Small RNA-seq of adult male and female mouse liver

Total RNA-seq analysis of mouse liver RNA following locked nucleic acids (LNAs) treatment to identify mRNA targets of mmu-miR-802-5p and mmu-miR-1948-5p in vivo. These datasets are part of a study where we used small RNA sequencing to discover 24 sex-biased mouse liver miRNAs, and then investigated the roles of two of these miRNAs in GH-regulated liver sex differences. Studies in pre-pubertal and young adult mice, and in mice where pituitary hormones are ablated or where sex-specific hepatic GH signaling is dysregulated, demonstrated that the male-biased miR-1948 and the female-biased miR-802 are both regulated by sex-specific pituitary GH secretory patterns, acquire sex specificity at puberty, and are dependent on the GH-activated transcription factor STAT5 for their sex-specific expression. Both miRNAs are within genomic regions characterized by sex-biased chromatin accessibility. miR-1948, a novel, uncharacterized miRNA, has essential features for correct Drosha/Dicer processing, generates a bona fide mature miRNA with strong strand bias for the 5p arm, and is bound by Argonaute in liver tissue, as is miR-802. In vivo studies using inhibitory locked nucleic acid sequences revealed that miR-1948-5p preferentially represses female-biased mRNAs and induces male-biased mRNAs in male liver, and conversely, miR-802-5p preferentially represses male-biased mRNAs and increases levels of female-biased mRNAs in female liver. Cytochrome P450 mRNAs were strongly enriched as targets of both miRNAs. Thus, miR-1948-5p and miR-802-5p are functional components of the GH regulatory network that shapes sex-differential gene expression in mouse liver. Overall design: Small RNA-seq libraries were generated from total liver RNA isolated from 8 week old male and female mice. Differential analysis between male and female small RNA-seq datasets identified sex-differential microRNAs.