Figure 6.

GLS1 expression in cortical neuron primary culture. A–C, Mitochondrial GLS1 labeling. Confocal immunofluorescence detection of labeling performed with anti-GLS1 (A) and anti-mitochondria (B) antibodies. Pictures were inverted and colors were indexed to show GLS1 in green and mitochondria in red. Colocalization of GLS1 and mitochondria labeling is shown in C. In each panel, an enlargement (5×) of the staining is shown in the top left, corresponding to a portion of the picture represented by the gray rectangle. GLS1 and mitochondria pictures were slightly shifted to show clearly the coincidence of staining patterns. D, E, Fluorescence detection of GLS1 expression with Alexa 488-conjugated anti-rabbit antibodies (green) and nuclear cell localization detected with DAPI (blue). The mitochondrial GLS1 immunofluorescence observed in wild-type culture (D) was absent in GLS1−/− neurons (E). Residual GLS1 nuclear labeling was evident, but this has been shown previously to be nonspecific (Laake et al., 1999).