|
Figure 4. Expression of SOX9 mRNA and protein in the developing male gonad of Xenopus tropicalis after metamorphosis. A-I: SOX9 expression in the male gonad after metamorphosis at (Test 4). A-C: In situ hybridization with SOX9 sense or antisense RNA probes. A: Section from male gonad at this stage hybridized with SOX9 sense probe as a control. B: Antisense probe. C: Fibronectin labeling was superimposed on the same section used for SOX9 mRNA detection to identify the hybridizing positive cells. Fibronectin outlined the testicular cords where SOX9 is expressed, whereas there is no SOX9 expression within the interstitial tissue positive for fibronectin. D: Histological cross section showing testicular cords (TC).G: High magnification of the square in D showing the supporting cells (indicated by arrowheads) which surround germ cells. E,H: Immunodetection of SOX9 protein. E: Frozen section stained with anti SOX9 antibody (green) and counterstained with Hoechst (blue). H: High magnification of the square in E shows by comparison with Fig. G that SOX9 immunostaining (green) is detected only within the nuclei of supporting cells (blue) that surround germ cells (indicated by asterisks). F: Frozen section double labeled with SOX9 (green) and laminin (read) and counterstained with Hoechst (blue), note the detection of laminin around testicular cords. I: High magnification of the square in F. Scale bars = 30 mu m in A-F; 20 mu m in G-I. |