Cao Yang, You Shuang, Yao Yang, Liu Zhi-Jin, Hazi Wureli, Li Cun-Yuan, Zhang Xiang-Yu, Hou Xiao-Xu, Wei Jun-Chang, Li Xiao-Yue, Wang Da-Wei, Chen Chuang-Fu, Zhang Yun-Feng, Ni Wei, Hu Sheng-Wei
College of Life Sciences, Shihezi University, Shihezi, Xinjiang 832003, China.
College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, China.
Asian-Australas J Anim Sci. 2018 Oct;31(10):1550-1557. doi: 10.5713/ajas.17.0563. Epub 2018 Apr 11.
Circular RNAs (circRNAs) are a newfound class of non-coding RNA in animals and plants. Recent studies have revealed that circRNAs play important roles in cell proliferation, differentiation, autophagy and apoptosis during development. However, there are few reports about muscle development-related circRNAs in livestock.
RNA sequencing analysis was employed to identify and annotate circRNAs from longissimus dorsi of sheep. Reverse transcription followed by real-time quantitative (q) polymerase chain reaction (PCR) analysis verified the presence of these circRNAs. Targetscan7.0 and miRanda were used to analyse the interaction of circRNA-microRNA (miRNA). To investigate the function of circRNAs, an experiment was conducted to perform enrichment analysis hosting genes of circRNAs using gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathways.
About 75.5 million sequences were obtained from RNA libraries of sheep skeletal muscle. These sequences were mapped to 729 genes in the sheep reference genome. We identified 886 circRNAs, including numerous circular intronic RNAs and exonic circRNAs. Reverse transcription PCR (RT-PCR) and DNA sequencing analysis confirmed the presence of several circRNAs. Real-Time RT-PCR analysis exhibited resistance of sheep circRNAs to RNase R digestion. We found that many circRNAs interacted with muscle-specific miRNAs involved in growth and development of muscle, especially circ776. The GO and KEGG enrichment analysis showed that hosting genes of circRNAs was involved in muscle cell development and signaling pathway.
The study provides comprehensive expression profiles of circRNAs in sheep skeletal muscle. Our study offers a large number of circRNAs to facilitate a better understanding of their roles in muscle growth. Meanwhile, we suggested that circ776 could be analyzed in future study.
环状RNA（circRNAs）是动植物中新发现的一类非编码RNA。最近的研究表明，circRNAs在发育过程中的细胞增殖、分化、自噬和凋亡中发挥重要作用。然而，关于家畜中与肌肉发育相关的circRNAs的报道较少。
采用RNA测序分析从绵羊背最长肌中鉴定和注释circRNAs。逆转录后进行实时定量（q）聚合酶链反应（PCR）分析以验证这些circRNAs的存在。使用Targetscan7.0和miRanda分析circRNA-微小RNA（miRNA）的相互作用。为了研究circRNAs的功能，进行了一项实验，使用基因本体（GO）和京都基因与基因组百科全书（KEGG）通路对circRNAs的宿主基因进行富集分析。
从绵羊骨骼肌的RNA文库中获得了约7550万个序列。这些序列被映射到绵羊参考基因组中的729个基因上。我们鉴定出886个circRNAs，包括许多环状内含子RNA和外显子circRNAs。逆转录PCR（RT-PCR）和DNA测序分析证实了几种circRNAs的存在。实时RT-PCR分析显示绵羊circRNAs对RNase R消化具有抗性。我们发现许多circRNAs与参与肌肉生长和发育的肌肉特异性miRNAs相互作用，尤其是circ776。GO和KEGG富集分析表明，circRNAs的宿主基因参与肌肉细胞发育和信号通路。
该研究提供了绵羊骨骼肌中circRNAs的全面表达谱。我们的研究提供了大量的circRNAs，有助于更好地理解它们在肌肉生长中的作用。同时，我们建议在未来的研究中可以对circ776进行分析。
