The alteration in skeletal muscle fiber is a critical factor affecting livestock meat quality traits and human metabolic diseases. Long non-coding RNAs (lncRNAs) are a diverse class of non-coding RNAs with a length of more than 200 nucleotides. However, the mechanisms underlying the regulation of lncRNAs in skeletal muscle fibers remain elusive. To understand the genetic basis of lncRNA-regulated skeletal muscle fiber development, we performed a transcriptome analysis to identify the key lncRNAs affecting skeletal muscle fiber and meat quality traits on a pig model. We generated the lncRNA expression profiles of fast-twitch Biceps femoris (Bf) and slow-twitch Soleus (Sol) muscles and identified the differentially expressed (DE) lncRNAs using RNA-seq and performed bioinformatics analyses. This allowed us to identify 4581 lncRNA genes among six RNA libraries and 92 DE lncRNAs between Bf and Sol which are the key candidates for the conversion of skeletal muscle fiber types. Moreover, we detected the expression patterns of lncRNA MSTRG.42019 in different tissues and skeletal muscles of various development stages. In addition, we performed a correlation analyses between the expression of DE lncRNA MSTRG.42019 and meat quality traits. Notably, we found that DE lncRNA MSTRG.42019 was highly expressed in skeletal muscle and its expression was significantly higher in Sol than in Bf, with a positive correlation with the expression of Myosin heavy chain 7 (MYH7) (r = 0.6597, p = 0.0016) and a negative correlation with meat quality traits glycolytic potential (r = −0.5447, p = 0.0130), as well as drip loss (r = −0.5085, p = 0.0221). Moreover, we constructed the lncRNA MSTRG.42019–mRNAs regulatory network for a better understanding of a possible mechanism regulating skeletal muscle fiber formation. Our data provide the groundwork for studying the lncRNA regulatory mechanisms of skeletal muscle fiber conversion, and given the importance of skeletal muscle fiber types in muscle-related diseases, our data may provide insight into the treatment of muscular diseases in humans.

中文翻译：

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探索与猪骨骼肌纤维类型和肉质性状相关的 lncRNA

骨骼肌纤维的改变是影响牲畜肉质性状和人体代谢疾病的关键因素。长链非编码 RNA (lncRNA) 是一类多样化的非编码 RNA，长度超过 200 个核苷酸。然而，骨骼肌纤维中 lncRNA 的调控机制仍然难以捉摸。为了了解 lncRNA 调控的骨骼肌纤维发育的遗传基础，我们进行了转录组分析，以确定影响猪模型骨骼肌纤维和肉质性状的关键 lncRNA。我们生成了快肌二头肌 (Bf) 和慢肌比目鱼 (Sol) 肌肉的 lncRNA 表达谱，并使用 RNA-seq 鉴定了差异表达 (DE) 的 lncRNA，并进行了生物信息学分析。这使我们能够在 6 个 RNA 文库中鉴定 4581 个 lncRNA 基因，在 Bf 和 Sol 之间鉴定出 92 个 DE lncRNA，它们是骨骼肌纤维类型转换的关键候选者。此外，我们检测了lncRNA MSTRG.42019在不同发育阶段的不同组织和骨骼肌中的表达模式。此外，我们还对 DE lncRNA MSTRG.42019 的表达与肉质性状进行了相关性分析。值得注意的是，我们发现DE lncRNA MSTRG.42019在骨骼肌中高表达，其在Sol中的表达显着高于Bf，与肌球蛋白重链7（MYH7）的表达呈正相关（r = 0.6597，p = 0.0016) 以及与肉质性状糖酵解潜能 (r = -0.5447, p = 0.0130) 以及滴漏损失 (r = -0.5085, p = 0.0221) 呈负相关。而且，我们构建了 lncRNA MSTRG.42019-mRNAs 调控网络，以更好地理解调控骨骼肌纤维形成的可能机制。我们的数据为研究骨骼肌纤维转换的 lncRNA 调控机制奠定了基础，鉴于骨骼肌纤维类型在肌肉相关疾病中的重要性，我们的数据可能为人类肌肉疾病的治疗提供见解。