title: Genetic diversities of MT-ND1 and MT-ND2 genes are associated with high-altitude adaptation in yak.
abstract: Tibetan yak (Bos grunniens) inhabiting the Qinghai-Tibet Plateau (QTP) where the average altitude is 4000 m, is specially adapted to live at these altitudes. Conversely, cattle (B. taurus) has been found to suffer from high-altitude hypertension or heart failure when exposed to these high altitudes. Two mitochondrial genes, MT-ND1 and MT-ND2, encode two subunits of NADH dehydrogenase play an essential role in the electron transport chain of oxidative phosphorylation (OXPHOS). We sequenced these two mitochondrial genes in two bovine groups (70 Tibetan yaks and 70 Xuanhan cattle) and downloaded 300 sequences of B. taurus (cattle), 93 sequences of B. grunniens (domestic yak), and 2 sequences of B. mutus (wild yak) from NCBI to increase our understanding of the mechanisms of adaptability to hypoxia at high altitudes in yaks compared to cattle. MT-ND1 SNP m.3907 C > T, present in all Tibetan yaks, was positively associated with high-altitude adaptation (p < .0006). Specially, mutation m.3638 A > G present in all cattle, resulting in the termination of transcription, was negatively associated with high-altitude adaptation (p < .0006). Additionally, MT-ND2 SNPs m.4351 G > A and m.5218 C > T also showed positive associations with high-altitude adaptation (p < .0004). MT-ND1 haplotypes H2, H3, H4, H6, and H7 showed positive associations but haplotype H20 had a negative association with high-altitude adaptation (p < .0008). Similarly, MT-ND2 haplotypes Ha1 Ha8, Ha10, and Ha11 were positively associated whereas haplotype Ha2 was negatively associated with adaptability to high-altitudes (p < .0008). Thus, MT-ND1 and MT-ND2 can be considered as candidate genes associated with adaptation to high-altitude environments.
authors.affiliation: a College of Animal Science and Technology, Sichuan Agricultural University , Chengdu , China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shi
authors.affiliation: b Chengdu Agricultural College , Chengdu , Sichuan , China.
authors.forename: Yongsong
authors.initials: Y
authors.lastname: Hu
authors.affiliation: a College of Animal Science and Technology, Sichuan Agricultural University , Chengdu , China.
authors.forename: Jie
authors.identifier: 0000-0001-8270-1035
authors.initials: J
authors.lastname: Wang
authors.affiliation: c Department of Animal Science , University of Florida , Gainesville , FL, USA.
authors.forename: Mauricio A
authors.initials: MA
authors.lastname: Elzo
authors.affiliation: a College of Animal Science and Technology, Sichuan Agricultural University , Chengdu , China.|d Chengdu Academy of Agriculture and Forestry Sciences , Chengdu , China.
authors.forename: Xue
authors.initials: X
authors.lastname: Yang
authors.affiliation: a College of Animal Science and Technology, Sichuan Agricultural University , Chengdu , China.
authors.forename: Songjia
authors.initials: S
authors.lastname: Lai
mesh_terms: D000220:Adaptation, Biological; D000531:Altitude; D000818:Animals; D002417:Cattle / Q000145:classification / Q000235:genetics; D056726:Genetic Association Studies / Q000379:methods*; D006239:Haplotypes; D009245:NADH Dehydrogenase / Q000737:chemistry / Q000235:genetics*; D010085:Oxidative Phosphorylation; D020641:Polymorphism, Single Nucleotide; D000072417:Protein Domains; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D021122:Protein Subunits; D009245:NADH Dehydrogenase
keywords: High-altitude adaptation; MT-ND1 gene; MT-ND2 gene; Tibetan yak