title: Unisexual reproduction of Cryptococcus gattii.
abstract: Cryptococcus gattii is a basidiomycetous human fungal pathogen that typically causes infection in tropical and subtropical regions and is responsible for an ongoing outbreak in immunocompetent individuals on Vancouver Island and in the Pacific Northwest of the US. Pathogenesis of this species may be linked to its sexual cycle that generates infectious propagules called basidiospores. A marked predominance of only one mating type (α) in clinical and environmental isolates suggests that a-α opposite-sex reproduction may be infrequent or geographically restricted, raising the possibility of an alternative unisexual cycle involving cells of only α mating type, as discovered previously in the related pathogenic species Cryptococcus neoformans. Here we report observation of hallmark features of unisexual reproduction in a clinical isolate of C. gattii (isolate 97/433) and describe genetic and environmental factors conducive to this sexual cycle. Our results are consistent with population genetic evidence of recombination in the largely unisexual populations of C. gattii and provide a useful genetic model for understanding how novel modes of sexual reproduction may contribute to evolution and virulence in this species.
authors.affiliation: Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America.
authors.forename: Sujal S
authors.initials: SS
authors.lastname: Phadke
authors.affiliation: Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America.
authors.forename: Marianna
authors.initials: M
authors.lastname: Feretzaki
authors.affiliation: Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America.
authors.forename: Shelly Applen
authors.initials: SA
authors.lastname: Clancey
authors.affiliation: Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America.
authors.forename: Olaf
authors.initials: O
authors.lastname: Mueller
authors.affiliation: Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America.
authors.forename: Joseph
authors.initials: J
authors.lastname: Heitman
mesh_terms: D056285:Cryptococcus gattii / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D048690:Fruiting Bodies, Fungal / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D049770:Genes, Mating Type, Fungal; D016681:Genome, Fungal; D025301:Hyphae / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D020935:MAP Kinase Signaling System; D011003:Ploidies