Figure 4. The percentage of binucleated RPE cells in different retinal regions in pigmented (black bars) and albino (blue bars) rats. In adult rodent retinas, many of the RPE cells were binucleated. The proportion of these have been determined in both pigmented (A) and albino (B) retinas. The retinas were divided into three roughly equal geographic regions: central, equatorial, and peripheral. In both pigmentation phenotypes the majority of the binucleated cells were located toward the central retina, although many were also found in equatorial regions. The distribution of these cells is the reverse pattern of that found for Ki67-positive cells shown in Figure 2. The differences in A and B are statistically significant (ANOVA, p<0.001). In both cases, the differences between the percentage of binucleated RPE cells between central and equatorial regions were not statistically significant. However, differences in the percentage of binucleated RPE cells found central and peripheral regions were significantly different (Newman-Keuls p<0.01). The differences between equatorial and peripheral regions were also statistically significant (Newman-Keuls p<0.01).