Multiple gene genealogies reveal recent dispersion and hybridization in the human pathogenic fungus Cryptococcus neoformans

  title={Multiple gene genealogies reveal recent dispersion and hybridization in the human pathogenic fungus Cryptococcus neoformans},
  author={Jianping Xu and Rytas Vilgalys and Thomas G. Mitchell},
  journal={Molecular Ecology},
Cryptococcus neoformans (= Filobasidiella neoformans) is a significant emerging fungal pathogen of humans. To understand the evolution of this pathogen, 34 strains were obtained from various locations around the world and fragments of four genes were sequenced from each. These strains represented all three varieties and five serotypes. The four sequenced genes are: (i) the mitochondrial large ribosomal subunit RNA; (ii) the internal transcribed spacer region of the nuclear rRNA, including ITS1… 

Mitochondrial Genome Polymorphisms in the Human Pathogenic Fungus Cryptococcus neoformans

A dynamic evolution of mitochondrial genomes in this important human fungal pathogen is revealed and the combined mitogenome exon-based phylogeny and intron distributions suggested that clades VNI, VNII and VNB could be further divided into sub-clades.

Recent evolution of the human pathogen Cryptococcus neoformans by intervarietal transfer of a 14-gene fragment.

Data indicate that DNA exchange between closely related sympatric varieties or species may be a recurrent theme in the evolution of fungal species, and suggests that although evolutionary divergence is the primary force driving speciation, rare introgression events also play a potentially important role.

Population genomics of Cryptococcus neoformans var. grubii reveals new biogeographic relationships and finely maps hybridization

While the three major lineages of C. grubii are well separated, recombination between the lineages has occurred, notably resulting in hybrid isolates with segmented ancestry across the genome, which provides evidence of substantial population structure.

Tracing Genetic Exchange and Biogeography of Cryptococcus neoformans var. grubii at the Global Population Level

Phylogenetic and population genomic analyses of isolates from Brazil reveal that the previously “African” VNB lineage occurs naturally in the South American environment, which suggests migration of the V NB lineage between Africa and South America prior to its diversification.

Chromosomal Rearrangements between Serotype A and D Strains in Cryptococcus neoformans

It is identified that overall, rearranged regions had recombination frequencies about half of those around syntenic regions, and the implications of these results on the genome structure, ecology, and evolution of C. neoformans are discussed.

Multiple gene genealogical analyses suggest divergence and recent clonal dispersal in the opportunistic human pathogen Candida guilliermondii.

DNA fragments were sequenced from five genes for each of 37 strains collected from Canada, China, the Philippines and Tanzania, revealing significant divergence and clonal dispersal in this important pathogenic yeast complex.

Correction: Genetic Diversity of the Cryptococcus Species Complex Suggests that Cryptococcus gattii Deserves to Have Varieties

The genetic variation found among all of these haploid monophyletic lineages in the Cryptococcus species complex indicates that they warrant varietal status.

Genetic Analysis of a Hybrid Cross between Cryptococcus neoformans and Cryptococcus deneoformans

There is mitotic recombination during the production of the hybrids, that there are genetic incompatibilities between C. neoformans and C. deneoformans, and that differences between the two species in virulencerelated traits are controlled by multiple quantitative genetic loci.

Comparative Gene Genealogies Indicate that Two Clonal Lineages of Cryptococcus gattii in British Columbia Resemble Strains from Other Geographical Areas

The results indicate that the C. gattii population in B.C. comprises at least two divergent lineages, corresponding to previously identified VGI and VGII molecular types.



Two divergent intragenomic rDNA ITS2 types within a monophyletic lineage of the fungus Fusarium are nonorthologous.

The results suggest that the ancestral ITS2 types may have arisen following an ancient interspecific hybridization or gene duplication which occurred prior to the evolutionary radiation of the Gibberella fujikuroi complex and related species of Fusarium.

Extensive allelic variation in Cryptococcus neoformans

The allelic variation suggested that there is extensive genomic diversity among C. neoformans clinical isolates from one geographic area and there is strong selection against amino acid changes in OMPPase.


Comparison of gene genealogies with a phylogeny inferred from DNA fingerprints and a combined phylogeny of the entire dataset identified convergent or parallel changes in fingerprints.

Origin of a new Phytophthora pathogen through interspecific hybridization.

Evidence from cytological behavior, additive nucleotide bases in repetitive internal transcribed spacer regions of the rRNA-encoding DNA (rDNA), and amplified fragment length polymorphisms of total DNA that a new, aggressive Phytophthora pathogen of alder trees in Europe comprises a range of heteroploid-interspecific hybrids indicates that they are of recent origin and that their evolution is continuing.

Molecular typing of Cryptococcus neoformans: taxonomic and epidemiological aspects.

The results suggest that there are two separate species rather than two varieties of Cryptococcus neoformans, and the isolates of each taxon that originated from restricted geographical areas often had identical or similar karyotypes and RAPD patterns, suggesting that clonal reproduction had occurred.

Concordance of gene genealogies reveals reproductive isolation in the pathogenic fungus Coccidioides immitis.

It is concluded that coccidioidomycosis can be caused by two distinct noninterbreeding taxa, which should aid the future study of the disease and illustrates the utility of the genealogical approach in population genetics.

Comparison of the electrophoretic karyotypes and chromosomal location of ten genes in the two varieties of Cryptococcus neoformans.

This work compared multiple isolates of the two varieties of Cryptococcus neoformans, as well as previously characterized representative isolates, for their electrophoretic karyotypes using pulsed-field electrophoresis to determine the size of the smallest chromosome.

Panglobal distribution of a single clonal lineage of the Irish potato famine fungus.

The genetic data are consistent with the hypothesis that the initial migration of P. infestans in the 1840s was from Mexico to the United States and that only a single genetic individual was transported to Europe and subsequently to the rest of the world.

Comparison of 5.8S ribosomal DNA sequences among the basidiomycetous yeast genera Cystofilobasidium, Filobasidium and Filobasidiella.

  • T. MitchellT. WhiteJ. W. Taylor
  • Biology
    Journal of medical and veterinary mycology : bi-monthly publication of the International Society for Human and Animal Mycology
  • 1992
Preliminary support for the phylogeny inferred from parsimony analysis of aligned 5.8S rDNA sequences was determined by bootstrapping and there was strong support for retaining Fl.