高原绵羊β3-肾上腺素受体基因（ADRB3）变异与适应性进化分析

摘要

为了探讨ADRB3基因变异及其与高原绵羊适应性进化关系,研究以‘甘肃高山细毛羊’‘藏绵羊’及‘滩羊’3个绵羊品种为观测对象,采用PCR-SSCP方法检测ADRB3基因部分内含子序列的遗传多态性,同时基于DA遗传距离用NJ 法进行系统聚类分析,明确3个绵羊品种与不同物种群体间的遗传进化关系.结果表明：3个绵羊品种共检测到5种等位基因(A,B,C,D和 E),构成了7种基因型(AA,AD,BD,BE,CC,CD和 DD),存在6个突变位点(T/C,C/T,A/G/C,T/C,A/C和T/C),‘滩羊’中未检测到等位基因 A和基因型 AA与 AD,优势等位基因与基因型在不同群体间各不相同；聚类结果显示,不同物种总体上分为2大类,其中绵羊、山羊和家牛等聚为一支,且‘藏绵羊’与‘甘肃高山细毛羊’之间的遗传距离最小,‘滩羊’次之；而大猩猩、人和小家鼠聚为一支.研究发现, ADRB3基因在3个绵羊群体中存在丰富的多态性,且存在群体间差异.ADRB3基因多态性丰富的绵羊品种在高海拔地区适应性能力较强,ADRB3基因可能在绵羊适应性进化中具有一定功能.%To study the variations of ADRB3 gene and its relationship with adaptive evolution of plat-eau sheep,the genetic polymorphhism of part of intron of ADRB3 gene in 3 plateau sheep breed(Gansu Al-pine Merino,Tibetan Sheep and Tan Sheep)were detected by PCR-SSCP,NJ tree were constructed by ge-netic distance (DA)to define the genetic relationship between three sheep and different species groups.The results showed that 6 SNPs (T/C,C/T,A/G/C,T/C,A/C and T/C)corresponding to 5 alleles (A,B,C,D and E)and performing 7 kinds of genotypes (AA,AD,BD,BE,CC,CD and DD)were detected in the intron of ADRB3 gene in 3 plateau sheep breed.The allele D with the frequency of 0.415 9 and genotype CD with the frequency of 0.254 0 were both the highest,and allele A and genotype AA/AD were not detected in Tan sheep.Clustering results showed that different species were divided into two categories,which sheep, goat and cattle populations were clustered together,and the genetic distance between Tibetan Sheep and Gansu Alpine Merino was the smallest,and Tan sheep were smaller.Meanwhile,gorillas,human and mice populations were clustered together.The results of this study showed that the intron of ADRB3 gene has abundant polymorphism in three different populations,and there are rich genetic diversities among different sheep populations.The breeds have stronger adaptive ability in high altitude if the ADRB3 gene has rich variants.Therefore the ADRB3 gene may play a certain role in adaptive evolution in sheep,and the results provided basic data on rational utilize and effective protect plateau special resources.