10个牛品种线粒体12S rRNA基因多态性分析

以鲁西牛、渤海黑牛、大别山牛、南阳牛、晋南牛、秦川牛、中国西门塔尔牛、日本和牛、海福特牛和安格斯牛10个牛品种共计353头牛为研究对象，利用单链构象多态性（SSCP）分子标记方法对其线粒体DNA 12S rRNA基因进行了多态性分析，结果发现该基因出现分布频率不同的3种单倍型（Ⅰ、Ⅱ、Ⅲ），其中单倍型Ⅰ出现的频率最低，仅在晋南牛1个个体中发现；单倍型Ⅱ在中国本地黄牛中都存在，在中国西门塔尔牛中的分布频率很低，但在3个国外品种海福特牛、安格斯牛和日本和牛中不存在；单倍型Ⅲ在这10个牛品种中均有分布，但以国外品种最丰富。计算平均多态信息含量，发现我国地方品种在0.232～0.423之间，基本属于中度多态，说明我国地方黄牛品种在12S rRNA上多态性比较丰富，国外品种较为贫乏；但是单倍型Ⅰ频率很低有丢失的趋势，需要对其进行保护。

Analysis of Mitochondrial 12S rRNA Gene Polymorphism in Cattle

The mitochondrial DNA 12S rRNA in seven Chinese local yellow cattle breeds, one cultivated breed and three imported breeds was studied by single-strand conformation polymorphism (SSCP). Three haplotypes (I, II , III) were detected, with haplotype I found only in one cattle of the Jinnan breed. Haplotype II did not appear in the foreign cattle breeds and low in Chinese-Simmental breed but was rich in Chinese local breeds. Haplotype III had the widest distribution and was present in ten cattle breeds. The average polymorphism information content (PIC) for Chinese cattle between 0.232-0.423 was modest, which suggested relative abundance of genetic resources for the Chinese native cattle.