南方鲇生长激素完整cDNA的克隆及其DNA序列分析

CLONING AND SEQUENCING OF FULL LENGTH cDNA IN SILURUS MERIDIONALIS GROWTH HORMONE

摘要: 采用RT-PCR法和3'、5'RACE(Rapid amplification of cDNA ends)法从南方鲇脑垂体RNA克隆出生长激素(Growth hormone,GH)cDNA。此cDNA全长1087nt(含 Poly(A),其5'端非编码区长52nt、阅读框(Open reading frame,ORF)长603nt、3'端非编码区长415nt。其推导的GH由200个氨基酸组成,其中前24个氨基酸为信号肽部分。氨基酸序列比较表明,南方鲇GH与Pangasianodon gigas、Ictalurus punctatus和Heteropneustes fossilis三种鲇类的同源性分别为97.5%和95.0%,与鲢、鳙、草、鲤和鲫鱼的GH同源性达76.0%以上,而与人的GH(Ⅰ、Ⅱ)同源性最低为31.0%和29.5%.

Abstract: The full length cDNA that encodes Siulurus meridionalis growth hormone(SmGH)was cloned from pituritary RNA with RT-PCR、3'and 5'RACE(rapid amplification of cDNA ends). The cDNA, about 1087nt long, had a coding sequence, 5'-and 3'-untranslated regions and a poly(A)chain. The cDNA could encode a prehormone of 200 amino acid(aa)including a putative signal peptide of 24aa. The primary structure of SmGH was compared with those of other 15 species growth hormones.