title: Pch2 modulates chromatid partner choice during meiotic double-strand break repair in Saccharomyces cerevisiae.
abstract: In most organisms, the segregation of chromosomes during the first meiotic division is dependent upon at least one crossover (CO) between each pair of homologous chromosomes. COs can result from chromosome double-strand breaks (DSBs) that are induced and preferentially repaired using the homologous chromosome as a template. The PCH2 gene of budding yeast is required to establish proper meiotic chromosome axis structure and to regulate meiotic interhomolog DSB repair outcomes. These roles appear conserved in the mouse ortholog of PCH2, Trip13, which is also involved in meiotic chromosome axis organization and the regulation of DSB repair. Using a combination of genetic and physical assays to monitor meiotic DSB repair, we present data consistent with pch2Δ mutants showing defects in suppressing intersister DSB repair. These defects appear most pronounced in dmc1Δ mutants, which are defective for interhomolog repair, and explain the previously reported observation that pch2Δ dmc1Δ cells can complete meiosis. Results from genetic epistasis analyses involving spo13Δ, rad54Δ, and mek1/MEK1 alleles and an intersister recombination reporter assay are also consistent with Pch2 acting to limit intersister repair. We propose a model in which Pch2 is required to promote full Mek1 activity and thereby promotes interhomolog repair.
authors.affiliation: Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853-2073, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Zanders
authors.forename: Megan
authors.initials: M
authors.lastname: Sonntag Brown
authors.forename: Cheng
authors.initials: C
authors.lastname: Chen
authors.forename: Eric
authors.initials: E
authors.lastname: Alani
mesh_terms: D000818:Animals; D015139:Blotting, Southern; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002842:Chromatids / Q000378:metabolism*; D003434:Crossing Over, Genetic; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D017353:Gene Deletion; D048369:MAP Kinase Kinase 1 / Q000235:genetics / Q000378:metabolism*; D008540:Meiosis; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D017385:Sequence Homology; D015398:Signal Transduction; D013573:Synaptonemal Complex / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; C528119:Pch2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D048369:MAP Kinase Kinase 1