Autonomous replication in Drosophila melanogaster tissue culture cells.
Autonomous replication in Drosophila melanogaster tissue culture cells.
复制标题
果蝇组织培养细胞中的自主复制。
作者：
Smith,JG;Calos,MP
本研究探讨了不同来源的DNA片段在培养的果蝇细胞中介导自主DNA复制的能力。我们从果蝇的Ultrabithorax基因中构建了一系列含有基因组DNA片段的质粒，并在转染到Schneider line 2细胞后测试了它们的自主复制。我们发现，所有含有果蝇DNA片段的质粒都能自主复制，含有随机的人和大肠杆菌基因组DNA片段的质粒也是如此。在没有选择的情况下，大多数质粒在转染后18天可检测到，这表明转染的DNA在果蝇细胞中保持不变，没有快速丢失或降解。所有含有果蝇、人类或细菌DNA的质粒都能在果蝇细胞中自主复制，这一发现表明，指导果蝇自主复制的信号具有较低程度的序列特异性。一个质粒上的启动的二维凝胶分析与许多分散的起始位点一致。低序列特异性和分散的起始位点也是人类细胞和Senopuseggs中自主复制的特征，并且可能是动物细胞中自主复制的一般特性。
This study addresses the ability of DNA fragments from various sources to mediate autonomous DNA replication in culturedDrosophila melanogastercells. We created a series of plasmids containing genomic DNA fragments from theUltrabithoraxgene ofDrosophilaand tested them for autonomous replication after transfection into Schneider line 2 cells. We found that all plasmids containingDrosophilaDNA fragments were able to replicate autonomously, as were plasmids containing random human andEscherichia coligenomic DNA fragments. Most of the plasmids were detectable 18 days after transfection in the absence of selection, suggesting that transfected DNA is maintained inDrosophilacells without rapid loss or degradation. The finding that all plasmids containingDrosophila, human, or bacterial DNA replicate autonomously inDrosophilacells suggests that the signals that direct autonomous replication inDrosophilacontain a low degree of sequence specificity. A two-dimensional gel analysis of initiation on one of the plasmids was consistent with many dispersed initiation sites. Low sequence specificity and dispersed initiation sites also characterize autonomous replication in human cells andSenopuseggs and may be general properties of autonomous replication in animal cells.