Expression Patterns of Hoxb Genes in the Xenopus Embryo Suggest Roles in Anteroposterior Specification of the Hindbrain and in Dorsoventral Patterning of the Mesoderm

摘要: Abstract Hox genes are thought to participate in patterning the anteroposterior (a-p) axis during vertebrate embryogenesis. In this investigation, spatial expression of six Hoxb was analyzed early embryos Xenopus laevis by situ hybridization. gene first detected late gastrulae/early neurulae, which stage, characteristic spatially colinear sequence already apparent. Dissection experiments indicated that establishment these localized patterns coincides with acquisition positional information along main body axis. The continued be expressed similar domains at all developmental stages examined, although there were some changes cellular level. Interestingly, 3′ genes, Hoxb-1, Hoxb-3, and Hoxb-4 very restricted future hindbrain, while Hoxb-5, Hoxb-7, Hoxb-9 transcripts present entire presumptive spinal cord. It thus notable 5′ exhibited different types domain than genes. These observations suggest may mechanisms regulating Expression analyzed, except Hoxb-4, predominantly detectable central nervous system or neural crest-derived structures. mRNA system, but interestingly, major site for somites. other tested failed show significant somitic mesoderm, from mesodermal tissues. trunk, CNS is regulated results obtained here did not explicitly support idea a code somites, we cannot rule out. Instead, data consistent role dorsoventral mesoderm.