Isolation, characterization, and genetic analysis of monosomic, aneuploid mutants of <i>Candida albicans</i>

Barton, Richard; Gull, Keith

doi:10.1111/j.1365-2958.1992.tb01998.x

Cited by 29 publications

(22 citation statements)

References 29 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If a strain has lost one homolog of a chromosome, it grows slowly (Barton and Gull 1992;Magee and Magee 1997;Janbon et al 1998). Janbon et al (1998) found that selection for growth on L-sorbose resulted in loss of one homolog of chromosome 5.…”

Section: Natural Aneuploidy In Candida Albicansmentioning

confidence: 99%

Fine-Resolution Physical Mapping of Genomic Diversity in Candida albicans

Chibana¹,

Beckerman²,

Magee³

2000

Genome Res.

View full text Add to dashboard Cite

It has been suggested that Candida albicans, a diploid asexual fungus, achieves genetic diversity by genomic rearrangement. This important human pathogen may provide a system in which to analyze alternate routes to genomic diversity. C. albicans has a highly variable karyotype; its chromosomes contain a middle repeated DNA sequence called the Major Repeat Sequence (MRS), composed of subrepeats HOK, RPS, and RB2. RPS is tandemly repeated while the other subrepeats occur once in each MRS. Chromosome 7, the smallest of the eight chromosomes, has been previously mapped. The complete physical map of this chromosome was used to analyze chromosome 7 diversity in six strains, including two well-characterized laboratory strains (1006 and WO-1) and four clinical ones. We found four types of events to explain the genomic diversity: 1) Chromosome length polymorphism (CLP) results from expansion and contraction of the RPS; 2) reciprocal translocation occurs at the MRS loci; 3) chromosomal deletion; and (4) trisomy of individual chromosomes. These four phenomena play an important role in generating genomic diversity in C. albicans.

show abstract

Section: Natural Aneuploidy In Candida Albicansmentioning

confidence: 99%

Fine-Resolution Physical Mapping of Genomic Diversity in Candida albicans

Chibana¹,

Beckerman²,

Magee³

2000

Genome Res.

View full text Add to dashboard Cite

show abstract

“…A number of studies have demonstrated that karyotypic differences exist between clinical isolates, including evidence for both monosomic and trisomic chromosomes (Rustchenko-Bulgac et al 1990;Rustchenko-Bulgac 1991;Barton and Gull 1992;Perepnikhatka et al 1999;Chibana et al 2000;Chen et al 2004). In one example, the presence of an extra isochromosome composed of the two left arms of Chromosome 5 mediates fluconazole resistance in a subset of clinical strains (Selmecki et al , 2008.…”

mentioning

confidence: 99%

Genetic and phenotypic intra-species variation in Candida albicans

et al. 2014

View full text Add to dashboard Cite

Candida albicans is a commensal fungus of the human gastrointestinal tract and a prevalent opportunistic pathogen. To examine diversity within this species, extensive genomic and phenotypic analyses were performed on 21 clinical C. albicans isolates. Genomic variation was evident in the form of polymorphisms, copy number variations, chromosomal inversions, subtelomeric hypervariation, loss of heterozygosity (LOH), and whole or partial chromosome aneuploidies. All 21 strains were diploid, although karyotypic changes were present in eight of the 21 isolates, with multiple strains being trisomic for Chromosome 4 or Chromosome 7. Aneuploid strains exhibited a general fitness defect relative to euploid strains when grown under replete conditions. All strains were also heterozygous, yet multiple, distinct LOH tracts were present in each isolate. Higher overall levels of genome heterozygosity correlated with faster growth rates, consistent with increased overall fitness. Genes with the highest rates of amino acid substitutions included many cell wall proteins, implicating fast evolving changes in cell adhesion and host interactions. One clinical isolate, P94015, presented several striking properties including a novel cellular phenotype, an inability to filament, drug resistance, and decreased virulence. Several of these properties were shown to be due to a homozygous nonsense mutation in the EFG1 gene. Furthermore, loss of EFG1 function resulted in increased fitness of P94015 in a commensal model of infection. Our analysis therefore reveals intra-species genetic and phenotypic differences in C. albicans and delineates a natural mutation that alters the balance between commensalism and pathogenicity.

show abstract

“…In particular, these species lack orthologs of HP1 and the methyltransferase specific for H3K9, although deacetylases are retained. Thus, Candida species could have a distinct type of centromere, which could impact the fidelity of chromosome segregation and contribute to the high rates of chromosome loss and aneuploidy observed in response to stress (27)(28)(29)(30)(31).…”

mentioning

confidence: 99%

Regional centromeres in the yeast Candida lusitaniae lack pericentromeric heterochromatin

Kapoor

Zhu

Froyd

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Point centromeres are specified by a short consensus sequence that seeds kinetochore formation, whereas regional centromeres lack a conserved sequence and instead are epigenetically inherited. Regional centromeres are generally flanked by heterochromatin that ensures high levels of cohesin and promotes faithful chromosome segregation. However, it is not known whether regional centromeres require pericentromeric heterochromatin. In the yeast Candida lusitaniae, we identified a distinct type of regional centromere that lacks pericentromeric heterochromatin. Centromere locations were determined by ChIP-sequencing of two key centromere proteins, Cse4 and Mif2, and are consistent with bioinformatic predictions. The centromeric DNA sequence was unique for each chromosome and spanned 4-4.5 kbp, consistent with regional epigenetically inherited centromeres. However, unlike other regional centromeres, there was no evidence of pericentromeric heterochromatin in C. lusitaniae. In particular, flanking genes were expressed at a similar level to the rest of the genome, and a URA3 reporter inserted adjacent to a centromere was not repressed. In addition, regions flanking the centromeric core were not associated with hypoacetylated histones or a sirtuin deacetylase that generates heterochromatin in other yeast. Interestingly, the centromeric chromatin had a distinct pattern of histone modifications, being enriched for methylated H3K79 and H3R2 but lacking methylation of H3K4, which is found at other regional centromeres. Thus, not all regional centromeres require flanking heterochromatin.centromere | heterochromatin | Candida | CSE4 | Sir2

show abstract

Isolation, characterization, and genetic analysis of monosomic, aneuploid mutants of Candida albicans

Cited by 29 publications

References 29 publications

Fine-Resolution Physical Mapping of Genomic Diversity in Candida albicans

Fine-Resolution Physical Mapping of Genomic Diversity in Candida albicans

Genetic and phenotypic intra-species variation in Candida albicans

Regional centromeres in the yeast Candida lusitaniae lack pericentromeric heterochromatin

Contact Info

Product

Resources

About