Cloning of the gene encoding the murine orphan receptor TAK1 and cell-type-specific expression in testis

We have cloned the gene encoding the mouse homologue of the orphan receptor, TAK1, a member of the nuclear receptor superfamily, from a mouse testis cDNA library. The amino acid sequence of mouse TAK1 (mTAK1) is highly homologous to that of human TAK1, with an overall identity of 98%. Northern blot analysis using RNA from different testicular cell types showed that the mTAK1 transcript is predominantly expressed in pachytene spermatocytes at a low level in round spermatids, but not in germ cells at earlier phases of spermatogenesis or in Sertoli cells. Southern analysis using genomic DNA prepared from a panel of hamster/human and mouse/human hybrid cell lines indicated that the TAK1 gene is located on human chromosome 3.