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Parallel adaptations of Japanese whiting, Sillago japonica under temperature stress
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  • Zhiqiang Han,
  • Xinyu Guo,
  • Qun Liu,
  • Shanshan Liu,
  • Zhixin Zhang,
  • shijun xiao,
  • Tianxiang Gao
Zhiqiang Han
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Xinyu Guo
BGI-Shenzhen
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Qun Liu
BGI-Shenzhen
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Shanshan Liu
BGI-Shenzhen
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Zhixin Zhang
Tokyo University of Marine Science and Technology Graduate School of Marine Science and Technology
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shijun xiao
Tibet Academy of Agricultural and Animal Husbandry Sciences
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Tianxiang Gao
Zhejiang Ocean University
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Abstract

Knowledge about the genetic adaptations of various organisms to heterogeneous environments in the Northwestern Pacific remains poorly understood. The mechanism by which organisms adapt to temperature in response to climate change must be determined. We sequenced the whole genomes of Sillago japonica individuals collected from different latitudinal locations along the coastal waters of China and Japan to detect the possible thermal adaptations. A total of 5.48 million single nucleotide polymorphisms (SNPs) from five populations revealed a complete genetic break between the China and Japan groups. This genetic structure was partly attributed to geographic distance and local adaptation. Although parallel evolution within species is comparatively rare at the DNA level, the shared natural selection genes between two isolated populations (Zhoushan and Ise Bay/Tokyo Bay) indicated possible parallel evolution at the genetic level induced by temperature. Our result proved that the process of temperature selection on isolated populations is repeatable. Additionally, the candidate genes were functionally related to membrane fluidity in cold environments and the cytoskeleton in high-temperature environments. These results advance our understanding of the genetic mechanisms underlying the rapid adaptations of fish species. Projections of species distribution models suggested that China and Japan groups may have different responses to future climate changes: the former could expand, whereas the latter may contract. The results of the present population genomic work expand our understanding of genetic differentiation and adaptation to changing environments.