Multi-locus sequence typing and phylogenetics of Cryptococcus neoformans AD hybrids

Area of Science:

• Medical Mycology
• Population Genetics
• Evolutionary Biology

Background:

• Hybrid AD strains of Cryptococcus neoformans are globally distributed but poorly understood.
• Their origins, diversity, and evolutionary dynamics require further investigation.

Purpose of the Study:

• To analyze the origin, diversity, and evolution of Cryptococcus neoformans AD hybrid strains.
• To compare AD hybrids with global haploid serotypes A and D strains.

Main Methods:

• Genotyping of 102 AD hybrid strains from 21 countries using mating type and seven-locus sequencing.
• Phylogenetic and population genetic analyses of allelic sequences.
• Comparison of AD hybrids with global haploid serotype A and D strains.

Main Results:

• Most AD hybrids showed loss of heterozygosity at analyzed loci.
• Phylogenetic analyses indicated multiple hybrid origins across continents, dating back one million years.
• Evidence for clonal reproduction, long-distance dispersal, and novel genetic diversity in AD hybrids and haploid populations was found.

Conclusions:

• AD hybrids can be effectively genotyped using established multi-locus sequencing typing methods.
• Novel genetic diversity exists in AD hybrids and haploid populations.
• AD hybrids exhibit multiple origins and dynamic evolution in nature.