[Study on mitochondrial DNA genetic diversity of some cattle breeds in China].
The complete mitochondrial D-loop sequences, 910 bp in length, in 22 individuals from 8 cattle breeds in China were analyzed. The results showed that A% + T% was about 61.65%. Comparisons of these 22 sequences revealed 66 polymorphic sites, and 5 types of mutation, transition, transversion, insertion, deletion and coexistence site of transition and transversion were observed,with the percentage of 81.82%, 6.06%, 7.57%, 3.03%, 1.52%, respectively. In reference to complete mtDNA D-loop of the European cattle as a control, eight Chinese cattle breeds were classified into 3 groups according to the average percentage of D-loop nucleotide variations. The lowest average percentage of mtDNA D-loop nucleotide variation was in Xizhen cattle, Mongolian cattle, Holstein, Qinchuan cattle with 0.37%, 0.44%, 0.52%, 0.66%, the mediate in Nanyang cattle and Jiaxian cattle with 1.91%, 2.02% and the highest in Jinnan cattle and Yueyang cattle with 4.47%, 4.73%, respectively. The average sequence divergence estimated from D-loop region within breeds and among breeds in China varied from 0.55% - 5.39% and 1.21% - 6.59%, respectively. Comparisons of these 22 sequences revealed 19 mitochondrial haplotypes, the percentage of haplotype was 86.36%, showing that abundant mitochondrial genetic diversity exists in Chinese cattle. The molecular phylogenetic tree of mtDNA D-loop of 8 Chinese cattle breeds was constructed by Neighbor-Joining method. The NJ tree indicated that these mtDNA sequences fell into 3 distinct haplotype groups, it also suggested in molecular level that there were probably 3 maternal origins, of which the main origins of Chinese cattle were from Bos taurus and Bos indicus.
Lei
Chu-Zhao
CZ
College of Animal Science and Technology, Northwest Sci-Tech University of Agriculture and Forestry, Shaanxi Key Laboratory of Agricultural Molecular Biology, Yangling 712100, China. leichuzhao1118@sina.com
Chen
Hong
H
Yang
Gong-She
GS
Song
Lin-Sheng
LS
Lei
Xue-Qin
XQ
Sun
Wei-Bin
WB
Li
Rui-Biao
RB
Liu
Xiao-Lin
XL
D000818:Animals; D001483:Base Sequence; D001947:Breeding; D002417:Cattle / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D014644:Genetic Variation; D006239:Haplotypes; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic
D004272:DNA, Mitochondrial