Figure 2

Aromatase cell localization in mouse fetal testis. A. Aromatase immunodetection in 17.5 dpc testes. Immunostaining was performed using an anti-aromatase antibody (MCA2077T, Serotec, France), followed by a biotin-conjugated secondary antibody and streptavidin-peroxidase visualization with DAB (Vector Laboratories). (a) A strong specific immunoreactivity was observed in Leydig cells within the interstitial tissue (arrows) and to a lesser extent in gonocytes (arrowheads). Inset is a higher magnification to show that aromatase is localized only in the cytoplasm of Leydig cells (arrows) and gonocytes (arrowheads) and is absent or not detectable in the Sertoli cells (asterisks). (b) Control section (ovary from adult pregnant rat): positive staining is observed in the corpora lutea (CL) but not in the pre-antral follicle (F), as previously described [13]. Scale bars = 5 μm. B. Double immunofluorescence staining for aromatase, 3βHSD (Leydig cell marker) and VASA (germ cell marker) in enriched gonocyte cultures. Immunostaining was performed using anti-aromatase (MCA2077T, Serotec, France) (green), anti-3βHSD (generous gift by J.I Mason) (red) and anti-VASA antibodies (ab13840, Abcam, France) (red). Aromatase expression was detected both in 3βHSD-positive cells and in VASA-positive cells. Nuclei were visualized with 4′-6 diaminido-2-phenylindole (DAPI) (blue). Scale bars = 10 μm.