Transcriptome analysis of miRNAs during myoblasts adipogenic differentiation

Intramuscular fat content is closely related to meat quality traits and has high heritability. miRNAs are a class of small non-coding RNA, which are highly conserved in animals and play important regulatory roles in adipogenesis. Therefore, they can be used as molecular markers for meat quality traits. Herein, we used in vitro model of myoblasts adipogenic differentiation to screen differential miRNAs by RNA-seq. A total of 71 differentially miRNAs were filtered, including 31 up-regulated miRNAs and 40 down-regulated miRNAs. Since, we selected 18 miRNAs for RT-qPCR validation, including some miRNAs likely miR-146a-5p, miR-210-3p, miR-199a, miR-224, and miR-214-3p that play important regulatory roles in adipogenesis. In addition, functional enrichment analysis results revealed that members of miRNA target genes were enriched into insulin signaling pathway and MAPK signaling pathway, which are closely related to adipogenesis. Taken together, these data will contribute to further investigate the function of miRNAs in intramuscular fat deposition. These differentially miRNAs can be developed as biomarkers for animal breeding.肌内脂肪含量与肉质性状密切相关，且具有较高的遗传力。miRNAs（microRNAs）是一类小型非编码RNA，在动物中高度保守，在脂肪生成过程中发挥重要调控作用，因此可作为肉质性状的分子标记。本研究利用成肌细胞成脂分化体外模型，通过RNA-seq（RNA测序）筛选差异表达miRNAs，最终共筛选得到71个差异表达miRNAs，其中31个为上调表达miRNAs，40个为下调表达miRNAs。据此，我们选取18个miRNAs开展RT-qPCR（实时荧光定量聚合酶链反应）验证，其中包括若干在脂肪生成中发挥关键调控作用的miRNAs，如miR-146a-5p、miR-210-3p、miR-199a、miR-224及miR-214-3p。此外，功能富集分析结果显示，miRNA靶基因集显著富集于与脂肪生成密切相关的胰岛素信号通路（insulin signaling pathway）及丝裂原活化蛋白激酶（MAPK）信号通路。综上，本研究数据可为进一步探究miRNAs在肌内脂肪沉积中的功能提供研究基础，所得差异表达miRNAs亦可开发为动物育种的生物标记物。