1. Figure 3. Cumulative labeling to measureTC − TS andGF at E14.
Figure 3. Cumulative labeling to measureTC − TS andGF at E14. Shown is BrdU immunoreactivity in E14 (A) euploid and (B) Ts16 cortical wall after BrdU had been injected every 2 hr for 14 hr. Most euploid VZ cells are BrdU+, whereas there are numerous examples of ectopic, nonproliferating cells (BrdU−) remaining within this proliferative layer in the Ts16 VZ (arrowheads). C, Repetitive injections with BrdU label successively more progenitors as they enter S-phase, and the LIs for euploid (solid line) and Ts16 (dashed line) rise linearly with similar slopes. The time at which PVE labeling reached a maximum (TC −TS) was 11.7 hr for both euploid and Ts16. The LI at TC −TS represents the GF of the PVE. Ts16 GF is reduced to 86% from the euploid value of 93%, indicating a decrease in the fraction of proliferating cells in the Ts16 PVE of 7%. Data points are means from each fetus analyzed. LI was significantly different at each time point; p values (pairedt test): 0.5 hr, p < ; 8 hr,p < 0.001; 11 hr, p < 0.05; 14 hr, p < 0.01.
Tarik F. Haydar et al. J. Neurosci. 2000;20:
©2000 by Society for Neuroscience