School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia.
Hanwoo Research Institute, National Institute of Animal Science, RDA, Pyeongchang, South Korea.
BMC Genomics. 2019 Feb 26;20(1):156. doi: 10.1186/s12864-019-5530-7.
Korean Hanwoo cattle are known for their high meat quality, especially their high intramuscular fat compared to most other cattle breeds. Different muscles have very different meat quality traits and a study of the myogenic process in satellite cells can help us better understand the genes and pathways that regulate this process and how muscles differentiate.
Cell cultures of Longissimus dorsi muscle differentiated from myoblast into multinucleated myotubes faster than semimembranosus. Time-series RNA-seq identified a total of 13 differentially expressed genes between the two muscles during their development. These genes seem to be involved in determining muscle lineage development and appear to modulate the expression of myogenic regulatory factors (mainly MYOD and MYF5) during differentiation of satellite cells into multinucleate myotubes. Gene ontology enriched terms were consistent with the morphological changes observed in the histology. Most of the over-represented terms and genes expressed during myoblast differentiation were similar regardless of muscle type which indicates a highly conserved myogenic process albeit the rates of differentiation being different. There were more differences in the enriched GO terms during the end of proliferation compared to myoblast differentiation.
The use of satellite cells from newborn Hanwoo calves appears to be a good model to study embryonic myogenesis in muscle. Our findings provide evidence that the differential expression of HOXB2, HOXB4, HOXB9, HOXC8, FOXD1, IGFN1, ZIC2, ZIC4, HOXA11, HOXC11, PITX1, SIM2 and TBX4 genes could be involved in the differentiation of Longissimus dorsi and Semimembranosus muscles. These genes seem to modulate the muscle fate of the satellite cells during myogenesis through a differential expression profile that also controls the expression of some myogenic regulatory factors (MYOD and MYF5). The number of differentially expressed genes across time was unsurprisingly large. In relation to the baseline day 0, there were 631, 155, 175, 519 and 586 DE genes in LD, while in SM we found 204, 0, 615, 761 and 1154 DE genes at days 1, 2, 4, 7 and 14 respectively.
韩牛以其高品质的肉质而闻名，尤其是其肌肉内脂肪含量高于其他大多数牛种。不同的肌肉具有非常不同的肉质特征，研究卫星细胞的成肌过程可以帮助我们更好地理解调节这一过程的基因和途径，以及肌肉是如何分化的。
与半膜肌相比，背最长肌的肌细胞培养物从成肌细胞分化为多核肌管的速度更快。时间序列 RNA-seq 在两种肌肉的发育过程中总共鉴定出 13 个差异表达基因。这些基因似乎参与了决定肌肉谱系发育，并似乎在卫星细胞分化为多核肌管的过程中调节成肌调节因子（主要是 MYOD 和 MYF5）的表达。基因本体论富集术语与组织学观察到的形态变化一致。无论肌肉类型如何，大多数在成肌细胞分化过程中表达的过度表达术语和基因都相似，这表明成肌过程高度保守，尽管分化速度不同。与成肌细胞分化相比，在增殖末期富集的 GO 术语有更多差异。
使用来自新生韩牛犊的卫星细胞似乎是研究肌肉胚胎发生的良好模型。我们的研究结果表明，HOXB2、HOXB4、HOXB9、HOXC8、FOXD1、IGFN1、ZIC2、ZIC4、HOXA11、HOXC11、PITX1、SIM2 和 TBX4 基因的差异表达可能参与了背最长肌和半膜肌的分化。这些基因似乎通过调节卫星细胞的肌肉命运来调节成肌过程，差异表达谱也控制一些成肌调节因子（MYOD 和 MYF5）的表达。随时间变化的差异表达基因数量非常大。与基线第 0 天相比，LD 中有 631、155、175、519 和 586 个差异表达基因，而在 SM 中，我们在第 1、2、4、7 和 14 天分别发现了 204、0、615、761 和 1154 个差异表达基因。
