贵州4个地方黄牛品种线粒体基因组遗传多样性与母系起源研究OA

Four local cattle breeds in Guizhou Province(Guanling cattle,Sinan cattle,Weining cattle,and Wuchuan black cattle)are important genetic resources in the Southwest region of China.However,their maternal genetic background has not yet been systematically evaluated using complete mitochondrial ge-nome data.In this study,complete mitochondrial DNA whole genomes were sequenced and assembled for 80 individuals from these four breeds.The sequences were compared with 11 known cattle haplotype refe-rence sequences,and phylogenetic trees and haplotype networks were constructed.A total of 68 complete mtDNA haplotypes and 441 variable sites were identified among the 80 individuals.The haplotype diversity was 0.990±0.006,the nucleotide diversity was 0.007 9±0.001 4,and the average number of nucleotide differences was 128.4,indicating abundant maternal genetic diversity in the four local cattle breeds of Guizhou.Phylogenetic analysis showed that the taurine lineage(T lineage)accounted for 52.50％(42/80),the indicine lineage(I lineage)accounted for 46.25％(37/80),and the rare aurochs Q lineage accounted for 1.25％(1/80).The taurine ancestry was mainly represented by the T3 lineage,whereas the indicine ances-try was dominated by the I1a sublineage.These results indicate that the four local cattle breeds in Guizhou have mixed maternal origins from both taurine and indicine cattle,with a relatively uniform population structure.The rare Q lineage detected in Wuchuan black cattle represents a rare remnant of ancient mater-nal ancestry in Chinese local cattle and has important conservation value.