Meiotic cohesin Rec8 imposes fitness costs on fission yeast gametes favoring the evolution of parental bias in gene expression

• 成果类型: Article
• 署名作者: Martins, Celso; Booth, Harry; Salat-Canela, Claudia; Hadjivasiliou, Zena; Vjestica, Aleksandar
• 署名单位: University of Lausanne; Francis Crick Institute; University of London; University College London; University of London; University College London; University of London; University College London
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2524968123
• 发表日期: 2026-07-07
• 页码: e2524968123
• 关键词: cell biology; EVOLUTION; sexual reproduction; yeast; schizosaccharomyces-pombe; MATING-TYPE; transcription factor; protein; differentiation; dimorphism; pheromone; selection; encodes; STE11P

摘要

Differences between partner gametes, which evolved repeatedly in eukaryotes, can contribute to the evolution of the sexes, sexual selection, and non-Mendelian inheritance. Yet, the empirical evidence for how functional asymmetries arise between initially equivalent gametes is limited. Here, we combine theoretical and experimental approaches in the fission yeast Schizosaccharomyces pombe to show how selective pressures acting concurrently on gametes and zygotes drive the evolution of gamete differences. We find that despite being morphologically identical, P- and M-type partner gametes invest asymmetrically in zygotic development by contributing different amounts of conserved meiotic cohesins. P-gametes preferentially produce the Rec8 cohesin that increases zygotic fitness but reduces gamete viability, revealing a trade-off between reproductive success and gamete survival. We demonstrate that this asymmetry is mediated by partner-specific communication and model its evolutionary dynamics using empirically determined parameters. Our results support classical theoretical predictions for the evolution of gamete differences and provide a mechanistic understanding of how molecular asymmetries between partners can originate from opposing selection pressures acting in species that lack morphologically distinct gametes.