Cell density (104 cells/mm3 ± SEM) in the dorsal neuroepithelium (PVE) of Fgf2 null mutant mice
| Genotype | Nondividing cells | Dividing cells | ||||
|---|---|---|---|---|---|---|
| E10.5 | E11.5 | E12.5 | E10.5 | E11.5 | E12.5 | |
| Wild type | 84.6 ± 5.7 | 119 ± 9.0 | 85.7 ± 27.2 | 559 ± 6.3 | 842 ± 26.5 | 713 ± 11.8 |
| Fgf2−/− | 116 ± 12.2 | 286 ± 83.7 | 112 ± 13.5 | 392 ± 20.4 | 747 ± 95.1 | 607 ± 57.8 |
| % of wild type | 137 | 240 | 131 | 70 | 89 | 85 |
Litters produced by crossing heterozygous parents were treated with BrdU in vivo at the indicated stages of development. Embryos were collected after an appropriate length of cumulative BrdU treatment (t = Tc − Ts) estimated to label all proliferating cells and subjected to stereological analyses. BrdU-labeled (dividing) and unlabeled (nondividing) cells were separately counted within the dorsal neuroepithelium in a systematically random manner using the optical disector. By ANOVA, there was a significant interaction of genotype with cell type (F = 14.8; p < 0.001). No significant interactions between genotype and age were found. Post hoc analyses revealed that the density of nondividing cells was significantly increased (p < 0.05), and the density of dividing cells was significantly decreased (p < 0.01) in Fgf2 knockout mice versus wild types (Sheffe's post hoctests).