Molecular recombination following conjugation in Escherichia coli.
Molecular recombination following conjugation in Escherichia coli.
复制标题
大肠杆菌中结合后的分子重组。
DOI：
10.1016/0022-2836(66)90068-4
复制
发表时间：
1966
影响因子：
5.6
通讯作者：
M. Riley
中科院分区：
文献类型：
--
作者：
A. Oppenheim;M. Riley
利用密度标记的F−细菌和3H标记的Hfr细菌研究了大肠杆菌接合后伴随遗传重组的分子事件。从交配细菌的培养物中分离DNA，并通过连续CsCl密度梯度离心进行分级。分离出含有3H和密度标记的DNA片段。将该“重组DNA”进行超声处理和变性程序，并通过CsCl密度梯度离心研究如此产生的片段。分离的重组分子具有以下性质：1. (1)交配前形成的两条F−链至少出现在某些分子中。(2)在插入3H标记DNA的区域中，两条预先存在的F−链都被替换. (3)3H标记DNA的几个小片段彼此相邻地插入. (4)3H标记和密度标记的DNA片段主要以非共价键连接。
Molecular events accompanying genetic recombination after conjugation inEscherichia colihave been studied using density-labeled F−bacteria and3H-labeled Hfr bacteria. DNA was isolated from a culture of mated bacteria and was fractionated by sequential CsCl density-gradient centrifugation. A fraction of the DNA was isolated which contained both3H and density labels. This “recombinant DNA” was subjected to sonication and denaturation procedures, and the fragments so produced were studied by CsCl density-gradient centrifugation.The recombinant molecules which were isolated had the following properties:1.(1) Both of the F−strands made before mating appeared in at least some of the molecules.2.(2) Both of the pre-existing F−strands were replaced in the region where the3H-labeled DNA was inserted.3.(3) Several small segments of3H-labeled DNA were inserted near one another.4.(4) The3H-labeled and density-labeled DNA segments appeared to be joined mainly by non-covalent bonds.