Chatterjee A K, Starr M P
J Bacteriol. 1973 Dec;116(3):1100-6. doi: 10.1128/jb.116.3.1100-1106.1973.
Stable donor strains of Erwinia amylovora were obtained from strain EA178R(1) (harboring an Escherichia coli F'lac) by selection for clones resistant to curing by acridine orange. These donor strains (EA178R(1)-99 and EA178R(1)-111) transfer chromosomal markers (arg, cys, gua, ilv, met, pro, ser, trp); the frequency of the appearance of recombinants prototrophic for Cys, Gua, Met, Ser, and Trp is highest (> 10(-5)), followed by recombinants prototrophic for Arg, Ilv, and Pro (10(-7) to 10(-5)). The results of interrupted matings, as well as the frequency of transmission of various markers, suggest that cys is transferred as an early marker by both donor strains. The Hfr state of these donor strains is rather likely on the basis of the following observations. The donor strains exhibit a relatively efficient and possibly oriented chromosome transfer; the Lac(+) character is not cured by acridine orange in these donor strains; and these donor strains do not transfer F.
通过筛选对吖啶橙消除作用具有抗性的克隆，从菌株EA178R(1)（携带大肠杆菌F'lac）获得了稳定的解淀粉欧文氏菌供体菌株。这些供体菌株（EA178R(1)-99和EA178R(1)-111）可转移染色体标记（arg、cys、gua、ilv、met、pro、ser、trp）；对Cys、Gua、Met、Ser和Trp呈原养型的重组体出现频率最高（>10(-5)），其次是对Arg、Ilv和Pro呈原养型的重组体（10(-7)至10(-5)）。中断杂交的结果以及各种标记的传递频率表明，cys作为早期标记由两种供体菌株转移。基于以下观察结果，这些供体菌株很可能处于高频重组（Hfr）状态。供体菌株表现出相对高效且可能定向的染色体转移；在这些供体菌株中，Lac(+)性状不会被吖啶橙消除；并且这些供体菌株不转移F因子。
