Vasph immunolocalization with anti-Cvh during <i>R. philippinarum</i> gonad differentiation.

<p>(A–C) Fluorescence microscope analysis on sections of a gonad at the beginning of its differentiation. (A) Two small spots result labeled in the connective tissue (c) between two intestinal loops (il), that are not labeled (250 µm bar). (B) In a magnification of A the staining of the early gonad is better visible (50 µm bar). (C) A following stage of gonadic development, in which the germ cells, strongly stained, start forming acini with some big cavities in the middle (50 µm bar). (D–F) Confocal analysis on sections of a more differentiated gonad. Anti-Cvh (red) and TO-PRO-3 iodide staining DNA (green). (D) Incipient acini with some Vasph stained cells visible on a line around the cavities; the numerous cells of the surrounding connective tissue are not labeled (50 µm bar). (E, F) Two images at various depths, within the same sample of D. (E) Germ cells with big nuclei and a strong Vasph-staining are visible (24 µm bar). (F) In a deeper region of the gonadic tissue observed in E, the labeled germ cells are located around a still empty acinus lumen (same magnification of E). (G, H) Confocal analysis on sections of female and male mature gonads. (G) Oocytes strictly packed in an enlongated acinus show a diffuse cytoplasmic immunolocalization of Vasph. In the biggest oocyte (o), some strongly labeled granules are seen in a region of the cytoplasm (asterisk) (30 µm bar). (H) Male acinus full of spermatozoa: a diffused staining is present only in the spermatogenic cells located near the acinus wall (50 µm bar).