Mutagenesis of the replication point by nitrosoguanidine: map and pattern of replication of the Escherichia coli chromosome.
Mutagenesis of the replication point by nitrosoguanidine: map and pattern of replication of the Escherichia coli chromosome.
复制标题
亚硝基胍复制点的诱变：大肠杆菌染色体的复制图和模式。
DOI：
10.1016/0022-2836(68)90315-x
复制
发表时间：
1968
影响因子：
5.6
通讯作者：
N. Guerola
中科院分区：
文献类型：
--
作者：
Enrique Cerdá;P. Hanawalt;N. Guerola
在大肠杆菌中，亚硝基胍诱发的突变大多位于染色体的复制点区域，用亚硝基胍处理来自同步培养物的连续样品，在相应基因复制时产生最大量的给定类型的突变。这就允许构建描述基因复制模式的染色体复制图。该图谱与标准遗传图谱基本一致。复制起点固定在染色体的确定位置，大致对应于标准接合图谱的50分钟，并且对于所有测试菌株（15 T-、K12 Hfr和K12 F-）都是相同的。在所研究的条件下，DNA复制的循环是连续的，没有延迟或重叠.作为该方法在DNA复制控制研究中的一个应用，本文提出了一个遗传学论证，即胸腺嘧啶饥饿导致新一轮DNA复制的启动，即使在保留胸腺嘧啶时染色体已经在复制。
The majority of the mutations induced by nitrosoguanidine inEscherichia coliare located in the replication point region of the chromosome.The treatment with nitrosoguanidine of successive samples from a synchronized culture produces a maximum of a given type of mutant at the time the corresponding gene is being replicated. This permits the construction of areplication mapof the chromosome that describes the pattern of the replication of the genes. This map is in general agreement with the standard genetic map. The origin of replication is fixed at a determined position of the chromosome, that corresponds roughly to 50 minutes of the standard conjugation map and is the same for all strains tested (a 15 T−, a K12 Hfr and a K12 F−). The direction of replication is clockwise, by reference to the same standard, and the cycles of DNA replication, under the conditions studied, succeed each other without delay or overlap.As an application of the method to the study of the control of DNA replication, a genetic demonstration is presented that thymine starvation leads to the initiation of a new round of DNA replication, even if the chromosome is already being replicated at the time thymine is withheld.