Fig. 8. Redistribution of Arr-EGFP fusion protein upon exposure of the retina to light and test of conservation of total protein. (A) Pseudocolor representation of the fluorescence intensity of a Xenopus rod expressing the fusion protein, Arr-EGFP 30 minutes after a 30 second light exposure that bleached all the rhodopsin; the dark adapted profile of the same rod is shown in Fig. 8A. (B) Intensity distributions along the rod in the dark (black) and 30 minutes (green for the IS; red for the OS) after the bleaching exposure. (C) Test of the hypothesis that total Arr-EGFP in the rod is conserved before and after the bleaching exposure. The mass of Arr-EGFP in the OS (red circles) and in the IS (green circles) was determined in the dark, and at 30 and 60 minutes after the bleaching exposure, and the sum (black circles) computed. For 10 rods from four separate pieces of retina, the same analysis was followed, and the data of each rod was normalized by the total Arr-EGFP in the cell in the dark (left axis). The scale on the right gives the Arr-EGFP mass for the average cell of the population; individual rods had up to 30 amols. Error bars are 95% confidence intervals. Conservation of Arr-EGFP is represented by the fact that the total (black circles) remains constant over the ca. 1.5 hour experiment. (D) 3D renderings of the distribution of Arr-EGFP of panel A at 30 minutes after the bleaching exposure: the leftmost images displays the fluorescence in a linear gradient; the middle and rightmost images show the brightest 5% voxels (green), and the dimmest 5% (red), in two orientations of the rod.