title: Mitochondrial DNA inheritance in the human fungal pathogen Cryptococcus gattii.
abstract: The inheritance of mitochondrial DNA (mtDNA) is predominantly uniparental in most sexual eukaryotes. In this study, we examined the mitochondrial inheritance pattern of Cryptococcus gattii, a basidiomycetous yeast responsible for the recent and ongoing outbreak of cryptococcal infections in the US Pacific Northwest and British Columbia (especially Vancouver Island) in Canada. Using molecular markers, we analyzed the inheritance of mtDNA in 14 crosses between strains within and between divergent lineages in C. gattii. Consistent with results from recent studies, our analyses identified significant variations in mtDNA inheritance patterns among strains and crosses, ranging from strictly uniparental to biparental. For two of the crosses that showed uniparental mitochondrial inheritance in standard laboratory conditions, we further investigated the effects of the following environmental variables on mtDNA inheritance: UV exposure, temperature, and treatments with the methylation inhibitor 5-aza-2'-deoxycytidine and with the ubiquitination inhibitor ammonium chloride. Interestingly, one of these crosses showed no response to these environmental variables while the other exhibited diverse patterns ranging from complete uniparental inheritance of the MATa parent mtDNA, to biparental inheritance, and to a significant bias toward inheritance of the MATα parental mtDNA. Our results indicate that mtDNA inheritance in C. gattii differs from that in its closely related species Cryptococcus neoformans.
authors.affiliation: Department of Biology, McMaster University, 1280 Main St West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Zixuan
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Biology, McMaster University, 1280 Main St West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Amanda
authors.initials: A
authors.lastname: Wilson
authors.affiliation: Department of Biology, McMaster University, 1280 Main St West, Hamilton, Ontario L8S 4K1, Canada. Electronic address: jpxu@mcmaster.ca.
authors.forename: Jianping
authors.initials: J
authors.lastname: Xu
mesh_terms: D000643:Ammonium Chloride / Q000494:pharmacology; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D002170:Canada; D056285:Cryptococcus gattii / Q000235:genetics*; D003455:Cryptococcus neoformans / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D000077209:Decitabine; D050259:Genes, Mitochondrial; D006801:Humans; D054875:Ubiquitination
chemical_list: D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D000643:Ammonium Chloride; D000077209:Decitabine; D001374:Azacitidine
keywords: Biparental mtDNA inheritance; Environmental factors; Inter-lineage cross; Intra-lineage cross; Uniparental mtDNA inheritance