Distinct roles of androgen receptor, estrogen receptor alpha, and BCL6 in the establishment of sex-biased DNA methylation in mouse liver

Abstract

Sexual dimorphism in gene regulation, including DNA methylation, is the main driver of sexual dimorphism in phenotypes. However, the questions of how and when sex shapes DNA methylation remain unresolved. Recently, using mice with different combinations of genetic and phenotypic sex, we identified sex-associated differentially methylated regions (sDMRs) that depended on the sex phenotype. Focusing on a panel of validated sex-phenotype dependent male- and female-biased sDMRs, we tested the developmental dynamics of sex bias in liver methylation and the impacts of mutations in the androgen receptor, estrogen receptor alpha, or the transcriptional repressor Bcl6 gene. True hermaphrodites that carry both unilateral ovaries and contralateral testes were also tested. Our data show that sex bias in methylation either coincides with or follows sex bias in the expression of sDMR-proximal genes, suggesting that sex bias in gene expression may be required for demethylation at certain sDMRs. Global ablation of AR, ESR1, or a liver-specific loss of BCL6, all alter sDMR methylation, whereas presence of both an ovary and a testis delays the establishment of male-type methylation levels in hermaphrodites. Moreover, the Bcl6-LKO shows dissociation between expression and methylation, suggesting a distinct role of BCL6 in demethylation of intragenic sDMRs.

Genetic variation in the Y chromosome and sex-biased DNA methylation in somatic cells in the mouse

“…Next, we asked if the expression levels of the other ubiquitously expressed gene candidates were different between mice with M. musculus musculus and M.musculus domesticus Y chromosomes. Expression levels of Eif2s3y , Uty , and Ddx3y were retrieved from our RNA-seq data for adult C57BL/6N (AlOgayil et al 2021 ) and B6.Y TIR livers (Zhuang et al 2020 ) and normalized to Kdm5d RNA levels. Ddx3y and Eif2s3y expression levels were significantly lower, whereas Uty levels were significantly higher in B6.Y TIR compared to C57BL/6N livers (Fig.…”

“…The majority of yDMRs overlap with TEs and most of the TE-related yDMRs have lower methylation in XY compared to XX mice (Table 1 ). Previous studies have established that gonadal sex has a major impact on DNA methylation in mouse liver (AlOgayil et al 2021 ; Hao and Waxman 2021 ; McCormick et al 2017 ; Reizel et al 2015 ; Zhuang et al 2020 ), whereas the X chromosome dosage predominantly affects DNA methylation of X-linked loci (Zhuang et al 2020 ). Here, we report that the Y chromosome influences DNA methylation of certain TEs.…”

“…Uty , Ddx3y , Eif2s3y , and Kdm5d expression data were retrieved from our previously published RNA-seq results from the livers of C57BL/6N males and B6.Y TIR mice (AlOgayil et al 2021 ; Zhuang et al 2020 ).…”

Postnatal developmental trajectory of sex-biased gene expression in the mouse pituitary gland

“…Pituitary-specific loss of AR in male mice result in increased Prl gene expression and serum PRL levels [ 78 ], and gonadotrope-specific loss of AR in female mice result in decreased Fshb gene expression and serum FSH and LH levels [ 79 ]. In addition, global AR ablation affects its repression of sex-biased genes in the liver by altering methylation levels at the promoter regions [ 80 ], whether this has a similar effect on pituitary sex-biased gene expression remains to be examined. We also predicted by Lisa that female-biased gene expression involved regulation by polycomb complexes PRC1 (CBX7) and PRC2 (SUZ12 and EZH2).…”

Liver Injury and Cell Survival in Non-Alcoholic Steatohepatitis Regulated by Sex-Based Difference through B Cell Lymphoma 6

“…In addition to Bcl6, AR and ESR1 regulated sex-biased gene expression through the production and maintenance of the sex differences of sDMRs. Thus, Bcl6 and other sex-related transcription factors regulate sex-biased gene expression via the direct bindings to the enhancer and promoter regions of these genes [ 51 ].…”