Intracellular redistribution of neuronal peroxisomes in response to ACBD5 expression
Fig 2
Live confocal imaging analysis of POs and mitochondria in hippocampal neurons.
(a) POs and mitochondria were identified by expression of EGFP-SKL and mCherry-mito-7, respectively (Scale bar: 10 μm). Images are displayed as maximum intensity projections. (b-d) Representative kymographs illustrating peroxisomal (b, c) and mitochondrial (d) movements. Kymograph (b) represents the region of the neurite highlighted in (a). The kymographs were generated from the proximal 30~40 μm of neurites, straight vertical lines show static POs and mitochondria; Fig 2B includes a rapid saltatory movement across approximately 10 μm. (e, f) Classification of PO and mitochondria motility into long range movements (> 10 μm), short range movements (5 μm– 10 μm), very short range movements (1 μm– 5 μm), and static organelles (< 1 μm) in myc-ACBD5 expressing and control neurons (total analysis time = 8 min). (g, h) Maximum and average speed (μm/s) of all measured POs and mitochondria in neurites of ACBD5 expressing and control cells. (j, k) Averaged total travelled distance (μm) of measured POs and mitochondria in ACBD5 expressing and control neurons. (i, l) Cumulative distribution of PO travelled distance and speed. (m) Directionality of PO movements in the neurites. Box plots show the PO motility as cumulative net displacement (μm) of anterograde and retrograde movements of all POs in response to ACBD5 expression. Proportions of anterograde (positive values) and retrograde (negative values) movements remain stable after ACBD expression. (n) Comparison of the maximal actual speed and average speed of POs with long range movement between the two groups. Number of organelles analyzed: in control neurons 323 POs, 307 mitochondria; in myc-ACBD5 expressing neurons 360 POs, 267 mitochondria.