Dressler D, Wolfson J, Magazin M
Proc Natl Acad Sci U S A. 1972 Apr;69(4):998-1002. doi: 10.1073/pnas.69.4.998.
In its first round of replication, the T7 chromosome follows a simple pattern, as viewed in the electron microscope. The iniation of DNA synthesis occurs about 17% from the genetic left end of the viral DNA rod. Bidirectional DNA synthesis from this origin then generates a replicating intermediate that we call an "eye form." In the eye form, when synthesis in the leftward direction reaches the left end of the viral chromosome, the molecule is converted into a Y-shaped replicating rod. The remaining growing point continues synthesis rightward, until presumably it runs off the right end of the DNA rod, thus terminating replication. Numerous T7 chromosomes were found in which a second round of replication had begun before the first round had finished. Analysis of these reinitiated DNA molecules showed that the second round of replication, like the first, began 17% from the end of the chromosome and involved bidirectional DNA synthesis.
在第一轮复制中，从电子显微镜观察，T7染色体遵循一种简单模式。DNA合成起始于病毒DNA棒状结构遗传左端约17%处。从这个起始点进行的双向DNA合成随后产生一个我们称为“眼形”的复制中间体。在眼形结构中，当向左合成到达病毒染色体左端时，分子转变为Y形复制棒。剩余的生长点继续向右合成，直到大概到达DNA棒状结构右端，从而终止复制。发现许多T7染色体在第一轮复制完成之前就已开始第二轮复制。对这些重新起始的DNA分子的分析表明，第二轮复制与第一轮一样，从染色体末端17%处开始，并涉及双向DNA合成。
