Immunohistochemistry of Bcl2-interacting-killer (Bik) protein in testes of control and treated zebrafish of the <i>tg</i>(<i>vas::egfp</i>) line.

<p>Merged images combine the eGFP filter (green; germ cell lineage), and dsRed filter (red; Bik protein) under epifluorescent light. A) Control fish 30 days post treatment (dpt) (D; 59.3 mg, 21.3 mm): only a few small points of Bik signal were detected. The cell lineage from which the signal originates could not be determined. The testes were developing normally with clusters of spermatogonia (sg) and spermatocytes (sc) visible. B) Anti-Gsdf-a treated fish 15 dpt (27.3 mg, 16.0 mm): The testis was extremely early in development with only a few spermatogonia expressing weak eGFP signal. No Bik signal was detected. C) Anti-Gsdf-b treated fish 30 dpt (86.4 mg, 23.4 mm): Only a very weak Bik signal is detected in the testes. Only presumptive spermatogonia (sg) and undifferentiated gonocytes (gc) were identified. D and E) Anti-Gdf9-a treated fish at 15 and 30 dpt, respectively (D: 46.2 mg, 20.3 mm, E: 138.7 mg, 26.5 mm): Bik signal was localized to clusters of spermatogonia. In contrast, the clusters of spermatocytes (sc) and spermatids (st) did not show Bik signal. F) Anti-CD205 treated fish at 30 dpt (128.4 mg, 25.1 mm): a strong Bik signal was detected throughout the testis. However, resolution was insufficient to determine from which cell types it originated. All scalebars represent 100 µm. White boxes identify area being shown with dsRed filter only.