Figure 5. Treatment with 0.1 mM PQ does not affect mitochondrial abundance.

Worms were treated with Mitotracker Red at 50 nM (final concentration) in M9 buffer for 20 min. All pictures were taken by confocal microscopy at 400×. A scale bar of 20 µm is shown in the upper right corner of the figure. For each genotype/treatment three tissues (hypodermis, muscle, and germline) were selected, and for each tissue at least five pictures from different worms were taken. An equal section of each picture was enlarged for quantitative comparisons. The percentage of surface occupied by mitochondria as stained by Mitotracker Red was measured and related to the total area of the selected region. A representative example for each tissue and condition is shown in the figure. The quantification for each sample is also shown in the figure below the enlarged areas. The sample size for the hypodermis was >15, and it was 5 for muscles and the germline. In muscles and in the hypodermis, the difference between the ETC mutants and the wild type was significant (p<0.001), while the difference between PQ treatment and untreated wild type worms was not. Thus, the nuo-6 and isp-1 mutations, but not treatment with 0.1 mM PQ, affect mitochondrial abundance.