Fig. 5. MuHV-4 genetic switching by Cre in LNs of Cre transgenic mice. (a) LN sections from naive LysM–Cre × Ai6–ZsGreen mice were stained for cell markers (red). Cre-triggered ZsGreen1 expression was visualized directly (green). Nuclei were stained with DAPI (blue). Arrows show examples of red/green co-localization, including CD169+ cells around the subcapsular sinus. Bars, 10 μm. (b) LysM–Cre mice were infected i.f. or i.n. with MHV-RG (105 p.f.u.). Viruses recovered from footpads (FP) and PLNs 5 days after i.f. infection, and from noses and SCLNs 7 days after i.n. infection were typed for Cre-mediated switching from red to green fluorescence. The percentage switched was calculated as 100 × green p.f.u./(green pf.u. + red p.f.u.). ○ and ⊕, Individual mice; × , means. PLN switching was not significantly different from that in the footpad, and SCLN switching was not significantly different from that in noses (P >0.05). (c) CD11c-Cre mice were infected i.f. or i.n. with MHV-RG, and recovered viruses were typed for Cre-mediated switching as in (b). Switching was significantly greater in PLNs than in the footpad, and significantly greater in SCLNs than in noses (*P < 0.001).
