The Drosophila simulans Y chromosome interacts with the autosomes to influence male fitness

J Evol Biol. 2017 Oct;30(10):1821-1825. doi: 10.1111/jeb.13141. Epub 2017 Aug 4.


The Y chromosome should degenerate because it cannot recombine. However, male-limited transmission increases selection efficiency for male-benefit alleles on the Y, and therefore, Y chromosomes should contribute significantly to variation in male fitness. This means that although the Drosophila Y chromosome is small and gene-poor, Y-linked genes are vital for male fertility in Drosophila melanogaster and the Y chromosome has large male fitness effects. It is unclear whether the same pattern is seen in the closely related Drosophila simulans. We backcrossed Y chromosomes from three geographic locations into five genetic backgrounds and found strong Y and genetic background effects on male fertility. There was a significant Y-background interaction, indicating substantial epistasis between the Y and autosomal genes affecting male fertility. This supports accumulating evidence that interactions between the Y chromosome and the autosomes are key determinants of male fitness.

Keywords: Drosophila simulans; ebony; coevolution; epistasis; fertility.

MeSH terms

  • Animals
  • Chromosomes / metabolism*
  • Drosophila simulans / genetics*
  • Genetic Fitness / genetics*
  • Male
  • Y Chromosome / metabolism*