Immuno-histological analyses of irradiation-induced apoptosis in mature proliferating tissues of adult medaka.

<p>(A) The sagittal section of whole-body adult medaka as a high-resolution seamless tiling image was cited from a web browser (<a href="https://ds.cc.yamaguchi-u.ac.jp/~vs_08_2p/newpage4.html" target="_blank">https://ds.cc.yamaguchi-u.ac.jp/~vs_08_2p/newpage4.html</a>; image from HdrR_M_221.). In mature medaka, actively proliferating tissues including pharyngeal epithelium, small intestine and testis (squared area with dotted outline in A) were examined 24 h after irradiation. PCNA-positive cells were present in a proliferating area of the pharyngeal epithelium (arrows in C), the bottom of intestinal folds (arrows in E) and in cysts of proliferating spermatogonial cells (Gb) in the testicular tissue (arrows in G). In contrast, no cleaved-caspase 3-positive signals were observed 24 h after irradiation in the pharyngeal epithelium (B) and the intestinal tissue (D). In the mature testis, many cleaved-caspase 3-positive cells were present in the Gb cysts (arrows in F) where PCNA-positive proliferating spermatogonial cells are localized (arrows in G), whereas no cleaved caspase 3 -positive cells were found in the Ga cysts, circled area with black dotted outline in F, where no PCNA positive cells were present (circled areas with black dotted outline in G). Scale bars = 50 μm.