DOI: 10.7554/elife.87198 ISSN: 2050-084X

Chromosome-level genome assembly of hadal snailfish reveals mechanisms of deep-sea adaptation in vertebrates

Wenjie Xu, Chenglong Zhu, Xueli Gao, Baosheng Wu, Han Xu, Mingliang Hu, Honghui Zeng, Xiaoni Gan, Chenguang Feng, Jiangmin Zheng, Jing Bo, Li-Sheng He, Qiang Qiu, Wen Wang, Shunping He, Kun Wang
  • General Immunology and Microbiology
  • General Biochemistry, Genetics and Molecular Biology
  • General Medicine
  • General Neuroscience

As the deepest vertebrate in the ocean, the hadal snailfish (Pseudoliparis swirei), which lives at a depth of 6,000–8,000 m, is a representative case for studying adaptation to extreme environments. Despite some preliminary studies on this species in recent years, including their loss of pigmentation, visual and skeletal calcification genes, and the role of trimethylamine N-oxide in adaptation to high-hydrostatic pressure, it is still unknown how they evolved and why they are among the few vertebrate species that have successfully adapted to the deep-sea environment. Using genomic data from different trenches, we found that the hadal snailfish may have entered and fully adapted to such extreme environments only in the last few million years. Meanwhile, phylogenetic relationships show that they spread into different trenches in the Pacific Ocean within a million years. Comparative genomic analysis has also revealed that the genes associated with perception, circadian rhythms, and metabolism have been extensively modified in the hadal snailfish to adapt to its unique environment. More importantly, the tandem duplication of a gene encoding ferritin significantly increased their tolerance to reactive oxygen species, which may be one of the important factors in their adaptation to high-hydrostatic pressure.

More from our Archive