BackgroundMuscle development is a complex progress that regulated by many factors, and non-coding RNA (ncRNA) is found to act as a vital part of performing normal function of muscle cells. Circular RNA(circRNA), a kind ncRNA with closed RNA, is reported to affect life process. However, there are limited studies about how circRNAs affect muscle development and this study is aimed to find how circ RNA Ribosomal modification protein rimK like family member B (circRIMKLB) affects muscle development.ResultsWe found circular circRIMKLB expressed differentially at different stages of muscle development. The results revealed that circRIMKLB could promote myoblasts proliferation and inhibits differentiation. MicroRNA-29c (miR-29c) was identified as a downstream of circRIMKLB by dual-luciferase reporter assay and RNA binding proteinImmunoprecipitation (RIP) assay. Besides, Channel subfamily J member 12 (KCNJ12) was proved to be a novel target of miR-29c via dual-luciferase reporter assay, quantitative real time polymerase chain reaction(qRT-PCR) and western blot. We also explored the effect of circRIMKLB and KCNJ12 on muscle regeneration after injury in vivo and found that circRIMKLB and KCNJ12 could participate in regulating cell cycle.ConclusionsIn conclusion, we proved circRIMKLB could sponge miR-29c to affect the expression level of KCNJ12 and eventually affect myoblast proliferation and differentiation and participate in cell cycle regulation in muscle regeneration after injury in vivo.