Characterization of structural variation in Tibetans reveals new evidence of high-altitude adaptation and introgression

Genome Biol. 2021 May 25;22(1):159. doi: 10.1186/s13059-021-02382-3.

Abstract

Background: Structural variation (SV) acts as an essential mutational force shaping the evolution and function of the human genome. However, few studies have examined the role of SVs in high-altitude adaptation and little is known of adaptive introgressed SVs in Tibetans so far.

Results: Here, we generate a comprehensive catalog of SVs in a Chinese Tibetan (n = 15) and Han (n = 10) population using nanopore sequencing technology. Among a total of 38,216 unique SVs in the catalog, 27% are sequence-resolved for the first time. We systematically assess the distribution of these SVs across repeat sequences and functional genomic regions. Through genotyping in additional 276 genomes, we identify 69 Tibetan-Han stratified SVs and 80 candidate adaptive genes. We also discover a few adaptive introgressed SV candidates and provide evidence for a deletion of 335 base pairs at 1p36.32.

Conclusions: Overall, our results highlight the important role of SVs in the evolutionary processes of Tibetans' adaptation to the Qinghai-Tibet Plateau and provide a valuable resource for future high-altitude adaptation studies.

Keywords: High-altitude adaptation; Long-read sequencing; Structural variation; Tibetan.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / genetics*
  • Altitude*
  • Animals
  • Ethnicity / genetics
  • Genomic Structural Variation*
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Male
  • Neanderthals / genetics
  • Repetitive Sequences, Nucleic Acid / genetics
  • Tibet
  • Young Adult