RT-PCR analysis of Odnd RNA expression. (A) Developing embryos. (B) Adult tissues. β-actin served as a loading control.

dnd RNA expression in adult germ cells by in situ hybridization. Mature testes and ovaries or their cryosections were hybridized with an antisense RNA probe, developed by chemical or fluorescent procedure and stained for nuclei by DAPI (blue), and analyzed by bright and fluorescent microscopy. (A?D) Testicular sections. (A) Chemical staining. The signal is strong in spermatogonia (sg) in the testicular periphery, reduced in primary (sc2) and secondary spermatocytes (sc2), and spermatids (st) but becomes barely detectable in sperm (sm). (B?D) Dual color FISH with Odnd and Ovasa probes. Odnd (B) and Ovasa (C) show overlapping expression patterns (D) at various spermatogenic stages. A notable difference is the intracellular distribution: the Odnd signal condenses and distributes discontinuously (B), whereas the Ovasa signal is diffuse (C and D). This difference is most evident in spermatogonia (arrows in the inserts of B?D). (E) Whole mount ovary showing the strong Odnd signal in oogonia and early oocytes. (F) Ovarian section. The dnd RNA is seen in oogonia and oocytes at all stages. (Insert in F) Merge of the Odnd signal and DAPI staining, highlighting the Odnd-positive oogonia at the germinal epithelium Somatic cells surrounding germ cells exhibit little signal. sg, spermatogonia; sc1 and sc2, primary and secondary spermatocytes; st, spermatids; sm, sperm; og, oogonia; romantic numbers, stages of oocytes.