Identification and expression of the mammalian homologue of Bicaudal-C

Translational activation and repression play an important role in the spati al-temporal regulation of gene expression in embryonic development. Bicauda l-C is an RNA-binding molecule believed to function at this post-transcript ional level. Loss-of-function mutants in Drosophila affect anterior-posteri or patterning because of ectopic and premature translation of the posterior determinant oskar. The Xenopus homologue of Bicaudal-C is one of the few m olecules that, when microinjected ectopically, results in endoderm formatio n in the absence of mesoderm induction. Here we report the sequence and exp ression pattern of the murine and human homologues of Bicaudal-C. The human gene is located on chromosome 10q21.2. Expression analysis in mouse using in situ hybridization detects expression of Bicaudal-C not only in domains detected in Xenopus. but also in previously unreported regions. As in Xenop us, mouse Bicaudal-C mRNA is found in the growing oocyte, Hensen's node. an d the developing kidney. Additionally, at later stages it is strongly expre ssed in the developing gut endoderm, in areas of cartilage formation, in pl euro-peritoneal membrane derivatives, in lung mesenchyme, and in the stroma of the ovary. We conclude that mouse Bicaudal-C is a maternally provided g ene product that is tightly regulated during mammalian cell differentiation . (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.