Fig. 1. Disruption of the PLC-1 gene in mouse ES cells. (A) Genomic structure coding the functional domains of the mouse PLC-1 protein, the structure of the targeting vector and predicted structure of the targeted plc-1 locus. The location of the hybridization probe, 0.4 kb XhoI-EcoRI fragment, and the expected sizes of the EcoRI and the KpnI fragments that hybridize with the probe are indicated. E, EcoRI; Xh, XhoI; Xb, XbaI; H, HindIII; K, KpnI. (B) Southern blot analysis of the ES cell clones. The plc-1^–/– ES cells were selected by culturing the plc-1^+/– ES cells in the increased dose of G418 as described in Materials and Methods. Genomic DNA isolated from wild-type (+/+), plc-1^+/– (+/–) and plc-1^–/– (–/–) ES cells were digested with EcoRI (left panel) or Kpn I (right panel) and hybridized with the probe shown in (A). The expected sizes of the wild-type and the mutated fragments are 3.3 kb and 1.3 kb, respectively, when digested with EcoRI, 8.0 kb and 5.2 kb, respectively, with KpnI. (C) Expression of the PLC-1 (left) and PLC-2 (right) proteins in the wild-type (+/+), plc-1^+/– (+/–) and plc-1^–/– (–/–) ES clones.