Maternal cold inducible RNA binding protein is required for embryonic kidney formation in Xenopus laevis

We cloned a major isoform of Xenopus homologue of cold inducible RNA bindin g protein (CIRP), XCIRP-1. XCIRP-1 was neither cold inducible nor essential for cell division during early embryonic development, Suppression of XCIRP -1 dose dependently produced tailbuds with deformations of the brain and in ternal organs. The defects were XCIRP-1 specific as they could be rescued b y sense transcript. Suppression of XCIRP-1 also disrupted the morphogenetic migration of the C3 blastomeres (lineaged to become the embryonic kidney, the pronephros), In animal cap explants, depletion of XCIRP-1 inhibited act ivin/retinoic acid induced expressions of pronephros related Xlim-1 and WT1 genes. These results suggest that XCIRP-1 is required for the specificatio n and morphogenetic lineage migration of the pronephros, (C) 2000 Federatio n of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.