The Y chromosomes of Drosophila simulans are highly polymorphic for their ability to suppress sex-ratio drive

Evolution. 2001 Apr;55(4):728-37. doi: 10.1554/0014-3820(2001)055[0728:tycods];2.


The sex-ratio trait, known in several species of Drosophila including D. simulans, results from meiotic drive of the X chromosome against the Y. Males that carry a sex-ratio X chromosome produce strongly female-biased progeny. In D. simulans, drive suppressors have evolved on the Y chromosome and on the autosomes. Both the frequency of sex-ratio X and the strength of the total drive suppression (Y-linked and autosomal) vary widely among geographic populations of this worldwide species. We have investigated the pattern of Y-linked drive suppression in six natural populations representative of this variability. Y-linked suppressors were found to be a regular component of the suppression, with large differences between populations in the mean level of suppression. These variations did not correspond to differences in frequency of discrete types of Y chromosomes, but to a more or less wide continuum of phenotypes, from nonsuppressor to partial or total suppressor. We concluded that a large diversity of Y-linked suppressor alleles exists in D. simulans and that some populations are highly polymorphic. Our results support the hypothesis that a Y-chromosome polymorphism can be easily maintained by a balance between meiotic drive and the cost of drive suppression.

MeSH terms

  • Animals
  • Drosophila / genetics*
  • Drosophila / physiology
  • Female
  • Male
  • Meiosis / genetics
  • Polymorphism, Genetic / genetics
  • Sex Ratio*
  • Statistics, Nonparametric
  • X Chromosome / genetics
  • X Chromosome / physiology
  • Y Chromosome / genetics*
  • Y Chromosome / physiology