细胞色素b基因标记绵羊种内亲缘关系的初步研究

Preliminary Study of Intraspecific Relationship of Sheep Based on Mitochondrial Cytochrome b Gene

[目的]从群体的角度,初步探讨细胞色素b(Cytb)基因标记绵羊种内亲缘关系。[方法]用PCR方法扩增出滩羊和洼地绵羊2个地方绵羊品种共112个个体的线粒体DNA(m tDNA)Cytb基因,用限制性内切酶EcoRΙ对其进行限制性长度多态性(RFLP)分析。[结果]在56个滩羊样品中,有51个个体检测到1个酶切位点,5个个体没有检测到切点,呈现出2种限制性态型。在56个洼地绵羊样品中均能检测到酶切位点,表现为1种限制性态型。[结论]受试绵羊品种线粒体DNA多态性较贫乏,且m tDNA Cytb基因在绵羊品种内、品种间都有很强的保守性。因此,Cytb基因标记绵羊种内亲缘关系有一定的局限性。

[Objective]To preliminarily explore the intraspecific relationship of sheep based on cytochrome b（Cyt b） gene of mitochondrial DNA（mtDNA）.[Method]The Cyt b gene sequences in 112 sheep individuals from two local sheep breeds were amplified by PCR.Then the amplified products were digested with EcoR Ι and analyzed by restriction fragment length polymorphism（RFLP）.[Result] As many as 56 samples from Tan sheep and 56 samples from Wadi sheep were detected.The results showed that amplified Cyt b gene in 51 individuals from Tan sheep had one EcoR Ι restriction site and no EcoR Ι restriction site in other 5 individuals,thus the Cyt b gene in Tan sheep showed two restriction morphs;the Cyt b gene in all Wadi sheep 56 individuals had one EcoR Ι restriction site and showed one restriction morph.[Conclusion]The polymorphism of mtDNA Cyt b gene in Tan sheep and Wadi sheep is poor,and the Cyt b gene sequences in sheep breeds is very conservative.Therefore,using Cyt b gene as gene marker to study the intraspecific relationship of sheep has some limitations.