Table_1_Circular RNA circSVIL Promotes Myoblast Proliferation and Differentiation by Sponging miR-203 in Chicken.docx

Circular RNAs (circRNAs), expressed abundantly and universally in various eukaryotes, are involved in growth and development of animals. Our previous study on circRNA sequencing revealed that circSVIL, an exonic circular, expressed differentially among skeletal muscle at 11 embryo age (E11), 16 embryo age (E16), and 1 day post-hatch (P1). In this study, we aim to investigate the effect of circSVIL on the development of skeletal muscle. We detected the expression level of circSVIL in embryonic leg muscle during E10 to P1. As a result, we found that circSVIL had a high expression level during late embryonic development of skeletal muscle. Through dual-luciferase assay, RNA immunoprecipitation and biotin-coupled miRNA pull down, we found chicken circSVIL could functions as miR-203 sponges and upregulated the mRNA level of c-JUN and MEF2C. In chicken, circSVIL could promote the proliferation and differentiation of myoblast, and antagonize the functions of miR-203. Altogether our data suggest that circSVIL promotes the embryonic skeletal muscle development by sequestering miR-203 in chicken.

环状RNA（circular RNAs, circRNAs）在多种真核生物中广泛且高丰度表达，参与动物的生长发育进程。本团队前期通过circRNA测序研究发现，外显子来源的环状RNA circSVIL在胚胎11日龄（E11）、16日龄（E16）以及孵化后1日龄（P1）的骨骼肌组织中呈现差异表达。本研究旨在探究circSVIL对骨骼肌发育的调控作用。我们检测了E10至P1阶段鸡胚胎腿部肌肉中circSVIL的表达水平，结果显示circSVIL在骨骼肌发育的胚胎晚期具有高表达特征。通过双荧光素酶报告基因检测（dual-luciferase assay）、RNA免疫沉淀（RNA immunoprecipitation）以及生物素偶联miRNA下拉实验（biotin-coupled miRNA pull down），我们发现鸡源circSVIL可作为miR-203的分子海绵，上调c-JUN与MEF2C的mRNA表达水平。在鸡体内，circSVIL可促进成肌细胞的增殖与分化，并拮抗miR-203的生物学功能。综上，本研究数据表明，鸡源circSVIL通过吸附miR-203，促进胚胎期骨骼肌的发育。