猪线粒体控制区微卫星(mtMs)变异及其分布特征

猪线粒体DNA长度因D-loop中mtMs序列重复数变异而不同。为阐明猪mtMs变异及其在不同群体中的分布特征,本研究对4个藏猪群体、八眉猪、烟台黑猪及3个引入猪群体共164个个体mtDNA D-loop全序进行测定,并与GenBank中发表的相关序列进行比对,分析了其中的重复单元核苷酸变异、重复次数及其在各群体间的分布规律。结果表明,因重复单元“5’-TGCGTACACG-3’”第2~4和10位上碱基变异,猪mtMs形成了以其为核心序列的多种重复单元(R^A^R^G)组成的复合结构,重复数介于3~47之间。单一重复(R^A)组成的mtMs结构在各群体中表现出分布优势,而大多数复合结构(R^AR^B)分布在国外选育群体中。藏猪的mtMs复合结构多达8个,R^AR^CR^E为其特有,另有5个与八眉猪共享。中国野猪和韩国地方猪种也有其特有mtMs结构。丰富的mtMs变异和特有结构与长期适应进化有关,本研究为地方猪种遗传资源及适应性研究提供了标记工具和理论基础。

The Variation and Distribution of Microsatellite in MtDNA D-loop of Pig

The number variation of mtMs sequence in D-loop lead to the length differences of mitochondrial DNA in procine.In this study,the mtDNA D-loop sequences of 164 individuals from four Tibetan pig populations,Bamei pig,Yantai black pig and three introduced pig populations were sequenced,and the nucleotide variation in repeat unit,number of repeats and their distribution among the populations were analyzed with the related data published in GenBank.The multiple repeat units(R^A^R^G),due to the nucleotide variation at positions 2~4 and 10in the repeat unit,with the"5'-TGCGTACACG-3'"(R^A)as core were presented in the mtMs of pig,and the number of repetitions is between 3~47.The mtMs structure with single repeat of R^Ashowed the advantage distribution in all of populations,and most of the composite structure with R^AR^Bwas distributed in foreign breeding populations.There are up to eight kinds of compound mtMs in Tibetan pigs,R^AR^CR^Eis its unique and 5 of them are shared with Bamei pigs.Chinese wild boar and Korean native pig also have their own unique mtMs structure.Abundant mtMs variation and endemic structure are associated with long-term adaptive evolution.This study provides a marker tool and theoretical basis for the research on genetic resources and adaptability of local pig breeds.