Figure 15. Strain differences in the number of neighboring RPE cells. Three genotypes, one wild type (WT), C57Bl/6J, and two models of
retinal degeneration, IRBP−/− and rd8 at postnatal day (P)30 and P720 were compared. The sample sizes were four to five animals for each genotype at P30, and three
animals for each genotype at P720. Although no significant differences in number of neighboring cells was present at P30,
both the IRBP−/− and the rd8 showed significantly higher average number of neighbors than their WT counterpart at P720. As the IRBP−/− aged from P30 to P720, average number of neighbors does not increase significantly. However, the rd8 showed a significant increase in average number of neighboring RPE cells from P30 to P720. A side is defined by a cell-to-cell
contact with a different cell. The total number of sides is equivalent to the number of neighboring cells.