OSI21 partially localizes on the endo-lysosomal system. Jongwoo Lee Myungchul Song Sujeong Hong 10.1371/journal.pgen.1003559.g005 https://plos.figshare.com/articles/figure/_OSI21_partially_localizes_on_the_endo_lysosomal_system_/713078 <p>Newly eclosed flies were exposed to bright light (2900 lux) for 90 min. A single ommatidium prepared from fly retina was visualized by confocal microscopy. (A–B) The OSI21 protein was marked with GFP. Each subcellular structure was marked with Lysotracker -Red (lysosomes, A) and Rhodopsin-RFP (endosomes, B). OSI21 partially localizes on lysosomes (Pearson's correlation coefficient: 0.617, A). OSI21 partially localizes on the rhodopsin positive vesicles (Pearson's correlation coefficient: 0.635, B). (A) <i>w; Rhi1::Gal4, UAS::Osi21-GFP/+</i> (B) <i>w; Rhi1::Gal4, UAS::Osi21-GFP/+; UAS::Rh1-RFP/+</i>. (arrowheads) lysosomes or endosomes colocalized with OSI21-GFP. Flies were kept in the 25°C fly culture room, 18 h light/8 h dark cycles. (C–D) Localization of endocytosed rhodopsin with lysosomes. Newly eclosed flies were exposed to bright light (2900 lux) for 90 min. A single ommatidium was prepared from fly retina and examined using confocal microscopy. GFP-labeled rhodopsin and Lysotracker -red were used for visualizing rhodopsin endocytosis and lysosomes. Lysosomes (red) in <i>norpA<sup>p24</sup></i> photoreceptor cells are smaller in number and are not overlapped with endocytosed rhodopsin (green) (Pearson's correlation coefficient: 0.342, C). (Arrowhead in C) Endocytosed rhodopsin escaped <i>Osi21</i> blockage, reflecting regular lysosomal rhodopsin-turnover. On the other hand, lysosomes are greatly proliferated and are colocalized with endocytosed rhodopsin in the <i>norpA<sup>p24</sup></i> mutant photoreceptor with a <i>Osi21-RNAi</i> transgene (Pearson's correlation coefficient: 0.604, D). (Arrowheads) Lysosomes collocalized with endocytosed rhodopsin. (C) <i>norpA<sup>p24</sup>; Rh1::Gal4, UAS::Rh1-GFP/+</i> (D) <i>norpA<sup>p24</sup>; Rh1::Gal4, UAS::Rh1-GFP/UAS::Osi21-RNAi</i>. (E) Relative number of green-labeled vesicles among red-labeled population was calculated from three representative photoreceptor cells of each genotype in triplicate. Error bars indicate SEM. ***p<0.01, **p<0.05.</p> 2013-06-06 00:51:18 genetics Genetic mutation mutagenesis Molecular genetics Gene identification and analysis Animal genetics Gene function Genetic screens Genetics of disease Model organisms Animal models Drosophila melanogaster Molecular cell biology Signal transduction Signaling in cellular processes Apoptotic signaling Calcium signaling G-protein signaling Cell death Cellular stress responses Membranes and sorting neuroscience Sensory systems Visual system Neurobiology of disease and regeneration localizes endo-lysosomal