Fig. 8. Laminar and regional distributions of infected cells 6 and 4 days after infections at E10.5. For control virus, 7535 cells in four embryos were analyzed 6 days after infection, and 2757 cells in five embryos were analyzed 4 days after infection. For EGFR virus, 8431 cells in three embryos were analyzed 6 days after infection, and 2293 cells in three embryos were analyzed 4 days after infection. (A) In dorsomedial cortex, the migration of EGFR-infected cells out to the cortical plate was reduced relative to control infected cells, with more of the EGFR-infected cells located in proliferative zones (VZ, SVZ) and the IZ 6 days after infection. By contrast, in dorsal (B), lateral (C) and ventrolateral cortex (D), EGFR-infected cells were found in greater proportions in sp/wm and MZ layers 6 days after infection. (E) In dorsal cortex 4 days post-infection, more of the EGFR-infected cells were located in proliferative zones, compared with control infected cells, suggesting that their migration to the sp/wm and MZ occurred between 4 and 6 days post-infection. (F) Comparison of the proportion of infected cells in different regions 4 and 6 days after infection revealed a dorsal to ventrolateral shift in EGFR-infected cells, but not control-infected cells. This suggests that EGFR-infected cells from dorsal cortex were diverted into the LCS. Asterisk indicates that the difference between the proportion of EGFR-infected cells in dorsal cortex at 4 days versus 6 days was significant (30.5±6.1 versus 10.5±2.9; P=0.04), as was the difference in ventrolateral cortex comparing 4 and 6 days (9.6±0.7 versus 30.1±4.7; P=0.01). (G) Micrograph of a clone of EGFR-infected cells in dorsal cortex 5 days post-infection. Note the radial alignment of cells in proliferative zones and the lateral displacement in the IZ. Inset: higher magnification image of cells in the IZ displaced laterally. (G) Model summarizing migration pathways containing EGFR-positive cells, ligands and the effects of EGFR misexpression. Pink circles represent cells expressing high endogenous EGFR, blue circles represent EGFR-infected cells, stippling represents ligands (HB-EGF and/or TGF
). Left, transverse view; right, sagittal view.
