Figure 5.

Conditional knockout of MCL-1 in the forebrain activates an exacerbated autophagic response. (A) Control and MCL-1^Δ/Δ mice. (B) Expression levels of various BCL-2 homologues in the cortices of animals of the indicated genotypes. (C) Brain morphology of MCL-1^Δ/Δ. Brain sections were stained with cresyl violet and imaged using a × 1 objective. (D–G) Cortical neurons around the lesion in MCL-1^Δ/Δ animals are positive for the autophagic marker LC3. Brain sections from animals with the indicated genotypes (P14 for E, G; P7 for H) were stained for LC3 (Green) and the neuronal marker NeuN (in H, red), along with the nuclear stain Hoechst (Blue). Confocal images were taken using × 10 (E) or × 63 (G, H) objectives. Scale bars=200 μm (E); 50 μm (G, H). Quantification of the LC3 staining is shown in D. The total number of cells was determined by counting the Hoechst-positive nuclei. Data are expressed as percent of LC3-positive cells in at least three animals per genotype±s.d. ^*P<0.01. (F) Quantification of the total surface area occupied by autophagosomes. Data are expressed as percent of total cortical area covered by autophagosomes in at least 16 EM images per genotype±s.d. P<0.005 (I) Representative EM images from MCL-1^+/Δ and MCL-1^Δ/Δ P14 mice. N, nucleus; ^*, autophagosomal structures; arrowheads, double membrane; arrow, mitochondrion inside a vesicle.