Contrôle biochimique de la récombinaison chez Saccharomyces cerevisiae

Hénaut, Alain; Luzzati, Mario

doi:10.1007/bf00267788

Cited by 4 publications

(2 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been shown that exposure of the cells to sporulation medium for limited times increases recombination although the meiotic division is not induced (24,25). Henaut and Luzzati (4) have also reported that the recombination ability of ade3 mutants is enhanced by starvation for histidine. In all these cases, the increased production of recombinants could be due to the derepression of factor(s) necessary for recombination.…”

Section: Resultsmentioning

confidence: 95%

“…A population of vegetative Saccharomyces cerevtsiae diploid cells is heterogeneous with respect to genetic recombinational ability, as can be seen from the relatively high coincidence of recombination at unlinked loci (1)(2)(3)(4). A possible interpretation of this heterogeneity is that some factor necessary for recombination is repressed in all but a small fraction of the cells.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Genetic evidence for inducibility of recombination competence in yeast.

Fabre¹,

Roman²

1977

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

View full text Add to dashboard Cite

Recombination between unirradiated chromosomes was induced by UV or x-ray irradiation of haploids followed by a mating with heteroallelic diploids of Saccharomyces cerevisiae. The selected event of intragenic recombination did not involve the participation of the irradiated chromosome and apparently was not caused by lesions introduced into the unirradiated chromosomes by some indirect process. The results favor the idea that recombination is repressed in the majority of vegetative cells and that one effect of radiation is the release of some factor(s) necessary for recombination. Consequently, the proportion of competent cells (i.e., cells able to recombine) in the population increases. This competent state seems necessary not only for the recombinational repair of radiation-induced lesions but also, since recombinants are produced in the absence of such lesions, for spontaneous recomlitnation. Photoreactivation of the UV-irradiated haploids led to a decrease in the production of recombinants. Hence, lesions in the DNA appear to be responsible for the induction of the recombinational ability.A population of vegetative Saccharomyces cerevtsiae diploid cells is heterogeneous with respect to genetic recombinational ability, as can be seen from the relatively high coincidence of recombination at unlinked loci (1-4). A possible interpretation of this heterogeneity is that some factor necessary for recombination is repressed in all but a small fraction of the cells. UV and ionizing radiations enhance the production of recombinants in heteroallelic diploids. Holliday (5-7) has suggested that these radiations derepress some recombination processes. One can therefore speculate that there are two effects which lead to the production of recombinants: one enlarges the pool of cells able to recombine, and the other introduces in the chromosomes prerecombinational lesions that promote recombination in the competent cells. A distinction between these effects is not possible when recombination is induced by irradiation of diploid cells or by irradiation of one of the two parental haploids that are mated to produce diploids (8, 9). In both cases, lesions are induced in the chromosomes, and their effects on recombination are inseparable from other hypothetical factors that lead to an increase in the size of the cell pool in which recombination can occur.In an attempt to separate these two effects, we sought to induce recombination in yeast without inducing lesions in the chromosomes that recombine. Haploids were irradiated with UV light or x-rays and then mated with heteroallelic diploids. The selected events of recombination are limited in the unirradiated chromosomes of the zygotes by the genetic constitution of the strains. An induction of recombinants was indeed observed and can be explained by an increase in the proportion of competent cells-i.e., cells capable of undergoing recombination.MATERIALS AND METHODS Strains. The strains described in the text were derived from the ade6 mutants isolated by Jones (10). Diplo...

show abstract

Section: Resultsmentioning

confidence: 95%

mentioning

confidence: 99%