Genome-Wide Identification and Characterization of Circular RNAs during Skeletal Muscle Development in Meat Rabbits

Abstract

Skeletal muscle development plays a vital role in muscle quality and yield in meat rabbits. Circular RNAs (circRNAs) are a new type of single-stranded endogenous non-coding RNAs involved in different biological processes. However, our knowledge of circRNAs regulating skeletal muscle development remains largely unknown in meat rabbits. In this study, we collected the leg muscle tissues of ZIKA rabbits at three key growth stages. By performing whole-transcriptome sequencing, we found the sequential expression of day 0- (D0-), D35-, and D70-selective mRNAs mainly functioned in muscle development, nervous development, and immune response during skeletal muscle development, respectively. Then, a combination of circRNA assembly from a circRNA-seq library and the whole-transcriptome sequencing data identified 6845 credible circRNAs in our samples. Most circRNAs were transcribed from exons of known genes, contained few exons, and showed short length, and these circRNAs were more conserved between rabbits and humans than between rabbits and mice. The upregulated circRNAs, which were synchronously changed with host genes, primarily played roles in MAPK signaling pathways and fatty acid biosynthesis. The prediction of circRNA–microRNA–mRNAs networks revealed that circRNAs might be the regulators that mainly functioned in rabbits’ muscle neuron development and metabolic processes. Our work provides a catalog of circRNAs regulating skeletal muscle development at key growth stages in rabbits and might give a new insight into rabbit breeding.

Transcriptome analysis of divergent residual feed intake phenotypes in the M. longissimus thoracis et lumborum of Wannan Yellow rabbits

“…Skeletal muscle is considered to be the main energy metabolic tissue in rabbits and plays an important role in regulating systemic homeostasis ( Fan et al, 2021 ). Rabbit meat quality is dictated by muscle fiber type and characteristics that arise during skeletal muscle development ( Du et al, 2022 ). The M. longissimus thoracis et lumborum is the largest erector spinae muscle and is commonly used for meat quality assessments in rabbits and other animals ( Zotte et al, 2022 ), thus providing an ideal model to study feed efficiency.…”