标题：Replication of Mitochondrial DNA in Mouse L Cells and Their Thymidine Kinase- Derivatives: Displacement Replication on a Covalently-Closed Circular Template
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1972
卷号：69
期号：12
页码：3810-3814
DOI：10.1073/pnas.69.12.3810
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Thymidine kinase- lines of mouse L cells incorporate thymidine exclusively into mitochondrial DNA. This fact permits assessment of labeled mitochondrial DNA components in ethidium bromide-cesium chloride gradients. Contaminating nuclear DNA is unlabeled and need not be removed. Elimination of the DNase treatment of purified mitochondria reveals that the replicative forms that exhibit displacement replication up to full genome size are covalently-closed circular molecules. Denaturation followed by brief renaturation of these larger replicating molecules produces closed-circular DNA with a deficiency of Watson-Crick turns, appearing as single-strand loops. This result suggests that displacement replication proceeds with nicking and rapid closure of the covalently-closed circular template.
关键词：electron microscopy ; mouse DNA ; density gradient centrifugation
