Figure 6

A, Expression of the MCMV IE gene promoter-lacZ in brain slices injected using a gene gun. DNA-coated gold particles were injected into brain slices from 7-day-old (a) and 21-day old BALB/c (b) mice. X-Gal staining was performed after 48 hours of incubation. Expression of the gene was observed as dots mainly in the SVZ. The amount of expression in brain slices from 21-day-old mice was markedly decreased (b). B, Quantitative analysis of expression of the MCMV IE gene promoter-lacZ in brain slices injected using a gene gun. Positive expression was estimated as dots per slice in the brain slices from 0-, 7-, 14-, and 21-day-old mice. Quantitative analysis showed that the amount of expression was almost the same in the brain slices from 0-day-old mice as in the slices from 7-day-old mice, but was markedly decreased in the brain slices from 14- and 21-day-old mice. ★ p < 0.05 compared with slices from 0-day-old mice. C, Quantitative analysis of expression of the MCMV IE gene promoter-lacZ in the cultured brain slices injected using a gene gun. The total number of X-Gal-positive cells increased significantly after the brain slices were cultured. ★ p < 0.05 compared with 0 days of culture.