山羊卵泡刺激素β-亚基cDNA的分子克隆与序列分析

Nucleotide sequence of cloned cDNA for β-subunit of goat follicle stimulating hormone and its sequence analysis

从新屠宰的母山羊脑垂体中提取总RNA,反转录获得cDNA,以此cDNA为模板用PCR法扩增目的片段,获得长为390bp的山羊卵泡刺激素β-亚基cDNA片段,与预期的目的片段大小一致。将它克隆至pMD-18-T-Verctor中,随机挑选2个阳性重组子进行测序,并将测序结果与绵羊、牛等多种哺乳动物该基因的核苷酸序列及相应氨基酸序列进行比较。结果表明,山羊的卵泡刺激素β-亚基基因与绵羊的该基因氨基酸同源性最高,达99.9%,只有1个氨基酸不同;与牛、猪、马、虎、人、大鼠的该基因氨基酸同源性分别为92.5%、91.7%、89.9%、89.1%、86.0%、83.7%。从核苷酸同源性来看,山羊的卵泡刺激素β-亚基基因与绵羊该基因的同源性最高,达98%;与牛、猪、马、虎、人、大鼠的核苷酸同源性为95%、90%、90%、88%、86%、84%。结果表明,尽管β-亚基基因有种的特异性,但在哺乳动物中其同源性还是很高的。

Total RNA was prepared from pituitary gland of new butchered goat.cDNA was synthesized by RT-PCR reaction and this cDNA was used as template in PCR amplification forβ-subunit gene of goat follicle stimulating hormone(FSH).The PCR product was390bp in1.2%agarose gel electrophoresis which just was the same length of the predicted FSHβ-subunit gene.Cloned it to pMD-18-T-Vector,selected2positive recombinants at random and analysized its sequence by DNA apparatus.The comparison of this amino acid sequence of FSHβ-subunit with some other mammalians' showed that it has higher homology with sheep's,bovine's,pig's,horse's,triger's,human's,rat's.The results show that although FSHβ-subunit gene shows species specificity,it is quite conserved among mam-malians.