Skip to Main content Skip to Navigation
Journal articles

Genetic Diversity and Genomic Plasticity of Cryptococcus neoformans AD Hybrid Strains

Abstract : Natural hybridization between two strains, varieties, or species is a common phenomenon in both plants and animals. Although hybridization may skew established gene pools, it generates population diversity efficiently and sometimes results in the emergence of newly adapted genotypes. Cryptococcus neoformans, which causes the most frequent opportunistic fungal infection in immunocompromised hosts, has three serotypes: A, D, and AD. Serotype-specific multilocus sequence typing and serotype-specific comparative genome hybridization were applied to investigate the genetic variability and genomic organization of C. neoformans serotype AD isolates. We confirm that C. neoformans serotype AD isolates are hybrids of serotype A and D strains. Compared with haploid strains, most AD hybrid isolates exhibit unique multilocus sequence typing genotypes, suggesting that multiple independent hybridization events punctuated the origin and evolutionary trajectory of AD hybrids. The MATa alleles from both haploid and AD hybrid isolates group closely to form a cluster or subcluster in both the serotype A and D populations. The rare and unique distribution of MATa alleles may restrict sexual reproduction between isolates of opposite mating types. The genetic diversity of the serotype D population, including haploid strains and serotype D genomes of the AD hybrid, is significantly greater than that of serotype A, and there are signatures of recombination within the serotype D population. Given that MATa isolates are relatively rare, both opposite-sex and same-sex mating may contribute to genetic recombination of serotype D in nature. Extensive chromosome loss was observed in AD hybrid isolates, which results in loss of heterozygosity in the otherwise-heterozygous AD hybrid genome. Most AD hybrid isolates exhibit hybrid vigor and are resistant to the antifungal drug FK506. In addition, the C. neoformans AD hybrid genome is highly dynamic, with continuous chromosome loss, which may be a facile route for pathogen evolution through which genotypic and phenotypic variation is generated.
Document type :
Journal articles
Complete list of metadatas

Cited literature [72 references]  Display  Hide  Download

https://hal-pasteur.archives-ouvertes.fr/pasteur-02194832
Contributor : Reine Bouyssie <>
Submitted on : Friday, July 26, 2019 - 9:45:52 AM
Last modification on : Wednesday, October 14, 2020 - 3:43:11 AM

File

Li Genetic diversity genomic.p...
Publication funded by an institution

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Collections

Citation

Wenjun Li, Anna Averette, Marie Desnos-Ollivier, Min Ni, Françoise Dromer, et al.. Genetic Diversity and Genomic Plasticity of Cryptococcus neoformans AD Hybrid Strains. G3, Genetics Society of America, 2012, 2 (1), pp.83-97. ⟨10.1534/g3.111.001255⟩. ⟨pasteur-02194832⟩

Share

Metrics

Record views

104

Files downloads

310