title: Mating-type locus of Cryptococcus neoformans: a step in the evolution of sex chromosomes.
abstract: The sexual development and virulence of the fungal pathogen Cryptococcus neoformans is controlled by a bipolar mating system determined by a single locus that exists in two alleles, alpha and a. The alpha and a mating-type alleles from two divergent varieties were cloned and sequenced. The C. neoformans mating-type locus is unique, spans >100 kb, and contains more than 20 genes. MAT-encoded products include homologs of regulators of sexual development in other fungi, pheromone and pheromone receptors, divergent components of a MAP kinase cascade, and other proteins with no obvious function in mating. The alpha and a alleles of the mating-type locus have extensively rearranged during evolution and strain divergence but are stable during genetic crosses and in the population. The C. neoformans mating-type locus is strikingly different from the other known fungal mating-type loci, sharing features with the self-incompatibility systems and sex chromosomes of algae, plants, and animals. Our study establishes a new paradigm for mating-type loci in fungi with implications for the evolution of cell identity and self/nonself recognition.
authors.affiliation: Department of Molecular Genetics and Microbiology, Howard Hughes Medical Institute, Duke University, Durham, North Carolina 27710, USA.
authors.forename: Klaus B
authors.initials: KB
authors.lastname: Lengeler
authors.forename: Deborah S
authors.initials: DS
authors.lastname: Fox
authors.forename: James A
authors.initials: JA
authors.lastname: Fraser
authors.forename: Andria
authors.initials: A
authors.lastname: Allen
authors.forename: Keri
authors.initials: K
authors.lastname: Forrester
authors.forename: Fred S
authors.initials: FS
authors.lastname: Dietrich
authors.forename: Joseph
authors.initials: J
authors.lastname: Heitman
mesh_terms: D000483:Alleles; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial; D015825:Chromosomes, Fungal / Q000235:genetics*; D003001:Cloning, Molecular; D003455:Cryptococcus neoformans / Q000235:genetics* / Q000502:physiology; D019143:Evolution, Molecular; D015966:Gene Expression Regulation, Fungal; D015723:Gene Library; D005800:Genes, Fungal / Q000235:genetics*; D049770:Genes, Mating Type, Fungal; D000072235:Mating Factor; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics*; D010675:Pheromones; D017422:Sequence Analysis, DNA
chemical_list: D010455:Peptides; D010675:Pheromones; D000072235:Mating Factor