青海高原两种沙蜥mtDNA的渐渗杂交

青海沙蜥和贵德沙蜥在共和沙珠玉地区重叠分布,形态和遗传显著不同。线粒体基因序列分析说明在重叠区两种蜥蜴mtDNA基因相互渗透。重叠区19个青海沙蜥个体中有1个具有贵德沙蜥线粒体基因型,但形态与青海沙蜥相似。6个贵德沙蜥个体中有1个具有青海沙蜥线粒体基因型,形态与贵德沙蜥相似。两种沙蜥在该地区的基因流动可能发生在共和古湖的退缩消失后次级相遇形成的。分子钟推测杂交发生的时间大约在19至16万年前,与古湖的消失时间(15万年前)相符。

Introgression of mtDNA between two Phrynocephalus lizards in Qinghai Plateau

Hybridization was observed between two viviparious toad-headed lizards, P.vlangalii and P.putjatia, in the sympatric region (Shazhuyu Village, Gonghe County,Qinghai Plateau). Reciprocal introgression of mtDNA occured between these two lizard species. One of 19 P.vlangalii individuals is observed to be a hybrid which has mtDNA genotype of P.putjatia. Moreover, one of 6 P.putjatia has mtDNA genotype of P.vlangalii. The hybridization between P.vlangalii and P.putjatia was estimated at about 0.19-0.16 million years ago, which coincide with the time of disappearence of the Paleo Gonghe Lake at 0.15 million years ago, suggesting that the two species experienced second contact. Genetic introgression might occurred after the two kinds of lizards disapersed into the contact region corresponding with the disappearing of the Paleo Gonghe Lake.