Cryptococcus amylolentus
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ABSTRACT:
PROVIDER: PRJNA387705 | ENA |
REPOSITORIES: ENA
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Project description:Species within the human pathogenic Cryptococcus species complex are major threats to public health, causing about one million infections globally each year. Cryptococcus amylolentus is the most closely known related species of the pathogenic Cryptococcus species complex, and it is non-pathogenic. Additionally, while pathogenic Cryptococcus species have bipolar mating systems with a single large MAT locus that represents a derived state in Basidiomycetes, C. amylolentus has a tetrapolar mating system with two MAT loci (P/R and HD) located on different chromosomes. Thus, studying C. amylolentus will shed light on the origin and evolution of pathogenesis, as well as the transition from tetrapolar to bipolar mating systems in the pathogenic Cryptococcus species. In this study, we sequenced, assembled, and annotated the genomes of two C. amylolentus isolates, CBS6039 and CBS6273, which are sexual and interfertile. Genome comparison between the two C. amylolentus isolates identified the boundaries and the complete gene contents of the P/R and HD MAT loci. Also, bioinformatics and ChIP-seq analyses showed that C. amylolentus has regional centromeres that are enriched with species-specific transposable and repetitive elements, similar to the centromeric structures in the pathogenic Cryptococcus species. Additionally, we found that while neither of the P/R and HD loci in C. amylolentus is physically linked to its centromere, both MAT loci exhibit centromere linkage in meiosis, suggesting the presence of recombinational suppressors and/or epistatic gene interactions in the inter MAT-CEN regions. Furthermore, genomic comparison between C. amylolentus and pathogenic Cryptococcus species provides evidence that chromosomal rearrangements mediated by intercentromeric recombination have occurred after the two lineages split from their common ancestor. We propose a model in which the evolution of the bipolar mating system was initiated by an ectopic recombination event mediated by repetitive elements located within the centromeric regions and shared between chromosomes. This translocation brought the P/R and HD loci onto the same chromosome, and was followed by chromosomal rearrangements that resulted in the two MAT loci becoming physically linked and eventually fused to form the single contiguous MAT locus that is now extant in the pathogenic Cryptococcus species.
2018-04-08 | GSE95128 | GEO
Project description:Cse4 ChIP seq of Cryptococcus amylolentus to identify centromeres
| PRJNA376407 | ENA
Project description:Genome and transcriptome sequencing of Cryptococcus amylolentus (CBS6039 isolate)
| PRJEB19939 | ENA
Project description:Aspergillus flavus and A. parasiticus are two of the most important aflatoxin-producing species that contaminate agricultural commodities worldwide. Both species are heterothallic and undergo sexual reproduction in laboratory crosses. Here, we examine the possibility of interspecific matings between A. flavus and A. parasiticus. These species can be distinguished morphologically and genetically, as well as by their mycotoxin profiles. Aspergillus flavus produces both B aflatoxins and cyclopiazonic acid (CPA), B aflatoxins or CPA alone, or neither mycotoxin; Aspergillus parasiticus produces B and G aflatoxins or the aflatoxin precursor O-methylsterigmatocystin, but not CPA. Only four out of forty-five attempted interspecific crosses between compatible mating types of A. flavus and A. parasiticus were fertile and produced viable ascospores. Single ascospore strains from each cross were isolated and were shown to be recombinant hybrids using multilocus genotyping and array comparative genome hybridization. Conidia of parents and their hybrid progeny were haploid and predominantly monokaryons and dikaryons based on flow cytometry. Multilocus phylogenetic inference showed that experimental hybrid progeny were grouped with naturally occurring A. flavus L strain and A. parasiticus. Higher total aflatoxin concentrations in some F1 progeny strains compared to midpoint parent aflatoxin levels indicate synergism in aflatoxin production; moreover, three progeny strains synthesized G aflatoxins that were not produced by the parents, and there was evidence of putative allopolyploidization in one strain. These results suggest that hybridization is an important diversifying force resulting in the genesis of novel toxin profiles in these agriculturally important species.
2015-10-01 | GSE61981 | GEO
Project description:Sexual reproduction in fungi is governed by a specialized genomic region called the mating-type locus (MAT). The human fungal pathogenic and basidiomycetous yeast Cryptococcus neoformans has evolved a bipolar mating system (a, ?) in which the MAT locus is unusually large (>100 kb) and encodes >20 genes including homeodomain (HD) and pheromone/receptor (P/R) genes. To understand how this unique bipolar mating system evolved, we investigated MAT in the closely related species Tsuchiyaea wingfieldii and Cryptococcus amylolentus and discovered two physically unlinked loci encoding the HD and P/R genes. Interestingly, the HD (B) locus sex-specific region is restricted (?2 kb) and encodes two linked and divergently oriented homeodomain genes in contrast to the solo HD genes (SXI1?, SXI2a) of C. neoformans and Cryptococcus gattii. The P/R (A) locus contains the pheromone and pheromone receptor genes but has expanded considerably compared to other outgroup species (Cryptococcus heveanensis) and is linked to many of the genes also found in the MAT locus of the pathogenic Cryptococcus species. Our discovery of a heterothallic sexual cycle for C. amylolentus allowed us to establish the biological roles of the sex-determining regions. Matings between two strains of opposite mating-types (A1B1×A2B2) produced dikaryotic hyphae with fused clamp connections, basidia, and basidiospores. Genotyping progeny using markers linked and unlinked to MAT revealed that meiosis and uniparental mitochondrial inheritance occur during the sexual cycle of C. amylolentus. The sexual cycle is tetrapolar and produces fertile progeny of four mating-types (A1B1, A1B2, A2B1, and A2B2), but a high proportion of progeny are infertile, and fertility is biased towards one parental mating-type (A1B1). Our studies reveal insights into the plasticity and transitions in both mechanisms of sex determination (bipolar versus tetrapolar) and sexual reproduction (outcrossing versus inbreeding) with implications for similar evolutionary transitions and processes in fungi, plants, and animals.
| S-EPMC3280970 | biostudies-literature
Project description:The kinase, putative endopeptidase and other peptides of small size (KEOPS) complex plays critical cellular functions in eukaryotes, but its pathobiological roles remains elusive in fungal pathogens. Here we comprehensively analyze the pathobiological functions of the KEOPS complex in fungal meningoencephalitis pathogen Cryptococcus neoformans. The cryptococcal KEOPS complex appears to have a linear arrangement of Pcc1-Kae1-Bud32-Cgi121, supported by physical interaction between Pcc1-Kae1, Kae1-Bud32, and Bud32-Cgi121, but does not have Gon7 ortholog, which is the part of the S. cerevisiae KEOPS complex. Deletion of PCC1, KAE1, and BUD32 causes severe growth defects with perturbed cell cycle control.
2022-10-18 | GSE208333 | GEO
Project description:We measured protein translation (by ribosome profiling) and RNA levels (by polyA-enriched RNA-seq) in Cryptococcus neoformans strain H99 and Cryptococcus neoformans strain JEC21. This is the first transcriptome-wide map of translation in this species complex.
2019-06-22 | GSE133125 | GEO
Project description:The Cryptococcus neoformans NRG1 gene was identified using gene microarrays to define putative transcription factor genes regulated by the cyclic AMP (cAMP) signal transduction pathway. Disruption of NRG1 results in delayed capsule formation and mating, two phenotypes that are directly controlled by cAMP signaling. Putative targets of the Nrg1 transcription factor were identified using a second genome microarray to define differences in the transcriptomes of the wild-type and nrg1 mutant strains. These experiments implicate Nrg1 in the transcriptional control of multiple genes involved in carbohydrate metabolism and substrate oxidation, as well as the UGD1 gene encoding a UDP-glucose dehydrogenase required for polysaccharide capsule production and cell wall integrity. In addition to being under transcriptional control of the cAMP pathway, Nrg1 contains a putative protein kinase A phosphorylation site; mutation of this motif results in reduced Nrg1 activity. Consistent with prior studies in hypocapsular mutants, the nrg1 mutant strain is attenuated in an animal model of disseminated cryptococcal disease.
2009-09-04 | GSE17887 | GEO