Figure 2. Planar distribution of apico-basal polarity proteins.

(A–F) Arm::GFP mosaics. (A) Characteristic distribution of Arm::GFP in a 32 h APF ommatidial epithelium. (B) GFP-labeled primary pigment cell. Note the even Arm::GFP distribution around the primary pigment cell cortex (+). (C–F) Even distribution of Arm::GFP around the cortices of the anterior (C), posterior (D), equatorial (E), and polar (F) cone cells. (G–M) Dlg1::GFP mosaics. (G) Characteristic distribution of Dlg1::GFP in the 32 hAPF ommatidial epithelium. (H) Dlg1::GFP is enriched on the outer interface of the primary pigment cell (+) while its inner interface shows a diffuse Dlg1::GFP signal (+/−). (I) Outer cone cell interfaces show diffuse Dlg1::GFP signal (+/−) while all cone-cone interfaces (J–M) show a strong and sharp Dlg1::GFP signal (+). (N–R) Baz::GFP mosaics. (N) Every interface of the 32 h APF ommatidial epithelium carries Baz::GFP. (O) Baz distribution in primary pigment cells. Baz is devoid from outer and inner primary pigment cells interfaces (−). Baz is specifically enriched at the zone of contact between adjacent primary pigment cells (+). (P) In anterior cone cells (left) Baz::GFP is specifically depleted from the interface shared with the polar cone cell (−) and present elsewhere (+). In posterior cone cells (right), Baz::GFP is specifically depleted on the interface with the equatorial cone cell (−). (Q) In equatorial cone cells, Baz::GFP is excluded from the interface with the anterior cone cell (−). (R) In polar cone cells, Baz::GFP is excluded from the interface with the posterior cone cell. In this figure and the following, insets contain a cartoon representation of the ommatidia where GFP positive cells are shown in green and GFP negative cells in white. To gain space, the posterior primary pigment cell is not shown. Note however that the protein distribution in posterior primary pigment cell is mirror symmetric to that in the anterior primary pigment cell (data not shown).