Figure 5

Lbx2 expression in embryonic an neonatal testis. Six μm paraffin sections of paraformaldehyde-fixed mouse testis were probed with DIG-labeled antisense (B and D) and sense (A) Lbx2 cRNA probes in in situ hybridization experiments. Lbx2 mRNA was detected by immunostaining using an alkaline phosphatase-coupled anti-DIG antibody (appears as a blue-purplish staining). Tissues were counterstained with Neutral Red to visualize nuclei. Lbx2 expression in the testis was assessed at E18 (B) and P1 (D). Immunohistochemistry for the Sertoli cell marker MIS was performed on testis sections at E18 (C) and P1 (E) as described in Methods and revealed using AEC (shows as a red-brownish staining). Expression of Lbx2 is evident within the cytoplasm of Sertoli cells by comparison with MIS staining. A weak but consistent Lbx2 staining is also observed in interstitial cells. Gonocytes are not labeled. No significant signal was detected with the sense probe (A). Go: gonocytes, S: Sertoli cells, I: interstitial cells. Magnifications: 200× (D, E), 400× (A-C).