CARL, T.F.*; KLYMKOWSKY, M.W.; HANKEN, J.: Multiple functions for the gene Slug in Xenopus laevis

The neural crest is a distinct population of embryonic cells found only in craniates. Several genes, including BMP-4and the zinc-finger transcription factor Slug, have been shown to mediate neural crest development in both chickens and mice. We examined the function of Slug in the frog Xenopus laevisby injecting antisense RNA (ASR) targeted to the 3′ UTR of Xenopus Slug (XSlug). Injection of XSlug ASR inhibits neural crest-cell migration and leads to reduction or loss of many neural crest derivatives, including pigment cells and cranial cartilages. Moreover, regions injected with XSlug ASR show significantly elevated levels of cell death, and expanded regions of the BMP-4antagonist, Chordin. In addition to its important role in neural crest migration,XSlugmay mediate the cell-death-signaling pathway and other significant developmental pathways in Xenopus laevis. Supported by NSF.