Molecular Phylogeny Of Tibetan Fox (Vulpes Ferrilata) Using Mitochondrial DNA Sequences

Tibetan fox ( Vulpes ferrilata) is wildly distributed in the Tibetan plateau of India, China and Nepal. There are two other Vupes genus species in China, Red fox and Corsac fox. Corsac fox occupy the area neighboring the Tibetan plateau, while the red fox can be seen throughout the northern hemisphere and Australia. Lack of ecological research and morphological similarity have led to some confusion in the classification and distribution of these foxes. No molecular examination of the phylogeny of Tibetan fox has been carried out previously. For the first time, we have sequence 2001bp of the cytochrome b, cytochrome oxidase I, cytochrome oxidase II of the mitochondrial DNA of Tibetan fox, trying to clarify the phylogenetic relationship of the Tibetan fox to other fox-like canids. Furthermore, Tibetan fox is the only Vulpes species that distributes exclusively in Tibetan plateau. Research of evolutionary relationship of Tibetan fox and its relative species can provide valuable information on how species adapted and dispersed in these area after the uprising of the Tibetan plateau.Phylogenetic trees based on 2001 bp of the cytochrome b, cytochrome oxidase I, cytochrome oxidase II of the mitochondrial DNA of Tibetan fox and constructed by three methods, UPGMA, NJ and MP support the same topology, in which Tibetan fox is closely related to red fox. Phylogenetic trees constructed based on 402bp of the cytochrome b indicate that Tibetan fox converges with corsac fox first, with bootstrap value of 97, 83, 67 in UPMGA NJ MP trees respectively. And then this branch converges with red fox with bootstrap value of 52 in UPGMA tree, 67 in NJ tree and 55 in MP tree, which is comparatively low. Sequence difference between Tibetan fox and corsac fox(5.5%) is significantly lower than that between Tibetan fox and red fox(9.6%) or that between corsac fox and red fox(9.8%). Our result shows that Tibetan fox is more closely related to corsac fox than to red fox.Based on corresponding molecular clock, red fox and Tibetan fox diverged about 4.8-6.4 Myr(million year) ago, while Tibetan fox diverged with corsac fox about 2.8 Myr ago. Combining with the history of the uprising of Tibetan plateau and physiognomoic evolution, we have come to the conclusion that Tibetan fox and corsac fox diverged at the forepart of the third phrase of the Himalayas formation movement,when the Tibetan plateau was about 2000m above the sea level. After this period, the whole Tibetan plateau, including Himalayas, rised up rapidly. We presume that the rapid upheaval of Tibetan plateau at these period is one of the major reason for the historical separation of these two species.