Studies On Sequence Diversity Of D-loop Region Of Mitochondrial DNA And Phylogenesis Among Tibetan Antelope, Tibetan Sheep And Tibetan Goat

Tibetan antelope is a rare wild species of our country.Its survival security is abstracting increasing attention of humanity. In this paper,the author sequenced its D-loop region of mtDNA and compared the region with that of Tibetan sheep and Tibetan goat which related to it and lives in the similar environment. This work made a basement for determinating relative relations of them ,classified status of Tibetan antelope and developing the next related research. It will also provides scientific evidence for making protected strategies of Tibetan antelope.It makes the following conclusion:1. High-efficient primers to amplify the D-loop region of Caprinae were designed. It will make a basement for the next relating work.2. The sequences of D-loop region of Tibetan antelope, Tibetan sheep and Tibetan goat was obtained. The length of this region of Tibetan antelope, Tibetan sheep and Tibetan goat is 1067bp, 1181bp(1106bp)and 1121bp respectively.3. The large length variation of Tibetan sheep' s D-loop region is caused by different numbers of tandem repeated sequences in this region. Tibetan sheep is divided into three genetype individuals:type A(three repeated sequences), type B(four repeated sequences) and type AB.4. For the first time, the clustered repeated sequences which lies in many bovidae animals was discoveryed in the D-loop region of Tibetan antelope. The number of copies of the tandem repeats is two.5. The diversity of the number of copies of the tandem repeats maybe be caused by replication slippage. The phenomenon of heteroplasmy is produced by paternal inheritance by any possibility.6. According to the nucleotide diversity within populations and the genetic distance between populations, the subpopulations of Tibetan sheep and Tibetan goat can' t be consided as breeds.7. Tibetan antelope and Tibetan sheep diverged about 591 Ma, Tibetan antelope and Tibetan goat diverged about 781 Ma. Tibetan sheep and Tibetan goat diverged about 769 Ma.8. Tibetan antelope should belongs to Caprinae subfamily of Bovidae family,not belongs to Antilopinae subfamily.