Diploids in the Cryptococcus neoformans Serotype A Population Homozygous for the α Mating Type Originate via Unisexual Mating Diploid α/α C. neoformans Isolates
2009

Same-Sex Mating in Cryptococcus neoformans and Its Role in Genetic Diversity

Sample size: 489 publication 10 minutes Evidence: high

Author Information

Author(s): Lin Xiaorong, Patel Sweta, Litvintseva Anastasia P., Floyd Anna, Mitchell Thomas G., Heitman Joseph

Primary Institution: Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America

Hypothesis

Diploid α/α isolates would be present in the largely unisexual Cryptococcus serotype A population.

Conclusion

The study found that unisexual mating produces diploid isolates of C. neoformans in nature, contributing to genetic diversity.

Supporting Evidence

  • Approximately 8% of the tested C. neoformans isolates were found to be diploid.
  • The majority of diploid isolates were serotype A with two copies of the α MAT locus allele.
  • Some diploids resulted from fusion of genetically distinct α cells, while others arose via endoreplication or clonal mating.
  • Phylogenetic analysis indicated that diploid strains are genetically distinct, suggesting multiple independent origins.

Takeaway

Some fungi can mate with themselves, and this study shows that this helps them create more types of themselves, which is important for their survival.

Methodology

The study tested 489 natural C. neoformans isolates for ploidy using fluorescence flow cytometry.

Limitations

The study did not find any natural triploids or tetraploids, suggesting instability of higher ploidy.

Participant Demographics

Isolates were collected from six continents including Asia, Africa, Australia, Europe, and North and South Americas.

Digital Object Identifier (DOI)

10.1371/journal.ppat.1000283

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