YEAST MITOCHONDRIAL-DNA SELECTIVITY DETECTED BY A FLUORESCENT METHOD

Yeast mitochondrial DNA (mDNA) may be selectively detected by using a specific stain, DAPI. Nuclear DNA (nDNA) was stained along with mitochondrial DNA in only three out of the fifteen yeast strains studied. Luminescent microscopy showed that the amount of mDNA varied and the size and shape of the fluorescently stained mitochondrial nuclei also differed in the diverse yeast strains. When the fixed preparation was treated with the DAPI stain, the fluorescence of the nDNA was intensified. Under these conditions, mDNA was detected in yeast which had the highest content of mDNA. The integrity of the mitochondria was disrupted in the fixation processes. Changes also occurred in the DNA molecule structure itself which reflected its interaction with the stain and respectively, with the level of fluorescence. This work touched upon important aspects of the interaction of the stain with native DNA and DNA subjected to different fixation methods that made up the composition of yeast nuclei and mitochondria.