Fig. 3. comm-HP specifically disrupts comm expression in vitro and in vivo but has no effect on sensory axon guidance. (A) Drosophila S2 cells expressing Comm-GFP in which Comm localises to intracellular vesicles (inset). (B) When comm-HP is co-expressed with comm-GFP, the number of fluorescing cells is very low. Most cells that do fluoresce show either low levels of fluorescence or a disrupted localisation (inset). (C) robo and comm-HP co-transfected cells. comm-HP does not affect the expression level or numbers of Robo-transfected cells. (D) When comm-HP is driven throughout the nervous system using elav-GAL4, sensory axon extension and guidance is unaffected. The elav-GAL4 driver was used to drive both UAS-comm-HP and UAS-GFP and axons were visualised with GFP. (E) Eagle-expressing neurones revealed with anti-Eagle antibody (green); these neurones also express Comm (F, yellow). (G) When comm-HP is driven in the Eg-positive neurones, Comm levels are reduced in these cells (arrows). However not all Eg-positive neurones are equally affected, as Comm protein remains within a subset of the Eg-positive neurones (arrowhead in G). The embryo in D shows a view of the ventral region of the PNS at stage 16, the embryo is oriented with anterior to the left and dorsal upwards. (E-G) show views of ventral regions of the CNS in stage 13 embryos oriented anterior upwards.