Fig. 6. fu function is required in prefollicular cells for posterior oocyte positioning. All ovarioles are oriented with the anterior-most region towards the top or top right-hand corner. (A-A'') fu^G3 mosaic ovariole double-stained with anti-Orb (A, red) and anti-ß-galactosidase (A', green) antibodies. (A'') Merge. fu⁺-expressing follicle cells are delimited by broken lines. (B,C) Wild-type (B) and fu^G3 mosaic germaria (C) triple-stained with DAPI (B,C), anti-Orb (B,B',C,C', red) and anti-ß-galactosidase (C', green) antibodies. fu⁺-expressing follicle cells in C' are delimited by broken lines and correspond primarily to stalk cells. Arrows in B' indicate posteriorly localized Orb-expressing oocytes and arrows in A, A'',C' to mislocalized Orb-expressing oocytes. Note that, in addition, the normal posterior subcellular localization of the Orb crescent within the oocyte (arrows in B') is perturbed in fu mosaic ovarioles (arrows in C').