Direct androgen receptor regulation of sexually dimorphic gene expression in the mammalian kidney
Mammalian organs exhibit distinct physiology, disease susceptibility and injury responses between the sexes. In the mouse kidney, sexually dimorphic gene activity maps predominantly to proximal tubule (PT) segments. Bulk RNA-seq data analyses demonstrated sex differences were established from 4 and 8 weeks after birth under gonadal control. Hormone injection studies and genetic removal of androgen and estrogen receptors highlighted direct androgen receptor (AR) mediated regulation of gene activity in PT cells as the primary regulatory mechanism. Single-nuclear multiomic analysis identified putative cis regulatory regions and cooperating factors mediating PT responses to AR activity. In the human kidney, a limited set of genes showed conserved sex-linked regulation. Comparative analysis of the mouse liver underscored organ-specific differences in the regulation of sexually dimorphic gene expression. The organ-specific pathways of sexual differentiation identified here raise interesting questions on the evolution, physiological significance, and disease-linkage of sexually dimorphic gene activity. Overall design: Whole kidneys were dissociated from adult male and female C57BL/6J mice and combined snRNA- and snATAC-seq was performed using the 10X Chromium multiome ATAC + gene expression kit. There were two genotypes: WT (Ar_c/y) and nephron-specific knockout of androgen receptor (Six2CRE/+, Ar_c/y).