Figure 1. Recombination efficiency varies across microglial CreER lines.

(A) Diagram of transgenes used to express CreER in Cx3cr1^{YFP–CreER (Litt)}, Cx3cr1^{CreER (Jung)}, Tmem119^CreER, Hexb^CreER, and P2ry12^CreER mice.

(B) Diagram of the Rosa26^mTmG allele and corresponding cellular fluorescence before and after Cre/loxP DNA recombination. loxP sites are indicated by yellow triangles.

(C) Diagram of experimental protocol used to assess tamoxifen (TAM)-induced Cre/loxP recombination of Rosa26^mTmG/+ in microglia by flow cytometry.

(D–H) Representative flow cytometry results show the percentage of mGFP⁺ (mG⁺) and mTomato⁺ (mT⁺) microglia from individual animals from each group.

(I) Quantification of the percentage of recombined mGFP⁺ microglia in microglial CreER lines showed increased recombination in TAM vs. oil for all five CreER lines (Student’s t tests: Cx3cr1^{YFP–CreER/+ (Litt)}:n = 5 oil, 5 TAM mice; Cx3cr1^{CreER/+ (Jung)}:n = 5 oil, 4 TAM mice; Tmem119^CreER/+:n = 8 oil, 7 TAM mice; Hexb^CreER/+: n = 9 oil, 10 TAM mice; P2ry12^CreER/+: n = 4 oil, 4 TAM mice; ****p < 0.0001). All data are presented as mean ± SEM. Individual data points indicate males (squares) and females (circles).

See also Figures S1 and S2 and Table S1.