Grisolia A B, D'Angelo G T, Porto Neto L R, Siqueira F, Garcia J F
Departamento de Apoio, Produção e Saúde Animal, Laboratório de Bioquímica e Biologia Molecular Animal, Universidade Estadual Paulista, Araçatuba, SP, Brasil.
Genet Mol Res. 2009 Jul 21;8(3):822-30. doi: 10.4238/vol8-3gmr548.
The myostatin gene, also known as GDF8 (growth differentiation factor 8), is located on bovine chromosome 2 (BTA2); it has three exons and two introns. Myostatin is specifically expressed during embryonic development and in adult skeletal muscle, functioning as a negative regulatory protein. Several cattle breeds (Piedmontese, Belgian Blue and Blond'Aquitaine, and others) show polymorphisms in this gene; these polymorphisms are directly related to the double muscling phenotype. We looked for polymorphisms in the Nellore cattle myostatin gene and compared them with those known for taurine breeds. Seven regions, covering the three exons of this gene, were amplified by polymerase chain reaction and sequenced, including the untranslated region. DNA from 30 adult Nellore animals was collected; DNA sequencing revealed three, seven and four polymorphisms in exons 1, 2 and 3, respectively. We found previously reported polymorphisms, as well as several new ones; for instance, 37 polymorphisms were found in the untranslated region segment, and in introns 1 and 2 there were one and three polymorphisms, respectively. The high degree of allelic heterogeneity in the myostatin gene could be related to its high mutation rate; it also could be the result of a long history of artificial selection for meat production, which has probably favored such modifications and maintained them in cattle populations. These polymorphisms identified in Nellore cattle could be useful for breeding programs.
肌肉生长抑制素基因，也被称为生长分化因子8（GDF8），位于牛的2号染色体（BTA2）上；它有三个外显子和两个内含子。肌肉生长抑制素在胚胎发育期间和成年骨骼肌中特异性表达，作为一种负调控蛋白发挥作用。几个牛品种（皮埃蒙特牛、比利时蓝牛和阿基坦黄牛等）在该基因中表现出多态性；这些多态性与双肌表型直接相关。我们在婆罗门牛的肌肉生长抑制素基因中寻找多态性，并将它们与已知的普通牛品种的多态性进行比较。通过聚合酶链反应扩增并测序了覆盖该基因三个外显子在内的七个区域，包括非翻译区。收集了30头成年婆罗门牛的DNA；DNA测序分别在第1、2和3外显子中揭示了3个、7个和4个多态性。我们发现了先前报道的多态性以及几个新的多态性；例如，在非翻译区片段中发现了37个多态性，在第1和第2内含子中分别有1个和3个多态性。肌肉生长抑制素基因中高度的等位基因异质性可能与其高突变率有关；这也可能是长期人工选择肉类生产的结果，这种选择可能有利于此类变异并在牛群中维持它们。在婆罗门牛中鉴定出的这些多态性可能对育种计划有用。
