Project description:Yeast Saccharomyces cerevisiae has been widely used as a model system for studying physiological and pharmacological action of small-molecular drugs. Here, a heterozygous diploid S. cerevisiae strain QSS4 was generated to determine whether drugs could induce chromosomal instability by determining the frequency of mitotic recombination. In combination of a custom SNP microarray, the patterns of chromosomal instability induced by drugs could also be explored at a whole genome level in QSS4. Using this system, we found Zeocin (a member of bleomycin family) treatment resulted in hundreds-fold higher rate of genomic alterations, including aneuploidy, loss of heterozygosity (LOH), and chromosomal rearrangement.
Project description:Carbendazim (Methyl benzimidazol-2-ylcarbamate; MBC) is an antimitotic drug used for broad-spectrum fungicide, antineoplastic and mutagen in microbial breeding. Using a customized SNP microarray technology, this work revealed the effect of MBC on genomic instability (loss of heterozygosity, chromosomal rearrangements and aneuploidy) in the diploid yeast Saccharomyces cerevisiae JSC25.
Project description:Yeast Saccharomyces cerevisiae has been widely used as a model system for studying genomic instability. In this study, heat-shock-induced genomic alterations were explored in the heterozygous diploid yeast strain JSC25-1. In combination of the whole-genome microarray, the patterns of chromosomal instability induced by heat shock could also be explored at a whole genome level. Using this system, we found heat-shock treatment resulted in hundreds-fold higher rate of genomic alterations, including aneuploidy and loss of heterozygosity (LOH).
Project description:Furfural is a potential mutagenic agent. To explore the global effect of furfural on genomic intergrity, chromosomal alterations in 14 furfural-treated isolates of JSC25-1 strain were determined by whole genome SNP microarrays at a resolution about 1kb. Our results showed furfural exposure results in striking elevations of both mitotic recombination and aneuploidy events in yeast.
Project description:DNA replication stress (DRS)-linked genomic instability has emerged as an important factor driving cancer development. To understand the mechanisms of DRS-associated genomic instability and phenotypic evolution, we mapped chromosomal alterations in a yeast strain with lowered expression of the replicative DNA polymerase δ. At a whole-genome level, we identified both hotspots of mitotic recombination and chromosome-specific aneuploidy dependent on decreased levels of DNA polymerase δ. The high rate of chromosome loss is likely a reflection of reduced DNA repair capacity in strains with low levels of DNA polymerase. Most recombinogenic DNA lesions were introduced during S or G2 phase, presumably as a consequence of broken replication forks.
Project description:We developed an artificial genome evolution system, which we termed ‘TAQing’, by introducing multiple genomic DNA double-strand breaks using a heat-activatable endonuclease in mitotic yeast. The heat-activated endonuclease, TaqI, induced random DSBs, which resulted in diverse types of chromosomal rearrangements including translocations. Array comparative genomic hybridization (aCGH) analysis was performed with cell-fused Saccharomyces cerevisiae strains induced genome evolution by TAQing system. Some of copy number variations (CNVs) induced by massive genome rearrangements were detected in the TAQed yeast strains.