Fig. 3.

PAPI and AGO3 colocalize in the nuage. (A) Quantitative RT-PCR analysis showing papi mRNA expression in embryos, 3rd instar larvae, pupae, ovaries, testes, adult female carcasses and adult male carcasses. (B) PAPI is primarily expressed in the cytoplasm. Purity of the nuclear and cytoplasmic fractions was confirmed using RNA PolII as a nuclear marker and GAPDH as a cytoplasmic marker. (C) Immunostaining of PAPI (green) in ovaries (a-c″) and embryos (d-d″). In adult fly ovaries, PAPI is localized to the cytoplasm, and is enriched in the germarium and the nuage. PAPI is cytoplasmic in embryos. No specific localization or strong deposition of PAPI was detected in early embryos. (D) PAPI partially colocalizes with AGO3 in the nuage (indicated by arrowheads) in ovaries and embryos. G, germarium; GSC, germline stem cells; GC, germline cyst; EC, egg chamber; FC, follicle cell; NC, nurse cells; S1, stage 1 egg chamber; PC, pole cells.