Identification of the MATa Mating-Type Locus of Cryptococcus neoformans Reveals a Serotype A MATa Strain thought to Have Been Extinct

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 97; no. 26; pp. 14455 - 14460
• Main Authors: Lengeler, K B, Wang, P, Cox, G M, Perfect, J R, Heitman, J
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 19.12.2000; National Acad Sciences; National Academy of Sciences; The National Academy of Sciences
• Subjects: Alleles; Amino Acid Sequence; Animals; Base Sequence; Biological Sciences; Congenic strains; Cryptococcosis - microbiology; Cryptococcus neoformans; Cryptococcus neoformans - classification; Cryptococcus neoformans - genetics; Cryptococcus neoformans - pathogenicity; Disease Models, Animal; DNA; DNA, Fungal; Enzymes; Extinction; Gels; Genes; Genes, Fungal; Genes, Mating Type, Fungal; Genetic Linkage; Genetic loci; Genetics; Genomics; Humans; Intracellular Signaling Peptides and Proteins; MAP Kinase Kinase Kinases; MAT^a gene; MATa gene; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Pathogens; Polymerase chain reaction; Protein Serine-Threonine Kinases - genetics; Proteins; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae Proteins; Sequence Homology, Amino Acid; Serotyping; STE20a gene; Ste20a protein; Virulence; Yeast
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.97.26.14455

Cryptococcus neoformans is an opportunistic fungal pathogen with a defined sexual cycle involving mating between haploid MATa and MATα cells. Here we describe the isolation of part of the MATa mating-type locus encoding a Ste20 kinase homolog, Ste20a. We show that the STE20a gene cosegregates with the MATa mating type in genetic crosses, maps within the mating-type locus on a 1.8-Mb chromosome, and is allelic with the MATα locus. We identify the first MATa isolate of the most common pathogenic variety of C. neoformans (serotype A, variety grubii) which had been thought to be extinct. This serotype A MATa strain is sterile, fails to produce mating pheromone, and is less virulent than a serotype A MATα strain in an animal model. Our studies illustrate an association of mating type with virulence and suggest that, like Candida albicans, pathogenic isolates of C. neoformans may be largely asexual.