Complete Dosage Compensation in Anopheles stephensi and the Evolution of Sex-Biased Genes in Mosquitoes.
Bottom Line: Furthermore, Culicinae mosquitoes, including the Aedes genus, have homomorphic sex-determining chromosomes, negating the need for dosage compensation.Autosomal and X-linked genes in An. stephensi showed very similar levels of expression in both males and females, indicating complete dosage compensation.In addition, we comparatively analyzed the differentially expressed genes between adult males and adult females in both species, investigated sex-biased gene chromosomal distribution patterns in An. stephensi and provided three examples where gene duplications may have enabled the acquisition of sex-specific expression during mosquito evolution.
Affiliation: Program of Genetics, Bioinformatics, and Computational Biology, Virginia Tech, Blacksburg, Virginia Department of Biochemistry, Virginia Tech, Blacksburg, Virginia.Show MeSH
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Mentions: We calculated the RPKM ratio for each pair of orthologs in An. stephensi and Ae. aegypti. We normalized the median RPKM ratio of An. stephensi autosomal genes to their orthologs in Ae. aegypti to 1 to adjust for differences in the overall expression levels between the species. After normalization, we observed that the median RPKM ratio of An. stephensi X-linked genes to their orthologs in Ae. aegypti was close to 1 in both sexes (fig. 2). These results indicate that there is dosage compensation for the X chromosome in male An. stephensi. The female X-linked gene expression level remained the same indicating that the dosage compensation mechanism is either exclusive to males or has been repressed in females.Fig. 2.—
Affiliation: Program of Genetics, Bioinformatics, and Computational Biology, Virginia Tech, Blacksburg, Virginia Department of Biochemistry, Virginia Tech, Blacksburg, Virginia.