Fig. 4. Sktl controls the PIP2 level at the oocyte cortex. (A-D) nosgal4>GFP-Sktl egg chambers. GFP-Sktl (A, green in C,D) colocalizes with actin (B, red in C,D) along nurse cell and oocyte cortex (merge in C,D). (E-H) PH-GFP distribution. PH-GFP (E, green in G,H) localizes at the actin (F, red in G,H) cortex of follicular cells, nurse cells and oocyte (merge in G,H). (I-K) Colocalization between PH-GFP (I, green in K) and nosgal4>RFP-Sktl (J, red in K) along the oocyte cortex and in the cytoplasm. (L-N) Wild-type Drosophila egg chamber expressing PH-GFP (L, green in N), co-stained with the plasma membrane marker LE lectin (M, red in N). PH-GFP localizes all along the plasma membrane of the oocyte (merge in N). Insets in L and N are magnifications of anterior margin and lateral cortex, respectively. (O-Q) sktl^2.3 mutant germline clones expressing PH-GFP (O, green in Q) co-stained with LE lectin (P, red in Q). The accumulation of PIP2 marker is greatly reduced all along the oocyte plasma membrane. Insets in O and Q are magnifications of anterior margin and lateral cortex, respectively. Arrows and arrowheads (I,J,K,L,N,O,Q) indicate the plasma membrane of the oocyte and follicle cells, respectively. Asterisk, nucleus.