Yang Rui, Liu Yinuo, Cheng Yunyun, Wang Chunli, Song Jie, Lu Guanhong, Feng Tianqi, Wang Siyao, Sun Xiaotong, Meng Jilun, Hao Linlin
College of Animal Science, Jilin University, Changchun, China.
Zhejiang Institute of Freshwater Fisheries, Huzhou, China.
Front Genet. 2021 Feb 22;12:607910. doi: 10.3389/fgene.2021.607910. eCollection 2021.
Maternally expressed gene 3 (MEG3) is a long non-coding RNA that is a crucial regulator of skeletal muscle development. Some single-nucleotide polymorphism (SNP) mutants in MEG3 had strong associations with meat quality traits. Nevertheless, the function and mechanism of MEG3 mutants on porcine skeletal muscle development have not yet been well-demonstrated. In this study, eight SNPs were identified in MEG3 of fat- and lean-type pig breeds. Four of these SNPs (g.3087C > T, g.3108C > T, g.3398C > T, and g.3971A > C) were significantly associated with meat quality and consisted of the CCCA haplotype for fat-type pigs and the TTCC haplotype for lean-type pigs. Quantitative real-time PCR results showed that the expression of MEG3-TTCC was higher than that of MEG3-CCCA in transcription level ( < 0.01). The stability assay showed that the lncRNA stability of MEG3-TTCC was lower than that of MEG3-CCCA ( < 0.05). Furthermore, the results of qRT-PCR, Western blot, and Cell Counting Kit-8 assays demonstrated that the overexpression of MEG3-TTCC more significantly inhibited the proliferation of porcine skeletal muscle satellite cells (SCs) than that of MEG3-CCCA ( < 0.05). Moreover, the overexpression of MEG3-TTCC more significantly promoted the differentiation of SCs than that of MEG3-CCCA ( < 0.05). The Western blot assay suggested that the overexpression of MEG3-TTCC and MEG3-CCCA inhibited the proliferation of SCs by inhibiting PI3K/AKT and MAPK/ERK1/2 signaling pathways. The overexpression of the two haplotypes also promoted the differentiation of SCs by activating the JAK2/STAT3 signaling pathway in different degrees. These data are valuable for further studies on understanding the crucial role of lncRNAs in skeletal muscle development.
母源表达基因3（MEG3）是一种长链非编码RNA，是骨骼肌发育的关键调节因子。MEG3中的一些单核苷酸多态性（SNP）突变体与肉质性状密切相关。然而，MEG3突变体对猪骨骼肌发育的功能和机制尚未得到充分证实。在本研究中，在脂肪型和瘦肉型猪品种的MEG3中鉴定出8个SNP。其中4个SNP（g.3087C>T、g.3108C>T、g.3398C>T和g.3971A>C）与肉质显著相关，脂肪型猪为CCCA单倍型，瘦肉型猪为TTCC单倍型。定量实时PCR结果显示，MEG3-TTCC在转录水平上的表达高于MEG3-CCCA（<0.01）。稳定性分析表明，MEG3-TTCC的lncRNA稳定性低于MEG3-CCCA（<0.05）。此外，qRT-PCR、蛋白质免疫印迹和细胞计数试剂盒-8检测结果表明，MEG3-TTCC的过表达比MEG3-CCCA更显著地抑制猪骨骼肌卫星细胞（SCs）的增殖（<0.05）。此外，MEG3-TTCC的过表达比MEG3-CCCA更显著地促进SCs的分化（<0.05）。蛋白质免疫印迹分析表明，MEG3-TTCC和MEG3-CCCA的过表达通过抑制PI3K/AKT和MAPK/ERK1/2信号通路来抑制SCs的增殖。这两种单倍型的过表达还通过不同程度地激活JAK2/STAT3信号通路促进SCs的分化。这些数据对于进一步研究lncRNAs在骨骼肌发育中的关键作用具有重要价值。
