南方鲇促生长激素释放激素基因的部分cDNA克隆及序列分析

Cloning and Sequence Analysis of a Fragment cDNA Encoding Growth Hormone-releasing Hormone in Southern Catfish

促生长激素释放激素(GHRH)是一种重要的内分泌激素,主要功能是调节脑垂体分泌生长激素(GH).实验旨在克隆分析南方鲇GHRH基因的cDNA序列.从南方鲇的脑组织中提取总RNA并反转录成cDNA,再根据已知GHRH基因的保守区域序列设计引物,通过反转录聚合酶链式反应(RT-PCR)实验,获得了一条334 bp的片段并进行了测序.序列信息分析表明,该序列与沟鲇的GHRH基因同源,相似性达99%.根据同源性检索结果推测该序列编码110个氨基酸,并基于该编码序列分析了南方鲇GHRH的功能结构域以及南方鲇同其他物种的遗传发生关系.

Growth hormone-releasing hormone（GHRH） is an important endocrinal hormone and involves in regulating the secretion of growth hormone in pituitary. This study will focus on cloning gene encoding GHRH of southern catfish. Total RNA was extracted from the brain of southern catfish. RT - PCR primer pairs for GHRH were designed based on the conserved domain of the known GHRH genes. A cDNA fragment with the length of 334 bp was obtained by RT- PCR. Bioinformatics analysis showed that the cDNA sequence have high identity （99%） with the cDNA encoding GHRH of channel catfish. According to homologous search, the authors predicted that this sequence encoded 110 amino acids. The functional domain and phylogenetic tree between southern catfish and other species were also surveyed based on the amino acid sequence.