Sex Chromosome Dosage Compensation in Heliconius Butterflies: Global yet Still Incomplete?

ABSTRACT: The evolution of heterogametic sex chromosomes is often-but not always-accompanied by the evolution of dosage compensating mechanisms that mitigate the impact of sex-specific gene dosage on levels of gene expression. One emerging view of this process is that such mechanisms may only evolve in male-heterogametic (XY) species but not in female-heterogametic (ZW) species, which will consequently exhibit "incomplete" sex chromosome dosage compensation. However, recent results suggest that at least some Lepidoptera (moths and butterflies) may prove to be an exception to this prediction. Studies in bombycoid moths indicate the presence of a chromosome-wide epigenetic mechanism that effectively balances Z chromosome gene expression between the sexes by reducing Z-linked expression in males. In co

SUBMITTER: Walters JR 

PROVIDER: S-EPMC4607515 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature