Fig. 3. In situ hybridization of hTR in mouse spermatogonia. A ³⁵S-riboprobe obtained from the hTR template was hybridized to spermatogonia that were either freshly withdrawn (A,E) or withdrawn after 24 hours in culture without (B,F) or with (C,G) Kitl. A sense probe (D,H) was used in T0 cultures to verify the specificity of hybridization. (A-D, represent brightfield images; E,F, represent darkfield.)