain of twist demonstrate the existence of extensive and long-lived mesodermal bands in a worm-shaped aculiferan, a situation which is similar to annelids but in stark contrast to conchiferans, where the mesodermal bands are usually rudimentary and ephemeral. Yet, in contrast to annelids, neither the bands of proliferating cells nor the twist expression domain show a separation into distinct serial subunits, which clearly argues against a segmented ancestry of mollusks. Furthermore, the lack of twist expression during the development of the ventromedian muscle argues against homology of a ventromedian longitudinal muscle in protostomes with the notochord of chordates.
Collapse
Affiliation(s)
- Emanuel Redl
- Faculty of Life SciencesDepartment of Integrative ZoologyUniversity of ViennaViennaAustria
| | - Maik Scherholz
- Faculty of Life SciencesDepartment of Integrative ZoologyUniversity of ViennaViennaAustria
| | - Tim Wollesen
- Faculty of Life SciencesDepartment of Integrative ZoologyUniversity of ViennaViennaAustria
| | - Christiane Todt
- University Museum, The Natural History CollectionsUniversity of BergenBergenNorway
| | - Andreas Wanninger
- Faculty of Life SciencesDepartment of Integrative ZoologyUniversity of ViennaViennaAustria
| |
Collapse
|
12
|
Seaver EC. Annelid models I: Capitella teleta. Curr Opin Genet Dev 2016; 39:35-41. [DOI: 10.1016/j.gde.2016.05.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/26/2016] [Accepted: 05/30/2016] [Indexed: 10/21/2022]
|
13
|
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: 4.8] [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.
Collapse
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
| |
Collapse
|
14
|
Kozin VV, Kostyuchenko RP. Evolutionary conservation and variability of the mesoderm development in spiralia: A peculiar pattern of nereid polychaetes. BIOL BULL+ 2016. [DOI: 10.1134/s1062359016030079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
15
|
Kozin VV, Filimonova DA, Kupriashova EE, Kostyuchenko RP. Mesoderm patterning and morphogenesis in the polychaete Alitta virens (Spiralia, Annelida): Expression of mesodermal markers Twist, Mox, Evx and functional role for MAP kinase signaling. Mech Dev 2016; 140:1-11. [PMID: 27000638 DOI: 10.1016/j.mod.2016.03.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 12/11/2022]
Abstract
Mesoderm represents the evolutionary youngest germ layer and forms numerous novel tissues in bilaterian animals. Despite the established conservation of the gene regulatory networks that drive mesoderm differentiation (e.g. myogenesis), mechanisms of mesoderm specification are highly variable in distant model species. Thus, broader phylogenetic sampling is required to reveal common features of mesoderm formation across bilaterians. Here we focus on a representative of Spiralia, the marine annelid Alitta virens, whose mesoderm development is still poorly investigated on the molecular level. We characterize three novel early mesodermal markers for A. virens - Twist, Mox, and Evx - which are differentially expressed within the mesodermal lineages. The Twist mRNA is ubiquitously distributed in the fertilized egg and exhibits specific expression in endomesodermal- and ectomesodermal-founder cells at gastrulation. Twist is expressed around the blastopore and later in a segmental metameric pattern. We consider this expression to be ancestral, and in support of the enterocoelic hypothesis of mesoderm evolution. We also revealed an early pattern of the MAPK activation in A. virens that is different from the previously reported pattern in spiralians. Inhibition of the MAPK pathway by U0126 disrupts the metameric Twist and Mox expression, indicating an early requirement of the MAPK cascade for proper morphogenesis of endomesodermal tissues.
Collapse
Affiliation(s)
- Vitaly V Kozin
- Department of Embryology, St. Petersburg State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia.
| | - Daria A Filimonova
- Department of Embryology, St. Petersburg State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia
| | - Ekaterina E Kupriashova
- Department of Embryology, St. Petersburg State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia
| | - Roman P Kostyuchenko
- Department of Embryology, St. Petersburg State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia.
| |
Collapse
|
16
|
Martín-Durán JM, Vellutini BC, Hejnol A. Evolution and development of the adelphophagic, intracapsular Schmidt's larva of the nemertean Lineus ruber. EvoDevo 2015; 6:28. [PMID: 26417429 PMCID: PMC4584431 DOI: 10.1186/s13227-015-0023-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 09/14/2015] [Indexed: 11/22/2022] Open
Abstract
Background The life cycle of many animals includes a larval stage, which has diversified into an astonishing variety of ecological strategies. The Nemertea is a group of spiralians that exhibits a broad diversity of larval forms, including the iconic pilidium. A pelagic planktotrophic pilidium is the ancestral form in the Pilidiophora, but several lineages exhibit deviations of this condition, mostly as a transition to pelagic lecithotrophy. The most extreme case occurs, however, in the Pilidiophoran Lineus ruber, which exhibits an adelphophagic intracapsular pilidium, the so-called Schmidt’s larva. Results We combined confocal laser scanning microscopy and gene expression studies to characterize the development and metamorphosis of the Schmidt’s larva of L. ruber. The larva forms after gastrulation, and comprises a thin epidermis, a proboscis rudiment and two pairs of imaginal discs from which the juvenile will develop. The cells internalized during gastrulation form a blind gut and the blastopore gives rise to the mouth of the larva and juvenile. The Schmidt’s larva eats other siblings that occupy the same egg capsule, accumulating nutrients for the juvenile. A gradual metamorphosis involves the differentiation of the juvenile cell types from the imaginal discs and the shedding of the larval epidermis. The expression of evolutionarily conserved anterior (foxQ2, six3/6, gsc, otx), endomesodermal (foxA, GATA456-a, twi-a) and posterior (evx, cdx) markers demonstrate that the juvenile retains the molecular patterning of the Schmidt’s larva. After metamorphosis, the juveniles stay over 20 days within the egg masses, until they are fully mature and hatch. Conclusions The evolution of the intracapsular Schmidt’s larva involved the loss of the typical feeding structures of the planktotrophic pilidium and a precocious formation of the imaginal discs, as also observed in other pelagic lecithotrophic forms. However, no special adaptations are observed related to adelphophagy. As in planktotrophic pilidium, the molecular mechanism patterning the juvenile is only active in the imaginal discs and not during the early development of the larva, suggesting two separate molecular programs during nemertean embryogenesis. Our results illuminate the diversification of larval forms in the Pilidiophora and Nemertea, and thus on the developmental mechanisms underlying metazoan larval evolution. Electronic supplementary material The online version of this article (doi:10.1186/s13227-015-0023-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- José M Martín-Durán
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
| | - Bruno C Vellutini
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
| |
Collapse
|
17
|
Brunet T, Lauri A, Arendt D. Did the notochord evolve from an ancient axial muscle? The axochord hypothesis. Bioessays 2015; 37:836-50. [PMID: 26172338 PMCID: PMC5054868 DOI: 10.1002/bies.201500027] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 06/03/2015] [Accepted: 06/05/2015] [Indexed: 12/20/2022]
Abstract
The origin of the notochord is one of the key remaining mysteries of our evolutionary ancestry. Here, we present a multi‐level comparison of the chordate notochord to the axochord, a paired axial muscle spanning the ventral midline of annelid worms and other invertebrates. At the cellular level, comparative molecular profiling in the marine annelids P. dumerilii and C. teleta reveals expression of similar, specific gene sets in presumptive axochordal and notochordal cells. These cells also occupy corresponding positions in a conserved anatomical topology and undergo similar morphogenetic movements. At the organ level, a detailed comparison of bilaterian musculatures reveals that most phyla form axochord‐like muscles, suggesting that such a muscle was already present in urbilaterian ancestors. Integrating comparative evidence at the cell and organ level, we propose that the notochord evolved by modification of a ventromedian muscle followed by the assembly of an axial complex supporting swimming in vertebrate ancestors.
Collapse
Affiliation(s)
- Thibaut Brunet
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Antonella Lauri
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Detlev Arendt
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| |
Collapse
|
18
|
Passamaneck YJ, Hejnol A, Martindale MQ. Mesodermal gene expression during the embryonic and larval development of the articulate brachiopod Terebratalia transversa. EvoDevo 2015; 6:10. [PMID: 25897375 PMCID: PMC4404124 DOI: 10.1186/s13227-015-0004-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 03/19/2015] [Indexed: 12/21/2022] Open
Abstract
Background Brachiopods undergo radial cleavage, which is distinct from the stereotyped development of closely related spiralian taxa. The mesoderm has been inferred to derive from the archenteron walls following gastrulation, and the primary mesoderm derivative in the larva is a complex musculature. To investigate the specification and differentiation of the mesoderm in the articulate brachiopod Terebratalia transversa, we have identified orthologs of genes involved in mesoderm development in other taxa and investigated their spatial and temporal expression during the embryonic and larval development of T. transversa. Results Orthologs of 17 developmental regulatory genes with roles in the development of the mesoderm in other bilaterian animals were found to be expressed in the developing mesoderm of T. transversa. Five genes, Tt.twist, Tt.GATA456, Tt.dachshund, Tt.mPrx, and Tt.NK1, were found to have expression throughout the archenteron wall at the radial gastrula stage, shortly after the initiation of gastrulation. Three additional genes, Tt.Pax1/9, Tt.MyoD, and Tt.Six1/2, showed expression at this stage in only a portion of the archenteron wall. Tt.eya, Tt.FoxC, Tt.FoxF, Tt.Mox, Tt.paraxis, Tt.Limpet, and Tt.Mef2 all showed initial mesodermal expression during later gastrula or early larval stages. At the late larval stage, Tt.dachshund, Tt.Limpet, and Tt.Mef2 showed expression in nearly all mesoderm cells, while all other genes were localized to specific regions of the mesoderm. Tt.FoxD and Tt.noggin both showed expression in the ventral mesoderm at the larval stages, with gastrula expression patterns in the archenteron roof and blastopore lip, respectively. Conclusions Expression analyses support conserved roles for developmental regulators in the specification and differentiation of the mesoderm during the development of T. transversa. Expression of multiple mesodermal factors in the archenteron wall during gastrulation supports previous morphological observations that this region gives rise to larval mesoderm. Localized expression domains during gastrulation and larval development evidence early regionalization of the mesoderm and provide a basis for hypotheses regarding the molecular regulation underlying the complex system of musculature observed in the larva. Electronic supplementary material The online version of this article (doi:10.1186/s13227-015-0004-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Yale J Passamaneck
- Kewalo Marine Laboratory, PBRC, University of Hawaii, 41 Ahui Street, Honolulu, HI 96813 USA ; The Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080 USA
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate, 55, 5008 Bergen, Norway
| | - Mark Q Martindale
- The Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080 USA
| |
Collapse
|
19
|
Molecular conservation of metazoan gut formation: evidence from expression of endomesoderm genes in Capitella teleta (Annelida). EvoDevo 2014; 5:39. [PMID: 25908956 PMCID: PMC4407770 DOI: 10.1186/2041-9139-5-39] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Accepted: 09/17/2014] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Metazoan digestive systems develop from derivatives of ectoderm, endoderm and mesoderm, and vary in the relative contribution of each germ layer across taxa and between gut regions. In a small number of well-studied model systems, gene regulatory networks specify endoderm and mesoderm of the gut within a bipotential germ layer precursor, the endomesoderm. Few studies have examined expression of endomesoderm genes outside of those models, and thus, it is unknown whether molecular specification of gut formation is broadly conserved. In this study, we utilize a sequenced genome and comprehensive fate map to correlate the expression patterns of six transcription factors with embryonic germ layers and gut subregions during early development in Capitella teleta. RESULTS The genome of C. teleta contains the five core genes of the sea urchin endomesoderm specification network. Here, we extend a previous study and characterize expression patterns of three network orthologs and three additional genes by in situ hybridization during cleavage and gastrulation stages and during formation of distinct gut subregions. In cleavage stage embryos, Ct-otx, Ct-blimp1, Ct-bra and Ct-nkx2.1a are expressed in all four macromeres, the endoderm precursors. Ct-otx, Ct-blimp1, and Ct-nkx2.1a are also expressed in presumptive endoderm of gastrulae and later during midgut development. Additional gut-specific expression patterns include Ct-otx, Ct-bra, Ct-foxAB and Ct-gsc in oral ectoderm; Ct-otx, Ct-blimp1, Ct-bra and Ct-nkx2.1a in the foregut; and both Ct-bra and Ct-nkx2.1a in the hindgut. CONCLUSIONS Identification of core sea urchin endomesoderm genes in C. teleta indicates they are present in all three bilaterian superclades. Expression of Ct-otx, Ct-blimp1 and Ct-bra, combined with previously published Ct-foxA and Ct-gataB1 patterns, provide the most comprehensive comparison of these five orthologs from a single species within Spiralia. Each ortholog is likely involved in endoderm specification and midgut development, and several may be essential for establishment of the oral ectoderm, foregut and hindgut, including specification of ectodermal and mesodermal contributions. When the five core genes are compared across the Metazoa, their conserved expression patterns suggest that 'gut gene' networks evolved to specify distinct digestive system subregions, regardless of species-specific differences in gut architecture or germ layer contributions within each subregion.
Collapse
|
20
|
Lauri A, Brunet T, Handberg-Thorsager M, Fischer AHL, Simakov O, Steinmetz PRH, Tomer R, Keller PJ, Arendt D. Development of the annelid axochord: insights into notochord evolution. Science 2014; 345:1365-8. [PMID: 25214631 DOI: 10.1126/science.1253396] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The origin of chordates has been debated for more than a century, with one key issue being the emergence of the notochord. In vertebrates, the notochord develops by convergence and extension of the chordamesoderm, a population of midline cells of unique molecular identity. We identify a population of mesodermal cells in a developing invertebrate, the marine annelid Platynereis dumerilii, that converges and extends toward the midline and expresses a notochord-specific combination of genes. These cells differentiate into a longitudinal muscle, the axochord, that is positioned between central nervous system and axial blood vessel and secretes a strong collagenous extracellular matrix. Ancestral state reconstruction suggests that contractile mesodermal midline cells existed in bilaterian ancestors. We propose that these cells, via vacuolization and stiffening, gave rise to the chordate notochord.
Collapse
Affiliation(s)
- Antonella Lauri
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg
| | - Thibaut Brunet
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg
| | - Mette Handberg-Thorsager
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg. Janelia Farm Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Antje H L Fischer
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg
| | - Oleg Simakov
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg
| | - Patrick R H Steinmetz
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg
| | - Raju Tomer
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg. Janelia Farm Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Philipp J Keller
- Janelia Farm Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Detlev Arendt
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg. Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany.
| |
Collapse
|
21
|
Fischer AHL, Mozzherin D, Eren AM, Lans KD, Wilson N, Cosentino C, Smith J. SeaBase: a multispecies transcriptomic resource and platform for gene network inference. Integr Comp Biol 2014; 54:250-63. [PMID: 24907201 DOI: 10.1093/icb/icu065] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Marine and aquatic animals are extraordinarily useful as models for identifying mechanisms of development and evolution, regeneration, resistance to cancer, longevity and symbiosis, among many other areas of research. This is due to the great diversity of these organisms and their wide-ranging capabilities. Genomics tools are essential for taking advantage of these "free lessons" of nature. However, genomics and transcriptomics are challenging in emerging model systems. Here, we present SeaBase, a tool for helping to meet these needs. Specifically, SeaBase provides a platform for sharing and searching transcriptome data. More importantly, SeaBase will support a growing number of tools for inferring gene network mechanisms. The first dataset available on SeaBase is a developmental transcriptomic profile of the sea anemone Nematostella vectensis (Anthozoa, Cnidaria). Additional datasets are currently being prepared and we are aiming to expand SeaBase to include user-supplied data for any number of marine and aquatic organisms, thereby supporting many potentially new models for gene network studies. SeaBase can be accessed online at: http://seabase.core.cli.mbl.edu.
Collapse
Affiliation(s)
- Antje H L Fischer
- *Marine Biological Laboratory, Woods Hole, MA 02543, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Systems & Control Engineering, University of Magna Graecia, 88100 Catanzaro, Italy*Marine Biological Laboratory, Woods Hole, MA 02543, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Systems & Control Engineering, University of Magna Graecia, 88100 Catanzaro, Italy
| | - Dmitry Mozzherin
- *Marine Biological Laboratory, Woods Hole, MA 02543, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Systems & Control Engineering, University of Magna Graecia, 88100 Catanzaro, Italy
| | - A Murat Eren
- *Marine Biological Laboratory, Woods Hole, MA 02543, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Systems & Control Engineering, University of Magna Graecia, 88100 Catanzaro, Italy
| | - Kristen D Lans
- *Marine Biological Laboratory, Woods Hole, MA 02543, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Systems & Control Engineering, University of Magna Graecia, 88100 Catanzaro, Italy
| | - Nathan Wilson
- *Marine Biological Laboratory, Woods Hole, MA 02543, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Systems & Control Engineering, University of Magna Graecia, 88100 Catanzaro, Italy
| | - Carlo Cosentino
- *Marine Biological Laboratory, Woods Hole, MA 02543, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Systems & Control Engineering, University of Magna Graecia, 88100 Catanzaro, Italy
| | - Joel Smith
- *Marine Biological Laboratory, Woods Hole, MA 02543, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Systems & Control Engineering, University of Magna Graecia, 88100 Catanzaro, Italy
| |
Collapse
|
22
|
Pfeifer K, Schaub C, Wolfstetter G, Dorresteijn A. Identification and characterization of a twist ortholog in the polychaete annelid Platynereis dumerilii reveals mesodermal expression of Pdu-twist. Dev Genes Evol 2013; 223:319-28. [PMID: 23817621 DOI: 10.1007/s00427-013-0448-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 06/11/2013] [Indexed: 01/26/2023]
Abstract
The basic helix-loop-helix transcription factor twist plays a key role during mesoderm development in Bilateria. In this study, we identified a twist ortholog in the polychaete annelid Platynereis dumerilii and analyze its expression during larval development, postlarval growth up to the adult stage, and caudal regeneration after amputation of posterior segments. At late larval stages, Pdu-twist is expressed in the mesodermal anlagen and in developing muscles. During adulthood and caudal regeneration, Pdu-twist is expressed in the posterior growth zone, in mesodermal cells within the newly forming segments and budding parapodia. Our results indicate that Pdu-twist is involved in mesoderm formation during larval development, posterior growth, and caudal regeneration.
Collapse
Affiliation(s)
- Kathrin Pfeifer
- Institut für Allgemeine und Spezielle Zoologie, Allgemeine Zoologie und Entwicklungsbiologie, Justus-Liebig-Universität Giessen, Germany
| | | | | | | |
Collapse
|
23
|
Farooq M, Choi J, Seoane AI, Lleras RA, Tran HV, Mandal SA, Nelson CL, Soto JG. Identification of 3'UTR sequence elements and a teloplasm localization motif sufficient for the localization of Hro-twist mRNA to the zygotic animal and vegetal poles. Dev Growth Differ 2012; 54:519-34. [PMID: 22587329 DOI: 10.1111/j.1440-169x.2012.01352.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The early localization of mRNA transcripts is critical in sorting cell fate determinants in the developing embryo. In the glossiphoniid leech, Helobdella robusta, maternal mRNAs, such as Hro-twist, localize to the zygotic teloplasm. Ten seven nucleotide repeat elements (AAUAAUA) called ARE2 and a predicted secondary structural motif, called teloplasm localization motif (TLM), are present in the 3'UTR of Hro-twist mRNA. We used site-directed mutagenesis, deletions, and microinjection of labeled, exogenous transcripts to determine if ARE2 elements, and the TLM, play a role in Hro-twist mRNA localization. Deleting the poly-A tail and the cytoplasmic polyadenylation element (CPE) had no effect on Hro-twist mRNA localization. Site-directed mutagenesis of nucleotides that altered ARE2 element sequences or the TLM suggest that the ARE2 elements and the TLM are important for Hro-twist mRNA localization to the teloplasm of pre-cleavage zygotes. Hro-Twist protein expression data suggest that the localization of Hro-twist transcripts in zygotes and stage two embryos is not involved in ensuring mesoderm specification, as Hro-Twist protein is expressed uniformly in most cells before gastrulation. Our data may support a shared molecular mechanism for leech transcripts that localize to the teloplasm.
Collapse
Affiliation(s)
- Mehrin Farooq
- Biological Sciences Department, San Jose State University, San Jose, CA 95192-0100, USA
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Abstract
Annelids (the segmented worms) have a long history in studies of animal developmental biology, particularly with regards to their cleavage patterns during early development and their neurobiology. With the relatively recent reorganisation of the phylogeny of the animal kingdom, and the distinction of the super-phyla Ecdysozoa and Lophotrochozoa, an extra stimulus for studying this phylum has arisen. As one of the major phyla within Lophotrochozoa, Annelida are playing an important role in deducing the developmental biology of the last common ancestor of the protostomes and deuterostomes, an animal from which >98% of all described animal species evolved.
Collapse
Affiliation(s)
- David E. K. Ferrier
- The Scottish Oceans Institute, the Gatty Marine Laboratory, University of St Andrews, East Sands, St Andrews, Fife, KY16 8LB, UK
| |
Collapse
|
25
|
Fischer AHL, Henrich T, Arendt D. The normal development of Platynereis dumerilii (Nereididae, Annelida). Front Zool 2010; 7:31. [PMID: 21192805 PMCID: PMC3027123 DOI: 10.1186/1742-9994-7-31] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Accepted: 12/30/2010] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The polychaete annelid Platynereis dumerilii is an emerging model organism for the study of molecular developmental processes, evolution, neurobiology and marine biology. Annelids belong to the Lophotrochozoa, the so far understudied third major branch of bilaterian animals besides deuterostomes and ecdysozoans. P. dumerilii has proven highly relevant to explore ancient bilaterian conditions via comparison to the deuterostomes, because it has accumulated less evolutionary change than conventional ecdysozoan models. Previous staging was mainly referring to hours post fertilization but did not allow matching stages between studies performed at (even slightly) different temperatures. To overcome this, and to provide a first comprehensive description of P. dumerilii normal development, a temperature-independent staging system is needed. RESULTS Platynereis dumerilii normal development is subdivided into 16 stages, starting with the zygote and ending with the death of the mature worms after delivering their gametes. The stages described can be easily identified by conventional light microscopy or even by dissecting scope. Developmental landmarks such as the beginning of phototaxis, the visibility of the stomodeal opening and of the chaetae, the first occurrence of the ciliary bands, the formation of the parapodia, the extension of antennae and cirri, the onset of feeding and other characteristics are used to define different developmental stages. The morphology of all larval stages as well as of juveniles and adults is documented by light microscopy. We also provide an overview of important steps in the development of the nervous system and of the musculature, using fluorescent labeling techniques and confocal laser-scanning microscopy. Timing of each developmental stage refers to hours post fertilization at 18 ± 0.1°C. For comparison, we determined the pace of development of larvae raised at 14°C, 16°C, 20°C, 25°C, 28°C and 30°C. A staging ontology representing the comprehensive list of developmental stages of P. dumerilii is available online. CONCLUSIONS Our atlas of Platynereis dumerilii normal development represents an important resource for the growing Platynereis community and can also be applied to other nereidid annelids.
Collapse
Affiliation(s)
- Antje HL Fischer
- Developmental Biology Unit, European Molecular Biology Laboratory, D-69117 Heidelberg, Germany
| | - Thorsten Henrich
- Developmental Biology Unit, European Molecular Biology Laboratory, D-69117 Heidelberg, Germany
- International College, Osaka University, A217 School of Science Main Building 1-1, Machikaneyama-machi, Toyonaka, Osaka, 560-0043, Japan
| | - Detlev Arendt
- Developmental Biology Unit, European Molecular Biology Laboratory, D-69117 Heidelberg, Germany
| |
Collapse
|
26
|
Layden MJ, Meyer NP, Pang K, Seaver EC, Martindale MQ. Expression and phylogenetic analysis of the zic gene family in the evolution and development of metazoans. EvoDevo 2010; 1:12. [PMID: 21054859 PMCID: PMC2988786 DOI: 10.1186/2041-9139-1-12] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 11/05/2010] [Indexed: 11/25/2022] Open
Abstract
Background zic genes are members of the gli/glis/nkl/zic super-family of C2H2 zinc finger (ZF) transcription factors. Homologs of the zic family have been implicated in patterning neural and mesodermal tissues in bilaterians. Prior to this study, the origin of the metazoan zic gene family was unknown and expression of zic gene homologs during the development of early branching metazoans had not been investigated. Results Phylogenetic analyses of novel zic candidate genes identified a definitive zic homolog in the placozoan Trichoplax adhaerens, two gli/glis/nkl-like genes in the ctenophore Mnemiopsis leidyi, confirmed the presence of three gli/glis/nkl-like genes in Porifera, and confirmed the five previously identified zic genes in the cnidarian Nematostella vectensis. In the cnidarian N. vectensis, zic homologs are expressed in ectoderm and the gastrodermis (a bifunctional endomesoderm), in presumptive and developing tentacles, and in oral and sensory apical tuft ectoderm. The Capitella teleta zic homolog (Ct-zic) is detectable in a subset of the developing nervous system, the foregut, and the mesoderm associated with the segmentally repeated chaetae. Lastly, expression of gli and glis homologs in Mnemiopsis. leidyi is detected exclusively in neural cells in floor of the apical organ. Conclusions Based on our analyses, we propose that the zic gene family arose in the common ancestor of the Placozoa, Cnidaria and Bilateria from a gli/glis/nkl-like gene and that both ZOC and ZF-NC domains evolved prior to cnidarian-bilaterian divergence. We also conclude that zic expression in neural ectoderm and developing neurons is pervasive throughout the Metazoa and likely evolved from neural expression of an ancestral gli/glis/nkl/zic gene. zic expression in bilaterian mesoderm may be related to the expression in the gastrodermis of a cnidarian-bilaterian common ancestor.
Collapse
Affiliation(s)
- Michael J Layden
- Pacific Biosciences Research Center, Kewalo Marine Laboratory, University of Hawaii, Manoa, 41 Ahui St Honolulu, HI 96813, USA.
| | | | | | | | | |
Collapse
|
27
|
Abstract
At least five animal phyla exhibit spiralian development, which is characterized by striking similarities in the geometry of the early cleavage pattern and the fate map of the blastula, along with similarities in larval morphology. Recent advances in reconstructing the phylogeny of spiralians and their relatives suggest that the common ancestor of a large clade of protostome phyla known as the Lophotrochozoa had spiralian development. In this minireview, I describe characteristics of spiralian development and some recent insights into its mechanisms and evolution.
Collapse
Affiliation(s)
- J David Lambert
- Department of Biology, University of Rochester, Rochester, NY 14607, USA.
| |
Collapse
|
28
|
Martín-Durán JM, Amaya E, Romero R. Germ layer specification and axial patterning in the embryonic development of the freshwater planarian Schmidtea polychroa. Dev Biol 2010; 340:145-58. [PMID: 20100474 DOI: 10.1016/j.ydbio.2010.01.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2009] [Revised: 01/15/2010] [Accepted: 01/15/2010] [Indexed: 10/19/2022]
Abstract
Although patterning during regeneration in adult planarians has been studied extensively, very little is known about how the initial planarian body plan arises during embryogenesis. Herein, we analyze the process of embryo patterning in the species Schmidtea polychroa by comparing the expression of genes involved in the establishment of the metazoan body plan. Planarians present a derived ectolecithic spiralian development characterized by dispersed cleavage within a yolk syncytium and an early transient embryo capable of feeding on the maternally supplied yolk cells. During this stage of development, we only found evidence of canonical Wnt pathway, mostly associated with the development of its transient pharynx. At these stages, genes involved in gastrulation (snail) and germ layer determination (foxA and twist) are specifically expressed in migrating blastomeres and those giving rise to the temporary gut and pharyngeal muscle. After yolk ingestion, the embryo expresses core components of the canonical Wnt pathway and the BMP pathway, suggesting that the definitive axial identities are established late. These data support the division of planarian development into two separate morphogenetic stages: a highly divergent gastrulation stage, which segregates the three germ layers and establishes the primary organization of the feeding embryo; and subsequent metamorphosis, based on totipotent blastomeres, which establishes the definitive adult body plan using mechanisms that are similar to those used during regeneration and homeostasis in the adult.
Collapse
|
29
|
Shimeld SM, Boyle MJ, Brunet T, Luke GN, Seaver EC. Clustered Fox genes in lophotrochozoans and the evolution of the bilaterian Fox gene cluster. Dev Biol 2010; 340:234-48. [PMID: 20096280 DOI: 10.1016/j.ydbio.2010.01.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 01/04/2010] [Accepted: 01/12/2010] [Indexed: 11/29/2022]
Abstract
FoxC, FoxF, FoxL1 and FoxQ1 genes have been shown to be clustered in some animal genomes, with mesendodermal expression hypothesised as a selective force maintaining cluster integrity. Hypotheses are, however, constrained by a lack of data from the Lophotrochozoa. Here we characterise members of the FoxC, FoxF, FoxL1 and FoxQ1 families from the annelid Capitella teleta and the molluscs Lottia gigantea and Patella vulgata. We cloned FoxC, FoxF, FoxL1 and FoxQ1 genes from C. teleta, and FoxC, FoxF and FoxL1 genes from P. vulgata, and established their expression during development. We also examined their genomic organisation in C. teleta and L. gigantea, and investigated local syntenic relationships. Our results show mesodermal and anterior gut expression is a common feature of these genes in lophotrochozoans. In L. gigantea FoxC, FoxF and FoxL1 are closely linked, while in C. teleta Ct-foxC and Ct-foxL1 are closely linked, with Ct-foxF and Ct-foxQ1 on different scaffolds. Adjacent to these genes there is limited evidence of local synteny. This demonstrates conservation of genomic organisation and expression of these genes can be traced in all three bilaterian Superphyla. These data are evaluated against competing theories for the long-term maintenance of gene clusters.
Collapse
Affiliation(s)
- Sebastian M Shimeld
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
| | | | | | | | | |
Collapse
|
30
|
Kerner P, Hung J, Béhague J, Le Gouar M, Balavoine G, Vervoort M. Insights into the evolution of the snail superfamily from metazoan wide molecular phylogenies and expression data in annelids. BMC Evol Biol 2009; 9:94. [PMID: 19426549 PMCID: PMC2688512 DOI: 10.1186/1471-2148-9-94] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Accepted: 05/09/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND An important issue concerning the evolution of duplicated genes is to understand why paralogous genes are retained in a genome even though the most likely fate for a redundant duplicated gene is nonfunctionalization and thereby its elimination. Here we study a complex superfamily generated by gene duplications, the snail related genes that play key roles during animal development. We investigate the evolutionary history of these genes by genomic, phylogenetic, and expression data studies. RESULTS We systematically retrieved the full complement of snail related genes in several sequenced genomes. Through phylogenetic analysis, we found that the snail superfamily is composed of three ancestral families, snail, scratchA and scratchB. Analyses of the organization of the encoded proteins point out specific molecular signatures, indicative of functional specificities for Snail, ScratchA and ScratchB proteins. We also report the presence of two snail genes in the annelid Platynereis dumerilii, which have distinct expression patterns in the developing mesoderm, nervous system, and foregut. The combined expression of these two genes is identical to that of two independently duplicated snail genes in another annelid, Capitella spI, but different aspects of the expression patterns are differentially shared among paralogs of Platynereis and Capitella. CONCLUSION Our study indicates that the snail and scratchB families have expanded through multiple independent gene duplications in the different bilaterian lineages, and highlights potential functional diversifications of Snail and ScratchB proteins following duplications, as, in several instances, paralogous proteins in a given species show different domain organizations. Comparisons of the expression pattern domains of the two Platynereis and Capitella snail paralogs provide evidence for independent subfunctionalization events which have occurred in these two species. We propose that the snail related genes may be especially prone to subfunctionalization, and this would explain why the snail superfamily underwent so many independent duplications leading to maintenance of functional paralogs.
Collapse
Affiliation(s)
- Pierre Kerner
- Programme Development and Neurobiology, Institut Jacques Monod, UMR 7592 CNRS/Université Paris Diderot – Paris 7, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
- Evolution et Développement des Métazoaires, Centre de Génétique Moléculaire- FRE 3144 CNRS, 1, av. de la terrasse, 91198 Gif-sur-Yvette, France
- UFR des Sciences du Vivant, Université Paris Diderot – Paris 7, 5, rue Marie-Andrée Lagroua Weill-Hallé, 75205 Paris Cedex 13, France
| | - Johanne Hung
- Evolution et Développement des Métazoaires, Centre de Génétique Moléculaire- FRE 3144 CNRS, 1, av. de la terrasse, 91198 Gif-sur-Yvette, France
| | - Julien Béhague
- Programme Development and Neurobiology, Institut Jacques Monod, UMR 7592 CNRS/Université Paris Diderot – Paris 7, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
- Evolution et Développement des Métazoaires, Centre de Génétique Moléculaire- FRE 3144 CNRS, 1, av. de la terrasse, 91198 Gif-sur-Yvette, France
| | - Martine Le Gouar
- Evolution et Développement des Métazoaires, Centre de Génétique Moléculaire- FRE 3144 CNRS, 1, av. de la terrasse, 91198 Gif-sur-Yvette, France
| | - Guillaume Balavoine
- Programme Development and Neurobiology, Institut Jacques Monod, UMR 7592 CNRS/Université Paris Diderot – Paris 7, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
- Evolution et Développement des Métazoaires, Centre de Génétique Moléculaire- FRE 3144 CNRS, 1, av. de la terrasse, 91198 Gif-sur-Yvette, France
| | - Michel Vervoort
- Programme Development and Neurobiology, Institut Jacques Monod, UMR 7592 CNRS/Université Paris Diderot – Paris 7, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
- Evolution et Développement des Métazoaires, Centre de Génétique Moléculaire- FRE 3144 CNRS, 1, av. de la terrasse, 91198 Gif-sur-Yvette, France
- UFR des Sciences du Vivant, Université Paris Diderot – Paris 7, 5, rue Marie-Andrée Lagroua Weill-Hallé, 75205 Paris Cedex 13, France
| |
Collapse
|
31
|
Thamm K, Seaver EC. Notch signaling during larval and juvenile development in the polychaete annelid Capitella sp. I. Dev Biol 2008; 320:304-18. [PMID: 18511030 DOI: 10.1016/j.ydbio.2008.04.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Revised: 02/25/2008] [Accepted: 04/06/2008] [Indexed: 02/02/2023]
Abstract
Notch signaling is involved in a large range of developmental processes, and has been functionally implicated in body plan segmentation in two of the three diverse segmented taxa, the vertebrates and arthropods. Here we investigate expression of Notch, Delta, and hes gene homologues during larval and juvenile development in the polychaete annelid Capitella sp. I., a member of the third group of segmented animals. During larval stages, CapI-Notch, CapI-Delta, CapI-hes2, and CapI-hes3 transcripts are initially detected in broad ectodermal domains in future segments as well as in the brain and foregut; later, CapI-Notch, CapI-Delta, and CapI-hes2 transcripts are detected in the presumptive chaetal sacs. In contrast, CapI-hes1 has a segmentally reiterated pattern in a restricted region of the mesoderm in each presumptive segment. CapI-Notch, CapI-Delta, CapI-hes2, and CapI-hes3 and CapI-hes1 are all expressed in the terminal growth zone that generates post-metamorphic segments, however, CapI-hes1 has a non-overlapping complementary expression pattern to that of CapI-Notch and CapI-Delta. CapI-Delta and CapI-Notch transcripts are localized to already formed segments, with posterior boundaries that correlate with the posterior boundary of the nascent segment, while CapI-hes1 lies posterior to CapI-Notch and CapI-Delta. The localization of CapI-Notch, CapI-Delta, and CapI-hes transcripts correlate with areas of rapid cell proliferation in Capitella, which include the brain, foregut, and terminal growth zone.
Collapse
Affiliation(s)
- Katrin Thamm
- Kewalo Marine Lab, PBRC/University of Hawaii, 41 Ahui Street, Honolulu, HI 96813, USA.
| | | |
Collapse
|
32
|
Boyle MJ, Seaver EC. Developmental expression of foxA and gata genes during gut formation in the polychaete annelid, Capitella sp. I. Evol Dev 2008; 10:89-105. [PMID: 18184360 DOI: 10.1111/j.1525-142x.2007.00216.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Most bilaterian animals have evolved a through gut that is regionally specialized along the anterior-posterior axis. In the polychaete annelid, Capitella sp. I, the alimentary canal is subdivided into a buccal cavity, pharynx, esophagus, midgut, and hindgut. Members of the Fox and GATA families of transcription factors have conserved functions in patterning ectodermal and endodermal gut components. We have isolated and characterized expression of one FoxA gene (CapI-foxA) and four GATA genes (CapI-gataB1, CapI-gataB2, CapI-gataB3, and CapI-gataA1) from Capitella sp. I. Both gene families are expressed in the developing gut of this polychaete. CapI-foxA, an ortholog of the FoxA subgroup, is expressed in vegetal hemisphere micromeres of cleavage-stage embryos, in multiple blastomeres within and surrounding the blastopore during gastrulation, and throughout morphogenesis of the pharynx, esophagus, and hindgut. The CapI-gataB genes group within the vertebrate GATA4/5/6 subfamily, appear to be products of lineage-specific gene duplication, and are expressed in specific domains of endomesoderm. CapI-gataB1 is expressed in endoderm precursors and throughout developing midgut endoderm, and is particularly prominent at anterior and posterior midgut boundaries. CapI-gataB2 is co-expressed with CapI-gataB1 in midgut endoderm, and is also expressed in visceral mesoderm. CapI-gataB3 is limited to and coexpressed with CapI-gataB2 in visceral mesoderm. CapI-gataA1 groups within the vertebrate GATA1/2/3 subfamily and is expressed primarily in ectodermal tissues of the brain, ventral nerve cord, lateral trunk, and both pharyngeal and esophageal regions of the foregut. Collectively, the CapI-foxA and CapI-gata genes show patterns of expression that span almost the entire length of the developing alimentary canal, consistent with a role in gut development.
Collapse
Affiliation(s)
- Michael J Boyle
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawaii, 41 Ahui Street, Honolulu, HI 96813, USA
| | | |
Collapse
|
33
|
Bergter A, Brubacher JL, Paululat A. Muscle formation during embryogenesis of the polychaete Ophryotrocha diadema (Dorvilleidae) - new insights into annelid muscle patterns. Front Zool 2008; 5:1. [PMID: 18171469 PMCID: PMC2254616 DOI: 10.1186/1742-9994-5-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2007] [Accepted: 01/02/2008] [Indexed: 11/10/2022] Open
Abstract
Background The standard textbook information that annelid musculature consists of oligochaete-like outer circular and inner longitudinal muscle-layers has recently been called into question by observations of a variety of complex muscle systems in numerous polychaete taxa. To clarify the ancestral muscle arrangement in this taxon, we compared myogenetic patterns during embryogenesis of Ophryotrocha diadema with available data on oligochaete and polychaete myogenesis. This work addresses the conflicting views on the ground pattern of annelids, and adds to our knowledge of the evolution of lophotrochozoan taxa. Results Somatic musculature in Ophryotrocha diadema can be classified into the trunk, prostomial/peristomial, and parapodial muscle complexes. The trunk muscles comprise strong bilateral pairs of distinct dorsal and ventral longitudinal strands. The latter are the first to differentiate during myogenesis. They originate within the peristomium and grow posteriorly through the continuous addition of myocytes. Later, the longitudinal muscles also expand anteriorly and form a complex arrangement of prostomial muscles. Four embryonic parapodia differentiate in an anterior-to-posterior progression, significantly contributing to the somatic musculature. Several diagonal and transverse muscles are present dorsally. Some of the latter are situated external to the longitudinal muscles, which implies they are homologous to the circular muscles of oligochaetes. These circular fibers are only weakly developed, and do not appear to form complete muscle circles. Conclusion Comparison of embryonic muscle patterns showed distinct similarities between myogenetic processes in Ophryotrocha diadema and those of oligochaete species, which allows us to relate the diverse adult muscle arrangements of these annelid taxa to each other. These findings provide significant clues for the interpretation of evolutionary changes in annelid musculature.
Collapse
Affiliation(s)
- Annette Bergter
- Department of Zoology, University of Osnabrueck, Barbarastr, 11, D-49069 Osnabrueck, Germany.
| | | | | |
Collapse
|