Overlapping functions of Cdx1, Cdx2, and Cdx4 in the development of the amphibian Xenopus tropicalis.
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.
Faas
Laura
L
Department of Biology, University of York, York, United Kingdom.
Isaacs
Harry V
HV
D000818:Animals; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008648:Mesoderm / Q000196:embryology / Q000378:metabolism; D005810:Multigene Family / Q000235:genetics; D016376:Oligonucleotides, Antisense / Q000235:genetics; D010641:Phenotype; D014176:Protein Biosynthesis / Q000235:genetics; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism; D014981:Xenopus / Q000196:embryology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics / Q000378:metabolism
D018398:Homeodomain Proteins; D016376:Oligonucleotides, Antisense; D051153:Wnt Proteins