Oh, that's disappointing. I thought you were going to provide an actual link from the study itself.
Here, allow me to do that.
Because most of the genes responsible for this asymmetric response to androgens are autosomal (see next section), they must be transregulated in response to the XX versus XY sex chromosome karyotype. Transregulation can occur in many ways, but recent studies demonstrate that the sex chromosome karyotype alone, independent of sex hormones, epigenetically regulates many autosomal genes (reviewed in Wijchers and Festenstein 2011). Epigenetic modi?cation (i.e., methylation, histone tail modi?cations, and nucleosome repositioning) is emerging as a pivotal factor controlling gene expression. For example, variation in the level of a single histone modi?cation (trimethylation of lysine residue-4 on histone-3; the H3K4me3 epi-mark) of gene promoters can account for almost 50% of the variation in genome-wide gene expression levels in the early mouse embryo (Mikkelsen et al. 2007). From these studies and others (see below), we conclude that XX- and XY-speci?c epi-marks almost certainly contribute to the differential sensitivity to androgens of XX and XY fetuses (Figure 1B)
"We conclude that XX- and XY-specific epi-marks almost certainly contribute to the differential sensitivity to androgens of XX and XY fetuses".
And how do the researchers define "epi-marks"?
We will use the term epi-marks to denote changes in chromatin structure that in?uence the transcription rate of genes (coding and noncoding, such as miRNAs), including nucleosome repositioning, DNA methylation, and/or modi?cation of histone tails, but not including changes in DNA sequence. It is now well established that a parent’s epi-marks sometimes carryover across generations and in?uence the phenotypes of offspring
Fluctuations in the levels of DNA methylation, nucleosome repositioning, or changes in chromatin structure are all secondary to alterations to other genes
Epigenetics is genetics. It's genes regulating the expression of other genes. The very fact that some of these epigenetic traits are transgenerational is because they are, in fact, encoded by genes.
This post was edited on 12/12 at 9:42 pm