Figure 7.

Genetic Dissection of Igf2 and Bax in Cortical Astrocyte Genesis and Survival

(A–M) Schematics of Igf2 expression in MADM-deletion paradigms, corresponding to predictions of growth/astrocyte genesis (?) and ratios (patUPD/matUPD [PP/MM]) in cells with matUPD (orange) and patUPD (green) (A); experimental MADM-labeling in CX at P21 in overview (B, E, H, and K) and at higher resolution (C, F, I, and L); and quantification of PP/MM ratios of cortical astrocytes (D, G, J, and M) in control, MADM-7^GT/TG;Emx1-Cre^+/− (B–D); paternal (E–G) or maternal (H–J) Igf2 deletion, MADM-7^GT/TG,Igf2;Emx1-Cre^+/−; and Igf2 full KO, MADM-7^{GT,Igf2/TG,Igf2};Emx1-Cre^+/− (K–M). Loss of Igf2 in astrocytes has no effect on PP/MM ratios, because comparisons of values in all Igf2 deletion paradigms relative to control were non-significant.

(N–Z) Schematics of Bax ablation in MADM-deletion paradigms, corresponding predictions of astrocyte survival (?) and ratios (PP/MM) in cells with matUPD (orange) and patUPD (green) (N); experimental MADM-labeling in CX at P21 in overview (O, R, U, and X) and at higher resolution (P, S, V, and Y); and quantification of PP/MM ratios of cortical astrocytes (Q, T, W, and Z) in control, MADM-7^GT/TG;Emx1-Cre^+/− (O–Q); paternal (R–T) or maternal (U–W) Bax deletion, MADM-7^GT/TG,Bax;Emx1-Cre^+/−; and Bax cKO, MADM-7^{GT,Bax/TG,Bax};Emx1-Cre^+/− (X–Z). In maternal Bax deletion (W) and Bax cKO animals, ratios of astrocytes (PP/MM) equalized to ∼1 and showed significant differences compared with control (Q) (mat deletion to control, ^∗∗p = 0.0061; cKO to control, ^∗p = 0.0207; t test). Bars and error bars represent mean ± SEM.

Cortical layers (C, F, I, L, P, S, V, and Y) are indicated (roman numerals). Scale bar: 50 μm (B, E, H, K, O, R, U, and X) and 60 μm (C, F, I, L, P, S, V, and Y). See also Figure S7.