Immunofluorescence showing localisation of 5mC (green) and 5hmC (red) between e18.5 and e21.5. One seminiferous cord is shown outlined in each image; germ cells are indicated by white arrows, and somatic cells within the seminiferous cord are indicated by blue arrows. Images show that 5mC (green) is undetectable in germ cells at e18.5 (A) but becomes detectable at e19.5 (B) (indicated by arrows) and is more marked in germ cells at e20.5 and e21.5 (C, D). In contrast, 5hmC is undetectable in germ cells between e18.5–e21.5 (red, arrows; A to D). Both forms of methylation are found in somatic cells throughout the time course. Scale bar = 50 μm.