关岭牛Y染色体遗传多样性与父系起源研究

Genetic Diversity of Y Chromosome and Paternal Origins in Guanling Cattle

[目的]探究关岭牛Y染色体遗传多样性及父系起源。[方法]采用PCR扩增、限制性酶切和生物信息学方法,分析关岭牛Y-SNP(USP9Y基因)和2个Y-STRs标记(INRA189和BM861)的遗传多样性。[结果]发现32头关岭牛USP9Y基因的PCR产物均为552bp,其中4头牛的552bp片段不能被SspI酶切开,属于普通牛Y2单倍型组,占0.125,其余28头牛的PCR产物均可被酶切成两条带(215bp和338bp),属于瘤牛Y3单倍型组,占0.875。2个Y-STRs标记INRA189和BM861在关岭牛品种均表现多态性(88/104bp和156/158bp)。结合Y-SNP与Y-STRs的分型结果,界定关岭牛有2种Y染色体单倍型Y2-104-158和Y3-88-156,其Y染色体单倍型多样度为0.2258±0.0882,表明关岭牛父系遗传多样性很低。[结论]关岭牛具有普通牛Y2和瘤牛Y3两种父系起源,其中瘤牛占明显优势。

[Objective] To explore the genetic diversity of Y chromosome and paternal origins in Guanling cattle. [Method] PCR amplification, restriction enzyme digestion and bioinformatics methods were used to detect the genetic diversity of Y-SNP （USP9Y gene） and two Y-STRs markers （INRA189 and BM861） in 32 Guanling cattle samples. [Results] The PCR product sizes of the USP9Y gene in 32 Guanling cattle were 552 bp. Among 32 samptes, the 552 bp fragment of four cattle could not be cut by restriction endonuclease SspI, indicating taurine Y2 haplogroup with the frequency of 0. 125; and the other 28 cattle could be cut into two bands （215 bp and 338 bp）, indicating zebu Y3 haplogroup with the frequency of 0. 875. Two Y chromosome microsatellite markers INRA189 and BM861 showed obvious polymorphism （88/104 bp and 156/158 bp） in Guanling cattle, respectively. Two Y chromosome haplotypes （Y2-104- 158 and Y3-88-156） were identified by combining Y-SNP and Y-STR genotyping data, and the Y chromosome haplotype diversity was 0. 2258 ± 0. 0882, indicating very low paternal genetic diversity in Guanling cattle. [Conclusion] Guanling cattle had two distinct paternal origins of Bos taurus Y2 and Bos indicus Y3, and Bos indicus was obviously predominant.