"Site-directed mutagenesis was carried out to modify both of the consensus binding sites in the pPGF11.13 DNA construct (see Fig. 2A). Christensen et al. (1996) had demonstrated by in vitro binding experiments that LAG-1 has strong affinity for the DNA sequence (A/G)TGGGAA, a consensus sequence previously determined for the Su(H)/CBF1 family of proteins (Tun et al., 1994; Brou et al., 1994). The mutated construct, pPGF11.13 ΔLAG-1, was injected in the germline and several stably transmitting lines were obtained. In more than 10 such lines that we analyzed, almost no detectable (Figs. 6C and 6D) or extremely weak (not shown) GFP fluorescence was observed in the uterine π progeny. In this experiment, the lin-11
::GFP expression in VC neurons and vulval cells serves as an internal control. The vulval, but not the VC neuron, expression was also reduced in all lines. While the uterine expression was largely absent, few worms showed some residual expression."