Romanova Iu M, Nastichkin I A, Martsinkovskaia A I, Rudnev I A, Petrovskaia V G
Mol Gen Mikrobiol Virusol. 1987 Sep(9):19-24.
The plasmid pSS120, determining the synthesis of species specific I phase antigen of Shigella sonnei is mobilized for genetic transfer into E. coli K12 recipient cells with the frequency 12-41%. The frequency depends on the type of mobilized plasmid and recipient strain. The I phase antigen is normally expressed in II phase recipient cells and in E. coli cells. During mobilization pSS120 forms cointegrates representing a recombinant of mobilizing and mobilized plasmids DNA. The study of pSS120 inheritance stability has shown the plasmid to be unstable during culturing of bacteria and to be partially lost from the parent Shigella sonnei strains as well as from the "hybrid" transconjugants obtained. The 60 Md plasmid present in the donor strains of Shigella sonnei is prone to structural fragmentation particularly expressed in Shigella sonnei/E. coli hybrids.
决定宋内志贺氏菌种特异性I相抗原合成的质粒pSS120，以12% - 41%的频率被转移用于基因导入大肠杆菌K12受体细胞。该频率取决于被转移质粒的类型和受体菌株。I相抗原通常在II相受体细胞和大肠杆菌细胞中表达。在转移过程中，pSS120形成共整合体，代表转移质粒和被转移质粒DNA的重组体。对pSS120遗传稳定性的研究表明，该质粒在细菌培养过程中不稳定，会从亲代宋内志贺氏菌菌株以及获得的“杂交”转接合子中部分丢失。宋内志贺氏菌供体菌株中存在的60 Md质粒易于发生结构断裂，这在宋内志贺氏菌/大肠杆菌杂种中尤为明显。
