College of Animal Science and Technology, Henan Agricultural University, Zhengzhou 450001, China.
College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China.
Genes (Basel). 2022 Oct 29;13(11):1974. doi: 10.3390/genes13111974.
Circular RNAs (circRNAs) play a significant regulatory role during skeletal muscle development. To identify circRNAs during postnatal skeletal muscle development in chickens, we constructed 12 cDNA libraries from breast muscle tissues of Chinese Gushi chickens at 6, 14, 22, and 30 weeks and performed RNA sequencing. In total, 2112 circRNAs were identified, and among them 79.92% were derived from exons. CircRNAs are distributed on all chromosomes of chickens, especially chromosomes 1-9 and Z. Bioinformatics analysis showed that each circRNA had an average of 38 miRNA binding sites, 61.32% of which have internal ribosomal entry site (IRES) elements. Furthermore, in total 543 differentially expressed circRNAs (DE-circRNAs) were identified. Functional enrichment analysis revealed that DE-circRNAs source genes are engaged in biological processes and muscle development-related pathways; for example, cell differentiation, sarcomere, and myofibril formation, mTOR signaling pathway, and TGF-β signaling pathway, etc. We also established a competitive endogenous RNA (ceRNA) regulatory network associated with skeletal muscle development. The results in this report indicate that circRNAs can mediate the development of chicken skeletal muscle by means of a complex ceRNA network among circRNAs, miRNAs, genes, and pathways. The findings of this study might help increase the number of known circRNAs in skeletal muscle tissue and offer a worthwhile resource to further investigate the function of circRNAs in chicken skeletal muscle development.
环形 RNA（circRNAs）在骨骼肌发育过程中发挥重要的调控作用。为了鉴定鸡出生后骨骼肌发育过程中的 circRNAs，我们构建了 12 个 cDNA 文库，来自中国古氏鸡的胸肌组织，分别在 6、14、22 和 30 周龄时进行 RNA 测序。总共鉴定出 2112 个 circRNAs，其中 79.92%来源于外显子。circRNAs 分布在鸡的所有染色体上，特别是染色体 1-9 和 Z。生物信息学分析表明，每个 circRNA 平均有 38 个 miRNA 结合位点，其中 61.32%具有内部核糖体进入位点（IRES）元件。此外，总共鉴定出 543 个差异表达的 circRNAs（DE-circRNAs）。功能富集分析表明，DE-circRNAs 来源基因参与生物学过程和与肌肉发育相关的途径；例如，细胞分化、肌节和肌原纤维形成、mTOR 信号通路和 TGF-β信号通路等。我们还建立了一个与骨骼肌发育相关的竞争性内源 RNA（ceRNA）调控网络。本报告的结果表明，circRNAs 可以通过 circRNAs、miRNAs、基因和途径之间复杂的 ceRNA 网络介导鸡骨骼肌的发育。本研究的结果可能有助于增加骨骼肌组织中已知 circRNAs 的数量，并为进一步研究 circRNAs 在鸡骨骼肌发育中的功能提供有价值的资源。
