Extreme heterogeneity in sex chromosome differentiation and dosage compensation in livebearers

Darolti, I; Wright, A E; Sandkam, B A; Morris, J; Bloch, N I; Farré, M; Fuller, R C; Bourne, G R; Larkin, D M; Breden, F; Mank, J E

Abstract

Morphologically and functionally distinct X and Y chromosomes have repeatedly evolved across the tree of life. However, the extent of differentiation between the sex chromosomes varies substantially across species. As sex chromosomes diverge, the Y chromosome gene activity decays, leaving genes on the sex chromosomes reduced to a single functional copy in males. Mechanisms have evolved to compensate for this reduction in gene dosage. Here, we perform a comparative analysis of sex chromosome systems across poeciliid species and uncover extreme variation in the degree of sex chromosome differentiation and Y chromosome degeneration. Additionally, we find evidence for a case of chromosome-wide dosage compensation in fish. Our findings have important implications for sex chromosome evolution and regulation.

Citation

Darolti, I., Wright, A. E., Sandkam, B. A., Morris, J., Bloch, N. I., Farré, M., …Mank, J. E. (in press). Extreme heterogeneity in sex chromosome differentiation and dosage compensation in livebearers. https://doi.org/10.1073/pnas.1905298116

• Journal Article Type: Article
• Acceptance Date: Aug 6, 2019
• Deposit Date: Sep 6, 2019
• Publicly Available Date: Sep 6, 2019
• Journal: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1073/pnas.1905298116
• Public URL: https://rvc-repository.worktribe.com/output/1380934