TABLE 2

Recombination frequencies in wild-type and mutant CHO cells

Expt.CrossaCell typebPlasmid 1/ClaIPlasmid 2/NheIFrequency (× 106)cnd
11AK1cpSV2neoS(B)XpneoAnN9.81
21BK1cpSV2neoS(B)CpneoAnNX26 ± 112
32AK1cpSV2neoS(B)XpneoAnN1116 ± 32
42BK1cpSV2neoS(B)CpneoAnN11X271
53K1cpSV2neoS(B)CpneoAnN11191
62BMTCHO+pSV2neoS(B)CpneoAnN11X101
72Bclone BpSV2neoS(B)CpneoAnN11X161
83MTCHO+pSV2neoS(B)CpneoAnN117.51
93clone BpSV2neoS(B)CpneoAnN11191
  • a Crosses are diagrammed in Figure 2; pSV2neo and pneoAn derivatives were linearized at ClaI and NheI sites, respectively.

  • b K1c and MTCHO+ cells are mismatch repair proficient, clone B cells are mismatch repair deficient.

  • c Recombination frequencies were calculated as the ratio of G418r colonies per cell electroporated. Values are averages ± range for experiments repeated twice. From 0.1 to 0.2 μg of each DNA were used in transfections; all frequencies are normalized to 0.1 μg of pSV2neo derivative.

  • d Number of repetitions.