Chatterjee A K, Starr M P
J Bacteriol. 1972 Jul;111(1):169-76. doi: 10.1128/jb.111.1.169-176.1972.
The episomic element F'lac(+) was transferred, probably by conjugation, from Escherichia coli to Lac(-) strains of Erwinia herbicola, Erwinia amylovora, and Erwinia chrysanthemi (but not to several other Erwinia spp. In preliminary trials). The lac genes in the exconjugants of the Erwinia spp. showed varying degrees of stability depending on the strain (stable in E. herbicola strains Y46 and Y74 and E. amylovora strain EA178, but markedly unstable in E. chrysanthemi strain EC16). The lac genes and the sex factor (F) were eliminated from the exconjugants by treatment with acridine orange, thus suggesting that both lac and F are not integrated in the Erwinia exconjugants. All of the tested Lac(+) exconjugants of E. herbicola strains Y46 and Y74 and E. amylovora strain EA178, but not of E. chrysanthemi strain EC 16, were sensitive to the F-specific phage M13. The heterogenotes (which harbored F'lac(+)) of E. herbicola strains Y46 and Y74, E. amylovora strain EA178, and E. chrysanthemi strain EC16 were able to transfer lac genes by conjugation to strains of E. herbicola, E. amylovora, E. chrysanthemi, Escherichia coli, and Shigella dysenteriae. The frequency of such transfer from Lac(+) exconjugants of Erwinia spp. was comparable to that achieved by using E. coli F'lac(+) as donors, thus indicating the stability, expression, and restriction-and-modification properties of the sex factor (F) in Erwinia spp.
附加体元件F'lac(+)可能通过接合作用从大肠杆菌转移至草生欧文氏菌、梨火疫欧文氏菌和菊欧文氏菌的Lac(-)菌株（但在初步试验中未转移至其他几种欧文氏菌属菌株）。欧文氏菌属菌株的接合后体中的lac基因根据菌株不同表现出不同程度的稳定性（在草生欧文氏菌Y46和Y74菌株以及梨火疫欧文氏菌EA178菌株中稳定，但在菊欧文氏菌EC16菌株中明显不稳定）。用吖啶橙处理接合后体可消除lac基因和性因子(F)，因此表明lac和F在欧文氏菌接合后体中均未整合。草生欧文氏菌Y46和Y74菌株以及梨火疫欧文氏菌EA178菌株的所有测试Lac(+)接合后体（但菊欧文氏菌EC16菌株的接合后体除外）对F特异性噬菌体M13敏感。草生欧文氏菌Y46和Y74菌株、梨火疫欧文氏菌EA178菌株以及菊欧文氏菌EC16菌株的异基因接合体（含有F'lac(+)）能够通过接合作用将lac基因转移至草生欧文氏菌、梨火疫欧文氏菌、菊欧文氏菌、大肠杆菌和痢疾志贺氏菌的菌株。欧文氏菌属菌株的Lac(+)接合后体的这种转移频率与使用大肠杆菌F'lac(+)作为供体所达到的频率相当，因此表明性因子(F)在欧文氏菌属菌株中的稳定性、表达以及限制和修饰特性。
