Abstract：
Muscle development is an important priority of pig breeding programs. There is a considerable variation in muscularity between the breeds, but the regulation mechanisms of genes underlying myogenesis are still unclear. Transcriptome data from two breeds of pigs with divergent muscularity (Mali and Hampshire) were integrated with histology, immunofluorescence and meat yield to identify differences in myogenesis during the early growth phase. The muscle transcriptomics analysis revealed 17,721 common, 1413 and 1115 unique transcripts to Hampshire and Mali, respectively. This study identified 908 differentially expressed genes (p < 0.05; log2FC > ±1) in the muscle samples, of which 550 were upregulated and 358 were downregulated in Hampshire pigs, indicating differences in physiological process related to muscle function and development. Expression of genes related to myoblast fusion (MYMK), skeletal muscle satellite cell proliferation (ANGPT1, CDON) and growth factors (HGF, IGF1, IGF2) were higher in Hampshire than Mali, even though transcript levels of several other myogenesis-related genes (MYF6, MYOG, MSTN) were similar. The number of fibers per fascicle and the expression of myogenic marker proteins (MYOD1, MYOG and PAX7) were more in Hampshire as compared to Mali breed of pig, supporting results of transcriptome studies. The results suggest that differences in muscularity between breeds could be related to the regulation of myoblast fusion and myogenic activities. The present study will help to identify genes that could be explored for their utility in the selection of animals with different muscularities.
摘要：
肌肉发育是猪育种计划的重要优先事项。品种之间的肌肉组织有相当大的差异，但是，有关肌生成基因的调控机制尚不清楚。将来自两个具有不同肌肉组织的猪品种（马里和汉普郡）的转录组数据与组织学相结合，免疫荧光和肉类产量，以确定在早期生长阶段的肌形成差异。肌肉转录组学分析显示17,721例常见，1413和1115年汉普郡和马里的独特成绩单，分别。这项研究确定了908个差异表达基因（p<0.05;log2FC>±1）在肌肉样品，汉普郡猪的550只上调，358只下调，表明与肌肉功能和发育有关的生理过程的差异。成肌细胞融合（MYMK）相关基因的表达，骨骼肌卫星细胞增殖（ANGPT1，CDON）和生长因子（HGF，汉普郡的IGF1，IGF2）高于马里，即使转录水平的几个其他肌生成相关基因(MYF6，MYOG，MSTN）相似。与马里猪品种相比，汉普郡的每束纤维数量和肌源性标记蛋白（MYOD1，MYOG和PAX7）的表达更多，支持转录组研究的结果。结果表明，品种之间肌肉组织的差异可能与成肌细胞融合和成肌活动的调节有关。本研究将有助于确定可以探索其在选择具有不同肌肉特性的动物中的效用的基因。
