Figure 1.
Opsin immunodetection in pigmented (C57/BL6) and albino (Swiss) mouse strains.
Flat mounted left retinas from a pigmented (A,B) and an albino (C,D) mouse where the L- and the S- opsin have been double immunodetected. S: superior, N: nasal, I: inferior, T: temporal. Bar: 1 mm.
Figure 2.
Opsin expression in pigmented and albino mice.
Magnifications from pigmented (A) and albino (B) mice flat mounted retinas showing L-opsin+cones, S-opsin+cones and their merged image. The rightmost column shows all-cones (both opsins developed with the same fluorophore). In the retinal drawings on the left, is shown the area where the magnifications were taken from. S-opsin+cones are sparse in the superior retina of the pigmented strain and abundant in the albino one. In both strains most genuine S-cones are found in the inferior retina. In the pigmented strain majority of genuine L-cones lay in the superior retina, while in the albino mouse majority of L-cones are dual. And so dual cones are found across the retina in the albino strain and mostly restricted to the ventral retina in the pigmented one. S: superior, N: nasal, I: inferior, T: temporal. Bar: 100 µm.
Table 1.
Total number of cones in the mouse retina.
Figure 3.
Percentage of genuine and dual cones in albino and pigmented mice.
Graph showing the percentage of genuine-L, genuine-S and dual cones in both strains. Percentages were calculated based on data from table 2 and considering 100% the total number of cones (Table 1, all-cones -both opsins-).
Table 2.
Number of genuine and dual cones in the mouse retina.
Figure 4.
Cone distribution in the mouse retina.
Isodensity maps showing the topography of cones in pigmented and albino mice. For each population and strain two left and two right retinas are shown. Notice that because L-opsin+ and S-opsin+ cones were double immunodetected the first and third, and the second and fourth map in each row are from the same retinas. All-cones maps were generated from another set of retinas in which both α-opsin antibodies were visualized using secondary antibodies coupled with the same fluorophore, hence all cones were taken into account irrespectively of their opsin expression. Below each map is shown the number of cones quantified in its corresponding retina. The colour scale density code is placed in the middle of the figure. LR: left retina, RR: right retina. S: superior, N: nasal, I: inferior, T: temporal. Bar: 1 mm.
Figure 5.
Distribution of RGCs and L-opsin+cones.
Isodensity maps showing the distribution RGCs and L-opsin+cones in the same retina of a pigmented (first row) and an albino (second row) mouse. Below each map is shown the number of cells quantified in its corresponding retina. Colour scale density code is at the bottom of the figure. S: superior, N: nasal, I: inferior, T: temporal. Bar: 1 mm.
Figure 6.
How to sample the mouse retina to accurately infer each cone population.
Schematic drawings of a right retina showing the minimum number of sampling areas of 0.052 needed to manually quantify and infer the total cone population in both strains. In each drawing are shown the cone density regions wherefrom the samples should be taken. The inference of the total cone population can be calculated following the mathematical formula at the bottom of the figure, where the retinal area should be previously measured in mm2, % of area low is 25, % of area medium is 30–90, % of area high is 30–45 (depending on the cone population, see drawings), sampling area is 0.05 mm2 and is the mean number of cones per density area (i.e. average of cones in the samples taken within each density region). S: superior, N: nasal, I: inferior, T: temporal.