FIG. 6.

Transverse sections of E10.5 Nup50^+/+ (left) and Nup50^−/− (right) embryos were immunostained with either anti-Ki-67 antibody or anti-p27^Kip1 antibody as indicated. Approximately equivalent sections from a region just caudal to the open portion of the Nup50^−/− neural tube are shown. Note the low Ki-67 and high p27^Kip1 expression in the marginal zone (MZ) compared to the germinal zone (GZ) of the neural tube in the wild-type embryo and the loss of this relationship in the Nup50-null embryo. The bottom image in each column is a higher-magnification image of the neural tube that clearly reveals the p27^Kip1 gradient in the normal neuroepithelium.