Specialization of the Drosophila nuclear export family protein Nxf3 for piRNA precursor export

CG13741 and Nxf3 impact dual-strand piRNA cluster biology. (A) Schematic representation of CG13741 as well as CG13741^Δ1 and CG13741^Δ2 mutants. (B) Cartoon displaying the Nxf3 domain structure and the generated nxf3^mut allele. Peptide coverage obtained by Nxf3 pull-down followed by mass spectrometry is indicated in blue. (C) Bar graphs showing fold changes in steady-state RNA levels of a housekeeping gene (act5c) and soma-specific (gypsy), intermediate (blood), and germline-specific (HeT-A and burdock) transposons in total ovarian RNA from the indicated genotypes (relative to heterozygote siblings and normalized to rp49). Error bars indicate standard deviation. n = 3. (D) Expression and localization of CG13741 in an egg chamber of control and CG13741^mut mutant flies are shown by immunofluorescence. A zoomed-in view of the indicated nurse cell nucleus is shown at the right. (Green) CG13741; (magenta) Lamin; (blue) DNA. Scale bar for egg chamber, 10 µm; scale bar for zoom-in, 2 µm. (E) As in D but showing the expression and localization of Nxf3 in control and nxf3^mut egg chambers. (Green) Nxf3; (magenta) Lamin; (blue) DNA. Scale bar for egg chamber, 10 µm; scale bar for zoom-in, 2 µm. (F) As in D but showing expression and localization of GFP-tagged CG13741 and GFP-tagged Nxf3 costained with Rhi. (Green) GFP; (red) Rhi; (blue) DNA. Scale bar, 2 µm. (G) As in D but showing expression and localization of the annotated and extended Nxf3 sequence tagged C-terminally with GFP-3xFlag and costained with an antibody to endogenous Nxf3. (Green) Nxf3; (red) Flag; (blue) DNA. Scale bar for egg chamber, 10 µm; scale bar for zoom-in, 2 µm.