The use of DNA demethylating agents has been popular in epigenetic studies. Recently, Cook and colleagues, in a 2015 American Naturalist article, claimed an effect of 5-aza-2'-deoxycytidine (5-aza-dC) on the sex ratio of a parasitoid wasp without verifying its effect on DNA methylation. We repeated the 5-aza-dC feeding treatment to test its effectiveness. We used bisulfite amplicon sequencing of 10 genes that either were heavily methylated, previously showed a response to 5-aza-dC, or were suggested to regulate fatty acid synthesis epigenetically, and we demonstrate that wasps fed 5-aza-dC did not show reduced DNA methylation at these loci. Therefore, the conclusion that demethylation shifts sex ratios upward needs reconsideration.
Keywords: Nasonia vitripennis; DNA methylation; bisulfite amplicon sequencing; fatty acid synthesis; parasitoid; sex ratio.