Identification of the MATa mating-type locus of Cryptococcus neoformans reveals a serotype A MATa strain thought to have been extinct.
Cryptococcus neoformans is an opportunistic fungal pathogen with a defined sexual cycle involving mating between haploid MATa and MATalpha 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 MATalpha 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 MATalpha 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.
Lengeler
K B
KB
Departments of Genetics, Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA.
Wang
P
P
Cox
G M
GM
Perfect
J R
JR
Heitman
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003453:Cryptococcosis / Q000382:microbiology; D003455:Cryptococcus neoformans / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D004271:DNA, Fungal; D004195:Disease Models, Animal; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D008040:Genetic Linkage; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D020930:MAP Kinase Kinase Kinases; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D012703:Serotyping; D014774:Virulence
D004271:DNA, Fungal; D047908:Intracellular Signaling Peptides and Proteins; D029701:Saccharomyces cerevisiae Proteins; D017346:Protein Serine-Threonine Kinases; D020930:MAP Kinase Kinase Kinases; C078754:STE20 protein, S cerevisiae