Colonization of BAFF-R−/− splenic follicles by eGFP+ MuHV-4. We infected BAFF-R−/− mice i.p. with eGFP+ MuHV-4 as for Fig. 5 and 4 or 8 days later stained splenic sections for eGFP (green) plus IgM (red) and, as a further cell type marker, either B220, MARCO, IgD, or CD169 (white). Nuclei were counter-stained with DAPI (blue). The boxed regions of the left-hand overviews (scale bars shows 100 μm) are shown at higher power in the right-hand zoomed images, with either merged or individual channels. Arrows show examples of eGFP+ cells.