Fig. 3. MT distribution is altered in sqd^j4B4 germline clones at mid-oogenesis, but bcd localization is normal. (A,B) FITC-conjugated -tubulin antibody staining of stage 9 wild-type oocytes (A) shows a gradient of MTs extending from the anterior cortex to the posterior, with the posterior being relatively free of tubulin staining. By contrast, stage 9 sqd^j4B4 germline clone oocytes (B) display an even distribution of tubulin staining along the entire oocyte cortex. (C-F) -tubulin staining following partial MT depolymerization reveals short MT stubs emanating from the anterior cortex of stage 9 wild-type oocytes (C), whereas in sqd^j4B4 germline clone oocytes, such stubs are visible along the entire oocyte cortex (D,F). The oocyte in F is slightly older than that shown in D. In PKA-C1^H2 germline clone oocytes, MT stubs are visible along the entire oocyte cortex, similarly to sqd^j4B4 mutants, but an additional strong posterior focus is also sometimes visible (E). (G,H) bcd RNA localization (purple) to the anterior cortex of stage 8-10 oocytes is not detectably altered in sqd^j4B4 germline clones (H), in contrast to another oocyte polarity mutant, mago¹/Df(2R)F36, which shows ectopic posterior bcd RNA (G). sqd mutant oocytes are smaller than wild-type oocytes at stages 8-10.