1
|
Green SA, Norris RP, Terasaki M, Lowe CJ. FGF signaling induces mesoderm in the hemichordate Saccoglossus kowalevskii. Development 2013; 140:1024-33. [PMID: 23344709 DOI: 10.1242/dev.083790] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
FGFs act in vertebrate mesoderm induction and also play key roles in early mesoderm formation in ascidians and amphioxus. However, in sea urchins initial characterizations of FGF function do not support a role in early mesoderm induction, making the ancestral roles of FGF signaling and mechanisms of mesoderm specification in deuterostomes unclear. In order to better characterize the evolution of mesoderm formation, we have examined the role of FGF signaling during mesoderm development in Saccoglossus kowalevskii, an experimentally tractable representative of hemichordates. We report the expression of an FGF ligand, fgf8/17/18, in ectoderm overlying sites of mesoderm specification within the archenteron endomesoderm. Embryological experiments demonstrate that mesoderm induction in the archenteron requires contact with ectoderm, and loss-of-function experiments indicate that both FGF ligand and receptor are necessary for mesoderm specification. fgf8/17/18 gain-of-function experiments establish that FGF8/17/18 is sufficient to induce mesoderm in adjacent endomesoderm. These experiments suggest that FGF signaling is necessary from the earliest stages of mesoderm specification and is required for all mesoderm development. Furthermore, they suggest that the archenteron is competent to form mesoderm or endoderm, and that FGF signaling from the ectoderm defines the location and amount of mesoderm. When considered in a comparative context, these data support a phylogenetically broad requirement for FGF8/17/18 signaling in mesoderm specification and suggest that FGF signaling played an ancestral role in deuterostome mesoderm formation.
Collapse
Affiliation(s)
- Stephen A Green
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA.
| | | | | | | |
Collapse
|
2
|
Love NR, Chen Y, Bonev B, Gilchrist MJ, Fairclough L, Lea R, Mohun TJ, Paredes R, Zeef LAH, Amaya E. Genome-wide analysis of gene expression during Xenopus tropicalis tadpole tail regeneration. BMC DEVELOPMENTAL BIOLOGY 2011; 11:70. [PMID: 22085734 PMCID: PMC3247858 DOI: 10.1186/1471-213x-11-70] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Accepted: 11/15/2011] [Indexed: 01/08/2023]
Abstract
Background The molecular mechanisms governing vertebrate appendage regeneration remain poorly understood. Uncovering these mechanisms may lead to novel therapies aimed at alleviating human disfigurement and visible loss of function following injury. Here, we explore tadpole tail regeneration in Xenopus tropicalis, a diploid frog with a sequenced genome. Results We found that, like the traditionally used Xenopus laevis, the Xenopus tropicalis tadpole has the capacity to regenerate its tail following amputation, including its spinal cord, muscle, and major blood vessels. We examined gene expression using the Xenopus tropicalis Affymetrix genome array during three phases of regeneration, uncovering more than 1,000 genes that are significantly modulated during tail regeneration. Target validation, using RT-qPCR followed by gene ontology (GO) analysis, revealed a dynamic regulation of genes involved in the inflammatory response, intracellular metabolism, and energy regulation. Meta-analyses of the array data and validation by RT-qPCR and in situ hybridization uncovered a subset of genes upregulated during the early and intermediate phases of regeneration that are involved in the generation of NADP/H, suggesting that these pathways may be important for proper tail regeneration. Conclusions The Xenopus tropicalis tadpole is a powerful model to elucidate the genetic mechanisms of vertebrate appendage regeneration. We have produced a novel and substantial microarray data set examining gene expression during vertebrate appendage regeneration.
Collapse
Affiliation(s)
- Nick R Love
- Faculty of Life Sciences, University of Manchester, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Abstract
Fibroblast growth factor (FGF) signalling has been implicated during several phases of early embryogenesis, including the patterning of the embryonic axes, the induction and/or maintenance of several cell lineages and the coordination of morphogenetic movements. Here, we summarise our current understanding of the regulation and roles of FGF signalling during early vertebrate development.
Collapse
Affiliation(s)
- Karel Dorey
- The Healing Foundation Centre, Michael Smith Building, Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Enrique Amaya
- The Healing Foundation Centre, Michael Smith Building, Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| |
Collapse
|
4
|
Concha ML, Signore IA, Colombo A. Mechanisms of directional asymmetry in the zebrafish epithalamus. Semin Cell Dev Biol 2009; 20:498-509. [DOI: 10.1016/j.semcdb.2008.11.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Accepted: 11/04/2008] [Indexed: 10/20/2022]
|
5
|
Fletcher RB, Harland RM. The role of FGF signaling in the establishment and maintenance of mesodermal gene expression in Xenopus. Dev Dyn 2008; 237:1243-54. [PMID: 18386826 DOI: 10.1002/dvdy.21517] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
FGF signaling is important for the formation of mesoderm in vertebrates, and when it is perturbed in Xenopus, most trunk and tail mesoderm fails to form. Here we have further dissected the activities of FGF in patterning the embryo by addressing its inductive and maintenance roles. We show that FGF signaling is necessary for the establishment of xbra expression in addition to its well-characterized role in maintaining xbra expression. The role of FGF signaling in organizer formation is not clear in Xenopus. We find that FGF signaling is essential for the initial specification of paraxial mesoderm but not for activation of several pan-mesodermal and most organizer genes; however, early FGF signaling is necessary for the maintenance of organizer gene expression into the neurula stage. Inhibition of FGF signaling prevents VegT activation of specific mesodermal transcripts. These findings illuminate how FGF signaling contributes to the establishment of distinct types of mesoderm.
Collapse
Affiliation(s)
- Russell B Fletcher
- Department of Molecular and Cell Biology, Center for Integrative Genomics, University of California, Berkeley, California 94720-3200, USA
| | | |
Collapse
|
6
|
Abstract
Asymmetries in the egg, established during oogenesis, set the stage for a cascade of intercellular signaling events leading to differential gene expression and subsequent tissue and organ formation. Maternally supplied Sox-type transcription factors have recently emerged as key components in the patterning of the early embryo and the regulation of embryonic stem cell differentiation. In deuterostomes, B1-type Soxs are asymmetrically localized to the future animal/ectodermal region where they act to suppress mesendodermal, and favor neuroectodermal differentiation, while vegetally localized F-type Soxs are involved in mesendodermal differentiation. Here, we review past observations and present new data from studies on the clawed frog Xenopus laevis. Animally localized Sox3 acts to inhibit Nodal (Xnr5 and Xnr6) expression, and induces the expression of genes (Ectodermin, Xema, and Coco) whose products repress Nodal signaling. Vegetally localized Sox7 positively regulates Nodal (Xnr4, Xnr5, and Xnr6) expression, as well as the expression of genes involved in mesodermal (Xmenf, Slug, and Snail) and endodermal (Endodermin and Sox17beta) differentiation. Given the evolutionary strategy of using common regulatory networks, it seems likely that a homologous Sox-Axis is active during embryonic development in many metazoans.
Collapse
Affiliation(s)
- Chi Zhang
- Department of Molecular, Cellular and Developmental Biology University of Colorado at Boulder Boulder, CO 80309-0347, USA
| | | |
Collapse
|
7
|
Zhang C, Carl TF, Trudeau ED, Simmet T, Klymkowsky MW. An NF-kappaB and slug regulatory loop active in early vertebrate mesoderm. PLoS One 2006; 1:e106. [PMID: 17205110 PMCID: PMC1762408 DOI: 10.1371/journal.pone.0000106] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Accepted: 11/23/2006] [Indexed: 01/11/2023] Open
Abstract
Background In both Drosophila and the mouse, the zinc finger transcription factor Snail is required for mesoderm formation; its vertebrate paralog Slug (Snai2) appears to be required for neural crest formation in the chick and the clawed frog Xenopus laevis. Both Slug and Snail act to induce epithelial to mesenchymal transition (EMT) and to suppress apoptosis. Methodology & Principle Findings Morpholino-based loss of function studies indicate that Slug is required for the normal expression of both mesodermal and neural crest markers in X. laevis. Both phenotypes are rescued by injection of RNA encoding the anti-apoptotic protein Bcl-xL; Bcl-xL's effects are dependent upon IκB kinase-mediated activation of the bipartite transcription factor NF-κB. NF-κB, in turn, directly up-regulates levels of Slug and Snail RNAs. Slug indirectly up-regulates levels of RNAs encoding the NF-κB subunit proteins RelA, Rel2, and Rel3, and directly down-regulates levels of the pro-apopotic Caspase-9 RNA. Conclusions/Significance These studies reveal a Slug/Snail–NF-κB regulatory circuit, analogous to that present in the early Drosophila embryo, active during mesodermal formation in Xenopus. This is a regulatory interaction of significance both in development and in the course of inflammatory and metastatic disease.
Collapse
Affiliation(s)
- Chi Zhang
- Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, United States of America
| | - Timothy F. Carl
- Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, United States of America
| | - Evan D. Trudeau
- Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, United States of America
| | - Thomas Simmet
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, University of Ulm, Ulm, Germany
| | - Michael W. Klymkowsky
- Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, United States of America
- * To whom correspondence should be addressed. E-mail:
| |
Collapse
|
8
|
Kumano G, Ezal C, Smith WC. ADMP2 is essential for primitive blood and heart development in Xenopus. Dev Biol 2006; 299:411-23. [PMID: 16959239 DOI: 10.1016/j.ydbio.2006.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 06/29/2006] [Accepted: 08/02/2006] [Indexed: 10/24/2022]
Abstract
We describe here the cloning of a new member of the TGF-beta family with similarity to the anti-dorsalizing morphogenetic proteins (ADMPs). This new gene, ADMP2, is expressed in a broad band of mesendoderm cells that appear to include the progenitors of the endoderm and the ventral mesoderm. Antisense morpholino oligonucleotide knockdown of ADMP2 results in near-complete disruption of primitive blood and heart development, while the development of other mesoderm derivatives, including pronephros, muscle and lateral plate is not disrupted. Moreover, the development of the primitive blood in ADMP2 knockdown embryos cannot be rescued by BMP. These results suggests that ADMP2 plays an early role in specifying presumptive ventral mesoderm in the leading edge mesoderm, and that ADMP2 activity may be necessary to respond to BMP signaling in the context of ventral mesoderm induction.
Collapse
Affiliation(s)
- Gaku Kumano
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | | | | |
Collapse
|
9
|
Lane MC, Sheets MD. Heading in a new direction: implications of the revised fate map for understanding Xenopus laevis development. Dev Biol 2006; 296:12-28. [PMID: 16750823 DOI: 10.1016/j.ydbio.2006.04.447] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Revised: 03/09/2006] [Accepted: 04/09/2006] [Indexed: 11/21/2022]
Abstract
Amphibian embryos have served as a model system for vertebrate axial patterning for more than a century. Recent changes to the Xenopus laevis fate map revised the assignment of the embryonic dorsal/ventral (back-to-belly) axis in pre-gastrula embryos and allowed the assignment of the rostral/caudal (head-to-tail) axis for the first time. Revising the embryonic axes after many years of experimentation changes our view of axial patterning in amphibians. In this review, we discuss the revised maps and axes, and show by example how the new map alters the interpretation of three experiments that form the foundations of amphibian embryology. We compare the revised amphibian fate map to the general maps of the protochordates, and discuss which features of the maps and early development are shared by chordates and which distinguish vertebrates. Finally, we offer an explanation for the formation of both complete and incomplete axes in the rescue assays routinely used to study axial patterning in Xenopus, and a model of amphibian axial patterning.
Collapse
Affiliation(s)
- Mary Constance Lane
- Department of Biomolecular Chemistry, School of Medicine, University of Wisconsin, Madison, WI 53706, USA.
| | | |
Collapse
|
10
|
Torres CBB, Goes VS, Goes AM, Pacífico LGG, Silva GAB, Junior NL, Alves JB. Fibroblast growth factor 9: Cloning and immunolocalisation during tooth development in Didelphis albiventris. Arch Oral Biol 2006; 51:263-72. [PMID: 16188224 DOI: 10.1016/j.archoralbio.2005.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2005] [Revised: 08/16/2005] [Accepted: 08/17/2005] [Indexed: 11/19/2022]
Abstract
There are no reports in literature about functional roles of fibroblast growth factor 9 (FGF-9) in tooth development in animals with complete tooth pattern. The classical model for studying tooth development is the mouse, which has small number of teeth and distinctive incisor and molar patterns. The opossum Didelphis albiventris with five upper and four lower incisors, one canine, three premolars, and four molars, on each side of the jaw, seems to be a convenient model to test results obtained in the mouse. Molecular expression studies indicate that FGF-9 participates in murine tooth initiation and regulation of morphogenesis. Searching for similarities and differences in FGF-9 expression between the opossum and the mouse, amino acid sequence and expression pattern of FGF-9 in the developing first molars of D. albiventris were characterised. FGF-9 cDNA sequence was obtained using RT-PCR and expressed in bacterial system for recombinant protein production and analysis of immunoreactivity. FGF-9 expression during tooth development was investigated by immunoperoxidase method. FGF-9 protein consists in a 209-residue polypeptide with a predicted molecular mass of 23.5 kDa. FGF-9 amino acid sequence has 98% of sequence identity to human and 97% to rodents. During tooth development, epithelial FGF-9 expression was seen at the dental lamina stage. Mesenchymal expression was seen at the bud stage and at the cap stage. No significant expression was found in the enamel knot. While in rodents FGF-9 is involved in initiation and regulation of tooth shape, it is suggested that it is only involved in tooth initiation in D. albiventris.
Collapse
Affiliation(s)
- Cristiane B B Torres
- Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, UFMG, Presidente Antônio Carlos Avenue 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil.
| | | | | | | | | | | | | |
Collapse
|
11
|
Constance Lane M, Davidson L, Sheets MD. BMP antagonism by Spemann's organizer regulates rostral–caudal fate of mesoderm. Dev Biol 2004; 275:356-74. [PMID: 15501224 DOI: 10.1016/j.ydbio.2004.08.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2004] [Revised: 08/03/2004] [Accepted: 08/10/2004] [Indexed: 11/16/2022]
Abstract
Recent revisions to the Xenopus fate map challenge the interpretation of previous maps and current models of amphibian axial patterning (Lane, M.C., Smith, W.C., 1999. The origins of primitive blood in Xenopus: implications for axial patterning. Development 126 (3), 423-434.; Lane, M.C., Sheets, M.D., 2000. Designation of the anterior/posterior axis in pregastrula Xenopus laevis. Dev. Biol. 225, 37-58). We determined the rostralmost contributions to both dorsal and ventral mesoderm concomitantly from marginal zone progenitors in stage 6 embryos. Data reveal an unequivocal rostral-to-caudal progression of both dorsal and ventral mesoderm across the pre-gastrula axis historically called the dorsal-ventral axis, and a dorsal-to-ventral progression from animal-to-vegetal in the marginal zone. These findings support the proposed revisions to the fate and axis orientation maps. Most importantly, these results raise questions about the role of the organizer grafts and organizer-derived BMP antagonists in the "induction" of secondary axes. We re-examine both phenomena, and find that organizer grafts and BMP antagonists evoke caudal-to-rostral mesodermal fate transformations, and not ventral-to-dorsal transformations as currently believed. We demonstrate that BMP antagonism evokes a second axis because it stimulates precocious mediolateral intercalation of caudal, dorsal mesoderm. The implications of these findings for models of organizer function in vertebrate axial patterning are discussed.
Collapse
Affiliation(s)
- Mary Constance Lane
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine, Madison, WI 53706, USA.
| | | | | |
Collapse
|
12
|
Collavin L, Kirschner MW. The secreted Frizzled-related protein Sizzled functions as a negative feedback regulator of extreme ventral mesoderm. Development 2003; 130:805-16. [PMID: 12506010 DOI: 10.1242/dev.00306] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The prevailing model of dorsal ventral patterning of the amphibian embryo predicts that the prospective mesoderm is regionalized at gastrulation in response to a gradient of signals. This gradient is established by diffusible BMP and Wnt inhibitors secreted dorsally in the Spemann organizer. An interesting question is whether ventrolateral tissue passively reads graded levels of ventralizing signals, or whether local self-organizing regulatory circuits may exist on the ventral side to control cell behavior and differentiation at a distance from the Organizer. We provide evidence that sizzled, a secreted Frizzled-related protein expressed ventrally during and after gastrulation, functions in a negative feedback loop that limits allocation of mesodermal cells to the extreme ventral fate, with direct consequences for morphogenesis and formation of the blood islands. Morpholino-mediated knockdown of Sizzled protein results in expansion of ventral posterior mesoderm and the ventral blood islands, indicating that this negative regulation is required for proper patterning of the ventral mesoderm. The biochemical activity of sizzled is apparently very different from that of other secreted Frizzled-related proteins, and does not involve inhibition of Wnt8. Our data are consistent with the existence of some limited self-organizing properties of the extreme ventral mesoderm.
Collapse
Affiliation(s)
- Licio Collavin
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | | |
Collapse
|
13
|
Kumano G, Smith WC. Revisions to the Xenopus gastrula fate map: implications for mesoderm induction and patterning. Dev Dyn 2002; 225:409-21. [PMID: 12454919 DOI: 10.1002/dvdy.10177] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
A revised fate map of the gastrula Xenopus embryo predicts the existence of patterning mechanisms that operate within the animal/vegetal axis of the mesoderm-forming marginal zone. We review here molecular and embryologic data that demonstrate that such mechanisms are present and that they operate independently of the Spemann organizer. Evidence suggests that polarized fibroblast growth factor activity in the animal/vegetal axis patterns this axis. We present a model of mesoderm induction and patterning that integrates the new data on Spemann organizer-independent animal/vegetal patterning with data on other inductive pathways known to act on the gastrula marginal zone.
Collapse
Affiliation(s)
- Gaku Kumano
- Neuroscience Research Institute, and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, USA
| | | |
Collapse
|