牦牛FSHR基因第10外显子的序列测定及比较研究

Sequencing of exon 10 of yak follicle-stimulating hormone receptor gene in comparison with Chinese Simmental and small-tail Han sheep

为探讨牦牛FSHR基因的序列特征,揭示该基因的变异和对家畜产子率的意义,应用PCR克隆技术,测定了牦牛、中国西门塔尔牛和小尾寒羊的FSHR基因第10外显子+1393 +2125位点间序列,进行了比较研究。结果表明:三畜种扩增区段的序列长度一致,但存在碱基突变,碱基变异率分别为:牦牛与中国西门塔尔牛1.12 %;牦牛与小尾寒羊2.88 %;中国西门塔尔牛与小尾寒羊2.59 %。牦牛序列与中国西门塔尔牛序列间有2处错义突变;牦牛序列与小尾寒羊序列有5处错义突变,错义突变位点数多于中国西门塔尔牛与小尾寒羊序列间的错义突变位点数。三畜种的碱基错义突变数目与它们产双胎率高低的趋势相一致。错义突变导致的第660位点氨基酸替换,牦牛和中国西门塔尔牛以可磷酸化的丝氨酸替代了小尾寒羊的苯丙氨酸。

In order to characterize sequence of yak follicle-stimulating hormone receptor gene and reveal significance of the gene mutation to litter, sequences from locus +1393 to locus +2125 of exon 10 of follicle-stimulating hormone receptor gene of yak were detected by polymerase chain reaction and cloning in comparison with Chinese Simmental and small-tail Han sheep.The results showed that sequence length were the same among the 3 breeds of domestic animals,but there were base mutations. Base-difference rate was 1.12 % between yak and Chinese Simmental, 2.88 % between yak and mall-tail Han sheep, 2.59 % between Chinese Simmental and mall-tail Han sheep respectively.There were 2 missense mutations between yak and Chinese Simmental, 5 between yak and mall-tail Han sheep, more than that between yak and Chinese Simmental. The change trude of Base-difference rate between 3 breeds was correspondent to their prolificacy. Missense mutation led to amino acid substitute at 660th locus, namely, serine which could be phosphorylated of yak and Chinese Simmental substitute to phenylalanine of small-tail Han sheep.