Endomembrane defects in photoreceptors with elevated PA levels. (A and B) TEM showing the ultrastructure of an ommatidium from wild-type eye cds1 (A) grown in bright light (B). (C) Higher magnification showing abnormal endomembrane accumulations (v) in the cell body of cds1. (E and F) Rhabdomere (r) degeneration and membranous structures (tv) seen when wild-type (E) but not K/R Pld (F) is expressed in photoreceptors. (G) High magnification view of expanded endomembrane structures. (H) Overexpression of rdgA causes accumulation of membranous and vesicular transport intermediates in the cell body. (D) GMR-GAL4 alone is normal. (I) Western blots showing expression of equivalent levels of wild-type and K/R Pld. The reductions in the levels of Rh1, NORPA, and TRP are seen only when wild-type Pld is overexpressed. (J) Western blot showing reduced levels of Rh1 in flies overexpressing Pld and cds1. Wild-type flies and cds1 grown in the dark are shown as controls. Control band shows equivalent levels of protein loading. n, nucleus; m, membranous transport intermediate. (I and J) Unit of measure, M r. Bars: (A, D, and H) 2 µm; (C and G) 1 µm.
