Phylogeny and sex chromosome evolution of palaeognathae

Research output: Contribution to journalJournal articlepeer-review

  • Zongji Wang
  • Jilin Zhang
  • Xiaoman Xu
  • Christopher Witt
  • Yuan Deng
  • Guangji Chen
  • Guanliang Meng
  • Shaohong Feng
  • Luohao Xu
  • Tamas Szekely
  • KU, thw266
  • Qi Zhou

Many paleognaths (ratites and tinamous) have a pair of homomorphic ZW sex chromosomes in contrast to the highly differentiated sex chromosomes of most other birds. To understand the evolutionary causes for the different tempos of sex chromosome evolution, we produced female genomes of 12 paleognathous species and reconstructed the phylogeny and the evolutionary history of paleognathous sex chromosomes. We uncovered that Palaeognathae sex chromosomes had undergone stepwise recombination suppression and formed a pattern of “evolutionary strata”. Nine of the 15 studied species' sex chromosomes have maintained homologous recombination in their long pseudoautosomal regions extending more than half of the entire chromosome length. We found that in older strata, the W chromosome suffered more serious functional gene loss. Their homologous Z-linked regions, compared with other genomic regions, have produced an excess of species-specific autosomal duplicated genes that evolved female-specific expression, in contrast to their broadly expressed progenitors. We speculate the “defeminization” of Z chromosome with underrepresentation of female-biased genes and slow divergence of sex chromosomes of paleognaths might be related to their distinctive mode of sexual selection targeting females that evolved in their common ancestors.

Original languageEnglish
JournalJournal of Genetics and Genomics
Volume49
Issue number2
Pages (from-to)109-119
Number of pages11
ISSN1673-8527
DOIs
Publication statusPublished - 2022

Bibliographical note

Publisher Copyright:
© 2021 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China

    Research areas

  • Comparative genomics, Paleognaths, Sex chromosome evolution, Sexual selection

ID: 287607185