Royal Veterinary College, University of London, London, United Kingdom.
The Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences (ICG SB RAS), Novosibirsk, Russia.
Mol Biol Evol. 2021 Jul 29;38(8):3093-3110. doi: 10.1093/molbev/msab078.
Native cattle breeds represent an important cultural heritage. They are a reservoir of genetic variation useful for properly responding to agriculture needs in the light of ongoing climate changes. Evolutionary processes that occur in response to extreme environmental conditions could also be better understood using adapted local populations. Herein, different evolutionary histories of the world northernmost native cattle breeds from Russia were investigated. They highlighted Kholmogory as a typical taurine cattle, whereas Yakut cattle separated from European taurines approximately 5,000 years ago and contain numerous ancestral and some novel genetic variants allowing their adaptation to harsh conditions of living above the Polar Circle. Scans for selection signatures pointed to several common gene pathways related to adaptation to harsh climates in both breeds. But genes affected by selection from these pathways were mostly different. A Yakut cattle breed-specific missense mutation in a highly conserved NRAP gene represents a unique example of a young amino acid residue convergent change shared with at least 16 species of hibernating/cold-adapted mammals from six distinct phylogenetic orders. This suggests a convergent evolution event along the mammalian phylogenetic tree and fast fixation in a single isolated cattle population exposed to a harsh climate.
本土牛种代表着重要的文化遗产。它们是遗传变异的储存库,有助于根据不断变化的气候条件,妥善应对农业需求。利用适应本地种群的方法,也可以更好地了解应对极端环境条件的进化过程。本文研究了俄罗斯最北部的世界本土牛种的不同进化历史。研究结果表明,科米半岛牛是典型的黄牛品种,而雅库特牛则在大约 5000 年前从欧洲黄牛中分离出来,含有许多祖先和一些新的遗传变异,使它们能够适应北极圈以上恶劣的生活条件。选择信号的扫描表明,这两个品种的许多与适应恶劣气候有关的共同基因途径都受到了选择的影响。但这些途径中受选择影响的基因大多不同。雅库特牛品种特有的一个高度保守的 NRAP 基因中的错义突变,是与至少 16 种来自六个不同系统发育阶元的冬眠/冷适应哺乳动物共享的年轻氨基酸残基趋同变化的独特例子。这表明沿着哺乳动物的系统发育树发生了趋同进化事件,并且在一个单一的、暴露在恶劣气候下的孤立牛群中快速固定。