Table 1.

Developmental appearance of cell cycle markers in ATM-deficient mice

Percentage of immunopositive neurons
PCNA Cyclin A
P10
+/+ 0 0
+/− 0 0
−/− 0 0
P20
+/+ 1.5 1.5
+/− 11.5 10.0
−/− 12.0 13.5
P30
+/+ 1.0 1.0
+/− 11.0 10.5
−/− 13.0 12.0
  • Cells were immunostained for calbindin and either PCNA or cyclin A. Beginning at random within a given section, 200 sequential calbindin-positive cells in the Purkinje cell layer were scored for the presence or absence of the cell cycle marker. Two parasagittal sections (a total of 400 cells) were scored for each animal.