Kumo physically interacts with Vas, SpnE, Aub and Piwi and its interaction with SpnE and Aub is mediated by tudor domains. (A) Western blots showing the co-immunoprecipitation of full-length Myc–Kumo with Vas, Aub, SpnE and Piwi from ovarian lysate. (B) Schematic diagram showing the Kumo variants tagged with FLAG transfected into S2 cells. Kumo-FL, full-length Kumo; Kumo-CT, harbouring all five tudor domains; and Kumo-NT, harbouring RING and B-box domains. (C) Western blots showing the co-immunoprecipitation of FLAG-tagged Kumo variants with Myc–Aub and Myc–SpnE using S2 cell lysate. Both Aub and SpnE are immunoprecipitated with FL- and CT-Kumo but not with NT-Kumo and the control IgG. (Lower panels) Western blots with anti-FLAG showing all examined Kumo variants efficiently pulled down. Asterisks denote nonspecific bands.