Microrna Profiling in Cattle Divergently Selected for Residual Feed Intake

Abstract

MicroRNAs (miRNAs) are short non-coding RNAs that post-transcriptionally regulate expression of mRNAs in many biological pathways. Here we report comprehensive miRNA profiles by deep sequencing in Angus cattle divergently selected for residual feed intake (RFI). Two miRNA libraries were constructed from pooled RNA extracted from livers of low and high RFI cattle, and sequenced with the Illumina Genome Analyser. We identified 305 known bovine miRNAs. bta-miR-143, bta-miR-30, bta-miR-122, bta-miR-378 and bta-let-7 were the top 5 most abundant miRNA families expressed in liver, representing more than 63% of expressed miRNAs. Mir-143 is the most expressed bovine miRNA in liver, and is up-regulated in high RFI cattle. Mir-122 is the second most expressed miRNA in liver and is down regulated in high RFI animals. The differentially expressed miRNAs may play important roles in the regulation of the bioprocesses responsible for variation in RFI in cattle.