B6;129S6-Gt(ROSA)26Sor^{tm14(CAG-tdTomato)Hze}/J

Common Name: Ai14; Ai14D; Ai14(RCL-tdT)-D

Ai14 is a Cre reporter allele designed to have a loxP-flanked STOP cassette preventing transcription of a CAG promoter-driven red fluorescent protein variant (tdTomato) - all inserted into the Gt(ROSA)26Sor locus. Ai14 mice express robust tdTomato fluorescence following Cre-mediated recombination. The Ai14 allele is very similar in design to the Ai9 allele - differing only in the absence (Ai14) or presence (Ai9) of an att site-flanked neo selection cassette at the 3' end of the targeted allele. Importantly, both Ai14 and Ai9 may exhibit low levels of tdTomato expression prior to exposure to Cre recombinase - but the tdTomato expression levels after Cre recombination are greater than those baseline levels. As such, it is recommended that researchers include Cre-negative controls to establish the baseline tdTomato levels in their experiments. See Detailed Description for additional details.