The transgene was generated by replacing exons 2 and 3 of neuromedin U receptor 1 (Nmur1 gene), in the mouse BAC RP23-403I3, with a P2A-iCre-T2A-EGFP cassette followed by an FRT-flanked Kanamycin cassette. The FRT flanked kanamycin cassette was removed by FLP-mediated recombination. The modified BAC construct was microinjected into the pronucleus of C57BL/6 zygotes and randomly integrated into the mouse genome. Founder line 1 was established and then subsequently maintained