Developmental Biology Group, Department of Animal Science, University of Wyoming, Laramie 82071, USA.
J Anim Sci. 2011 Feb;89(2):583-90. doi: 10.2527/jas.2010-3386. Epub 2010 Sep 17.
Enhancing muscle growth while reducing fat accumulation improves the efficiency of animal production. The fetal stage is crucial for skeletal muscle development. Fetal muscle development involves myogenesis, adipogenesis, and fibrogenesis from mesenchymal multipotent cells (MC), which are negatively affected by maternal nutrient deficiencies. Enhancing myogenesis increases the lean-to-fat ratio of animals, enhancing intramuscular adipogenesis increases intramuscular fat that is indispensible for the superior eating properties of meat because fat is the major contributor to meat flavor. The promotion of fibrogenesis leads to the accumulation of connective tissue, which contributes to the background toughness of meat and is undesirable. Thus, it is essential to regulate MC differentiation to enhance lean growth and improve meat quality. To date, our understanding of mechanisms regulating the lineage commitment of MC is limited. In this review, we first discuss the impact of maternal nutrient deficiency on fetal development, offspring body composition, and meat quality. Because maternal nutrition affects fetal muscle through altering MC differentiation, we then review several important extracellular morphogens regulating MC differentiation, including hedgehog, Wingless and Int (Wnt), and bone morphogenic proteins. Possible involvement of epigenetic modifications associated with histone deacetylases class IIa and histone acetyltransferase, p300, in MC differentiation is also discussed.
在减少脂肪积累的同时增强肌肉生长可提高动物生产效率。胎儿期对于骨骼肌发育至关重要。胎儿肌肉发育涉及由间充质多能细胞（MC）分化而来的肌生成、脂肪生成和纤维生成，母体营养缺乏会对其产生负面影响。增强肌生成可增加动物的瘦肉与脂肪比例，促进肌内脂肪生成可增加肌内脂肪，这对于提高肉的优良食用品质是必不可少的，因为脂肪是肉味的主要贡献者。纤维生成的促进会导致结缔组织的积累，这会增加肉的背景韧性，这是不理想的。因此，调节 MC 分化以增强瘦肉生长和改善肉质至关重要。迄今为止，我们对调节 MC 谱系分化的机制的理解还很有限。在这篇综述中，我们首先讨论了母体营养缺乏对胎儿发育、后代体组成和肉质的影响。由于母体营养通过改变 MC 分化来影响胎儿肌肉，因此我们随后综述了几种调节 MC 分化的重要细胞外形态发生素，包括 hedgehog、Wingless 和 Int（Wnt）以及骨形态发生蛋白。还讨论了与组蛋白去乙酰化酶 IIa 和组蛋白乙酰转移酶 p300 相关的表观遗传修饰可能参与 MC 分化。
