Open AccessMnd1/Hop2 Facilitates Dmc1-Dependent Interhomolog Crossover Formation in Meiosis of Budding Yeast
Author(s) -
Jill M. Henry,
Raymond Camahort,
Douglas Rice,
Laurence Florens,
Selene K. Swanson,
Michael P. Washburn,
Jennifer L. Gerton
Publication year - 2006
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.26.8.2913-2923.2006
Subject(s) - rad51 , homologous recombination , biology , genetic recombination , ectopic recombination , genetics , flp frt recombination , meiosis , site specific recombination , chromosomal crossover , mitotic crossover , saccharomyces cerevisiae , recombination , heteroduplex , mutant , dna , recombinase , yeast , gene
During meiosis, each chromosome must pair with its homolog and undergo meiotic crossover recombination in order to segregate properly at the first meiotic division. Recombination in meiosis inSaccharomyces cerevisiae relies on twoEscherichia coli recA homologs, Rad51 and Dmc1, as well as the more recently discovered heterodimer Mnd1/Hop2. Meiotic recombination inS. cerevisiae mnd1 andhop2 single mutants is initiated via double-strand breaks (DSBs) but does not progress beyond this stage; heteroduplex DNA, joint molecules, and crossovers are not detected. Whereashop2 andmnd1 single mutants are profoundly recombination defective, we show thatmnd1 rad51 ,hop2 rad51 , andmnd1 rad17 double mutants are able to carry out crossover recombination. Interestingly, noncrossover recombination is absent, indicating a role for Mnd1/Hop2 in the designation of DSBs for noncrossover recombination. We demonstrate that in therad51 mnd1 double mutant, recombination is more likely to occur between repetitive sequences on nonhomologous chromosomes. Our results support a model in which Mnd1/Hop2 is required for DNA-DNA interactions that help ensure Dmc1-mediated stable strand invasion between homologous chromosomes, thereby preserving genomic integrity.