Chelly J, Kaplan J C, Maire P, Gautron S, Kahn A
Unité de Génétique et Pathologie moléculaires, INSERM 129, Paris, France.
Nature. 1988 Jun 30;333(6176):858-60. doi: 10.1038/333858a0.
The gene that is defective in patients with Duchenne and Becker muscular dystrophy consists of about 60 short exons scattered along a gigantic DNA region that spans some 2 megabase pairs. The encoded protein, dystrophin, was recently characterized as a component of muscle intracellular membranes of low abundance. The dystrophin messenger RNA is difficult to study in both normal and pathological tissue specimens because it is large (14 kilobases) and scarce (0.01-0.001% of total muscle mRNA). We report here that efficient in vitro co-amplifications of the mRNAs of the dystrophin gene and of a reporter gene, aldolase A, by the polymerase chain reaction procedure enables us to obtain a quantitative estimate of the dystrophin gene transcript. A processed, transcribed segment was thus detected in 13 different human tissues. It ranged from 0.02-0.12% of total mRNA in skeletal muscle to 25,000 times less in lymphoblastoid cells.
患有杜兴氏和贝克氏肌肉营养不良症的患者体内存在缺陷的基因由大约60个短外显子组成，这些外显子散布在一个跨越约200万个碱基对的巨大DNA区域中。最近发现，所编码的蛋白质——抗肌萎缩蛋白是肌肉细胞内膜中含量较低的一种成分。由于抗肌萎缩蛋白信使核糖核酸（mRNA）体积大（14千碱基）且数量稀少（占肌肉总mRNA的0.01 - 0.001%），因此在正常和病理组织样本中都很难对其进行研究。我们在此报告，通过聚合酶链反应程序，可实现抗肌萎缩蛋白基因的mRNA与报告基因醛缩酶A的mRNA高效体外共扩增，从而使我们能够对抗肌萎缩蛋白基因转录本进行定量评估。由此在13种不同的人体组织中检测到了一个经过加工的转录片段。其在骨骼肌中占总mRNA的0.02 - 0.12%，而在淋巴母细胞中则比骨骼肌少25000倍。
