Leibovitch S A, Leibovitch M P, Hillion J, Kruh J, Harel J
Biochem Biophys Res Commun. 1984 Mar 15;119(2):630-9. doi: 10.1016/s0006-291x(84)80296-x.
Single-stranded DNA (ssDNA) mainly consisting of transcription sites was probed with cDNA actin clones for studying the expression of actin specific genes during myogenesis in the L6 line of rat myogenic cells. As compared with total nuclear DNA, ssDNA from myoblasts and myotubes was found greatly enriched in sequences complementary to both muscular and non muscular actin sequences. In contrast, ssDNA from spleen, hepatocytes or hepatoma cells was found enriched only in sequences complementary to non muscle actin cDNA. Actin specific sequences accumulated in the ssDNA fraction are almost entirely derived from the coding DNA strand. The DNAase I sensitivity of the actin genes sequences in myogenic and non myogenic cells correlated the data obtained with the ssDNA fraction. It is concluded that the muscle specific actin genes is either transcriptionally active or at least exist in an active configuration in the proliferating myoblasts as well as in the terminally differentiated myotubes.
为研究大鼠成肌细胞L6系在肌生成过程中肌动蛋白特异性基因的表达，用肌动蛋白cDNA克隆探测主要由转录位点组成的单链DNA（ssDNA）。与总核DNA相比，发现来自成肌细胞和肌管的ssDNA在与肌肉和非肌肉肌动蛋白序列互补的序列中大量富集。相反，发现来自脾脏、肝细胞或肝癌细胞的ssDNA仅在与非肌肉肌动蛋白cDNA互补的序列中富集。ssDNA组分中积累的肌动蛋白特异性序列几乎完全来自编码DNA链。肌生成和非肌生成细胞中肌动蛋白基因序列对DNA酶I的敏感性与ssDNA组分获得的数据相关。得出的结论是，肌肉特异性肌动蛋白基因在增殖的成肌细胞以及终末分化的肌管中要么转录活跃，要么至少以活跃的构型存在。
