How do small chromosomes know they are small? Maximizing meiotic break formation on the shortest yeast chromosomes Review

Authors: Murakami, H.; Mu, X.; Keeney, S.
Review Title: How do small chromosomes know they are small? Maximizing meiotic break formation on the shortest yeast chromosomes
Abstract: The programmed formation of DNA double-strand breaks (DSBs) in meiotic prophase I initiates the homologous recombination process that yields crossovers between homologous chromosomes, a prerequisite to accurately segregating chromosomes during meiosis I (MI). In the budding yeast Saccharomyces cerevisiae, proteins required for meiotic DSB formation (DSB proteins) accumulate to higher levels specifically on short chromosomes to ensure that these chromosomes make DSBs. We previously demonstrated that as-yet undefined cis-acting elements preferentially recruit DSB proteins and promote higher levels of DSBs and recombination and that these intrinsic features are subject to selection pressure to maintain the hyperrecombinogenic properties of short chromosomes. Thus, this targeted boosting of DSB protein binding may be an evolutionarily recurrent strategy to mitigate the risk of meiotic mis-segregation caused by karyotypic constraints. However, the underlining mechanisms are still elusive. Here, we discuss possible scenarios in which components of the meiotic chromosome axis (Red1 and Hop1) bind to intrinsic features independent of the meiosis-specific cohesin subunit Rec8 and DNA replication, promoting preferential binding of DSB proteins to short chromosomes. We also propose a model where chromosome position in the nucleus, influenced by centromeres, promotes the short-chromosome boost of DSB proteins. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.
Keywords: chromosome structure; meiosis; dna double-strand breaks; chromosome segregation; recombination; chromosome evolution
Journal Title: Current Genetics
Volume: 67
Issue: 3
ISSN: 0172-8083
Publisher: Springer  
Date Published: 2021-06-01
Start Page: 431
End Page: 437
Language: English
DOI: 10.1007/s00294-021-01160-9
PUBMED: 33604699
PROVIDER: scopus
PMCID: PMC8141002
Notes: Review -- Export Date: 1 July 2021 -- Source: Scopus
Citation Impact
MSK Authors
  1. Scott N Keeney
    120 Keeney
  2. Xiaojing Mu
    3 Mu