Fig. 6. Amphiphysin organizes the rhabdomere membrane domain in photoreceptor neurons. (A,B) Transmission electron microscopy analysis of photoreceptor cells overexpressing Amph. GMR-GAL4 is a transgenic line that contains the glass enhancer driving GAL4. This line provides strong expression of GAL4 in every cell posterior to the morphogenetic furrow. (A) GMR-GAL4 control. One copy of the transgenic line does not result in any detectable defects. (B) The addition of one copy of UAS-Amph results in split and ectopic rhabdomeres (asterisks) or the loss of rhabdomeres (arrowhead). (C,D) Optical sections through the developing retinal epithelium 55 hours APF stained for actin. (C) GMR-GAL4 control. F-Actin localizes in tight crescents on the apical surface of each photoreceptor cell. (D) GMR-GAL4 and UAS-Amph. The overexpression of Amph results in F-Actin accumulating in tight ball like structures versus the characteristic crescents seen in the control. (E,F) Optical sections through the developing retinal epithelium 55 hours APF stained for Bifocal. (E) GMR-GAL4 control. Bifocal localizes to the apical surface of photoreceptor cells. (F) GMR-GAL4 and UAS-Amph. Bifocal is mislocalized in each of the photoreceptor cells overexpressing Amph. (G,H) Optical sections through the developing retinal epithelium 55 hours APF stained for Discs large (red) and Amph (green). (G) GMR-GAL4 control. Amph shows normal apical localization. (H) GMR-GAL4 and UAS-Amph. The overexpression of Amph results in the delocalization of Amph from the apical surface of photoreceptor cells but overexpression does not affect patterning of the ommatidia.
