Rafii F, Crawford D L
Department of Bacteriology and Biochemistry, University of Idaho, Moscow 83843.
Appl Environ Microbiol. 1988 Jun;54(6):1334-40. doi: 10.1128/aem.54.6.1334-1340.1988.
The conjugative plasmid pIJ101 and its conjugative nondeletion derivatives pIJ303 and pIJ211 were tested for their transferability between strains of Streptomyces on laboratory media and in the soil environment. Their roles in the mobilization of the cloning vector plasmid pIJ702, a nonconjugative deletion derivative of pIJ101, were also examined. Biparental and triparental crosses were performed on agar slants and in sterile soil between the plasmid donor Streptomyces lividans and several recipient Streptomyces strains previously isolated from soil. Conjugative plasmids were transferred to seven recipients in slant crosses and to three recipients in soil. Plasmids isolated from recipients showed restriction fragment patterns identical to that of the original plasmid in S. lividans. Plasmid pIJ303 was transferred less frequently in soil than on slants, and the frequency of transfer was higher at 30 degrees C than at the other temperatures examined. Transconjugant Streptomyces strains differed in their ability to maintain pIJ303. The nonconjugative plasmid pIJ702 was mobilized on agar slants into S. coelicolor 2708, which already contains a self-transmissible plasmid. Plasmid pIJ702 was also mobilized into S. flavovirens, Streptomyces sp. strain 87A, and S. parvulus on slants and in sterile soil after triparental crosses with two donors, one containing pIJ702 and the other containing either pIJ101 or pIJ211. The presence of a conjugative plasmid donor was required for the transfer of pIJ702 to S. parvulus 1234, S. flavovirens 28, and Streptomyces sp. strain 87A. Plasmid pIJ702 was always transferred in its normal, autonomous form. Chromosomal recombination also occurred in transconjugants after the transfer of pIJ702. This is the first report of gene transfer between Streptomyces strains in soil.
对接合质粒pIJ101及其接合非缺失衍生物pIJ303和pIJ211在实验室培养基和土壤环境中，在链霉菌菌株之间的可转移性进行了测试。还研究了它们在克隆载体质粒pIJ702（pIJ101的非接合缺失衍生物）的转移中的作用。在琼脂斜面上和无菌土壤中，在质粒供体变铅青链霉菌与先前从土壤中分离的几种受体链霉菌菌株之间进行了双亲杂交和三亲杂交。接合质粒在斜面杂交中转移到7个受体中，在土壤中转移到3个受体中。从受体中分离的质粒显示出与变铅青链霉菌中原始质粒相同的限制性片段模式。质粒pIJ303在土壤中的转移频率低于在斜面上的转移频率，并且在30℃时的转移频率高于在所检测的其他温度下。转接合子链霉菌菌株在维持pIJ303的能力上有所不同。非接合质粒pIJ702在琼脂斜面上转移到已经含有自我传递质粒的天蓝色链霉菌2708中。在与两个供体进行三亲杂交后，其中一个含有pIJ702，另一个含有pIJ101或pIJ211，质粒pIJ702在斜面和无菌土壤中也转移到了黄弗氏链霉菌、链霉菌87A菌株和微小链霉菌中。将pIJ702转移到微小链霉菌1234、黄弗氏链霉菌28和链霉菌87A菌株中需要接合性质粒供体的存在。质粒pIJ702总是以其正常的自主形式转移。在pIJ702转移后，转接合子中也发生了染色体重组。这是关于土壤中链霉菌菌株之间基因转移的首次报道。
