Extended Data Figure 1. Generation of R26^Cyp1a1 allele.

a, The endogenous Rosa26 locus, the gene targeting vector, the targeted Rosa26 allele including the Neo resistance gene cassette (R26^Cyp1a1-neoR), the targeted allele (R26^LSL-Cyp1a1) after FLPe-mediated recombination and the ubiquitously expressed R26^Cyp1a1 are schematically depicted to scale. A minigene composed of the coding sequences of mouse Cyp1a1 and rat Thy1 connected by a 2A sequence followed by the woodchuck hepatitis virus derived regulatory element (WPRE) and a bovine growth hormone polyadenylation site (bGH pA). b, Expression of rat THY1 in indicated cell types in the colon of R26^Cyp1a1 , IEC^Cyp1a1 (Villin-Cre), Rag1^Cyp1a1 (Rag1-Cre) strains.