Integrated analysis of miRNA-mediated ceRNA networks in ovine skeletal muscle development

Abstract Background: The embryo stage is a key period for sheep skeletal muscle growth and development. Proliferation, differentiation, and hypertrophy of fibers affect muscle growth potential directly. Analyzing transcriptome data is of great significance for revealing important time nodes of fetus muscle development and screening related regulation factors. Muscle development is a complex biological process, including a intricate network of multiple factor interactions. Among them, non-coding RNA, especially miRNA-mediated regulation, plays a fine regulatory role. The purpose of this study was to investigate the important genes and transcripts involved in the genetic mechanism of embryos skeletal muscle development in late pregnancy. Results: Herein we did a small RNA sequencing(RNA-Seq) of embryo at 85 days (D85N), 105 days (D105N) and 135 days(D135N), then performed bioinformatic analysis in order to identify the miRNA-mediated co-expression networks. Our findings identified 505 DE-miRNAs. Integrating the current miRNA data and the previously obtained lncRNA data, multiple networks were constructed, including miRNA-mRNA, miRNA-target gene(TG)-pathway, lncRNA-miRNA-mRNA, and miRNA-TG-transcription factor (TF) network. The results showed that the miRNA-mRNA network and lncRNA-miRNA-mRNA network identified three important lncRNAs (MSTRG.3533, MSTRG.4324, and MSTRG.1470) and three miRNAs(miR-493-3p, miR-3959-3p and miR-410-5p). The four genes ( TEAD1 , ZBTB34 , GSK3B, and POGLUT1 ) and three transcription factors (C / EBPbeta, TFIID, and PR B) play a key regulatory role in the miRNA-TG-TF network. Notably, a similar trend of gene expression was reported by RT-qPCR for RNA-seq data. Conclusions: This study identified three miRNAs, three lncRNAs, four genes, and three transcription factors, and revealed their crucial role in fetal fibrogenesis and lipid metabolism. It also shows that D105N is a pivotal turning point from myotube differentiation to fiber hypertrophy. These findings provide valuable references for network interaction patterns, which helps to evaluate the biological significance of skeletal muscle in the late development stage.