Arrangement of mitochondrial nucleoids during life cycle of Saccharomyces cerevisiae.

Abstract

The fluorescent dye, 4',6-diamidino-2-phenylindole (DAPI) intensely stains cytoplasmic DNA in plant (1) and yeast cells (2, 3). In Saccharomyces yeast cells, mitochondrial DNA (mtDNA) was observed as a bright nucleoid "chondriolite" (2) and with a "string-of-beads" appearance (3) during growth. On the other hand, the role and behavior of mtDNA might be attractive in relation to nuclear division during meiosis of Saccharomyces cerevisiae, since active functioning of mitochondria is essential for sporulation (4-6). We report here that mtDNAs aggregate and form structures with a "string-of-beads" appearance and then separate again into individual "chondriolites" during the meiosis-sporulation and cell division cycles.