title: Temperature-dependency of electron-transport activity in mitochondria with exogenous mitochondrial DNA in Drosophila.
abstract: In mitochondrial DNA (mtDNA) heteroplasmy induced artificially in Drosophila melanogaster (Matsuura et al., 1989), foreign mtDNA derived from D. mauritiana was selectively transmitted at 25 degrees C but was lost at 19 degrees C (Niki et al., 1989; Matsuura et al., 1990, 1991). To investigate temperature-dependent factors in the selective transmission of mtDNA, the temperature-dependency of electron-transport activity of mitochondria from D. melanogaster in which endogenous mtDNA was completely replaced by the foreign mtDNA was compared with that of D. melanogaster and D. mauritiana. For NADH-oxidase activity, the optimum temperature of D. mauritiana mitochondria was 35 degrees C while for two types of mitochondria from D. melanogaster each possessing either endogenous or exogenous mtDNA, maximum activity was noted at 32 degrees C. This observation suggests that the temperature-dependency of mitochondrial electron-transport activity is mainly determined by a nuclear genome. NADH-cytochrome c reductase and cytochrome c oxidase activities were not significantly different among the three types of mitochondria. The temperature-dependency of mitochondrial function apparently is not involved in the temperature-dependent selective transmission of mtDNA in the heteroplasmic state.
authors.affiliation: Department of Biology, Ochanomizu University, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nagata
authors.forename: E T
authors.initials: ET
authors.lastname: Matsuura
mesh_terms: D000818:Animals; D003574:Cytochrome c Group / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism* / Q000648:ultrastructure; D004579:Electron Transport; D008928:Mitochondria / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D013696:Temperature
chemical_list: D003574:Cytochrome c Group; D004272:DNA, Mitochondrial; D009097:Multienzyme Complexes; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases