Mitochondrial inheritance in yeast

This chapter reviews some of the approaches that have been taken to elucidate mitochondrial sorting in yeast zygotes that involve the simultaneous immunofluorescent tracking of mitochondrial (mt) DNA and mitochondrial proteins. The segregation of mitochondrial constituents during the formation and outgrowth of diploid progeny that arise from zygotes formed among the matings of haploid yeast cells is of particular interest, because parental mtDNAs recombine promiscuously in zygotes and segregate very rapidly, these events must involve mitochondrial fusion, mixing, and segregation. The chapter focuses on the kinetic relationship among the sorting of mtDNA, detected with the DNA-specific dye, 4',6'- diamino-2-phenylindole (DAPI), and mitochondrial matrix protein detected by indirect immunofluorescence. The analysis of these mitochondrial constituents in synchronously mating populations has revealed that their mixing in zygotes is neither coordinate nor random. Once the number of each zygote type has been scored for all time points, their relative abundance is plotted as a function of time. The immunofluorescence detection of the mitochondrial inheritance in yeast is also discussed. © 1995, Elsevier Inc.