FIGURE 7:

Mutation in csul prevents piNG-body assembly. (A) Western blots of testis extracts of csul mutants probed with anti-Stellate antibodies. Stellate hyperexpression is strong in both csul^RM50/Df(2R)Jp7 and csul^RM50/Df 23692 transheterozygous allelic combinations. Testes of cry and yw flies were used as positive and negative controls, respectively. Anti-actin antibodies were used as a loading control. (B) Northern blot analysis of small RNAs from the csul testes (see Materials and Methods for details). Antisense Su(Ste) piRNAs but neither miR-8 miRNA nor esiRNA-1 was absent owing to csul mutations. 2S rRNA was used as a loading control. (C) Immunofluorescence staining of the testes from csul^RM50/Df(2R)Jp7 transheterozygous and heterozygous flies. In csul transheterozygous flies (−/−), no piNG-body formation can be observed, but Vasa-stained small nuage granules remain detectable. The Aub signals are randomly distributed in the cytoplasm of spermatocytes and do not colocalize with the Vasa-stained nuage material. Testes were stained with anti-Vasa (green) and anti-Aub (red) antibodies. Scale bars, 5 μm.