On the mechanism of UV and γ-ray-induced intrachromosomal recombination in yeast cells synchronized in different stages of the cell cycle

Galli, Alvaro; Schiestl, Robert H.

doi:10.1007/bf02191597

Cited by 58 publications

(39 citation statements)

References 32 publications

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“…The arrangement of direct repeats theoretically allows three types of recombination events generating a functional reporter gene from the recombination construct (Figure 3; Schiestl et al, 1988;Bolag et al, 1989;Haber, 1992;Belmaaza and Chartrand, 1994;Lichtenstein et al, 1994;Galli and Schiestl, 1995;Klein, 1995;Pâ ques and Haber, 1999). Two types of recombination events that can generate recombination sectors are unequal reciprocal recombination and gene conversion between sister chromatids or homologous chromosomes.…”

Section: Recombination Events Resulting From Homologous Interactions mentioning

confidence: 99%

Interchromatid and Interhomolog Recombination in Arabidopsis thaliana

Ries²,

et al. 2004

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Intermolecular recombination events were monitored in Arabidopsis thaliana lines using specially designed recombination traps consisting of tandem disrupted b-glucuronidase or luciferase reporter genes in direct repeat orientation. Recombination frequencies (RFs) varied between the different lines, indicating possible position effects influencing intermolecular recombination processes. The RFs between sister chromatids and between homologous chromosomes were measured in plants either hemizygous or homozygous for a transgene locus. The RFs in homozygous plants exceeded those of hemizygous plants by a factor of >2, implying that in somatic plant cells both sister chromatid recombination and recombination between homologous chromosomes exist for recombinational DNA repair. In addition, different DNA-damaging agents stimulated recombination in homozygous and hemizygous plants to different extents in a manner dependent on the type of DNA damage and on the genomic region. The genetic and molecular analysis of recombination events showed that most of the somatic recombination events result from gene conversion, although a pop-out event has also been characterized.

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Section: Recombination Events Resulting From Homologous Interactions mentioning

confidence: 99%

Interchromatid and Interhomolog Recombination in Arabidopsis thaliana

Ries²,

et al. 2004

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“…First, the rate of spontaneous translocations in rad9 mutants is approximately 10-or 1,000-fold less than the rates of spontaneous allelic or intrachromatid events (ICE) in RAD9 ϩ , respectively, and thus if the same number of recombinants are stimulated in these assays, enhanced allelic events or ICE may be too few to detect among background events. Second, ICE and allelic recombination assays detect recombination events that are not associated with exchange of flanking markers and occur predominately by deletion (21,52) and gene conversion (23), respectively, whereas translocations occur by recombination associated with exchange of flanking markers. Because mitotic gene conversion and reciprocal exchange can occur by independent pathways (29) and mutants may be hyper-Rec for one pathway but not the other (2), it may not be surprising that mutations in checkpoint genes may elevate particular types of mitotic recombination.…”

Section: Discussionmentioning

confidence: 99%

The Saccharomyces cerevisiae RAD9 Checkpoint Reduces the DNA Damage-Associated Stimulation of Directed Translocations

Fasullo

Bennett

AhChing

et al. 1998

Molecular and Cellular Biology

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Genetic instability in the Saccharomyces cerevisiae rad9 mutant correlates with failure to arrest the cell cycle in response to DNA damage. We quantitated the DNA damage-associated stimulation of directed translocations in RAD9؉ and rad9 mutants. Directed translocations were generated by selecting for His ؉ prototrophs that result from homologous, mitotic recombination between two truncated his3 genes, GAL1::his3-⌬5 and trp1::his3-⌬3::HOcs. Compared to RAD9 ؉ strains, the rad9 mutant exhibits a 5-fold higher rate of spontaneous, mitotic recombination and a greater than 10-fold increase in the number of UV-and X-ray-stimulated His ؉ recombinants that contain translocations. The higher level of recombination in rad9 mutants correlated with the appearance of nonreciprocal translocations and additional karyotypic changes, indicating that genomic instability also occurred among non-his3 sequences. Both enhanced spontaneous recombination and DNA damage-associated recombination are dependent on RAD1, a gene involved in DNA excision repair. The hyperrecombinational phenotype of the rad9 mutant was correlated with a deficiency in cell cycle arrest at the G 2 -M checkpoint by demonstrating that if rad9 mutants were arrested in G 2 before irradiation, the numbers both of UV-and ␥-ray-stimulated recombinants were reduced. The importance of G 2 arrest in DNA damageinduced sister chromatid exchange (SCE) was evident by a 10-fold reduction in HO endonuclease-induced SCE and no detectable X-ray stimulation of SCE in a rad9 mutant. We suggest that one mechanism by which the RAD9-mediated G 2 -M checkpoint may reduce the frequency of DNA damage-induced translocations is by channeling the repair of double-strand breaks into SCE.It has been postulated that DNA damage-induced cell cycle arrest at cell cycle checkpoints maintains genomic stability by allowing time for DNA repair prior to the replication or division of damaged chromatids (67, 68). Consistent with this idea, mutations in genes controlling cell cycle arrest at the G 1 -S checkpoint and G 2 -M checkpoint confer enhanced genetic instability. For example, p53 mutations, which confer deficiencies in the G 1 -S checkpoint, are correlated with enhanced spontaneous and UV-stimulated amplification of CAD genes (35, 73). Cells cultured from patients with ataxia telangiectasia that are deficient in cell cycle arrest at both the G 1 -S and G 2 -M cell cycle checkpoints (7, 49) also exhibit higher frequencies of chromosomal rearrangements, including translocations (37) and deletions (38), and chromosome end-to-end joining (41).In Saccharomyces cerevisiae, DNA-damaging agents stimulate mitotic, homologous recombination and induce cell cycle arrest at cell cycle checkpoints (31, 59). For example, DNA damage-associated recombination between his3 fragments positioned at predetermined loci can result in chromosomal rearrangements, including translocations (18, 19), duplications (16), and deletions (54). HO endonuclease-generated doublestrand breaks (DSBs) stimulate ectopic gene conversi...

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“…Intermediates in NER include nicks and short gaps, which have been proposed as initiators of recombination (see below) either directly or in relation to stalled replication forks. 8,26,27 The nicks and gaps created by NER could be recombinogenic with or without being processed to DSBs (Fig. 1B and C).…”

Section: Genetic Recombinationmentioning

confidence: 99%