Parasex generates highly recombinant progeny in Candida albicans with increased virulence

Area of Science:

• Microbiology
• Mycology
• Genetics

Background:

• Candida albicans is a significant human fungal pathogen.
• It primarily reproduces via mitotic growth but can also engage in a parasexual cycle.
• The genome plasticity facilitated by the parasexual cycle, compared to meiosis, is not well understood.

Purpose of the Study:

• To investigate the genomic landscape generated by the parasexual cycle in Candida albicans.
• To compare the genome plasticity of the parasexual cycle with that of conventional meiosis.
• To understand the impact of parasexual recombination on fungal pathogen phenotypes and adaptation.

Main Methods:

• Induced parasexual crosses between genetically distinct Candida albicans strains.
• Analyzed the genotypic makeup of parasexual progeny using whole-genome sequencing and selective genotyping.
• Assessed pathogenesis-related phenotypes including filamentation, drug response, and in vivo fitness.

Main Results:

• The parasexual cycle in C. albicans induces substantial recombination and chromosome shuffling, mirroring meiosis.
• Parasexual progeny exhibited genotypic diversity linked to variations in inherited, recombinant genomes.
• Phenotypic diversity was observed in filamentation, drug response, and in vivo fitness among progeny.

Conclusions:

• The parasexual cycle allows non-meiotic eukaryotes to escape purely asexual reproduction.
• It confers the ability for rapid adaptation to diverse host niches for commensal and pathogenic fungi.
• Parasex contributes significantly to the evolutionary potential of Candida albicans.