| The complete mitochondrial control region of 66 southern Chinese cattle in 9 populations was sequenced and analyzed by PCR, sequencing and bioinformation methods. In order to clarify the genetic diversity,genetic relationship and origin of cattle in south China, we retrieved another 124 seqrences of 17 cattle populations in south China. Together with the 124 sequences in GenBank, 190 sequences of 26 populations from south China were analyzed. The results showed as follows:1,A total of 71 variations in the 66 sequences of 9 southern Chinese populations were detected, making for 7.8% of all the 910 nucleotides in D-loop. There were 21 singleton variable sites and 50 parsimony informative sites sorted by type of informative sites, and 65 transition sites and 6 transversion sites sorted by type of substitute. The rate of transition and transversion is 10.8. There was a site of coexisting of transition and transversion, 4 sites of insertion or deletion. The frequency of polymorphism sites in five different domain of D-loop: 1～240 bp, 241～610 bp, 611～712 bp, 713～850 bp and 851～910 bp are 13.16%, 65.7%, 2.63%, 15.79%, 2.63%, respectively. The mean number of nucleotide differences (k) is 21.758, and nucleotide diversity (π) is 2.399%.2,30 haplotypes were detected in 66 sequences according to the 71 variations, 20 of them were of Bos taurus and 10 were of Bos indicus, and the whole haplotype diversity (Hd) was 0.839±0.044. The 26 individuals of Bos taurus made a well-distribution in the 20 Bos taurus haplotypes, with a haplotype diversity of 0.960, indicating a high genetic diversity for Bos taurus populations in south China. While the distribution of 40 Bos indicus individuals in the 10 Bos indicus haplotypes is relatively uneven, with 26 individuals sharing the same haplotype i1, displaing a haplotype diversity of 0.5731. The NJ tree constructed from haplotypes of 9 southern Chinese cattle populations based on Kimura-2-parameter genetic distance showed that 30 haplotypes fall into two clades, corresponding to Bos indicus and Bos Taurus.3,Of the 9 cattle populations in south China, Zhaotong cattle in Yunnan Province and Liangshan cattle in Sichuan Province showed the most aboundent haplotype diversity and the farthest genetic distance with the other populations; Contrarily, Jinjiang cattle in Jiangxi Province and Xiangxi cattle in Hunan Province showed the most sparing haplotype diversity,intraspecies genetic diversity, and the closest genetic distance between each other. The NJ tree constructed from interspecies genetic distance showed Pingwu cattle in Sichuan Province display a most distinct clustering with the other populations.4,111 variations in all were detected in110 sequences from 26 southern Chinese cattle populations, making for 12.2% of all 910 nucleotides. There were 41 singleton variable sites and 70 parsimony informative sites, and 92 transition sites and 18 transversion sites. The rate of transition and transversion is 5.11. There were four sites of coexisting of transition and transversion, seven sites of insertion or deletion. The frequency of polymorphism sites in five different domain of D-loop are 22.88%, 53.39%,1.70%, 14.41%, 7.63%, respectively. Mean number of nucleotide differences is 22.518, and nucleotide diversity is 2.510%. Comparison of 190 sequences revealed 77 haplotypes, with a haplotype diversity of 0.873±0.022. NJ tree constructed from haplotypes showed that all 77 haplotypes fall into two clades, one of them was compose of 47 haplotypes sharing by 80 individuals of Bos taurus and the other comprise of 30 haplotypes sharing by 110 individuals of Bos indicus. Comparison with zebu (Bos indicus) from Africa,Bali cattle and Bos bangten disclosed the individual Xuanhan-A7 demonstrateing the closest genetic relationship with Bali cattle. This may indicate that cattle in south China once received limited Bali parentage, but not enough to form a third kind of cattle. Populations of Sichuan Province frequently showing special clustering suggest there may be some unknow parentage in Sichuan cattle besides Bos indicus and Bos taurus. Yunnan cattle and Guizhou cattle's parentage of Bos indicus differed with that from India.5,The southern Chinese taurus clade group into three lineage: T2, T3 and T4, and the percentage were 16.25%,68.75%,15%, respectively; While zebu clade contain two lineages: I1 and I2, and the percentage were 93.64% and 6.36%, with only 7 individuals in lineage I2. A special haplotype i1 was discovered playing a core role in southern Chinese zebu.6,In a try made to discuss the relationship between i1 and other, we find the haplotype structure for Bos indicus of southern Chinese cattle and Indian cattle are homologous, so there might be a deriving origin from Indian for Chinese zebu. According to the zebu haplotype diversity in every populations, a presumption that zebu immigrate to north China through two routes followed with consequently. Togerther with the present geographic patterns, we deduce that Hainan Province and Yungui Plateau may be potential origin centers for Chinese zebu.
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