摘要
利用ClustalW软件对我国5个家驴品种26个个体的mtDNAD loop区399bp序列进行同源序列比对,共检测到核苷酸多态位点23个,只有转换1种类型,约占所测核苷酸的5.76%。以欧洲驴D loop作对照,我国5个家驴品种D loop区序列的平均核苷酸变异率为1.80%,其中凉州驴的平均核苷酸变异率为0.35%,云南驴为1.25%,关中驴为2.30%,新疆驴为2.91%,佳米驴为2.20%。家驴品种内与品种间mtDNAD loop区序列歧异度分别为0.25%～5.01%和4.51%～5.51%,说明家驴品种间D loop区序列多态性比较丰富。在所测家驴个体中,mtDNAD loop序列由11种单倍型组成,单倍型比例为42.31%,表明我国家驴mtDNA遗传多态性正逐步丧失,需要加强其种质资源保护。引用GenBank中亚洲野驴和欧洲家驴的序列,构建了我国5个家驴品种的NJ分子系统树,首次从分子水平证实中国家驴可能起源于非洲野驴,而与亚洲野驴无关。
The mitochondrial DNA(mtDNA)D-loop sequences with 399 bp in 26 individuals from 5 donkey breeds in China were analyzed.Aligned by Clustal W software,the results showed that 23 polymorphic nucleotide sites and only transition with the percentage of 5.76% in 399 bp were observed.In reference to mtDNA D-loop sequences of European domestic donkey as a control,the average percentage of mtDNA D-loop nucleotide variation in 5 Chinese donkey breeds was 1.80%.The average percentages of D-loop nucleotide variation from Liangzhou donkey (LZ),Yunnan donkey (YN),Guanzhong donkey (GZ),Xinjiang donkey (XJ) and Jiami donkey (JM) were 0.35%,1.25%,2.30%,2.91% and 2.20% respectively.The average sequence divergence estimated from D-loop sequences varied from 0.25%～5.01% within breeds and 4.51%～5.51% (among) breeds,respectively,demonstrating that there existed rather abundant mitochondrial genetic diversity in Chinese donkeys.Comparisons of the 26 sequences revealed 11 mitochondrial haplotypes;the percentage of haplotype was 42.31%.This phenomenon demonstrated that the mitochondrial genetic diversity in Chinese donkey breeds is being reduced.It is urgent to protect the genetic resources of Chinese donkey.The molecular phylogenetic tree of mtDNA D-loop sequences in 5 Chinese donkey breeds,6 sequences of Asian wild ass(Equus asinus kiang,Equus asinus kulan,Equus asinus hemionus;)and 4 sequences of European domestic donkeys from GenBank was constructed by Neighbor-Joining method.It was the first time proved in molecular level that the origin of Chinese donkey breeds was from African wild ass (Equus africanus africanus and Equus africanus somaliensis),not from Asian wild ass as bescribed in the paper.
基金
国家自然科学基金(编号:30471238)
西北农林科技大学重大专项基金
西北农林科技大学科研专项基金(编号:04ZM003)资助~~
