miRNAs are short noncoding RNAs that post-transcriptionally regulate gene expression by binding to complementary regions of the target mRNA. The miRNAs associated with the deposition of intramuscular fat (IMF) content in pigs, which is an important meat quality trait, still remain to be investigated. In this study, the longissimus dorsi muscles (LDMs) from 234 individuals were collected from Yorkshire pigs at 90 kg body weight and the miRNA deep sequencing was conducted by using two tailed groups which were taken five individuals each from high (2.94 ± 0.04%) and low (1.62 ± 0.02%) IMF samples. The results showed that total 268 mature miRNAs were identified, of which 70 were previously known, 162 were conserved among species and 36 were identified specifically in pigs. Moreover, 28 miRNAs involved in adipogenesis were differentially expressed in the two groups, and five out of 16 miRNAs were validated by quantitative PCR (qPCR) using stem loop primers. Our results may serve as a fundamental basis for understanding the roles of miRNA in IMF development in pigs. The miRNAs identified in our study can be utilized for research IMF trait in pig population and will provide further clues to the study of meat quality regulatory mechanisms.
Keywords: Pig; intramuscular fat; miRNA.