Meiotic recombination frequencies are affected by nutritional states in Saccharomyces cerevisiae

Abstract

Meiotic recombination in the yeast Saccharomyces cerevisiae is initiated by programmed double-strand breaks at selected sites throughout the genome (hotspots). ␣-Hotspots are binding sites for transcription factors. Double-strand breaks at ␣-hotspots require binding of transcription factor but not high levels of transcription per se. We show that modulating the production of the transcription factor Gcn4p by deletion or constitutive transcription alters the rate of gene conversion and crossing-over at HIS4. In addition, we show that alterations in the metabolic state of the cell change the frequency of gene conversion at HIS4 in a Gcn4p-dependent manner. We suggest that recombination data obtained from experiments using amino acid and other biosynthetic genes for gene disruptions and͞or as genetic markers should be treated cautiously. The demonstration that Gcn4p affects transcription of more than 500 genes and that the recombinationally ''hottest'' ORFs tend to be Gcn4p-regulated suggest that the metabolic state of a cell, especially with respect to nitrogen metabolism, is a determinant of recombination rates. This observation suggests that the effects of metabolic state may be global and may account for some as yet unexplained features of recombination in higher organisms, such as the differences in map length between the sexes.

The Role of Advantageous Mutations in Enhancing the Evolution of a Recombination Modifier

“…Furthermore, if background deleterious mutations are frequent, recombination has an extra advantage in aiding purifying selection and is even more likely to evolve than in the presence of beneficial mutations alone. Such a scenario was discussed by Hadany and Feldman (2005) and could explain why recombination is more likely to occur in new, stressed environments (Abdullah and Borts 2001;Grishkan et al 2003).…”

Exploiting Spore-Autonomous Fluorescent Protein Expression to Quantify Meiotic Chromosome Behaviors in Saccharomyces cerevisiae

“…The system is potentially amenable to automated scoring, which would further increase throughput. Removing tetrad dissection and subsequent scoring as rate-limiting steps opens the door to rapidly interrogating strains under a wide variety of environmental conditions, which is of interest given that temperature and other factors are known to affect meiotic chromosome dynamics in wild-type and certain mutants (Abdullah and Borts 2001;Börner et al 2004;Chan et al 2009;Cotton et al 2009). …”

The histone methylase Set2p and the histone deacetylase Rpd3p repress meiotic recombination at the HIS4 meiotic recombination hotspot in Saccharomyces cerevisiae

“…As described in the Introduction, many mutations that reduce HIS4 transcription (deletion of transcription factors or their binding sites upstream of HIS4) also reduce HIS4 meiotic recombination (11,(18)(19)(20)47). White et al (60) showed, however, that deletion of the TATAA sequence upstream of HIS4 significantly decreased HIS4 expression, but had no effect on meiotic recombination.…”

“…In cells sporulated at 25°, this DSB is responsible for initiating about half of HIS4 conversion events (16). The binding of four transcription factors (Bas1p, Bas2p, Rap1p, and Gcn4p) is required for optimal levels of this DSB (16,(18)(19)(20). One role of these transcription factors is presumably to recruit chromatin-modifying complexes to the HIS4 promoter.…”

“…Although we cannot rule out an indirect effect of hda1 on recombination, HIS4 gene expression is elevated about three-fold by the hda1 mutation in one study (30), although no effect on expression was found in another study (29). NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptAs described in the Introduction, many mutations that reduce HIS4 transcription (deletion of transcription factors or their binding sites upstream of HIS4) also reduce HIS4 meiotic recombination (11,(18)(19)(20)47). White et al (60) showed, however, that deletion of the TATAA sequence upstream of HIS4 significantly decreased HIS4 expression, but had no effect on meiotic recombination.…”