BOVINE SRY GENE LOCUS - CLONING AND TESTICULAR EXPRESSION

The bovine SRY gene was cloned by a combination of anchored polymerase chain reaction (PCR) amplification of genomic restriction fragments a nd reverse transcription-PCR (RT-PCR) of testicular RNA. We report 180 0 bp of combined genomic and cDNA sequences including 311 bp of 5' ups tream sequences, an open reading frame of 687 bp, and 202 bp of sequen ces corresponding to the 3' end of the mRNA. The bovine SRY gene encod es a deduced (predicted on the basis of a cDNA sequence) protein produ ct of 229 amino acids, with sequence conservation between species, not ably in the region of the high-mobility group (HMG) domain or HMG box. Outside of the HMG box, the bovine SRY structure shows greater resemb lance to the human SRY than to the mouse Sry. As with human SRY promot er sequences, putative binding sites for sp1 and for SRY itself are se en in the bovine SRY promoter region. Unlike the human SRY promotor, C AAT and TATA box motifs are present in the bovine sequences. Southern analysis and PCR amplification of male and female bovine genomic DNA s how that the described sequences are specific to the Y chromosome. Nor thern analysis of bull testicular RNA demonstrated low levels of expre ssion of the bovine SRY gene in adult testes with a major poly(A) spec ies at 1.9 kb. RT-PCR amplification of bull testicular RNA revealed mu ltiple sites of polyadenylation, but sequencing showed no consensus po lyadenylation signal.