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Rapid evolution of a Y-chromosome heterochromatin protein underlies sex chromosome meiotic drive.
Proc Natl Acad Sci U S A, 113(15):4110-5.
Sex chromosome meiotic drive, the non-Mendelian transmission of sex chromosomes,is the expression of an intragenomic conflict that can have extreme evolutionaryconsequences. However, the molecular bases of such conflicts remain poorly understood. Here, we show that a young and rapidly evolving X-linked heterochromatin protein 1 (HP1) gene, HP1D2, plays a key role in the classical Paris sex-ratio (SR) meiotic drive occurring in Drosophila simulans Driver HP1D2alleles prevent the segregation of the Y chromatids during meiosis II, causing female-biased sex ratio in progeny. HP1D2 accumulates on the heterochromatic Y chromosome in male germ cells, strongly suggesting that it controls the segregation of sister chromatids through heterochromatin modification. We show that Paris SR drive is a consequence of dysfunctional HP1D2 alleles that fail toprepare the Y chromosome for meiosis, thus providing evidence that the rapid evolution of genes controlling the heterochromatin structure can be a significant source of intragenomic conflicts.
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