Mitogenomic analysis of Chinese snub-nosed monkeys: Evidence of positive selection in XXXX dehydrogenase genes in high-altitude adaptation.

@entity1 @entity2125 @entity535 @entity26 @entity21875 @entity519 @entity44517
Chinese snub-nosed monkeys belong to the genus @entity44517 and are limited in distribution to six isolated mountainous areas in the temperate regions of Central and Southwest China. Compared to the other members of the subfamily Colobinae (or leaf-eating monkeys), these endangered primates are unique in being adapted to a high altitude environment and display a remarkable ability to tolerate low temperatures and @entity519 . They thus offer an interesting organismal model of adaptation to extreme environmental stress. Mitochondria generate energy by oxidative phosphorylation (OXPHOS) and play important roles in @entity26 usage and energy metabolism. We analyzed the mitochondrial genomes of two Chinese snub-nosed monkey species and eight other colobines in the first attempt to understand the genetic basis of high altitude adaptation in non- @entity1 primates. We found significant evidence of positive selection in one Chinese snub-nosed monkey, @entity44517 , which is suggestive of adaptive change related to high altitude and cold weather stress. In addition, our study identified two potentially important adaptive @entity535 residues (533 and 3307) in the NADH2 and @entity2125 6 genes, respectively. Surprisingly, no evidence for positive selection was found in @entity21875 (the other Chinese snub-nosed monkey analyzed). This finding is intriguing, especially considering that @entity21875 inhabits a higher altitudinal distribution than @entity44517 . We hypothesize that a different adaptive genetic basis to high altitude survival exists in @entity21875 from those seen in other mammals, and that positive selection and functionally associated mutations in this species may be detected in nuclear genes related to energy and @entity26 metabolism. More information on the structure, function, and evolution of mitochondrial and nuclear genomes in Chinese snub-nosed monkeys is required to reveal the molecular mechanisms that underlie adaptations to high altitude survival in non- @entity1 primates.
