Identification of candidate CircRNA associated with intramuscular fat deposition in Duroc pigs

In order to investigate the potential mechanisms affecting the intramuscular fat content, high-throughput RNA sequencing was employed to assess the expression profiles of circRNAs in the longissimus dorsi tissues of Duroc pigs with high and low IMF content. A total of 230 circRNAs showed significantly differential expression levels between the HIMF and LIMF groups. GO annotation revealed that the host genes of these circRNAs were associated with responses to lipids, such as lipid tube assembly, lipid metabolic process, etc. Moreover, the KEGG enrichment analysis indicated that the host genes of these circRNAs were enriched in the AMP-activated protein kinase signaling pathway, fatty acid metabolism, etc. Several key circRNAs involved in lipid metabolism were screened, including novel_circ_0001751, novel_circ_0018596, novel_circ_0000494, etc. In addition, five circRNA-miRNA interaction networks were constructed. Notably, this study demonstrates for the first time the role of novel_circ_0018596 and novel_circ_0000494 in controlling IMF deposition in Duroc pigs.