Fig. 4. Proliferation levels in the Tfr3 and Tfr7 lens lineage. (A) Histological section from an E10.5 mouse embryo showing typical BrdU labeling; the blue fluorescence identifies all nuclei, while the red identifies BrdU-positive cells. Both the total number of cells and the number of BrdU-positive cells in the lens pit were counted within the boundaries indicated (white lines) and the proportion of positive cells calculated. The results of this analysis for wild-type and Tfr7/Tfr7 homozygous mice is shown in B. This indicates that there is a statistically significant reduction in proliferative index in the transgenics at E10.5. (C) An E13.5 wild-type lens section showing typical detection of BrdU incorporation. The section is overlaid with the radial grid used for counting. The graph (D) shows the BrdU labeling index at E13.5 in a series of radial sectors that represent different lens domains. In wild-type mice (blue trace) there are two peaks of proliferation at 20° and 160°; this represents a location adjacent to the immature anterior chamber and is a typical proliferation pattern for the mouse lens (McAvoy, 1978). The Tfr3/Tfr3 (orange trace) and Tfr7/Tfr7 (red trace) transgenic mice show reduced levels of proliferation; the Tfr7/Tfr7 transgenic mice are more severely affected. Standard errors are represented by vertical bars.
