Meiotic cohesin Rec8 imposes fitness costs on fission yeast gametes to drive evolution of parental bias in gene expression
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ABSTRACT: Differences between partner gametes, which evolved repeatedly in unicellular and multicellular eukaryotes, are central to biological phenomena such as non-Mendelian inheritance and sexual selection1–4. How functional asymmetries first emerge between equivalent partners is poorly understood due to limited experimental evidence. Here, we report that in the isogamous fission yeast Schizosaccharomyces pombe, partner P- and M-gametes differentially invest into zygotic development by making unequal amounts of the conserved meiotic cohesin Rec85. Driven by asymmetric partner communication, P-gametes produce Rec8 before fertilization to promote meiotic fidelity and production of viable spores in zygotes. However, this early Rec8 expression also causes genomic instabilities6 and imposes a fitness cost on P-gametes, revealing a trade-off between sexual success and gamete survival. Using biologically parametrized model and experimental evolution, we show that the Rec8 costs and benefits drive selection for biased parental investment and evolution of mating populations. Our work dissects a molecular mechanism that selects for functional gamete asymmetries in an isogamous species, providing rare experimental evidence for an early step in the evolution of gamete dimorphism.
ORGANISM(S): Schizosaccharomyces pombe
PROVIDER: GSE293837 | GEO | 2025/07/03
REPOSITORIES: GEO
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