BMC Evolutionary Biology | |
Demasculinization of the Anopheles gambiae X chromosome | |
Kalle Magnusson1  Antonio M Mendes2  Gareth J Lycett3  | |
[1] Department of Life Sciences, Imperial College London, London, UK;Division of Biology, California Institute of Technology, Pasadena, USA;Liverpool School of Tropical Medicine, London, UK | |
关键词: Anopheles gambiae; demasculinization; germline x-chromosome inactivation; sexual antagonism; dosage compensation; | |
DOI : 10.1186/1471-2148-12-69 | |
学科分类:生物科学(综合) | |
来源: BioMed Central | |
【 摘 要 】
In a number of organisms sex-biased genes are non-randomly distributed between autosomes and the shared sex chromosome X (or Z). Studies on Anopheles gambiae have produced conflicting results regarding the underrepresentation of male-biased genes on the X chromosome and it is unclear to what extent sexual antagonism, dosage compensation or X-inactivation in the male germline, the evolutionary forces that have been suggested to affect the chromosomal distribution of sex-biased genes, are operational in Anopheles. We performed a meta-analysis of sex-biased gene expression in Anopheles gambiae which provides evidence for a general underrepresentation of male-biased genes on the X-chromosome that increased in significance with the observed degree of sex-bias. A phylogenomic comparison between Drosophila melanogaster, Aedes aegypti and Culex quinquefasciatus also indicates that the Anopheles X chromosome strongly disfavours the evolutionary conservation of male-biased expression and that novel male-biased genes are more likely to arise on autosomes. Finally, we demonstrate experimentally that transgenes situated on the Anopheles gambiae X chromosome are transcriptionally silenced in the male germline. The data presented here support the hypothesis that the observed demasculinization of the Anopheles X chromosome is driven by X-chromosome inactivation in the male germline and by sexual antagonism. The demasculinization appears to be the consequence of a loss of male-biased expression, rather than a failure in the establishment or the extinction of male-biased genes.
【 授权许可】
CC BY
【 预 览 】
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