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Unisexual reproduction of Cryptococcus gattii.

Phadke SS, Feretzaki M, Clancey SA, Mueller O, Heitman J - PLoS ONE (2014)

Bottom Line: 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.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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America.

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.

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Related in: MedlinePlus

Growth at high temperature stimulates hyphal development.The cells were grown on solid YPD media at 30°C, 37°C and 38°C for 2, 3, 4, and 5 days in the dark. Solo cultures were spotted on MS media and incubated at room temperature for 5 days in the dark and hyphal development was visualized by microscopy and photographed. Scale bar = 50 µm.
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pone-0111089-g004: Growth at high temperature stimulates hyphal development.The cells were grown on solid YPD media at 30°C, 37°C and 38°C for 2, 3, 4, and 5 days in the dark. Solo cultures were spotted on MS media and incubated at room temperature for 5 days in the dark and hyphal development was visualized by microscopy and photographed. Scale bar = 50 µm.

Mentions: To investigate the role of high temperature in hyphal development we incubated C. gattii VGII R265, VGIII 97/433, C. neoformans var. grubii H99, and C. neoformans var. neoformans JEC21 strains on rich YPD media at 30°C, 37°C, and 38°C for 2, 3, 4, and 5 days in the dark. The seed cultures were spotted on MS, Filamentation agar, or V8 media pH = 7.0 and incubated in the dark, at room temperature. We found that high temperature stimulates filamentation in 97/433 with hyphae appearing as soon as 5 days post inoculation of solo cultures (Figure 4). Deletion of CRG1 or overexpression of MAT2 or ZNF2 in 97/433 increased hyphal development generating more condensed and longer hyphae at the periphery of the culture. On the other hand, neither the C. neoformans var. grubii strain H99 nor the C. gattii strain R265 strains generated heat-induced hyphae following prolonged incubation in different nutrient limiting media (Figure 4).


Unisexual reproduction of Cryptococcus gattii.

Phadke SS, Feretzaki M, Clancey SA, Mueller O, Heitman J - PLoS ONE (2014)

Growth at high temperature stimulates hyphal development.The cells were grown on solid YPD media at 30°C, 37°C and 38°C for 2, 3, 4, and 5 days in the dark. Solo cultures were spotted on MS media and incubated at room temperature for 5 days in the dark and hyphal development was visualized by microscopy and photographed. Scale bar = 50 µm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4206507&req=5

pone-0111089-g004: Growth at high temperature stimulates hyphal development.The cells were grown on solid YPD media at 30°C, 37°C and 38°C for 2, 3, 4, and 5 days in the dark. Solo cultures were spotted on MS media and incubated at room temperature for 5 days in the dark and hyphal development was visualized by microscopy and photographed. Scale bar = 50 µm.
Mentions: To investigate the role of high temperature in hyphal development we incubated C. gattii VGII R265, VGIII 97/433, C. neoformans var. grubii H99, and C. neoformans var. neoformans JEC21 strains on rich YPD media at 30°C, 37°C, and 38°C for 2, 3, 4, and 5 days in the dark. The seed cultures were spotted on MS, Filamentation agar, or V8 media pH = 7.0 and incubated in the dark, at room temperature. We found that high temperature stimulates filamentation in 97/433 with hyphae appearing as soon as 5 days post inoculation of solo cultures (Figure 4). Deletion of CRG1 or overexpression of MAT2 or ZNF2 in 97/433 increased hyphal development generating more condensed and longer hyphae at the periphery of the culture. On the other hand, neither the C. neoformans var. grubii strain H99 nor the C. gattii strain R265 strains generated heat-induced hyphae following prolonged incubation in different nutrient limiting media (Figure 4).

Bottom Line: 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.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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America.

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.

Show MeSH
Related in: MedlinePlus