|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
|
Fig. 4. Quantification of the spatial distribution of EGFP in living Xenopus rods. (A) EGFP distribution in a single rod. The voxels corresponding to the rod identified in Fig. 3B (white arrow) were excised from the stack of 2D CLSM scans, and projected onto a plane parallel to the OS axis: the panel is a false-color representation of the fluorescence distribution in the average of three scans spanning a thickness of 1.5 µm. The black line through the image is the automatically determined `z-spline' path through the cell's core along which a fluorescence intensity profile was computed. (B) Fluorescence intensity profiles of 8 rods from the piece of retina illustrated in Fig. 3, segregated with colors to indicate different levels of fluorescence: red for most intense, green for mid-level and blue for least intense (the profile of the rod of panel A is identified with a thickened red line). Panels A and B are aligned on the abscissa, and the profiles of all rods have been aligned at the junction between the IS and OS (x=0). The colored symbols at the left give the mean (±s.d.) fluorescence of the voxels of the entire IS of each rod having the top 5th percentile of intensities (comprising, on average, 460 voxels per rod). In the OS region the spline goes through the center or `core' of the rod discs, whereas in the IS the spline randomly encounters high and low fluorescence voxels. (C) The profile distribution of each rod in panel B has been normalized by the value of the corresponding colored circle plotted at the left of the graph. The thickened black line plots the average of the normalized intensity profiles of the 15 rods `cut' from the piece of retina illustrated in Fig. 3. The black symbol to the left represents the normalization value (unity), and the error bar gives the average coefficient of variation (s.d./mean) of the top 5th percentile of voxels of the inner segments of the 15 rods. (D) Grand average normalized intensity distributions of rods expressing EGFP. Data such as shown in panel C were pooled from 57 rods whose profiles were extracted from CLSM scans of 11 pieces of retina from 5 Xenopus tadpoles and froglets ranging from 4 weeks to 9 months of age. Error bars are 95% confidence intervals. (The average trace from panel C is shown in light gray for comparison.)
|
