Dataset Information


Impaired resection of meiotic double-strand breaks channels repair to nonhomologous end joining in Caenorhabditis elegans.

ABSTRACT: Repair of double-strand DNA breaks (DSBs) by the homologous recombination (HR) pathway results in crossovers (COs) required for a successful first meiotic division. Mre11 is one member of the MRX/N (Mre11, Rad50, and Xrs2/Nbs1) complex required for meiotic DSB formation and for resection in Saccharomyces cerevisiae. In Caenorhabditis elegans, evidence for the MRX/N role in DSB resection is limited. We report the first separation-of-function allele, mre-11(iow1) in C. elegans, which is specifically defective in meiotic DSB resection but not in formation. The mre-11(iow1) mutants displayed chromosomal fragmentation and aggregation in late prophase I. Recombination intermediates and crossover formation was greatly reduced in mre-11(iow1) mutants. Irradiation-induced DSBs during meiosis failed to be repaired from early to middle prophase I in mre-11(iow1) mutants. In the absence of a functional HR, our data suggest that some DSBs in mre-11(iow1) mutants are repaired by the nonhomologous end joining (NHEJ) pathway, as removing NHEJ partially suppressed the meiotic defects shown by mre-11(iow1). In the absence of NHEJ and a functional MRX/N, meiotic DSBs are channeled to EXO-1-dependent HR repair. Overall, our analysis supports a role for MRE-11 in the resection of DSBs in middle meiotic prophase I and in blocking NHEJ.


PROVIDER: S-EPMC3700128 | BioStudies | 2013-01-01T00:00:00Z

REPOSITORIES: biostudies

Similar Datasets

2018-01-01 | S-EPMC5948970 | BioStudies
2019-01-01 | S-EPMC6827578 | BioStudies
2013-01-01 | S-EPMC3567172 | BioStudies
| S-EPMC3561951 | BioStudies
2008-01-01 | S-EPMC2515202 | BioStudies
2011-01-01 | S-EPMC3064790 | BioStudies
2013-01-01 | S-EPMC3610664 | BioStudies
1000-01-01 | S-EPMC1069622 | BioStudies
2020-01-01 | S-EPMC7308329 | BioStudies
2011-01-01 | S-EPMC3177864 | BioStudies