Fig. 7. Rab11 is required for osk mRNA transport to the posterior pole and for its subsequent anchoring and translation. (A-C) The distribution of osk mRNA (A,B) and protein (C) in wild-type oocytes. Osk mRNA is transported to the posterior end of the oocyte during stage 8 and forms a ball-shaped complex (A). During stage 9, the ball resolved into a cap-shaped structure (B) that persists through the completion of oogenesis. Osk (C) is first detected coincident with the osk mRNA ball to cap transition. (D-G) The distribution of osk mRNA (D,E,G) and protein (F) in rab11^P2148 GLCs. osk mRNA is slow to accumulate at the posterior pole of rab11^P2148 GLCs. A mass of osk mRNA is often seen at the center of stage 8 rab11^P2148 GLCs (D), possibly reflecting stalled transport. Ultimately, osk mRNA reaches the posterior pole of rab11^P2148 GLCs, but the mRNA remains as a ball (E), or often breaks up into several smaller balls (G). Consistent with a defect in anchoring, the osk mRNA is not translated as evident by the absence of detectable Osk (F).