Analysis of fatty acid composition and miRNA profile in adipose tissue after application of Allium mongolicum Regel extract in diet of sheep

Extensive regulation of microRNAs (miRNAs) that belong to a type of endogenous small noncoding RNAs on gene expression in sheep has been recognised. Meanwhile, utilisation of water extract of Allium mongolicum Regel (WEA) in diet of sheep has been proved to regulate fatty acid composition and flavour in mutton. However, the regulatory mechanism remains unclear. We conducted miRNA and mRNA sequencing in this study. Briefly, 30 male small-tailed Han sheep (4.5 months old) were randomly assigned to two groups. A basal diet with 3.4 g center dot sheep(-1)center dot d(-1) WEA supplementation (WEA group) or with no WEA supplementation (CON group) was fed to sheep, respectively. Subcutaneous and visceral adipose tissue samples were collected during slaughter after 75-day feeding experiment. We obtained 30 differentially expressed miRNAs (DE-miRNAs) after application of WEA in diet of sheep in subcutaneous adipose tissue. Likewise, 15 DE-miRNAs in visceral adipose tissue were identified. A total of 746 differentially expressed mRNAs (DE-mRNAs) with 90 lipid-related DE-mRNAs in subcutaneous adipose tissue and 569 DE-mRNAs with 73 lipid-related DE-mRNAs in visceral adipose tissue were identified after WEA supplementation. The intersection genes from predicted target genes of DE-miRNAs by databases and actual DE-mRNAs by mRNA sequencing were enriched in several lipid-related pathways both in subcutaneous adipose and in visceral adipose tissue. We constructed differential miRNAs-mRNAs networks by Cytoscape software. Our results will help to explain regulatory mechanism of fatty acid composition in mutton by dietary WEA and will provide a theoretical basis for rational use of the plant extract in diet of sheep. HIGHLIGHTS center dot Utilisation of Allium mongolicum Regel water extract led to alterations of endogenous miRNA and gene expression profiles in subcutaneous and visceral adipose tissue of sheep.center dot Allium mongolicum Regel water extract improved nutritional value and flavour of mutton by changing fatty acid composition in adipose tissue.center dot Establishment of miRNA-mRNA regulatory network with regard to manipulation of fatty acid composition in mutton by Allium mongolicum Regel water extract, and provided a theoretical basis for rational utilisation of this plant extract in diet of sheep.