Figure 2. Independent recombination of the two floxed alleles at the single-cell level in the P2ry12^CreER double reporter (Ai9:R26-YFP) mouse line.

Evaluation of the TAM-dependent recombination of either the Ai9-tdTomato or R26-YFP allele, which are both located in the R26 loci in a double reporter mouse in the P2ry12^CreER line, suggests that, although, on a populational level, Ai9-tdTomato reporter has a higher probability of being recombined compared with the R26-YFP allele, at the single-cell level, the recombination of each individual allele can be independent and does not always follow the size of the floxed region rule.

(A) Experimental timeline.

(B–E) IHC evaluation of the recombination of microglia on either of the reporter expression. Note tdTomato⁺:YFP⁺ double-positive microglia (orange arrow), more abundant tdTomato⁺:YFP⁻ microglia (white arrow), and the less abundant YFP⁺:tdTomato⁻ microglia (white arrowhead).

(F and G) Representative FACS plots for no color control or the double reporter flow analysis.

(H–L) Graphs showing the percentage of cells based on reporter expression of total reporter⁺ cells from FACS-sorted double-positive cells; each data point is from a single FACS sample from a single animal.

(M–Q) Graphs showing the percentage of cells based on reporter expression of total IBA1⁺ cells sampled from IHC on the cortex; each data point is the average of 3 sampled images from a single animal.

Mean ± SEM. Scale bar, 100 μm. See also Table S1.