Xwnt-2b is a novel axis-inducing Xenopus Wnt, which is expressed in embryonic brain

Xwnt-2b is a novel member of the Wnt gene family and is 73–74% similar to human and mouse Wnt-2 proteins. Starting from stage 15, Xwnt-2b transcripts are localized to a non-contiguous stripe in the anterior neural plate of the Xenopus embryo. In the tailbud, Xwnt-2b is expressed along the dorsoanterior side of the prosencephalon-mesencephalon boundary. At the tadpole stages, the brain-specific expression fades, but the total amount of Xwnt-2b mRNA does not decline due to activation of its expression in non-brain areas. Microinjection of Xwnt-2b mRNA into a ventral blastomere of 4–8-cell embryos results in the formation of complete secondary body axes. These results suggest that Xwnt-2b is a member of the axis-inducing Wnts and that it is involved in brain development and in later organogenesis.