1
|
Ectopic expression of Cripto-1 in transgenic mouse embryos causes hemorrhages, fatal cardiac defects and embryonic lethality. Sci Rep 2016; 6:34501. [PMID: 27687577 PMCID: PMC5043281 DOI: 10.1038/srep34501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 09/15/2016] [Indexed: 12/23/2022] Open
Abstract
Targeted disruption of Cripto-1 in mice caused embryonic lethality at E7.5, whereas we unexpectedly found that ectopic Cripto-1 expression in mouse embryos also led to embryonic lethality, which prompted us to characterize the causes and mechanisms underlying embryonic death due to ectopic Cripto-1 expression. RCLG/EIIa-Cre embryos displayed complex phenotypes between embryonic day 14.5 (E14.5) and E17.5, including fatal hemorrhages (E14.5-E15.5), embryo resorption (E14.5-E17.5), pale body surface (E14.5-E16.5) and no abnormal appearance (E14.5-E16.5). Macroscopic and histological examination revealed that ectopic expression of Cripto-1 transgene in RCLG/EIIa-Cre embryos resulted in lethal cardiac defects, as evidenced by cardiac malformations, myocardial thinning, failed assembly of striated myofibrils and lack of heartbeat. In addition, Cripto-1 transgene activation beginning after E8.5 also caused the aforementioned lethal cardiac defects in mouse embryos. Furthermore, ectopic Cripto-1 expression in embryonic hearts reduced the expression of cardiac transcription factors, which is at least partially responsible for the aforementioned lethal cardiac defects. Our results suggest that hemorrhages and cardiac abnormalities are two important lethal factors in Cripto-1 transgenic mice. Taken together, these findings are the first to demonstrate that sustained Cripto-1 transgene expression after E11.5 causes fatal hemorrhages and lethal cardiac defects, leading to embryonic death at E14.5-17.5.
Collapse
|
2
|
|
3
|
Katsu K, Tatsumi N, Niki D, Yamamura KI, Yokouchi Y. Multi-modal effects of BMP signaling on Nodal expression in the lateral plate mesoderm during left-right axis formation in the chick embryo. Dev Biol 2012. [PMID: 23206893 DOI: 10.1016/j.ydbio.2012.11.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
During development of left-right asymmetry in the vertebrate embryo, Nodal plays a central role for determination of left-handedness. Bone morphogenetic protein (BMP) signaling has an important role for regulation of Nodal expression, although there is controversy over whether BMP signaling has a positive or negative effect on Nodal expression in the chick embryo. As BMP is a morphogen, we speculated that different concentrations might induce different responses in the cells of the lateral plate mesoderm (LPM). To test this hypothesis, we analyzed the effects of various concentrations of BMP4 and NOGGIN on Nodal expression in the LPM. We found that the effect on Nodal expression varied in a complex fashion with the concentration of BMP. In agreement with previous reports, we found that a high level of BMP signaling induced Nodal expression in the LPM, whereas a low level inhibited expression. However, a high intermediate level of BMP signaling was found to suppress Nodal expression in the left LPM, whereas a low intermediate level induced Nodal expression in the right LPM. Thus, the high and the low intermediate levels of BMP signaling up-regulated Nodal expression, but the high intermediate and low levels of BMP signaling down-regulated Nodal expression. Next, we sought to identify the mechanisms of this complex regulation of Nodal expression by BMP signaling. At the low intermediate level of BMP signaling, regulation depended on a NODAL positive-feedback loop suggesting the possibility of crosstalk between BMP and NODAL signaling. Overexpression of a constitutively active BMP receptor, a constitutively active ACTIVIN/NODAL receptor and SMAD4 indicated that SMAD1 and SMAD2 competed for binding to SMAD4 in the cells of the LPM. Nodal regulation by the high and low levels of BMP signaling was dependent on Cfc up-regulation or down-regulation, respectively. We propose a model for the variable effects of BMP signaling on Nodal expression in which different levels of BMP signaling regulate Nodal expression by a balance between BMP-pSMAD1/4 signaling and NODAL-pSMAD2/4 signaling.
Collapse
Affiliation(s)
- Kenjiro Katsu
- Division of Pattern Formation, Department of Organogenesis, Institute of Molecular Embryology and Genetics, 2-2-1 Honjo, Kumamoto 860-0811, Japan
| | | | | | | | | |
Collapse
|
4
|
Abstract
Abstract
The embryonic heart initially consists of only two cell layers, the endocardium and the myocardium. The epicardium, which forms an epithelial layer on the surface of the heart, is derived from a cluster of mesothelial cells developing at the base of the venous inflow tract of the early embryonic heart. This cell cluster is termed the proepicardium and gives rise not only to the epicardium but also to epicardium-derived cells. These cells populate the myocardial wall and differentiate into smooth muscle cells and fibroblasts, while the contribution to the vascular endothelial lineage is uncertain. In this review we will discuss the signaling molecules involved in recruiting mesodermal cells to undergo proepicardium formation and guide these cells to the myocardial surface. Marker genes which are suitable to follow these cells during proepicardium formation and cell migration will be introduced. We will address whether the proepicardium consists of a homogenous cell population or whether different cell lineages are present. Finally the role of the epicardium as a source for cardiac stem cells and its importance in cardiac regeneration, in particular in the zebrafish and mouse model systems is discussed.
Collapse
Affiliation(s)
- Jan Schlueter
- 1Harefield Heart Science Centre, National Heart
and Lung Institute, Imperial College London, Hill End Road, Harefield,
Middlesex, UB9 6JH, United Kingdom
| | - Thomas Brand
- 1Harefield Heart Science Centre, National Heart
and Lung Institute, Imperial College London, Hill End Road, Harefield,
Middlesex, UB9 6JH, United Kingdom
| |
Collapse
|
5
|
Huang S, Ma J, Liu X, Zhang Y, Luo L. Geminin is required for left-right patterning through regulating Kupffer's vesicle formation and ciliogenesis in zebrafish. Biochem Biophys Res Commun 2011; 410:164-9. [PMID: 21539812 DOI: 10.1016/j.bbrc.2011.04.085] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 04/19/2011] [Indexed: 10/18/2022]
Abstract
Geminin plays an important role in coordinating the cell cycle with anterior-posterior patterning during embryonic development. However, whether it is involved in the regulation of left-right (LR) patterning remains unknown. Here, we reported that geminin is required for setting up heart and visceral laterality during zebrafish development. Defective heart and visceral laterality was observed in geminin morphants. Further study demonstrated that the left-sided nodal/spaw in the lateral plate mesoderm (LPM) as well as the sideness of its downstream targets lefty2 and lefty1 was perturbed in geminin morphants. Upstream of the left-sided Nodal signal along the regulatory cascade of LR asymmetry, knock down of geminin resulted in defective Kupffer's vesicle (KV) formation and ciliogenesis rather than middle line defects. Predominant distribution of an antisense morpholino against geminin in dorsal forerunner cells (DFCs) led to defective KV morphogenesis and perturbed LR asymmetry, similar to those of geminin morphants, indicating a cell-autonomous role of geminin in regulating KV formation and ciliogenesis. Our results demonstrate that geminin is required for proper KV formation and ciliogenesis, thus playing an important part in setting up LR asymmetry.
Collapse
Affiliation(s)
- Sizhou Huang
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Chongqing 400715, China
| | | | | | | | | |
Collapse
|
6
|
Gerhart J, Pfautz J, Neely C, Elder J, DuPrey K, Menko AS, Knudsen K, George-Weinstein M. Noggin producing, MyoD-positive cells are crucial for eye development. Dev Biol 2009; 336:30-41. [PMID: 19778533 DOI: 10.1016/j.ydbio.2009.09.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 09/15/2009] [Accepted: 09/15/2009] [Indexed: 11/15/2022]
Abstract
A subpopulation of cells expresses MyoD mRNA and the cell surface G8 antigen in the epiblast prior to the onset of gastrulation. When an antibody to the G8 antigen was applied to the epiblast, labeled cells were later found in the ocular primordia and muscle and non-muscle forming tissues of the eyes. In the lens, retina and periocular mesenchyme, G8-positive cells synthesized MyoD mRNA and the bone morphogenetic protein inhibitor Noggin. MyoD expressing cells were ablated in the epiblast by labeling them with the G8 MAb and lysing them with complement. Their ablation in the epiblast resulted in eye defects, including anopthalmia, micropthalmia, altered pigmentation and malformations of the lens and/or retina. The right eye was more severely affected than the left eye. The asymmetry of the eye defects in ablated embryos correlated with differences in the number of residual Noggin producing, MyoD-positive cells in ocular tissues. Exogenously supplied Noggin compensated for the ablated epiblast cells. This study demonstrates that MyoD expressing cells serve as a Noggin delivery system to regulate the morphogenesis of the lens and optic cup.
Collapse
Affiliation(s)
- Jacquelyn Gerhart
- Lankenau Institute for Medical Research, 100 Lancaster Avenue, Wynnewood, PA 19096, USA
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Schlueter J, Brand T. A right-sided pathway involving FGF8/Snai1 controls asymmetric development of the proepicardium in the chick embryo. Proc Natl Acad Sci U S A 2009; 106:7485-90. [PMID: 19365073 PMCID: PMC2678653 DOI: 10.1073/pnas.0811944106] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Indexed: 01/30/2023] Open
Abstract
The proepicardium (PE) is a transient structure that forms at the venous pole of the embryonic vertebrate heart. This cardiac progenitor cell population gives rise to the epicardium, coronary vasculature, and fibroblasts. In the chicken embryo, the PE displays left-right (L-R) asymmetry and develops only on the right side, while on the left only a vestigial PE is formed, which subsequently gets lost by apoptosis. In this study, we analyzed how the L-R asymmetry pathway affects PE formation. Experimental manipulation of left-side determinants such as Shh, Nodal, and Cfc as well as forced expression of Pitx2 had no effect on the sidedness of PE development. In contrast, inhibition of early-acting regulators of L-R axis formation such as H(+)/K(+)-ATPase or primitive streak apoptosis affected the sidedness of PE development. Experimental interference with the right-side determinants Fgf8 or Snai1 prevented PE formation, whereas ectopic left-sided expression of Fgf8 or Snai1 resulted in bilateral PE development. These data provide novel insight into the molecular control of asymmetric morphogenesis suggesting that also the right side harbors an instructive signaling pathway that is involved in the control of PE development. This pathway might be of general relevance for setting up L-R asymmetries at the venous pole of the heart.
Collapse
Affiliation(s)
- Jan Schlueter
- Cell and Developmental Biology, University of Würzburg, Biocenter, Am Hubland, 97974 Würzburg, Germany
| | - Thomas Brand
- Cell and Developmental Biology, University of Würzburg, Biocenter, Am Hubland, 97974 Würzburg, Germany
| |
Collapse
|
8
|
Raya Á, Izpisúa Belmonte JC. Insights into the establishment of left–right asymmetries in vertebrates. ACTA ACUST UNITED AC 2008; 84:81-94. [DOI: 10.1002/bdrc.20122] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
9
|
Schlueter J, Brand T. Left-right axis development: examples of similar and divergent strategies to generate asymmetric morphogenesis in chick and mouse embryos. Cytogenet Genome Res 2007; 117:256-67. [PMID: 17675867 DOI: 10.1159/000103187] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Accepted: 08/24/2006] [Indexed: 12/18/2022] Open
Abstract
Left-right asymmetry of internal organs is widely distributed in the animal kingdom. The chick and mouse embryos have served as important model organisms to analyze the mechanisms underlying the establishment of the left-right axis. In the chick embryo many genes have been found to be asymmetrically expressed in and around the node, while the same genes in the mouse show symmetric expression patterns. In the mouse there is strong evidence for an establishment of left-right asymmetry through nodal cilia. In contrast, in the chick and in many other organisms left-right asymmetry is probably generated by an early-acting event involving membrane depolarization. In both birds and mammals a conserved Nodal-Lefty-Pitx2 module exists that controls many aspects of asymmetric morphogenesis. This review also gives examples of divergent mechanisms of establishing asymmetric organ formation. Thus there is ample evidence for conserved and non-conserved strategies to generate asymmetry in birds and mammals.
Collapse
Affiliation(s)
- J Schlueter
- Cell and Developmental Biology, University of Würzburg, Würzburg, Germany
| | | |
Collapse
|
10
|
Gerhart J, Elder J, Neely C, Schure J, Kvist T, Knudsen K, George-Weinstein M. MyoD-positive epiblast cells regulate skeletal muscle differentiation in the embryo. J Cell Biol 2006; 175:283-92. [PMID: 17060497 PMCID: PMC2064569 DOI: 10.1083/jcb.200605037] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Accepted: 09/15/2006] [Indexed: 11/22/2022] Open
Abstract
MyoD mRNA is expressed in a subpopulation of cells within the embryonic epiblast. Most of these cells are incorporated into somites and synthesize Noggin. Ablation of MyoD-positive cells in the epiblast subsequently results in the herniation of organs through the ventral body wall, a decrease in the expression of Noggin, MyoD, Myf5, and myosin in the somites and limbs, and an increase in Pax-3-positive myogenic precursors. The addition of Noggin lateral to the somites compensates for the loss of MyoD-positive epiblast cells. Skeletal muscle stem cells that arise in the epiblast are utilized in the somites to promote muscle differentiation by serving as a source of Noggin.
Collapse
Affiliation(s)
- Jacquelyn Gerhart
- Center for Chronic Disorders of Aging, Philadelphia College of Osteopathic Medicine, Philadelphia, PA 19131, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
Schlueter J, Männer J, Brand T. BMP is an important regulator of proepicardial identity in the chick embryo. Dev Biol 2006; 295:546-58. [PMID: 16677627 DOI: 10.1016/j.ydbio.2006.03.036] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Revised: 03/16/2006] [Accepted: 03/28/2006] [Indexed: 10/24/2022]
Abstract
The proepicardium (PE) is a transient structure formed by pericardial coelomic mesothelium at the venous pole of the embryonic heart and gives rise to several cell types of the mature heart. In order to study PE development in chick embryos, we have analyzed the expression pattern of the marker genes Tbx18, Wt1, and Cfc. During PE induction, the three marker genes displayed a left-right asymmetric expression pattern. In each case, expression on the right side was stronger than on the left side. The left-right asymmetric gene expression observed here is in accord with the asymmetric formation of the proepicardium in the chick embryo. While initially the marker genes were expressed in the primitive sinus horn, subsequently, expression became confined to the PE mesothelium. In order to search for signaling factors involved in PE development, we studied Bmp2 and Bmp4 expression. Bmp2 was bilaterally expressed in the sinus venosus. In contrast, Bmp4 expression was initially expressed unilaterally in the right sinus horn and subsequently in the PE. In order to assess its functional role, BMP signaling was experimentally modulated by supplying exogenous BMP2 and by inhibiting endogenous BMP signaling through the addition of Noggin. Both supplying BMP and blocking BMP signaling resulted in a loss of PE marker gene expression. Surprisingly, both experimental situations lead to cardiac myocyte formation in the PE cultures. Careful titration experiments with exogenously added BMP2 or Noggin revealed that PE-specific marker gene expression depends on a low level of BMP signaling. Implantation of BMP2-secreting cells or beads filled with Noggin protein into the right sinus horn of HH stage 11 embryos resulted in downregulation of Tbx18 expression, corresponding to the results of the explant assay. Thus, a distinct level of BMP signaling is required for PE formation in the chick embryo.
Collapse
Affiliation(s)
- Jan Schlueter
- Cell and Developmental Biology, Theodor-Boveri-Institute, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | | | | |
Collapse
|
12
|
Simard A, Di Pietro E, Young CR, Plaza S, Ryan AK. Alterations in heart looping induced by overexpression of the tight junction protein Claudin-1 are dependent on its C-terminal cytoplasmic tail. Mech Dev 2006; 123:210-27. [PMID: 16500087 DOI: 10.1016/j.mod.2005.12.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Revised: 12/21/2005] [Accepted: 12/21/2005] [Indexed: 10/25/2022]
Abstract
In vertebrates, the positioning of the internal organs relative to the midline is asymmetric and evolutionarily conserved. A number of molecules have been shown to play critical roles in left-right patterning. Using representational difference analysis to identify genes that are differentially expressed on the left and right sides of the chick embryo, we cloned chick Claudin-1, an integral component of epithelial tight junctions. Here, we demonstrate that retroviral overexpression of Claudin-1, but not Claudin-3, on the right side of the chick embryo between HH stages 4 and 7 randomizes the direction of heart looping. This effect was not observed when Claudin-1 was overexpressed on the left side of the embryo. A small, but reproducible, induction of Nodal expression in the perinodal region on the right side of the embryo was noted in embryos that were injected with Claudin-1 retroviral particles on their right sides. However, no changes in Lefty,Pitx2 or cSnR expression were observed. In addition, Flectin expression remained higher in the left dorsal mesocardial folds of embryos with leftwardly looped hearts resulting from Claudin-1 overexpression on the right side of the embryo. We demonstrated that Claudin-1's C-terminal cytoplasmic tail is essential for this effect: mutation of a PKC phosphorylation site in the Claudin-1 C-terminal cytoplasmic domain at threonine-206 eliminates Claudin-1's ability to randomize the direction of heart looping. Taken together, our data provide evidence that appropriate expression of the tight junction protein Claudin-1 is required for normal heart looping and suggest that phosphorylation of its cytoplasmic tail is responsible for mediating this function.
Collapse
Affiliation(s)
- Annie Simard
- Departments of Pediatrics and Human Genetics, McGill University, Montréal, Que., Canada
| | | | | | | | | |
Collapse
|
13
|
Onuma Y, Yeo CY, Whitman M. XCR2, one of three Xenopus EGF-CFC genes, has a distinct role in the regulation of left-right patterning. Development 2005; 133:237-50. [PMID: 16339189 DOI: 10.1242/dev.02188] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Members of the EGF-CFC family facilitate signaling by a subset of TGFbeta superfamily ligands that includes the nodal-related factors and GDF1/VG1. Studies in mouse, zebrafish, and chick point to an essential role for EGF-CFC proteins in the action of nodal/GDF1 signals in the early establishment of the mesendoderm and later visceral left-right patterning. Antisense knockdown of the only known frog EGF-CFC factor (FRL1), however, has argued against an essential role for this factor in nodal/GDF1 signaling. To address this apparent paradox, we have identified two additional Xenopus EGF-CFC family members. The three Xenopus EGF-CFC factors show distinct patterns of expression. We have examined the role of XCR2, the only Xenopus EGF-CFC factor expressed in post-gastrula embryos, in embryogenesis. Antisense morpholino oligonucleotide-mediated depletion of XCR2 disrupts left-right asymmetry of the heart and gut. Although XCR2 is expressed bilaterally at neurula stage, XCR2 is required on the left side, but not the right side, for normal left-right patterning. Left-side expression of XNR1 in the lateral plate mesoderm depends on XCR2, whereas posterior bilateral expression of XNR1 does not, suggesting that distinct mechanisms maintain XNR1 expression in different regions of neurula-tailbud embryos. Ectopic XCR2 on the right side initiates premature right-side expression of XNR1 and XATV, and can reverse visceral patterning. This activity of XCR2 depends on its co-receptor function. These observations indicate that XCR2 has a crucial limiting role in maintaining a bistable asymmetry in nodal family signaling across the left-right axis.
Collapse
Affiliation(s)
- Yasuko Onuma
- Department of Developmental Biology, Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA 02115, USA
| | | | | |
Collapse
|
14
|
Ramsdell AF. Left–right asymmetry and congenital cardiac defects: Getting to the heart of the matter in vertebrate left–right axis determination. Dev Biol 2005; 288:1-20. [PMID: 16289136 DOI: 10.1016/j.ydbio.2005.07.038] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Revised: 07/21/2005] [Accepted: 07/26/2005] [Indexed: 01/20/2023]
Abstract
Cellular and molecular left-right differences that are present in the mesodermal heart fields suggest that the heart is lateralized from its inception. Left-right asymmetry persists as the heart fields coalesce to form the primary heart tube, and overt, morphological asymmetry first becomes evident when the heart tube undergoes looping morphogenesis. Thereafter, chamber formation, differentiation of the inflow and outflow tracts, and position of the heart relative to the midline are additional features of heart development that exhibit left-right differences. Observations made in human clinical studies and in animal models of laterality disease suggest that all of these features of cardiac development are influenced by the embryonic left-right body axis. When errors in left-right axis determination happen, they almost always are associated with complex congenital heart malformations. The purpose of this review is to highlight what is presently known about cardiac development and upstream processes of left-right axis determination, and to consider how perturbation of the left-right body plan might ultimately result in particular types of congenital heart defects.
Collapse
Affiliation(s)
- Ann F Ramsdell
- Department of Cell and Developmental Biology and Anatomy, School of Medicine and Program in Women's Studies, College of Arts and Sciences, University of South Carolina, Columbia, SC 29208, USA.
| |
Collapse
|
15
|
Chu J, Ding J, Jeays-Ward K, Price SM, Placzek M, Shen MM. Non-cell-autonomous role for Cripto in axial midline formation during vertebrate embryogenesis. Development 2005; 132:5539-51. [PMID: 16291788 DOI: 10.1242/dev.02157] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Several membrane-associated proteins are known to modulate the activity and range of potent morphogenetic signals during development. In particular, members of the EGF-CFC family encode glycosyl-phosphatidylinositol (GPI)-linked proteins that are essential for activity of the transforming growth factor beta (TGFbeta) ligand Nodal, a factor that plays a central role in establishing the vertebrate body plan. Genetic and biochemical studies have indicated that EGF-CFC proteins function as cell-autonomous co-receptors for Nodal; by contrast, cell culture data have suggested that the mammalian EGF-CFC protein Cripto can act as a secreted signaling factor. Here we show that Cripto acts non-cell-autonomously during axial mesendoderm formation in the mouse embryo and may possess intercellular signaling activity in vivo. Phenotypic analysis of hypomorphic mutants demonstrates that Cripto is essential for formation of the notochordal plate, prechordal mesoderm and foregut endoderm during gastrulation. Remarkably, Cripto null mutant cells readily contribute to these tissues in chimeras, indicating non-cell-autonomy. Consistent with these loss-of-function analyses, gain-of-function experiments in chick embryos show that exposure of node/head process mesoderm to soluble Cripto protein results in alterations in cell fates toward anterior mesendoderm, in a manner that is dependent on Nodal signaling. Taken together, our findings support a model in which Cripto can function in trans as an intercellular mediator of Nodal signaling activity.
Collapse
Affiliation(s)
- Jianhua Chu
- Center for Advanced Biotechnology and Medicine and Departments of Pediatrics, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | | | | | | | | | | |
Collapse
|
16
|
Matsui H, Ikeda K, Nakatani K, Sakabe M, Yamagishi T, Nakanishi T, Nakajima Y. Induction of initial cardiomyocyte α-actin—smooth muscle α-actin—in cultured avian pregastrula epiblast: A role for nodal and BMP antagonist. Dev Dyn 2005; 233:1419-29. [PMID: 15977172 DOI: 10.1002/dvdy.20477] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
During early cardiogenesis, endoderm-derived bone morphogenetic protein (BMP) induces the expression of both heart-specific transcription factors and sarcomeric proteins. However, BMP antagonists do not inhibit the expression of the "initial heart alpha-actin"--smooth muscle alpha-actin (SMA)--which is first expressed in the anterior lateral mesoderm and then recruited into the initial myofibrils (Nakajima et al. [2002] Dev. Biol. 245:291-303). Therefore, mechanisms that regulate the expression of SMA in the heart-forming mesoderm are not well-understood. Regional explantation experiments using chick blastoderm showed that the posterolateral region of the epiblast differentiated into cardiomyocytes. Posterior epiblast cultured with or without the associated hypoblast showed that interaction between the tissues of these two germ layers at the early pregastrula stage (stages X-XI) was a prerequisite for the expression of SMA. Posterior epiblast that is cultured without hypoblast could also be induced to express SMA if TGF-beta or activin was added to the culture medium. However, neither neutralizing antibodies against TGF-betas nor follistatin perturbed the expression of SMA in cultured blastoderm. Adding BMP to the cultured blastoderm inhibited the expression of SMA, whereas BMP antagonists, such as chordin, were able to induce the expression of SMA in cultured posterior epiblast. Furthermore, adding lefty-1, a nodal antagonist, to the blastoderm inhibited the expression of SMA, and nodal plus BMP antagonist up-regulated the expression of SMA in cultured posterior epiblast. Results indicate that the interaction between the tissues of the posterior epiblast and hypoblast is necessary to initiate the expression of SMA during early cardiogenesis and that nodal and BMP antagonist may play an important role in the regulation of SMA expression.
Collapse
Affiliation(s)
- Hiroko Matsui
- Department of Anatomy, Graduate School of Medicine, Osaka City University, Abenoku, Osaka, Japan
| | | | | | | | | | | | | |
Collapse
|
17
|
Bianco C, Strizzi L, Normanno N, Khan N, Salomon DS. Cripto-1: an oncofetal gene with many faces. Curr Top Dev Biol 2005; 67:85-133. [PMID: 15949532 DOI: 10.1016/s0070-2153(05)67003-2] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Human Cripto-1 (CR-1), a member of the epidermal growth factor (EGF)-CFC family, has been implicated in embryogenesis and in carcinogenesis. During early vertebrate development, CR-1 functions as a co-receptor for Nodal, a transforming growth factor beta (TGFbeta) family member and is essential for mesoderm and endoderm formation and anterior-posterior and left-right axis establishment. In adult tissues, CR-1 is expressed at a low level in all stages of mammary gland development and expression increases during pregnancy and lactation. Overexpression of CR-1 in mouse mammary epithelial cells leads to their transformation in vitro and, when injected into mammary glands, produces ductal hyperplasias. CR-1 can also enhance migration, invasion, branching morphogenesis and epithelial to mesenchymal transition (EMT) of several mouse mammary epithelial cell lines. Furthermore, transgenic mouse studies have shown that overexpression of a human CR-1 transgene in the mammary gland under the transcriptional control of the mouse mammary tumor virus (MMTV) promoter results in mammary hyperplasias and papillary adenocarcinomas. Finally, CR-1 is expressed at high levels in approximately 50 to 80% of different types of human carcinomas, including breast, cervix, colon, stomach, pancreas, lung, ovary, and testis. In conclusion, EGF-CFC proteins play dual roles as embryonic pattern formation genes and as oncogenes. While during embryogenesis EGF-CFC proteins perform specific and regulatory functions related to cell and tissue patterning, inappropriate expression of these molecules in adult tissues can lead to cellular proliferation and transformation and therefore may be important in the etiology and/or progression of cancer.
Collapse
Affiliation(s)
- Caterina Bianco
- Tumor Growth Factor Section, Mammary Biology & Tumorigenesis Laboratory Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | | | | | | |
Collapse
|
18
|
Wang S, Yu X, Zhang T, Zhang X, Zhang Z, Chen Y. Chick Pcl2 regulates the left-right asymmetry by repressing Shh expression in Hensen's node. Development 2004; 131:4381-91. [PMID: 15294861 DOI: 10.1242/dev.01269] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Asymmetric expression of sonic hedgehog (Shh) in the left side of Hensen's node, a crucial step for specifying the left-right (LR) axis in the chick embryo, is established by the repression of Shhexpression in the right side of the node. The transcriptional regulator that mediates this repression has not been identified. We report the isolation and characterization of a novel chick Polycomblike 2 gene, chick Pcl2, which encodes a transcription repressor and displays an asymmetric expression, downstream from Activin-βB and Bmp4, in the right side of Hensen's node in the developing embryo. In vitro mapping studies define the transcription repression activity to the PHD finger domain of the chick Pcl2 protein. Repression of chick Pcl2expression in the early embryo results in randomized heart looping direction,which is accompanied by the ectopic expression of Shh in the right side of the node and Shh downstream genes in the right lateral plate mesoderm (LPM), while overexpression of chick Pcl2 represses Shh expression in the node. The repression of Shh by chick Pcl2 was also supported by studies in which chick Pcl2 was overexpressed in the developing chick limb bud and feather bud. Similarly,transgenic overexpression of chick Pcl2 in the developing mouse limb inhibits Shh expression in the ZPA. In vitro pull-down assays demonstrated a direct interaction of the chick Pcl2 PHD finger with EZH2, a component of the ESC/E(Z) repressive complex. Taken together with the fact that chick Pcl2 was found to directly repress Shh promoter activity in vitro, our results demonstrate a crucial role for chick Pcl2 in regulating LR axis patterning in the chick by silencing Shh in the right side of the node.
Collapse
Affiliation(s)
- Shusheng Wang
- Division of Developmental Biology, Department of Cell and Molecular Biology and Center for Bioenvironmental Research, Tulane University, New Orleans, LA 70118, USA
| | | | | | | | | | | |
Collapse
|
19
|
Hashimoto H, Rebagliati M, Ahmad N, Muraoka O, Kurokawa T, Hibi M, Suzuki T. The Cerberus/Dan-family protein Charon is a negative regulator of Nodal signaling during left-right patterning in zebrafish. Development 2004; 131:1741-53. [PMID: 15084459 DOI: 10.1242/dev.01070] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have isolated a novel gene, charon, that encodes a member of the Cerberus/Dan family of secreted factors. In zebrafish, Fugu and flounder, charon is expressed in regions embracing Kupffer's vesicle, which is considered to be the teleost fish equivalent to the region of the mouse definitive node that is required for left-right (L/R) patterning. Misexpression of Charon elicited phenotypes similar to those of mutant embryos defective in Nodal signaling or embryos overexpressing Antivin(Atv)/Lefty1, an inhibitor for Nodal and Activin. Charon also suppressed the dorsalizing activity of all three of the known zebrafish Nodal-related proteins (Cyclops, Squint and Southpaw), indicating that Charon can antagonize Nodal signaling. Because Southpaw functions in the L/R patterning of lateral plate mesoderm and the diencephalon, we asked whether Charon is involved in regulating L/R asymmetry. Inhibition of Charon's function by antisense morpholino oligonucleotides (MOs) led to a loss of L/R polarity, as evidenced by bilateral expression of the left side-specific genes in the lateral plate mesoderm (southpaw, cyclops, atv/lefty1, lefty2 and pitx2) and diencephalon (cyclops, atv/lefty1 and pitx2), and defects in early (heart jogging) and late (heart looping) asymmetric heart development, but did not disturb the notochord development or the atv/lefty1-mediated midline barrier function. MO-mediated inhibition of both Charon and Southpaw led to a reduction in or loss of the expression of the left side-specific genes, suggesting that Southpaw is epistatic to Charon in left-side formation. These data indicate that antagonistic interactions between Charon and Nodal (Southpaw), which take place in regions adjacent to Kupffer's vesicle, play an important role in L/R patterning in zebrafish.
Collapse
Affiliation(s)
- Hisashi Hashimoto
- National Research Institute of Aquaculture, Nansei, Mie 516-0193, Japan
| | | | | | | | | | | | | |
Collapse
|
20
|
Linask KK, Han MD, Linask KL, Schlange T, Brand T. Effects of antisense misexpression of CFC on downstream flectin protein expression during heart looping. Dev Dyn 2004; 228:217-30. [PMID: 14517993 DOI: 10.1002/dvdy.10383] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Dextral looping of the heart is regulated on multiple levels. In humans, mutations of the genes CFC and Pitx2/RIEG result in laterality-associated cardiac anomalies. In animal models, a common read-out after the misexpression of laterality genes is heart looping direction. Missing in these studies is how laterality genes impact on downstream morphogenetic processes to coordinate heart looping. Previously, we showed that Pitx2 indirectly regulates flectin protein by regulating the timing of flectin expression in one heart field versus the other (Linask et al. [2002] Dev. Biol. 246:407-417). To address this question further we used a reported loss-of-function approach to interfere with chick CFC expression (Schlange et al. [2001] Dev. Biol. 234:376-389) and assaying for flectin expression during looping. Antisense CFC treatment results in abnormal heart looping or no looping. Our results show that regardless of the sidedness of downstream Pitx2 expression, it is the sidedness of predominant flectin protein expression in the extracellular matrix of the dorsal mesocardial folds and splanchnic mesoderm apposed to the foregut wall that is associated directly with looping direction. Thus, Pitx2 can be experimentally uncoupled from heart looping. The flectin asymmetry continues to be maintained in the secondary heart field during looping.
Collapse
Affiliation(s)
- Kersti K Linask
- Department of Cell Biology, University of Medicine and Dentistry of New Jersey-SOM, Stratford, New Jersey, USA.
| | | | | | | | | |
Collapse
|
21
|
Abstract
TGFss signals belonging to the Nodal family set up the embryonic axes, induce mesoderm and endoderm, pattern the nervous system, and determine left-right asymmetry in vertebrates. Nodal signaling activates a canonical TGFss pathway involving activin receptors, Smad2 transcription factors, and FoxH1 coactivators. In addition, Nodal signaling is dependent on coreceptors of the EGF-CFC family and antagonized by the Lefty and Cerberus families of secreted factors. Additional modulators of Nodal signaling include convertases that regulate the generation of the mature signal, and factors such as Arkadia and DRAP1 that regulate the cellular responses to the signal. Complex regulatory cascades and autoregulatory loops coordinate Nodal signaling during early development. Nodals have concentration-dependent roles and can act both locally and at a distance. These studies demonstrate that Nodal signaling is modulated at almost every level to precisely orchestrate tissue patterning during vertebrate embryogenesis.
Collapse
Affiliation(s)
- Alexander F Schier
- Developmental Genetics Program, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA.
| |
Collapse
|
22
|
Abstract
The heart develops from two bilateral heart fields that are formed during early gastrulation. In recent years, signaling pathways that specify cardiac mesoderm have been extensively analyzed. In addition, a battery of transcription factors that regulate different aspects of cardiac morphogenesis and cytodifferentiation have been identified and characterized in model organisms. At the anterior pole, a secondary heart field is formed, which in its molecular make-up, appears to be similar to the primary heart field. The cardiac outflow tract and the right ventricle to a large extent are derivatives of this anterior heart field. Cardiac mesoderm receives positional information by which it is patterned along the three body axes. The molecular control of left-right axis development has received particular attention, and the underlying regulatory network begins to emerge. Cardiac chamber development involves the activation of a transcription program that is different from the one present in the primary heart field and regulates cardiac morphogenesis in a region-specific manner. This review also attempts to identify areas in which additional research is needed to fully understand early cardiac development.
Collapse
Affiliation(s)
- Thomas Brand
- Department of Cell and Molecular Biology, Technical University of Braunschweig, 38106 Braunschweig, Germany.
| |
Collapse
|
23
|
Yamamoto M, Mine N, Mochida K, Sakai Y, Saijoh Y, Meno C, Hamada H. Nodal signaling induces the midline barrier by activating Nodal expression in the lateral plate. Development 2003; 130:1795-804. [PMID: 12642485 DOI: 10.1242/dev.00408] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The transcription factor Foxh1 mediates Nodal signaling. The role of Foxh1 in left-right (LR) patterning was examined with mutant mice that lack this protein in lateral plate mesoderm (LPM). The mutant mice failed to express Nodal, Lefty2 and Pitx2 on the left side during embryogenesis and exhibited right isomerism. Ectopic introduction of Nodal into right LPM, by transplantation of left LPM or by electroporation of a Nodal vector, induced Nodal expression in wild-type embryos but not in the mutant. Ectopic Nodal expression in right LPM also induced Lefty1 expression in the floor plate. Nodal signaling thus initiates asymmetric Nodal expression in LPM and induces Lefty1 at the midline. Monitoring of Nodal activity in wild-type and Foxh1 mutant embryos suggested that Nodal activity travels from the node to left LPM, and from left LPM to the midline.
Collapse
Affiliation(s)
- Masamichi Yamamoto
- Developmental Genetics Group, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamada-oka, Suita, Osaka 565-0871, Japan
| | | | | | | | | | | | | |
Collapse
|
24
|
Abstract
Congenital heart defects are common in humans, but the underlying basis for these defects is not well understood. It has been clear that abnormal heart development is at the root of these diseases, but the genes involved have remained elusive until recently. This review focuses on recent advances in our understanding of mammalian heart formation, and how some of these processes, when disrupted, lead to congenital heart defects.
Collapse
Affiliation(s)
- B G Bruneau
- Program in Cardiovascular Research, the Hospital for Sick Children, Department of Molecular and Medical Genetics, University of Toronto, ON, Canada.
| |
Collapse
|
25
|
Linask KK. Regulation of heart morphology: current molecular and cellular perspectives on the coordinated emergence of cardiac form and function. BIRTH DEFECTS RESEARCH. PART C, EMBRYO TODAY : REVIEWS 2003; 69:14-24. [PMID: 12768654 DOI: 10.1002/bdrc.10004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND During early heart development, in addition to cells being induced to differentiate into cardiomyocytes, pathways are activated that lead to cardiac morphogenesis or the development of form. METHODS Orchestration of organogenesis involves the incremental activation of regulatory pathways that lead to pivotal transition points, such as cardiac compartment delineation and looping. Each embryonic stage sets up the correct patterning of morphoregulatory molecules that will regulate the next process, until an organ is formed from the mesoderm layer after gastrulation. The current review provides an understanding of the morphoregulatory, cell adhesion and extracellular matrix-mediated, processes that coordinate development of heart form with that of function. The period reviewed encompasses the formation of a definitive cardiac compartment from the lateral plate mesoderm to the time-point in which the single, beating heart tube loops directionally to the right. Looping results in the correct spatial orientation for subsequent modeling of the four-chambered heart. Even subtle alterations in looping can form the basis upon which malformations of the inlet or the outlet regions of the heart, or both, are superimposed. RESULTS In the future, DNA microarray data sets may allow modeling the specific sequence of gene regulatory dynamics leading to these transition points to discover the regulatory "modes" that the cells adopt during heart organogenesis. The regulatory genes, however, can only specify the proteins that will be present. CONCLUSIONS To fully understand the timing and mechanisms underlying heart development, it is necessary to define the sequential synthesis, patterning, and interaction of the proteins, and of still other receptors, which eventually drive cells to organize into functioning organs.
Collapse
Affiliation(s)
- Kersti K Linask
- Department of Cell Biology, University of Medicine and Dentistry of New Jersey-SOM Stratford, NJ 08084, USA.
| |
Collapse
|
26
|
Brand T, Andrée B, Schlange T. Molecular characterization of early cardiac development. Results Probl Cell Differ 2003; 38:215-38. [PMID: 12132397 DOI: 10.1007/978-3-540-45686-5_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Affiliation(s)
- Thomas Brand
- Institute of Biochemistry and Biotechnology, Department of Cell and Molecular Biology, Technical University of Braunschweig, Spielmannstr. 7, 38106 Braunschweig, Germany
| | | | | |
Collapse
|
27
|
Bertocchini F, Stern CD. The hypoblast of the chick embryo positions the primitive streak by antagonizing nodal signaling. Dev Cell 2002; 3:735-44. [PMID: 12431379 DOI: 10.1016/s1534-5807(02)00318-0] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The hypoblast (equivalent to the mouse anterior visceral endoderm) of the chick embryo plays a role in regulating embryonic polarity. Surprisingly, hypoblast removal causes multiple embryonic axes to form, suggesting that it emits an inhibitor of axis formation. We show that Cerberus (a multifunctional antagonist of Nodal, Wnt, and BMP signaling) is produced by the hypoblast and inhibits primitive streak formation. This activity is mimicked by Cerberus-Short (CerS), which only inhibits Nodal. Nodal misexpression can initiate an ectopic primitive streak, but only when the hypoblast is removed. We propose that, during normal development, the primitive streak forms only when the hypoblast is displaced away from the posterior margin by the endoblast, which lacks Cerberus.
Collapse
Affiliation(s)
- Federica Bertocchini
- Department of Anatomy and Developmental Biology, University College London, Gower Street, WC1E 6BT, London, United Kingdom
| | | |
Collapse
|
28
|
Fischer A, Viebahn C, Blum M. FGF8 acts as a right determinant during establishment of the left-right axis in the rabbit. Curr Biol 2002; 12:1807-16. [PMID: 12419180 DOI: 10.1016/s0960-9822(02)01222-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND FGF8 has been implicated in the transfer of left-right (L-R) asymmetry from the embryonic midline (node) to the lateral plate mesoderm (LPM). Surprisingly, opposite roles have been described in chick and mouse. In mouse, FGF8 is required for the left-asymmetric expression of nodal, lefty2, and Pitx2. In chick, FGF8 represses nodal and Pitx2 on the right side. This discrepancy could reflect evolutionary differences between birds and mammals. Alternatively, the right-asymmetric expression of fgf8, which is not found in mouse, at the chick node may be a prerequisite of right-sided function. Finally, chick (blastodisc) and mouse (egg cylinder) differ with respect to the topology of the early gastrula/neurula embryo. RESULTS The rabbit blastodisc was investigated as an additional mammalian L-R model system. While nodal, lefty, and Pitx2 showed asymmetric expression in the left LPM, fgf8 and all other midline marker genes were symmetrically expressed at the node like in mouse. Left-sided application of FGF8 repressed the endogenous transcription of nodal as well as ectopic expression induced by the parallel administration of BMP4. Right-sided inhibition of FGF8 signaling induced bilateral marker gene expression, demonstrating that, in rabbit, FGF8 acts as a right determinant like in chick. CONCLUSIONS These findings suggest that the anatomy of the early embryo (blastodisc versus egg cylinder) rather than taxonomical differences or asymmetry in expression constitutes an important determinant of FGF8 function in L-R axis formation. The rabbit may provide a useful model for early human embryogenesis, as human embryos develop via a blastodisc as well.
Collapse
Affiliation(s)
- Anja Fischer
- Forschungszentrum Karlsruhe, Institute of Toxicology and Genetics, PO Box 3640, 76021 Karlsruhe, Germany
| | | | | |
Collapse
|
29
|
Piedra ME, Ros MA. BMP signaling positively regulates Nodal expression during left right specification in the chick embryo. Development 2002; 129:3431-40. [PMID: 12091313 DOI: 10.1242/dev.129.14.3431] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Exogenous application of BMP to the lateral plate mesoderm (LPM) of chick embryos at the early somite stage had a positive effect on Nodal expression. BMP applications into the right LPM were followed by a rapid activation of Nodal, while applications into the left LPM resulted in expansion of the normal domain of Nodal expression. Conversely, blocking of BMP signaling by Noggin in the left LPM interfered with the activation of Nodal expression. These results support a positive role for endogenous BMP on Nodal expression in the LPM. We also report that BMP positively regulates the expression of Caronte, Snail and Cfc in both the left and right LPM. BMP-treated embryos had molecular impairment of the midline with downregulation of Lefty1, Brachyury and Shh but we also show that the midline defect was not sufficient to induce ectopic Nodal expression. We discuss our findings in the context of the known molecular control of the specification of left-right asymmetry.
Collapse
Affiliation(s)
- M Elisa Piedra
- Departamento de Anatomía y Biología Celular, Facultad de Medicina, Universidad de Cantabria, 39011 Santander, Spain
| | | |
Collapse
|
30
|
Schlange T, Arnold HH, Brand T. BMP2 is a positive regulator of Nodal signaling during left-right axis formation in the chicken embryo. Development 2002; 129:3421-9. [PMID: 12091312 DOI: 10.1242/dev.129.14.3421] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A model of left-right axis formation in the chick involves inhibition of bone morphogenetic proteins by the antagonist Car as a mechanism of upregulating Nodal in the left lateral plate mesoderm. By contrast, expression of CFC, a competence factor, which is absolutely required for Nodal signaling in the lateral plate mesoderm is dependent on a functional BMP signaling pathway. We have therefore investigated the relationship between BMP and Nodal in further detail. We implanted BMP2 and Noggin-expressing cells into the left lateral plate and paraxial mesoderm and observed a strong upregulation of Nodal and its target genes Pitx2 and Nkx3.2. In addition Cfc, the Nodal type II receptor ActrIIa and Snr were found to depend on BMP signaling for their expression. Comparison of the expression domains of Nodal, Bmp2, Car and Cfc revealed co-expression of Nodal, Cfc and Bmp2, while Car and Nodal only partially overlapped. Ectopic application of BMP2, Nodal, and Car as well as combinations of this signaling molecules to the right lateral plate mesoderm revealed that BMP2 and Car need to synergize in order to specify left identity. We propose a novel model of left-right axis formation, which involves BMP as a positive regulator of Nodal signaling in the chick embryo.
Collapse
Affiliation(s)
- Thomas Schlange
- Cell and Molecular Biology, Technical University Braunschweig, Germany
| | | | | |
Collapse
|
31
|
Hamada H, Meno C, Watanabe D, Saijoh Y. Establishment of vertebrate left-right asymmetry. Nat Rev Genet 2002; 3:103-13. [PMID: 11836504 DOI: 10.1038/nrg732] [Citation(s) in RCA: 388] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The generation of morphological, such as left-right, asymmetry during development is an integral part of the establishment of a body plan. Until recently, the molecular basis of left-right asymmetry was a mystery, but studies indicate that Nodal and the Lefty proteins, transforming growth factor-beta-related molecules, have a central role in generating asymmetric signals. Although the initial mechanism of symmetry breaking remains unknown, developmental biologists are beginning to analyse the pathway that leads to left-right asymmetry establishment and maintenance.
Collapse
Affiliation(s)
- Hiroshi Hamada
- Division of Molecular Biology, Institute for Molecular and Cellular Biology, Osaka University, and CREST, Japan.
| | | | | | | |
Collapse
|
32
|
|
33
|
Long S, Ahmad N, Rebagliati M. Zebrafish hearts and minds: nodal signaling in cardiac and neural left-right asymmetry. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2002; 67:27-36. [PMID: 12858520 DOI: 10.1101/sqb.2002.67.27] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- S Long
- Department of Anatomy and Cell Biology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
| | | | | |
Collapse
|