Fig. 3. PAS reaction and anti-SF-1/Ad4BP or anti-SOX9 staining of two consecutive mirror sections of 11.5-dpc XY gonads demonstrating that glycogen accumulation occurs in pre-Sertoli cell lineage. PAS reaction (red staining) and immunohistochemical staining (brown staining) with anti-SF-1/Ad4BP (a marker for precursor cells of both Sertoli and Leydig cells; A,B) or anti-SOX9 (pre-Sertoli cell marker; C,D) Ab were performed using two consecutive mirror sections of the same PFA-fixed specimens. For comparison, images of immunostained mirror sections are computationally reversed. Plates B and D are the merged images of PAS reaction (left) and immunoreaction (right; reversed images) in plates A and C, respectively. Plates B and D also include higher magnification images (right), indicated by the boxed area in the corresponding left plate. PAS-positive cells clearly overlap with gonadal somatic cells expressing SF-1/Ad4BP (arrows in B) or SOX9 (arrows in D) in the XY gonads. ms, mesonephros. Bar, 50 µm.