Morphology and dynamics of mitochondria in Mougeotia sp.

Abstract

Mougeotia sp. are widely distributed freshwater algae that have a characteristic chloroplast rotation response to incident light. he mechanics of the response have been elucidated, but no work regarding the bioenergetics of this process has been eported. The current study examined the morphology and movement dynamics of mitochondria in this alga. A novel method, tilizing DASPMI (dimethylaminostyrylmethylpyridiniumiodine) fluorescent dye, was developed to allow vital mitochondrial taining while avoiding sequestration of the dye by numerous cytoplasmic vesicles and then used to study mitochondrial ynamics. Mitochondria were elongated tubular structures that were significantly asymmetrically located in the perinuclear nd chloroplast edge regions. The mitochondria displayed small amplitude undirected movements with occasional highvelocity ursts of directional movement which were of greater magnitude. These latter movements were inhibited by a 30-min ncubation with latrunculin (50 μM), but were unaffected by incubation with colchicine (10 μM), indicating that the actin, but ot the microtubule cytoskeleton, is involved. The method used and the findings reported will allow research to be undertaken n the contribution of the chondriome to the chloroplast rotation response and other aspects of the bioenergetics of this organism. © 2010 British Phycological Society.