Chromosome-level genome assembly of the kiang (Equus kiang) illuminates genomic basis for its high-altitude adaptation  

作　　者：Chuang ZHOU Xiaofeng ZHENG Kexin PENG Kaize FENG Bisong YUE Yongjie WU 

机构地区：[1]Key Laboratory of Bioresources and Ecoenvironment(Ministry of Education),College of Life Sciences,Sichuan University,Chengdu,China

出　　处：《Integrative Zoology》2024年第6期1199-1210,共12页整合动物学(英文版)

基　　金：supported by the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0501);the National Natural Science Foundation of China(No.32270454).

摘　　要：The kiang(Equus kiang)can only be observed in the Qinghai–Tibet Plateau(QTP).The kiang displayed excellent athletic performance in the high-altitude environment,which attracted wide interest in the investigation of the potential adaptive mechanisms to the extreme environment.Here,we assembled a chromosome-level genome of the kiang based on Hi-C sequencing technology.A total of 324.14 Gb clean data were generated,and the chromosomelevel genome with 26 chromosomes(25+X)and scaffold N50 of 101.77 Mb was obtained for the kiang.The genomic synteny analysis revealed large-scale chromosomal rearrangement during the evolution process of Equus species.Phylogenetic and divergence analyses revealed that the kiang was the sister branch to the ass and diverged from a common ancestor at approximately 13.5 Mya.The expanded gene families were mainly related to the hypoxia response,metabolism,and immunity.The kiang suffered a significant loss of olfaction-related genes,which might indicate decreased olfactory sensibility.Positively selected genes(PSGs)detected in the kiang were mainly associated with hypoxia response.Especially,there were two species-specific missense amino acid mutations in the PSG STAT3 annotated in the hypoxia-inducible factor 1 signal pathway,which may play an important role in the high-altitude adaptation of the kiang.Moreover,structure variations in the kiang genome were also identified,which possibly contributed to the high-altitude adaptation of the kiang.Comparative analysis revealed a lot of speciesspecific insertions and deletions in the kiang genome,such as PIK3CB and AKT with 3258 and 189 bp insertions in the intron region,respectively,possibly affecting the expression and regulation of hypoxia-related downstream pathways.This study provided valuable genomic resources,and our findings help a better understanding of the underlying adaptive strategies to the high-altitude environment in the kiang.

关 键 词：chromosome-level genome high-altitude adaptation kiang missense mutation positive selection structural variation 

分 类 号：R73[医药卫生—肿瘤]