MOLECULAR-CLONING, GENETIC-MAPPING, AND DEVELOPMENTAL EXPRESSION OF ABOVINE TRANSFORMING-GROWTH-FACTOR-BETA (TGF-BETA) TYPE-I RECEPTOR

A full-length cDNA encoding the bovine transforming growth factor beta (TGF-beta) receptor type I (bT beta R-I) was isolated from a placenta cDNA library. The deduced protein sequence of 499 residues contains a single transmembrane domain, a cysteine-rich extracellular domain, an d an intracellular kinase domain with predicted serine/threonine speci ficity. The amino acid sequence is 96% and 95% identical with its huma n and mouse homologues, respectively. Genetic mapping assigned the TGF BR1 gene to bovine chromosome 8 at a male genetic distance of 2 centim organ from D8S28. Assuming conservation of gene order, the linkage dat a define a breakpoint in mammalian chromosome evolution. Both TGF-beta receptor type I and II mRNAs were found to be expressed in bovine ooc ytes and preimplantation two-cell, four-cell, eight-cell, morula-, and blastocyst-stage embryos, as determined by heminested reverse transcr iption polymerase chain reaction (RT-PCR). The mRNA expression pattern s of TGF-beta receptor types I, II, and III in a variety of bovine org an tissues were examined by Northern blot hybridization, and highest l evels were detected in lung and ovary. (C) 1998 Wiley-Liss, Inc.