内蒙古达里湖及岗更湖东北雅罗鱼D—loop基因序列及多样性研究

文章对内蒙古达里湖和岗更湖东北雅罗鱼（LeuciscuswaleckiiDybowski）的mtDNAD—loop序列进行扩增，获得了896bp的同源基因序列，得到的同源基因片段中A、T、c和G碱基的平均含量，达里湖群体为32．0％、32．2％、21．3％和14．5％；岗更湖群体为32．0％、32．2％、21．4％和14．5％；达里湖和岗更湖鱼群D—loop基因CG含量相当，未见明显差异。2个群体内和群体间都存在丰富的序列多态性，两湖群体的D—loop基因896个位点中存在可变位点33个，其余位点较为保守；达里湖30尾鱼D—loop基因含有多态性位点／突变位点21个，11个单倍型；岗更湖30尾鱼D—loop基因含有多态性位点／突变体位点31个，17个单倍型；岗更湖鱼群D—loop基因多样性高于达里湖。遗传距离计算显示，岗更湖和达里湖鱼群之间的平均遗传距离为0．0070；达里湖鱼群之间的平均遗传距离为0．0036；岗更湖鱼群之间的平均遗传距离为0．0074。岗更湖鱼群D—loop基因的平均遗传距离大于达里湖鱼，前者群体D—loop基因进化速度大于后者。

D-loop gene sequence and diversity of Leuciscus waleckii Dybowski in Dali Lake and Ganggeng Lake in Inner Mongolia

We amplified the mtDNA D-loop sequence in two stocks of Leuciscus waleckii Dybowski in Dali Lake and Ganggeng Lake in Inner Mongolia, having obtained 896 bp gene sequences; the average contents of T, C, A and G of homological fragments were 32.0% , 32. 2% , 21.3% , 14. 5% and 32. 0% , 32. 2% , 21.4% , 14. 5% in Dali Lake stock and Ganggeng Lake stock, respec- tively, with no significant difference. The inter- and intra-population of the two stocks had high degree of sequence polymorphism. There were 33 variable sites in 896 D-loop gene loci in the two stocks, and the rest sites were more conservative. The D-loop genes of 30 fish in Dali Lake contained 21 polymorphisms/mutations and 11 haplotypes; while those in Ganggeng Lake contained 31 polymor- phisms/mutations and 17 haplotypes. The diversity of D-loop gene in Ganggeng Lake stock was higher than that in Dali Lake stock. Genetic distance calculation shows that the average genetic distance between Ganggeng Lake and Dali Lake stocks was O. 007 0 （ Dali Lake ： 0. 003 6, Ganggeng Lake ： 0. 007 4）. The genetic distance of the D-loop gene in Ganggeng Lake stock was greater than that in Dali Lake stock, and the evolution speed of the former was faster than that of the latter.