Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan.
Global Station for Big Data and Cybersecurity, GI-CoRE, Hokkaido University, Sapporo, Japan.
Genome Biol Evol. 2022 May 3;14(5). doi: 10.1093/gbe/evac068.
For more than 100 years, house mice (Mus musculus) have been used as a key animal model in biomedical research. House mice are genetically diverse, yet their genetic background at the global level has not been fully understood. Previous studies have suggested that they originated in South Asia and diverged into three major subspecies, almost simultaneously, approximately 110,000-500,000 years ago; however, they have spread across the world with the migration of modern humans in prehistoric and historic times (∼10,000 years ago to the present day) and have undergone secondary contact, which has complicated the genetic landscape of wild house mice. In this study, we sequenced the whole-genome sequences of 98 wild house mice collected from Eurasia, particularly East Asia, Southeast Asia, and South Asia. Although wild house mice were found to consist of three major genetic groups corresponding to the three major subspecies, individuals representing admixtures between subspecies were more prevalent in East Asia than has been previously recognized. Furthermore, several samples exhibited an incongruent pattern of genealogies between mitochondrial and autosomal genomes. Using samples that likely retained the original genetic components of subspecies with the least admixture, we estimated the pattern and timing of divergence among the subspecies. The estimated divergence time of the three subspecies was 187,000-226,000 years ago. These results will help us to understand the genetic diversity of wild mice on a global scale, and the findings will be particularly useful in future biomedical and evolutionary studies involving laboratory mice established from such wild mice.
一百多年来，家鼠（Mus musculus）一直被用作生物医学研究的重要动物模型。家鼠遗传多样性丰富，但它们的全球遗传背景尚未完全了解。先前的研究表明，家鼠起源于南亚，大约在 11 万至 50 万年前，几乎同时分化为三个主要亚种；然而，随着现代人类在史前和历史时期（约 1 万年前至今）的迁徙，它们已经遍布世界各地，并发生了二次接触，这使得野生家鼠的遗传格局变得复杂。在这项研究中，我们对来自欧亚大陆，特别是东亚、东南亚和南亚的 98 只野生家鼠的全基因组序列进行了测序。尽管野生家鼠被发现由三个主要遗传群体组成，对应于三个主要亚种，但亚种间杂交个体在东亚比以前认为的更为普遍。此外，一些样本表现出线粒体和常染色体基因组之间的系统发育模式不一致。利用可能保留了原始遗传成分且杂交最少的样本，我们估计了亚种间的分化模式和时间。三个亚种的估计分化时间为 18.7 万至 22.6 万年前。这些结果将有助于我们在全球范围内了解野生小鼠的遗传多样性，并且对于未来涉及从这些野生小鼠建立的实验室小鼠的生物医学和进化研究将特别有用。
