This kit includes strains of S. typhimurium LT2 which carry Fprime factors which carry genes derived from E. coli K12, representing a large part (but not all) of the chromosome of E. coli. They were constructed originally by Brooks Low, and transferred into S. typhimurium by conjugation. These conjugates were originally reported by Sanderson and Hartman,1978, Microbiol. Revs 42:417519. Later L. Csonka and colleagues inserted transposons bearing antibiotic resistance to the Fprime factor, in order to increase the value of these Fprime factors for genetic analysis.
The strains are described in Sanderson and Roth, 1988, Microbiol. Revs 52:485532. The chromosome of these strains is S. typhimurium LT2; all are recA+, but the fact that the DNA on the Fprime factor is from E. coli and has low homology with S. typhimurium DNA means that the probability of insertion of the Fprime factor is low.
In about half of the18 strains the Fprime factor is wild type for replication; in the other half it is temperaturesensitive, i.e. unable to replicate normally at temperatures significantly higher than 30 degrees C. These strains must be grown at 30 degrees C in broth, otherwise the Fprime factor will be lost unless selective pressure is applied, and even then strains in which the Fprime factor is inserted into the chromosome will likely be isolated. These strains can be used with selection at high temperature to obtain Hfr strains.
The Fprime factor can be retained in the strain by growing in the presence of the antibiotic (tetracycline for Tn10, kanamycin for Tn5). Transfer of the antibiotic resistance by conjugation can be selected directly, and other genes on the Fprime factor can be detected as unselected markers.
List of strains of S. typhimurium with Fprime factors which carry chromosomal genes of E. coli K12, as well as transposon Tn5 or Tn10.
Additonal genetic information can be found by searching the SGSC online search site (Start new search)









TL851  1370  F104  977  leu+ proB+ A+ zzf20::Tn10  purB655 (del)proBA47  PyrB (Ura) Tc R  Pro+  R 
TL852  1371  F'104  977  leu+ proB+ A+ zzf20::Tn10  purB655 (del)proBA47  PyrB (Ura) Tc R  Pro+  S 
TL873  1372  F'128  68  ProB+ A+ zzf20::Tn10 argF+ lacI4000phi(lacIZ) Y+  argI537 ara9 fol1  Ara Fol Tc R  Arg+ Lac +  R 
TL874  1373  F'128  68  ProB+ A+ zzf20::Tn10 argF+ lacI4000phi(lacIZ) Y+  argI537 ara9 fol1  Ara Fol Tc R  Arg+ Lac +  S 
TL275  1374  F'128  68  ProB+ A+ argF+ lacI4000phi(lacIZ) Y+, Tn5 in unknown location on F'128  (del)proBA21 pyrA8 argR5 fol181 rpsL201  PyrA (arg+ Ura) Fol Sm R Km R  Pro+  R 
TT1948  323  F'152  1217  nadA+ zzf20::Tn10  his0124 hisB2142 nad506 hut+ galE542  His Tc R  Nad+ Gal+  R 
TL853  1375  F'148  3234, 4244  his+ zzf20::Tn10  trpA49 pncA15 hisD9953::MudI1734  Trp PncA Km R Tc R  His+  R 
TL854  1376  F'148  3234, 4244  his+ zzf20::Tn10  trpA49 pncA15 hisD9953::MudI1734 zcc628::Tn5  Trp PncA Km R Tc R  His+  S 
TL1600  1533  F'129  4451  his+ zzf20::Tn10  his2236 proC1909::Mud18 rpsL1  His+ Pro Sm R  His+  S 
TL1178  1390  F'198  5056  cysA+ zzf20::Tn10  thr469::Mud18  Thr Ap R Tc R    R 
TL1179  1391  F'198  5056  cysA+ zzf20::Tn10  thr469::Mud18  Thr Ap R Tc R    S 
TL870  1392  F'143  5662  cysC+ zzf20::Tn10  cysC519 rpsL1  Sm R Tc R  Cys+  R 
TL871  1393  F'143  5662  cysC+ zzf20::Tn10  cysC519 rpsL1  Sm R Tc R  Cys+  S 
TL863  1394  F'116  5966  lysA+ serA+ zzf20::Tn10  lys554 serA790 his644  His Tc R  Lys+ Ser+  R 
TL864  1395  F'116  5966  lysA+ serA+ zzf20::Tn10  lys554 serA790 his644  His Tc R  Lys+ Ser+  S 
TL860  1396  F'140  6781  cysG+ argD+ zzf20::Tn10  argD455 (del)proBA rpsL1  Pro Sm R Tc R  Arg+  S 
TL865  1397  F'117  9497  purB+ zzf20::Tn10  pyrB64 hisD6414 mel  His Tc R  PyrB+  R 
TL866  1398  F'117  9497  purB+ zzf20::Tn10  pyrB64 hisD6414 mel  His Tc R  PyrB+  S 
(a) The Fprime factors of E. coli wre originally described by Low (1972. Bacteriol. Rev. 36: 587607). However, the location of the genes carried is given according to edition VII of the E. coli Map (Bachmann, B.J., 1983. Microbiol. Rev. 47:180230) in which the minutes have been modified
(b) The temperaturesensitive mutation in F' ts114 lac (Jacob et al., 1963. Cold Springs Harbour Symp. Quant. Biol. 28:329348, which makes the plasmid unable to replicate at high tempeature, is linked by P22 transduction to the transposon insertion zzf20::Tn10 (constructed by Chumley et al., 1979. Genetics 91: 639655). The new F factors were made by transducing from an Fprime factor carrying both ts114 and zzf20::Tn10 into the E. coli F factors. All isolates selected carried the transposon; some are temperature sensitive (carry the ts allele), whereas others are temperature resistant. Those which are temperature sensitive must be grown at 30 degrees C to prevent loss of the plasmid or insertion of the plasmid into the chrommosome.
References:
Chumley, F.G., Menzel, R., and Roth, J.R. 1979. Hfr formation directed by Tn10. Genetics 91:639655.
Sanderson, K.E. and Hartman, P.E. 1978. Linkage map of S. typhimurium, edition V. Microbiol. Rev. 42:471519
Sanderson, K.E. and Roth, J.R. 1988. Linkage map of S. typhimurium, edition VII. Microbiol. Rev. 52:485532.
Sanderson, K.E. 1996. Fmediated conjugation, F+ strains, and Hfr strains of Salmonella typhimurium and Salmonella albony. In E. coli and Salmonella, editon 2, F.C. Neidhardt et at., (editors), ASM press, pps 24062412