The coding sequence for the first 173 amino-acids (containing the conserved DNA-binding domain) was replaced with a tdTomato fluorescent marker cassette. A loxP site, an FRT site flanked neomycin resistance gene cassette and a second loxP site were inserted into intron 1. The neo cassette was removed through subsequent cre-mediated recombination. This creates a knockout reporter allele, with the reporter gene expressed from the promoter of the targeted gene. (J:255683)