藏猪EGLN1基因exon 4及部分内含子变异研究

青藏高原的高寒低氧极端环境影响动物的正常生存和物种繁衍,藏猪在长期的适应性驯化中对低氧环境有着更强的适应能力。本研究对高海拔猪种藏猪(甘孜藏猪、迪庆藏猪、西藏藏猪和合作藏猪)和八眉猪以及低海拔猪种烟台黑猪、长白猪和大白猪EGLN1基因exon 4及部分内含子的核苷酸序列进行测定和分析。结果表明:在EGLN1基因exon 4序列的266bp处发生了C→T的颠换,藏猪和八眉猪在该位点均为C,而烟台黑猪和引入的选育猪种长白猪、大白猪在该位点出现了C/T杂合现象;基于变异位点的等位基因C和T共界定了3种基因型(CC、CT、TT),C和CC分别是高海拔地方猪种藏猪和八眉猪的唯一等位基因和基因型;而在低海拔选育猪种中,CC基因型频率仅为0.20,其他2种基因型均为0.40,T为优势等位基因,频率达到0.60,而等位基因C的频率仅为0.40。本研究认为,高海拔猪种(2 300 m以上)藏猪和八眉猪与低海拔猪种烟台黑猪、长白猪和大白猪在EGLN1基因上存在特征性遗传变异,根据等位基因(C和T)及基因型(CC、CT、TT)在海拔上的特征差异,推测可能与不同地理区域条件下的长期适应性驯化有关。

Research on EGLN1 Exon 4 and Partial Intron of Tibetan Pig

Environmental extremes at high altitude seriously affect the survival and reproduction of animals. However, the better adaptability of Tibetan pig to high altitude harsh environment is formed under long-term adaptive domestication. This study is for Tibetan pig(Ganzi Tibetan pig, Diqing Tibetan pig, Tibet Tibetan pig and Hezuo Tibetan pig) and Bamei pig at high altitude, Yantai black pigs, Landrace pig and Large white pig at low altitude EGLN1 four exons and part of the intron nucleotide sequence was determined and analyzed, the results show that EGLN1 gene Exon 4 C/T in the 266 bp, Tibetan pig and Bamei pig in this site are C, Yantai black pigs and the selected breeding pigs of Landrace pig, Large white pig in this site can be C or T. Three genotypes(CC, CT, TT) were defined based on the alleles C and T of the variant site, C and CC are the only alleles and genotypes of Tibetan pig and Bamei pig at high altitude. However, the selected breeding pigs at low altitude,genotype frequency of CC is only 0.20, both of the genotype frequency of CT and TT is 0.04, T is the dominant allele, the gene frequency of T is 0.60, However, the gene frequency of C could only be 0.04. It shows that Landrace pig, Large white pig and Yantai black pigs have gotten complex genetic background in breeding, but the Tibetan pigs on Tibetan Plateau and the surrounding Bamei pig have formed genetic trait to adapt the hypoxic environment under long-term adaptive domestication.