Figure 3.

(A and B) Interkinetic nuclear movement in the ventricular zone. BrdUrd-labeled cells that are in dark brown are in the S phase in the outer half of the ventricular zone, whereas [³H]thymidine cells that have black dots are in G2 and M and are mostly located at the ventricular surface. The position and number of the single- and double-labeled cells are similar in wild-type Lis1+/+ (A) and Lis1/sLis1 (B) embryos, indicating that both interkinetic nuclear movements and cell cycle kinetics are similar. (C) Illustration of the position of the sections (in blue box) in F–H. (D, E, and F) Distribution of cells labeled with BrdUrd at E13.5 in the CP of E15.5 embryos. Sections were cut through the occipital cortex of E15.5 embryos, and the difference in the distribution of BrdUrd-labeled cells between wild type and mutants was analyzed. Although in the Lis1+/+ mice (D), most of the labeled cells (dark) are in the superficial portion of the CP, in the Lis1/sLis1 mice (E), the labeled cells are more equally distributed. The CP was marked, divided in half (the position of the division is marked by an arrow), and labeled cells counted in the superficial (CPs) and interior portions. (F–H) Distribution of cells labeled with BrdUrd at E13.5 in the CP of E17.5 embryos. Sections were cut through the occipital cortex of E17.5 embryos, and the difference in the distribution of BrdUrd-labeled cells between wild type and mutants was analyzed. The width of the CP is marked by an arrow. The position of the subplate (SP) is marked as well. (F) Section in a wild-type embryo. (G and H) Sections in mutant embryos.