Fig. 4. Loss of function of Polo affects meiotic progression and BicD polarized transport. (A) A wild-type germarium stained for SCs (red, white in A') and BicD (green, white in A''). SC formation is initiated in two to four cells in region 2a, and is then restricted to one cell in region 2b. BicD accumulation in meiotic cells begins in region 2a. Through region 2b, BicD redistributes to the posterior of the oocyte. (B) A polo¹/polo⁹ germarium. Meiosis does not initiate properly in region 2a. Cysts often contain abnormal SCs, and meiosis restriction to one cell is delayed. BicD starts to accumulate in pro-oocytes only in region 2b. In region 3, BicD is still at the anterior of the oocyte. (C) A mosaic polo⁹ follicle at stage 7 with a single mutant cell (arrow) marked by the absence of nuclear GFP (green, white in C'). In this nurse cell, the amount of BicD protein (red, white in C'') is higher than in the neighboring wild-type nurse cells, but lower than in the oocyte (arrowhead). DNA is shown in blue.