Novel mutants of Escherichia coli that produce recombinogenic lesions in DNA. II. Properties of recombinogenic lambda phages grown on bacteria carrying arl mutations.
Novel mutants of Escherichia coli that produce recombinogenic lesions in DNA. II. Properties of recombinogenic lambda phages grown on bacteria carrying arl mutations.
复制标题
大肠杆菌的新突变体可在 DNA 中产生重组损伤。
DOI：
10.1016/0022-2836(80)90142-4
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发表时间：
1980
影响因子：
5.6
通讯作者：
Hays,JB
中科院分区：
文献类型：
--
作者：
Korba,BE;Hays,JB
在含有突变的大肠杆菌上生长数轮的 Lambda 重复噬菌体在随后的测试感染中以更高的频率（高出 3 至 6 倍）重组。 Arl-噬菌体（生长的 onarlbacteria）重组的增强可以通过改变遗传连锁的测定以及标准测定来证明，标准测定测量重复噬菌体（EDTA 敏感）到单拷贝噬菌体（EDTA 抗性）的转化。在噬菌体+细菌的后续生长过程中，增强重组的累积潜力消失了。 Arl-噬菌体在多个位点具有与对照噬菌体相同的突变频率；arl细菌本身表现出正常的突变率。 Arl-噬菌体具有正常的铺板效率和浮力密度。从Arl-噬菌体中提取的DNA与在arl+细菌上生长的噬菌体中提取的DNA表现出相同的链中断频率、相同的超螺旋密度（当体内环化时）以及相同的热变性特征。在存在 λ 阻遏物的情况下，Arl-噬菌体的重组率非常低，与正常噬菌体的情况一样。紫外线照射（80 J/m2）Arl-噬菌体的重组频率是未照射Arl-噬菌体和照射对照噬菌体频率总和的两倍以上。当E. 或E. 噬菌体中的任一者时，观察到Arl-噬菌体的重组显着增加。 coliRecBC 或 RecE（但不是 RecF）途径处于活跃状态。
Lambda duplication phages grown for several rounds onEscherichia colistrains containingarlmutations were recombined at elevated frequencies (3 to 6-fold higher) in subsequent test infections. Enhanced recombination of Arl−phages (grown onarlbacteria) was demonstrable by assays for altered genetic linkages as well as by the standard assay, which measures the conversion of duplication phages (EDTA-sensitive) to single-copy phages (EDTA-resistant). The accumulated potential for enhanced recombination was lost during subsequent growth of the phages onarl+bacteria. Arl−phages had the same mutation frequencies, at a variety of loci, as control phages;arlbacteria themselves exhibited normal mutation rates. Arl−phages had normal plating efficiencies and buoyant densities. DNA extracted from Arl−phages exhibited the same frequency of strand interruption, the same superhelical density (when circularizedin vivo), and the same thermal denaturation profile as DNA from phages grown onarl+bacteria. Recombination of Arl−phages in the presence of λ repressor was very low, as is the case for normal phages. The recombination frequency of ultraviolet light irradiated (80 J/m2) Arl−phages was more than twice the sum of the frequencies for unirradiated Arl−phages and irradiated control phages. Substantially increased recombination of Arl−phages was observed when either theE. coliRecBC, or RecE (but not RecF) pathway was active.