A floxed lacZ-IRES cassette with a splice acceptor and a frt-flanked neo cassette were inserted between exon 8 and 9 and an additional loxP site was inserted upstream of exon 8. Cre-mediated recombination was used to remove exon 8 and the lacZ cassette. The absence of alpha1-chimaerin and alpha2-chimaerin was confirmed by western blot analysis on total brain extracts. (J:128724)