Functional Role of circRNAs in the Regulation of Fetal Development, Muscle Development, and Lactation in Livestock

Abstract

circRNAs are a class of endogenous noncoding RNA molecules with closed loop structures. They are mainly responsible for regulating gene expression in eukaryotic cells. With the emergence of high-throughput RNA sequencing (RNA-Seq) and new types of bioinformatics tools, thousands of circRNAs have been discovered, making circRNA one of the research hotspots. Recent studies have shown that circRNAs play an important regulatory role in the growth, reproduction, and formation of livestock products. They can not only regulate mammalian fetal growth and development but also have important regulatory effects on livestock muscle development and lactation. In this review, we briefly introduce the putative biogenic pathways and regulatory functions of circRNA and highlight our understanding of circRNA and its latest advances in fetal development, muscle development, and lactation biogenesis as well as expression in livestock. This review will provide a theoretical basis for the research and development of related industries.

Figure 1

The main formation of circRNAs: 1: circRNAs are formed after introns in the lasso structure are excised; 2: intron pairing driving cyclization, thus forming circRNAs; 3: the RNA-binding protein specifically binds to flanking introns at both ends of the RNA, thus forming circRNAs.

Figure 2

“+ +” means promotion, “- -” means inhibition, and the arrow points to the regulation direction.