Study on sequence variation of mitochondrial cytochrome b gene and phlogenetic relationships of two kinds of Cashmere goats

【Objective】The objective of the present study is to study the origin phylogenic relationship between Liaoning new breed of Cashmere goats and Inner Mongolia Arbus Cashmere goats.【Method】Cytochrome b gene of sixteen Cashmere goats were sequenced and analyzed. 【Result】 The sequences were compared and analyzed by using MEGA software, and the results showed that the whole sequence is 1 140 bp by analyzing nucleotide homology sequences and base composition of Cytb gene. Comparisons of these isogenous sequences we define 11 mitochondrial haplotypes, and the percentage of haplotype is 68.75%. It suggests that Liaoning new breed of Cashmere goats and Inner Mongolia Arbus Cashmere goats are rich in hereditary variability. According to Cytb molecular clocks and the phylogenetic trees, the approximate divergent time between Cashmere goats and other Capra hircus is almost 0.4×104 a, whereas that between Capra hircus and Pseudois nayaur is 3-6 Ma and that between Capra hircus and Ovis aries is 4-7 Ma. 【Conclusion】We have successfully sequenced and analyzed the sequences of two kinds of Cashmere goats, which makes the base of molecule evolution and genetic characteristic in the studying of Cashmere goats.