The dampening of lipid droplet oscillatory movement in nitrogen starved filamentous fungi by a low dose of mitochondrial respiration inhibitor

Abstract

Lipid droplets (LDs) are small mobile organelles conserved in all eukaryotic cells. We wanted to test if the LD movement can be muffled by an incomplete inhibition of mitochondrial respiration, induced by treating hyphae of filamentous fungus Phycomyces blakesleeanus with 0.5 mM sodium azide. Nitrogen starved hyphae were used, in order to obtain LDs in larger sizes and numbers. The data obtained unequivocally showed: 1. Sodium azide treatment dramatically reduces the LD velocity and the distances LDs travel; 2. LDs in both controls and in azide-treated hyphae oscillate in a small confined space instead of travelling through the cell; 3. Azide-treated LDs oscillate less frequently and in smaller confinement than controls.