Fig. 6: Ensheathing glial cells show polarized plasma membrane domains.

Representative images are shown. a Projection of a confocal stack of a third instar larval ventral nerve cord coexpressing PH-AKT-GFP and PH-PLCδ-mCherry in ensheathing glial cells (EG) [83E12-Gal4, UAS-PH-AKT-GFP, UAS-PH-PLCδ-mCherry]. The dashed white line indicates the position of the orthogonal section shown in (b). b Orthogonal section showing the dorsal aspect of the neuropil. The boxed area is shown in higher magnification in (c–e). The dashed areas were subsequently used for quantification of GFP and mCherry localization. f Quantification of GFP/mCherry distribution in larval and adult ensheathing glia. The ratio of red (PLCδ-mCherry shown in magenta) and green (PH-AKT-GFP) fluorescent pixels of the areas indicated in (c) is plotted. The mean and standard deviation is shown. g Schematic view of a dorsal ensheathing glial cell. The neuropil facing domain is characterized by a high PIP₂ content, whereas PIP₃ is concentrated on the baso-lateral domain, where Nrv2 is predominantly localized, too. The blue dot indicates the position of a neuron. h Coexpression of Nrv2::GFP and 83E12-Gal4, UAS-mCherry in the ventral nerve cord of third instar larva. The boxed area is shown in higher magnification in (i, j). Note the preferential localization of Nrv2 at the basolateral cell domain of the ensheathing glia (arrows). Only little Nrv2 is found at the apical domain (open arrow head). Additional expression of Nrv2 is seen in the blood–brain barrier (filled arrowhead). k Quantification of polarized Nrv2::GFP localization. The mean and standard deviation is shown. Scale bars in a, b, h: 50 µm; in b–e, i, j: 25 µm. Source data are provided as a Source Data file.