Li Meng, Zhang Na, Zhang Wanfeng, Hei Wei, Cai Chunbo, Yang Yang, Lu Chang, Gao Pengfei, Guo Xiaohong, Cao Guoqing, Li Bugao
College of Animal Science, Shanxi Agricultural University, Taigu, 030801, China.
BMC Genomics. 2021 May 1;22(1):320. doi: 10.1186/s12864-021-07645-8.
Circular RNA (circRNA), a novel class of non-coding RNA, has a closed-loop structure with important functions in skeletal muscle growth. The purpose of this study was to investigate the role of differentially expressed circRNAs (DEcircRNAs), as well as the DEcircRNA-miRNA-mRNA regulatory network, at different stages of porcine skeletal muscle development. Here, we present a panoramic view of circRNA expression in porcine skeletal muscle from Large White and Mashen pigs at 1, 90, and 180 days of age.
We identified a total of 5819 circRNAs. DEcircRNA analysis at different stages showed 327 DEcircRNAs present in both breeds. DEcircRNA host genes were concentrated predominately in TGF-β, MAPK, FoxO, and other signaling pathways related to skeletal muscle growth and fat deposition. Further prediction showed that 128 DEcircRNAs could bind to 253 miRNAs, while miRNAs could target 945 mRNAs. The constructed ceRNA network plays a vital role in skeletal muscle growth and development, and fat deposition. Circ_0015885/miR-23b/SESN3 in the ceRNA network attracted our attention. miR-23b and SESN3 were found to participate in skeletal muscle growth regulation, also playing an important role in fat deposition. Using convergent and divergent primer amplification, RNase R digestion, and qRT-PCR, circ_0015885, an exonic circRNA derived from Homer Scaffold Protein 1 (HOMER1), was confirmed to be differentially expressed during skeletal muscle growth. In summary, circ_0015885 may further regulate SESN3 expression by interacting with miR-23b to function in skeletal muscle.
This study not only enriched the circRNA library in pigs, but also laid a solid foundation for the screening of key circRNAs during skeletal muscle growth and intramural fat deposition. In addition, circ_0015885/miR-23b/SESN3, a new network regulating skeletal muscle growth and fat deposition, was identified as important for increasing the growth rate of pigs and improving meat quality.
环状RNA（circRNA）是一类新型的非编码RNA，具有闭环结构，在骨骼肌生长中发挥重要作用。本研究旨在探讨差异表达的环状RNA（DEcircRNA）以及DEcircRNA- miRNA- mRNA调控网络在猪骨骼肌发育不同阶段的作用。在此，我们展示了大白猪和马身猪在1日龄、90日龄和180日龄时骨骼肌中circRNA表达的全景图。
我们共鉴定出5819个circRNA。不同阶段的DEcircRNA分析表明，两个品种中均存在327个DEcircRNA。DEcircRNA宿主基因主要集中在TGF-β、MAPK、FoxO以及其他与骨骼肌生长和脂肪沉积相关的信号通路中。进一步预测表明，128个DEcircRNA可以与253个miRNA结合，而miRNA可以靶向945个mRNA。构建的ceRNA网络在骨骼肌生长发育和脂肪沉积中起着至关重要的作用。ceRNA网络中的Circ_0015885/miR-23b/SESN3引起了我们的关注。发现miR-23b和SESN3参与骨骼肌生长调控，在脂肪沉积中也起重要作用。通过收敛和发散引物扩增、RNase R消化和qRT-PCR，证实来源于荷马支架蛋白1（HOMER1）的外显子circRNA circ_0015885在骨骼肌生长过程中差异表达。总之，circ_0015885可能通过与miR-23b相互作用进一步调节SESN3表达，从而在骨骼肌中发挥作用。
本研究不仅丰富了猪的circRNA文库，也为筛选骨骼肌生长和肌内脂肪沉积过程中的关键circRNA奠定了坚实基础。此外，circ_0015885/miR-23b/SESN3这一调节骨骼肌生长和脂肪沉积的新网络被确定对提高猪的生长速度和改善肉质具有重要意义。
