Meiotic Recombination Initiation in and around Retrotransposable Elements in Saccharomyces cerevisiae Journal Article

   

Authors:	Sasaki, M.; Tischfield, S. E.; Van Overbeek, M.; Keeney, S.
Article Title:	Meiotic Recombination Initiation in and around Retrotransposable Elements in Saccharomyces cerevisiae
Abstract:	Meiotic recombination is initiated by large numbers of developmentally programmed DNA double-strand breaks (DSBs), ranging from dozens to hundreds per cell depending on the organism. DSBs formed in single-copy sequences provoke recombination between allelic positions on homologous chromosomes, but DSBs can also form in and near repetitive elements such as retrotransposons. When they do, they create a risk for deleterious genome rearrangements in the germ line via recombination between non-allelic repeats. A prior study in budding yeast demonstrated that insertion of a Ty retrotransposon into a DSB hotspot can suppress meiotic break formation, but properties of Ty elements in their most common physiological contexts have not been addressed. Here we compile a comprehensive, high resolution map of all Ty elements in the rapidly and efficiently sporulating S. cerevisiae strain SK1 and examine DSB formation in and near these endogenous retrotransposable elements. SK1 has 30 Tys, all but one distinct from the 50 Tys in S288C, the source strain for the yeast reference genome. From whole-genome DSB maps and direct molecular assays, we find that DSB levels and chromatin structure within and near Tys vary widely between different elements and that local DSB suppression is not a universal feature of Ty presence. Surprisingly, deletion of two Ty elements weakened adjacent DSB hotspots, revealing that at least some Ty insertions promote rather than suppress nearby DSB formation. Given high strain-to-strain variability in Ty location and the high aggregate burden of Ty-proximal DSBs, we propose that meiotic recombination is an important component of host-Ty interactions and that Tys play critical roles in genome instability and evolution in both inbred and outcrossed sexual cycles. © 2013 Sasaki et al.
Journal Title:	PLoS Genetics
Volume:	9
Issue:	8
ISSN:	1553-7390
Publisher:	Public Library of Science
Date Published:	2013-08-01
Start Page:	e1003732
Language:	English
DOI:	10.1371/journal.pgen.1003732
PROVIDER:	scopus
PMCID:	PMC3757047
PUBMED:	24009525
DOI/URL:	http://www.scopus.com/inward/record.url?eid=2-s2.0-84883427789&partnerID=40&md5=2cb29ec6fa8cac73b3ed82f9e43acd5e
Notes:	--- - "Export Date: 1 October 2013" - "Source: Scopus"

https://synapse.mskcc.org/synapse/works/has_related_data_chk/46133