FIGURE 4:
Furrow ingression seems independent of possible roles for Asap at the PM. (A) A steppkeshRNA metaphase embryo with furrow tips expanded to form abnormal basal membranes (shown as a 3D reconstruction of ∼10–12 peripheral cell compartments and as xy-sections from the embryo surface to below the nuclei; compare to the shRNA control embryo in Figure 1, B and C). (B) Quantifications of Asap-Steppke and control double RNAi experiments. Note that the furrow loss with Asap RNAi dominates over the furrow tip expansion that otherwise occurs with Step RNAi. N, number of metaphase embryos counted for each genotype (compiled from two or more experiments, each with similar results). (C) Top, cross-sections of the equatorial somatic region reveal intact furrows with control shRNA and loss of furrows with Asap, Arf1, and AP-2α RNAi (embryos at interphase). Middle, projections of the posterior pole show the formation of PGCs with control, Asap, and Arf1 RNAi but not with AP-2α RNAi. Amphiphysin marks the PM. The PGCs are round and protrude from the posterior pole (arrows). Bottom, quantifications of the presence of PGCs. N, embryo numbers (compiled from two or more experiments, each with similar results). Constructs expressed as in Figure 1.