Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Overlapping functions of Cdx1, Cdx2, and Cdx4 in the development of the amphibian Xenopus tropicalis.

ABSTRACT: Using Xenopus tropicalis, we present the first analysis of the developmental effects that result from knocking down the function of the three Cdx genes present in the typical vertebrate genome. Knockdowns of individual Cdx genes lead to a similar range of posterior defects; compound Cdx knockdowns result in increasingly severe posterior truncations, accompanied by posterior shifts and reduction of 5' Hox gene expression. We provide evidence that Cdx and Wnt3A genes are components of a positive feedback loop operating in the posterior axis. We show that Cdx function is required during later, but not early stages of development, for correct regional specification of the endoderm and morphogenesis of the gut. Our results support the hypothesis that during amphibian development the overall landscape of Cdx activity in the embryo is more important than the specific function of individual Cdx proteins.

SUBMITTER: Faas L

PROVIDER: S-EPMC2701559 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Overlapping functions of Cdx1, Cdx2, and Cdx4 in the development of the amphibian Xenopus tropicalis.

Faas Laura L Isaacs Harry V HV

Developmental dynamics : an official publication of the American Association of Anatomists 20090401 4

Using Xenopus tropicalis, we present the first analysis of the developmental effects that result from knocking down the function of the three Cdx genes present in the typical vertebrate genome. Knockdowns of individual Cdx genes lead to a similar range of posterior defects; compound Cdx knockdowns result in increasingly severe posterior truncations, accompanied by posterior shifts and reduction of 5' Hox gene expression. We provide evidence that Cdx and Wnt3A genes are components of a positive f ...[more]

PMID: 19301404

Similar Datasets

Cdx1 and Cdx2 exhibit transcriptional specificity in the intestine.

Project description:The caudal-related homeodomain transcription factors Cdx1 and Cdx2 are expressed in the developing endoderm with expression persisting into adulthood. Cdx1(-/-) mutants are viable and fertile and display no overt intestinal phenotype. Cdx2 null mutants are peri-implantation lethal; however, conditional mutation approaches have revealed that Cdx2 is required for patterning the intestinal epithelium and specification of the colon. Cdx2 is also necessary for homeostasis of the intestinal tract in the adult, where Cdx1 and Cdx2 appear to functionally overlap in the distal colon, but not during intestinal development. Cdx1 and Cdx2 exhibit complete overlap of expression in the intestine, although they differ in their relative levels, with Cdx1 maximal in the distal colon and Cdx2 peaking in the proximal cecum. Moreover, Cdx1 protein is graded along the crypt-villus axis, being abundant in the crypts and diminishing towards the villi. Cdx2 is expressed uniformly along this axis, but is differentially phosphorylated; the functional relevance of these expression domains and phosphorylation is currently unknown. Cdx1 and Cdx2 have been suggested to exhibit functional specificity in the intestinal tract. In the present study, using cell-based models, we found that relative to Cdx1, Cdx2 was significantly less potent at effecting a transcriptional response from the Cdx1 promoter, a known Cdx target gene. We subsequently assessed this relationship in vivo using a "gene swap" approach and found that Cdx2 cannot substitute for Cdx1 in this autoregulatory loop. This is in marked contrast with the ability of Cdx2 to support Cdx1 expression and function in paraxial mesoderm and vertebral patterning, thus providing novel in vivo evidence of context-dependent transcriptional specificity between these transcription factors.

| S-EPMC3559873 | biostudies-literature

The dynamic TCRδ: TCRδ chains in the amphibian Xenopus tropicalis utilize antibody-like V genes.

Project description:The content and organization of the Xenopus tropicalis TCRα/δ locus was determined. This locus is highly conserved among tetrapods, with the genes encoding the TCRδ chains embedded with those encoding TCRα. However, the frog TCRα/δ is unusual in that it contains V genes that appear indistinguishable from those in the IgH locus (VH). These V genes, termed VHδ, make up 70% of the V genes at the TCRδ locus and are expressed exclusively in TCRδ chains. Finding TCRδ chains that use antibody-like V domains in frogs is similar to the situation in shark TCRδ variants and TCRμ in marsupials. These results suggest that such unconventional TCR may be more widespread across vertebrate lineages than originally thought and raise the possibility of previously unrealized subsets of T cells. We also revealed close linkage of TCRα/δ, IgH, and Igλ in Xenopus which, in combination with linkage analyses in other species, is consistent with the previous models for the emergence of these antigen receptor loci.

| S-EPMC3086071 | biostudies-literature

Genetic screens for mutations affecting development of Xenopus tropicalis.

Project description:We present here the results of forward and reverse genetic screens for chemically-induced mutations in Xenopus tropicalis. In our forward genetic screen, we have uncovered 77 candidate phenotypes in diverse organogenesis and differentiation processes. Using a gynogenetic screen design, which minimizes time and husbandry space expenditures, we find that if a phenotype is detected in the gynogenetic F2 of a given F1 female twice, it is highly likely to be a heritable abnormality (29/29 cases). We have also demonstrated the feasibility of reverse genetic approaches for obtaining carriers of mutations in specific genes, and have directly determined an induced mutation rate by sequencing specific exons from a mutagenized population. The Xenopus system, with its well-understood embryology, fate map, and gain-of-function approaches, can now be coupled with efficient loss-of-function genetic strategies for vertebrate functional genomics and developmental genetics.

| S-EPMC1475704 | biostudies-literature

Unexpected metabolic disorders induced by endocrine disruptors in Xenopus tropicalis provide new lead for understanding amphibian decline.

Project description:Despite numerous studies suggesting that amphibians are highly sensitive to endocrine disruptors (EDs), both their role in the decline of populations and the underlying mechanisms remain unclear. This study showed that frogs exposed throughout their life cycle to ED concentrations low enough to be considered safe for drinking water, developed a prediabetes phenotype and, more commonly, a metabolic syndrome. Female Xenopus tropicalis exposed from tadpole stage to benzo(a)pyrene or triclosan at concentrations of 50 ng?L-1 displayed glucose intolerance syndrome, liver steatosis, liver mitochondrial dysfunction, liver transcriptomic signature, and pancreatic insulin hypersecretion, all typical of a prediabetes state. This metabolic syndrome led to progeny whose metamorphosis was delayed and occurred while the individuals were both smaller and lighter, all factors that have been linked to reduced adult recruitment and likelihood of reproduction. We found that F1 animals did indeed have reduced reproductive success, demonstrating a lower fitness in ED-exposed Xenopus Moreover, after 1 year of depuration, Xenopus that had been exposed to benzo(a)pyrene still displayed hepatic disorders and a marked insulin secretory defect resulting in glucose intolerance. Our results demonstrate that amphibians are highly sensitive to EDs at concentrations well below the thresholds reported to induce stress in other vertebrates. This study introduces EDs as a possible key contributing factor to amphibian population decline through metabolism disruption. Overall, our results show that EDs cause metabolic disorders, which is in agreement with epidemiological studies suggesting that environmental EDs might be one of the principal causes of metabolic disease in humans.

| S-EPMC5948982 | biostudies-literature

Plasticity of lung development in the amphibian, Xenopus laevis.

Project description:Contrary to previous studies, we found that Xenopus laevis tadpoles raised in normoxic water without access to air can routinely complete metamorphosis with lungs that are either severely stunted and uninflated or absent altogether. This is the first demonstration that lung development in a tetrapod can be inhibited by environmental factors and that a tetrapod that relies significantly on lung respiration under unstressed conditions can be raised to forego this function without adverse effects. This study compared lung development in untreated, air-deprived (AD) and air-restored (AR) tadpoles and frogs using whole mounts, histology, BrdU labeling of cell division and antibody staining of smooth muscle actin. We also examined the relationship of swimming and breathing behaviors to lung recovery in AR animals. Inhibition and recovery of lung development occurred at the stage of lung inflation. Lung recovery in AR tadpoles occurred at a predictable and rapid rate and correlated with changes in swimming and breathing behavior. It thus presents a new experimental model for investigating the role of mechanical forces in lung development. Lung recovery in AR frogs was unpredictable and did not correlate with behavioral changes. Its low frequency of occurrence could be attributed to developmental, physical and behavioral changes, the effects of which increase with size and age. Plasticity of lung inflation at tadpole stages and loss of plasticity at postmetamorphic stages offer new insights into the role of developmental plasticity in amphibian lung loss and life history evolution.

| S-EPMC3863417 | biostudies-literature

Expression of odorant receptor family, type 2 OR in the aquatic olfactory cavity of amphibian frog Xenopus tropicalis.

Project description:Recent genome wide in silico analyses discovered a new family (type 2 or family H) of odorant receptors (ORs) in teleost fish and frogs. However, since there is no evidence of the expression of these novel OR genes in olfactory sensory neurons (OSN), it remains unknown if type 2 ORs (OR2) function as odorant receptors. In this study, we examined expression of OR2 genes in the frog Xenopus tropicalis. The overall gene expression pattern is highly complex and differs depending on the gene and developmental stage. RT-PCR analysis in larvae showed that all of the OR2? genes we identified were expressed in the peripheral olfactory system and some were detected in the brain and skin. Whole mount in situ hybridization of the larval olfactory cavity confirmed that at least two OR2? genes so far tested are expressed in the OSN. Because tadpoles are aquatic animals, OR2? genes are probably involved in aquatic olfaction. In adults, OR2? genes are expressed in the nose, brain, and testes to different degrees depending on the genes. OR2? expression in the olfactory system is restricted to the medium cavity, which participates in the detection of water-soluble odorants, suggesting that OR2?s function as receptors for water-soluble odorants. Moreover, the fact that several OR2?s are significantly expressed in non-olfactory organs suggests unknown roles in a range of biological processes other than putative odorant receptor functions.

| S-EPMC3324471 | biostudies-literature

Phylogenetic and developmental study of CD4, CD8 α and β T cell co-receptor homologs in two amphibian species, Xenopus tropicalis and Xenopus laevis.

Project description:CD4 and CD8 co-receptors play critical roles in T cell development and activation by interacting both with T cell receptors and MHC molecules. Although homologs of these genes have been identified in many jawed vertebrates, there are still unresolved gaps concerning their evolution and specialization in MHC interaction and T cell function. Using experimental and computational procedures we identified CD4, CD8α and CD8β gene homologs both in Xenopus tropicalis, whose full genome has been sequenced, and its sister species Xenopus laevis. Multiple alignments of deduced amino acid sequences reveal a poor conservation of the residues involved in binding of CD4 to MHC class II, and CD8α to class I in non-mammalian species, presumably related to the co-evolutionary pressure of MHC I and II genes. Phylogenetic study suggests that Xenopodinae co-receptor genes are more closely related to their homologs in other tetrapods than those of bony fish. Furthermore, the developmental and cell-specific expression patterns of these genes in X. laevis are very similar to that of mammals. X. laevis CD4 is mainly expressed by peripheral non-CD8 T cells and detected in the thymus as early as four days post-fertilization (dpf) at the onset of thymic organogenesis. CD8β expression is specific to adult surface CD8(+) T cells and thymocytes, and is first detected in the thymus at 5 dpf in parallel with productive TCRγ transrcipts, whereas productive TCRβ and α rearrangements are not detected before 7-9 dpf.

| S-EPMC3073561 | biostudies-literature

Revealing mitf functions and visualizing allografted tumor metastasis in colorless and immunodeficient Xenopus tropicalis.

Project description:Transparent immunodeficient animal models not only enhance in vivo imaging investigations of visceral organ development but also facilitate in vivo tracking of transplanted tumor cells. However, at present, transparent and immunodeficient animal models are confined to zebrafish, presenting substantial challenges for real-time, in vivo imaging studies addressing specific biological inquiries. Here, we employed a mitf-/-/prkdc-/-/il2rg-/- triple-knockout strategy to establish a colorless and immunodeficient amphibian model of Xenopus tropicalis. By disrupting the mitf gene, we observed the loss of melanophores, xanthophores, and granular glands in Xenopus tropicalis. Through the endogenous mitf promoter to drive BRAFV600E expression, we confirmed mitf expression in melanophores, xanthophores and granular glands. Moreover, the reconstruction of the disrupted site effectively reinstated melanophores, xanthophores, and granular glands, further highlighting the crucial role of mitf as a regulator in their development. By crossing mitf-/- frogs with prkdc-/-/il2rg-/- frogs, we generated a mitf-/-/prkdc-/-/il2rg-/- Xenopus tropicalis line, providing a colorless and immunodeficient amphibian model. Utilizing this model, we successfully observed intravital metastases of allotransplanted xanthophoromas and migrations of allotransplanted melanomas. Overall, colorless and immunodeficient Xenopus tropicalis holds great promise as a valuable platform for tumorous and developmental biology research.

| S-EPMC10915148 | biostudies-literature

A genetic map of Xenopus tropicalis.

Project description:We present a genetic map for Xenopus tropicalis, consisting of 2886 Simple Sequence Length Polymorphism (SSLP) markers. Using a bioinformatics-based strategy, we identified unique SSLPs within the X. tropicalis genome. Scaffolds from X. tropicalis genome assembly 2.0 (JGI) were scanned for Simple Sequence Repeats (SSRs); unique SSRs were then tested for amplification and polymorphisms using DNA from inbred Nigerian and Ivory Coast individuals. Thus identified, the SSLPs were genotyped against a mapping cross panel of DNA samples from 190 F2 individuals. Nearly 4000 SSLPs were genotyped, yielding a 2886-marker genetic map consisting of 10 major linkage groups between 73 and 132cM in length, and 4 smaller linkage groups between 7 and 40cM. The total effective size of the map is 1658cM, and the average intermarker distance for each linkage group ranged from 0.27 to 0.75cM. Fluorescence In Situ Hybridization (FISH) was carried out using probes for genes located on mapped scaffolds to assign linkage groups to chromosomes. Comparisons of this map with the X. tropicalis genome Assembly 4.1 (JGI) indicate that the map provides representation of a minimum of 66% of the X. tropicalis genome, incorporating 758 of the approximately 1300 scaffolds over 100,000bp. The genetic map and SSLP marker database constitute an essential resource for genetic and genomic analyses in X. tropicalis.

| S-EPMC3098391 | biostudies-literature

Generation and Care of Xenopus laevis and Xenopus tropicalis Embryos.

Project description:Robust and efficient protocols for fertilization and early embryo care of Xenopus laevis and Xenopus tropicalis are essential for experimental success, as well as maintenance and propagation of precious animal stocks. The rapid growth of the National Xenopus Resource has required effective implementation and optimization of these protocols. Here, we discuss the procedures used at the National Xenopus Resource, which we found helpful for generation and early upkeep of Xenopus embryos and tadpoles.

| S-EPMC6396978 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data