RRC ID 76193
Author Hicks T, Trivedi S, Eppert M, Bowman R, Tian H, Dafalla A, Crahan C, Smolikove S, Silva N.
Title Continuous double-strand break induction and their differential processing sustain chiasma formation during Caenorhabditis elegans meiosis.
Journal Cell Rep
Abstract Faithful chromosome segregation into gametes depends on Spo11-induced DNA double-strand breaks (DSBs). These yield single-stranded 3' tails upon resection to promote crossovers (COs). While early Mre11-dependent end resection is the predominant pathway in most organisms, Exo1 or Dna2/BLM can also contribute to the efficient processing of meiotic DSBs. Although its enzymatic activity has been thoroughly dissected, the temporal dynamics underlying Spo11 activity have remained mostly elusive. We show that, in Caenorhabditis elegans, SPO-11-mediated DSB induction takes place throughout early meiotic prophase I until mid-late pachynema. We find that late DSBs are essential for CO formation and are preferentially processed by EXO-1 and DNA-2 in a redundant fashion. Further, EXO-1-DNA-2-mediated resection ensures completion of conservative DSB repair and discourages activation of KU-dependent end joining. Taken together, our data unveil important temporal aspects of DSB induction and identify previously unknown functional implications for EXO-1-DNA-2-mediated resection activity in C. elegans.
Volume 40(13)
Pages 111403
Published 2022-9-27
DOI 10.1016/j.celrep.2022.111403
PII S2211-1247(22)01240-2
PMID 36170820
MeSH Animals Caenorhabditis elegans* / genetics Caenorhabditis elegans* / metabolism Caenorhabditis elegans Proteins* / genetics Caenorhabditis elegans Proteins* / metabolism Chromosomes / metabolism DNA Breaks, Double-Stranded DNA Repair Meiosis
Resource
C.elegans