Panel A: Two heat maps showing the distribution of PIP3 and PIP2 in an embryo during nuclear cycle 10. The left heat map displays GFP:Grp1[PH] with PIP3 enrichment at the poles of buds indicated by cyan arrows. The right heat map shows PLC[PH]:mCherry with PIP2 enrichment in the interbud regions indicated by white arrows. Both heat maps use a color scale ranging from low to high intensity, with a scale bar of 20 micrometers. Panel B: Two orthogonal views of the embryo showing the distribution of PIP3 and PIP2 at the pole bud furrows. The top heat map displays GFP:Grp1[PH] with no significant enrichment at the bud furrow. The bottom heat map shows PLC[PH]:mCherry with PIP2 enrichment at the bud furrow indicated by white arrows. Both heat maps use a color scale ranging from low to high intensity, with a scale bar of 10 micrometers.
(related to Fig. 7): PIP2 and PIP3 occupy separate membrane compartments of the embryo and the posterior pole. (A) Embryos from mothers expressing GFP:Grp1[PH] and PLCγ[PH]:mCherry were live imaged, mounted on their posterior pole. The embryo is in nuclear cycle 10, prior to PGC formation. Timing is approximately 5 min before mitosis. Enrichment of the PIP3 biosensor is seen at the poles of buds (cyan arrows). PIP2 is enriched in the interbud regions (white arrows). The image shows the maximum intensity projection of a 20 µm section. Images are pseudo-colored with the fire LUT. Scale bar = 20 µm. (B) Orthogonal view of the embryo from B to visualize pole bud furrows. PIP2 but not PIP3 is enriched at the bud furrow (white arrows). Images are pseudo-colored with the fire LUT. Scale bar = 20 µm.