Supplementary Figure 2.

Loss of selective TRCs in DTA-expressing animals

Upper diagram illustrates the strategy used to target DTA or GFP to selective populations of TRCs. BAC constructs contained the entire T1R2 or PKD2L1 genes with the IRES-Cre added downstream of the termination codon, but upstream of polyA-addition signals. In both cases, the transgenic constructs included at least 50Kb of flanking sequences upstream and downstream of the target gene (see Methods). Fidelity of Cre and reporter expression in the correct cell types was confirmed by double labeling with a variety of TRC-specific gene probes. Lower panels show in situ hybridization experiments examining the presence of sweet (T1Rs), bitter (T2Rs) or PKD2L1-expressing cells in the two engineered lines. Targeting of DTA to T1R2- or PKD2L1-expressing cells eliminates over 95% of their respective TRC population. In situ hybridization probes were as in Figure 1.