Cloning and bioinformatics analysis of a fragment cDNA encoding growth hormone-releasing hormone in Tibetan sheep

Total RNA was extracted from the hypothalamus tissues of Tibetan sheep using Trizol method and cDNA was amplified by reverse transcription polymerase chain reaction( RT-PCR). The cDNA of Tibetan sheep GHRH gene was cloned from the amplified PCR product and sequenced. The cDNA was 207 bp in length and showed 99% homology with that of common sheep registered in Gen Bank from the starting position(86) to 292 bp. The cDNA sequence encodes 69 amino acid residues and contains a signal peptide sequence which has a GLUCA domain characterizing glucagon-like hormone at amino acid31 to 57.