Harada K, Kameda M, Suzuki M, Shigehara S, Mitsuhashi S
J Bacteriol. 1967 Apr;93(4):1236-41. doi: 10.1128/jb.93.4.1236-1241.1967.
The R(21)(TC) factor, obtained by transduction of the R(10)(TC.CM.SM.SA) factor with phage epsilon to group E Salmonella, is not transferable by the normal conjugal process. However, when R(21)(TC)(+) transductants are infected with the F(13) factor, the nontransferable R(21)(TC) factor acquires transmissibility by conjugation. R(21)(TC)(+) conjugants of Escherichia coli K-12, to which only the R(21)(TC) factor was transmitted by cell-to-cell contact from an F' R(+) donor, were still unable to transfer their R(21)(TC) factor by conjugation. In crosses between Hfr and F(-)E. coli K-12 strains containing R(21)(TC), the gene responsible for tetracycline resistance was located on the E. coli K-12 chromosome between lac and pro, near lac.
通过用噬菌体ε将R(10)(TC.CM.SM.SA)因子转导至E群沙门氏菌而获得的R(21)(TC)因子，不能通过正常的接合过程进行转移。然而，当R(21)(TC)(+)转导子被F(13)因子感染时，不可转移的R(21)(TC)因子通过接合获得了可传递性。仅通过细胞间接触从F' R(+)供体传递了R(21)(TC)因子的大肠杆菌K-12的R(21)(TC)(+)接合子，仍然无法通过接合转移其R(21)(TC)因子。在含有R(21)(TC)的Hfr和F(-)大肠杆菌K-12菌株之间的杂交中，负责四环素抗性的基因位于大肠杆菌K-12染色体上lac和pro之间，靠近lac。
