title: Analysis of the cytochrome c oxidase subunit 1 (COX1) gene reveals the unique evolution of the giant panda.
abstract: As the rate-limiting enzyme of the mitochondrial respiratory chain, cytochrome c oxidase (COX) plays a crucial role in biological metabolism. "Living fossil" giant panda (Ailuropoda melanoleuca) is well-known for its special bamboo diet. In an effort to explore functional variation of COX1 in the energy metabolism behind giant panda's low-energy bamboo diet, we looked at genetic variation of COX1 gene in giant panda, and tested for its selection effect. In 1545 base pairs of the gene from 15 samples, 9 positions were variable and 1 mutation leaded to an amino acid sequence change. COX1 gene produces six haplotypes, nucleotide (pi), haplotype diversity (Hd). In addition, the average number of nucleotide differences (k) is 0.001629±0.001036, 0.8083±0.0694 and 2.517, respectively. Also, dN/dS ratio is significantly below 1. These results indicated that giant panda had a low population genetic diversity, and an obvious purifying selection of the COX1 gene which reduces synthesis of ATP determines giant panda's low-energy bamboo diet. Phylogenetic trees based on the COX1 gene were constructed to demonstrate that giant panda is the sister group of other Ursidae.
authors.affiliation: Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an 625014, Sichuan, China. Electronic address: 80262886@qq.com.
authors.forename: Yao-Dong
authors.initials: YD
authors.lastname: Hu
authors.affiliation: Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an 625014, Sichuan, China.
authors.forename: Hui-Zhong
authors.initials: HZ
authors.lastname: Pang
authors.affiliation: China Conservation and Research Center for Giant Panda, Wolong, 623006, China.
authors.forename: De-Sheng
authors.initials: DS
authors.lastname: Li
authors.affiliation: China Conservation and Research Center for Giant Panda, Wolong, 623006, China.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Ling
authors.affiliation: Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an 625014, Sichuan, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Lan
authors.affiliation: Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an 625014, Sichuan, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an 625014, Sichuan, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an 625014, Sichuan, China.
authors.forename: Di-Yan
authors.initials: DY
authors.lastname: Li
authors.affiliation: China Conservation and Research Center for Giant Panda, Wolong, 623006, China.
authors.forename: Rong-Ping
authors.initials: RP
authors.lastname: Wei
authors.affiliation: China Conservation and Research Center for Giant Panda, Wolong, 623006, China.
authors.forename: He-Min
authors.initials: HM
authors.lastname: Zhang
authors.affiliation: China Conservation and Research Center for Giant Panda, Wolong, 623006, China. Electronic address: wolongpanda@qq.com.
authors.forename: Cheng-Dong
authors.initials: CD
authors.lastname: Wang
mesh_terms: D000818:Animals; D051545:Cyclooxygenase 1 / Q000145:classification / Q000235:genetics*; D019143:Evolution, Molecular; D006239:Haplotypes; D010802:Phylogeny; D021122:Protein Subunits / Q000235:genetics; D012641:Selection, Genetic; D001503:Ursidae / Q000235:genetics*
chemical_list: D021122:Protein Subunits; D051545:Cyclooxygenase 1
keywords: Ailuropoda melanoleuca; COX1; Genetic diversity; Purifying selection