Email updates

Keep up to date with the latest news and content from Genome Biology and BioMed Central.

Open Access Research

Genome-wide survey of post-meiotic segregation during yeast recombination

Eugenio Mancera1, Richard Bourgon23, Wolfgang Huber1 and Lars M Steinmetz1*

  • * Corresponding author: Lars M Steinmetz larsms@embl.de

  • † Equal contributors

Author affiliations

1 European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany

2 European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge CB10 1SD, UK

3 Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080-4990, USA

For all author emails, please log on.

Citation and License

Genome Biology 2011, 12:R36  doi:10.1186/gb-2011-12-4-r36

Published: 11 April 2011

Abstract

Background

When mismatches in heteroduplex DNA formed during meiotic recombination are left unrepaired, post-meiotic segregation of the two mismatched alleles occurs during the ensuing round of mitosis. This gives rise to somatic mosaicism in multicellular organisms and leads to unexpected allelic combinations among progeny. Despite its implications for inheritance, post-meiotic segregation has been studied at only a few loci.

Results

By genotyping tens of thousands of genetic markers in yeast segregants and their clonal progeny, we analyzed post-meiotic segregation at a genome-wide scale. We show that post-meiotic segregation occurs in close to 10% of recombination events. Although the overall number of markers affected in a single meiosis is small, the rate of post-meiotic segregation is more than five orders of magnitude larger than the base substitution mutation rate. Post-meiotic segregation took place with equal relative frequency in crossovers and non-crossovers, and usually at the edges of gene conversion tracts. Furthermore, post-meiotic segregation tended to occur in markers that are isolated from other heterozygosities and preferentially at polymorphism types that are relatively uncommon in the yeast species.

Conclusions

Overall, our survey reveals the genome-wide characteristics of post-meiotic segregation. The results show that post-meiotic segregation is widespread in meiotic recombination and could be a significant determinant of allelic inheritance and allele frequencies at the population level.