Grobet L, Martin L J, Poncelet D, Pirottin D, Brouwers B, Riquet J, Schoeberlein A, Dunner S, Ménissier F, Massabanda J, Fries R, Hanset R, Georges M
Department of Genetics, Faculty of Veterinary Medicine, University of Liège, Belgium.
Nat Genet. 1997 Sep;17(1):71-4. doi: 10.1038/ng0997-71.
An exceptional muscle development commonly referred to as 'double-muscled' (Fig. 1) has been seen in several cattle breeds and has attracted considerable attention from beef producers. Double-muscled animals are characterized by an increase in muscle mass of about 20%, due to general skeletal-muscle hyperplasia-that is, an increase in the number of muscle fibers rather than in their individual diameter. Although the hereditary nature of the double-muscled condition was recognized early on, the precise mode of inheritance has remained controversial; monogenic (domainant and recessive), oligogenic and polygenic models have been proposed. In the Belgian Blue cattle breed (BBCB), segregation analysis performed both in experimental crosses and in the outbred population suggested an autosomal recessive inheritance. This was confirmed when the muscular hypertrophy (mh) locus was mapped 3.1 cM from microsatellite TGLA44 on the centromeric end of bovine chromosome 2 (ref. 5). We used a positional candidate approach to demonstrate that a mutation in bovine MSTN, which encodes myostatin, a member of the TGF beta superfamily, is responsible for the double-muscled phenotype. We report an 11-bp deletion in the coding sequence for the bioactive carboxy-terminal domain of the protein causing the muscular hypertrophy observed in Belgian Blue cattle.
一种异常的肌肉发育，通常被称为“双肌”（图1），已在多个牛品种中被发现，并引起了牛肉生产商的广泛关注。双肌动物的特征是肌肉质量增加约20%，这是由于全身骨骼肌增生，即肌肉纤维数量增加而非单个直径增加。尽管双肌状况的遗传性质很早就被认识到，但精确的遗传模式仍存在争议；已提出单基因（显性和隐性）、寡基因和多基因模型。在比利时蓝牛品种（BBCB）中，在实验杂交和远交群体中进行的分离分析表明是常染色体隐性遗传。当肌肉肥大（mh）基因座被定位到牛2号染色体着丝粒末端的微卫星TGLA44距离3.1厘摩处时，这一点得到了证实（参考文献5）。我们使用定位候选方法来证明，编码肌肉生长抑制素（一种转化生长因子β超家族成员）的牛MSTN中的一个突变，是造成双肌表型的原因。我们报告了该蛋白质生物活性羧基末端结构域编码序列中的一个11碱基对缺失，这导致了在比利时蓝牛中观察到的肌肉肥大。
