The BAC RP23-278N11 was used to make a transgene expressing Gpbar1. It was modified to contain the rabbit beta-globin intron, an inactive cre/ERT2 fusion, and frt-flanked neo cassette downstream of the Vil1 promoter for genotyping purposes. The neo cassette was removed by germ line, flp mediated recombination. One line was created with 6 copies of the transgene and Gpbar1 expression restricted to most tissues normally expression Gpbar1.