title: Formation of interference-sensitive meiotic cross-overs requires sufficient DNA leading-strand elongation.
abstract: Meiosis halves diploid genomes to haploid and is essential for sexual reproduction in eukaryotes. Meiotic recombination ensures physical association of homologs and their subsequent accurate segregation and results in the redistribution of genetic variations among progeny. Most organisms have two classes of cross-overs (COs): interference-sensitive (type I) and -insensitive (type II) COs. DNA synthesis is essential for meiotic recombination, but whether DNA synthesis has a role in differentiating meiotic CO pathways is unknown. Here, we show that Arabidopsis POL2A, the homolog of the yeast DNA polymerase-ε (a leading-strand DNA polymerase), is required for plant fertility and meiosis. Mutations in POL2A cause reduced fertility and meiotic defects, including abnormal chromosome association, improper chromosome segregation, and fragmentation. Observation of prophase I cell distribution suggests that pol2a mutants likely delay progression of meiotic recombination. In addition, the residual COs in pol2a have reduced CO interference, and the double mutant of pol2a with mus81, which affects type II COs, displayed more severe defects than either single mutant, indicating that POL2A functions in the type I pathway. We hypothesize that sufficient leading-strand DNA elongation promotes formation of some type I COs. Given that meiotic recombination and DNA synthesis are conserved in divergent eukaryotes, this study and our previous study suggest a novel role for DNA synthesis in the differentiation of meiotic recombination pathways.
authors.affiliation: State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plants Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200438, China;
authors.forename: Jiyue
authors.initials: J
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plants Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200438, China;
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plants Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200438, China;
authors.forename: Cong
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plants Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200438, China;
authors.forename: Yue
authors.initials: Y
authors.lastname: Hong
authors.affiliation: State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plants Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200438, China;
authors.forename: Hang
authors.initials: H
authors.lastname: Su
authors.affiliation: State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plants Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200438, China;
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Biology and the Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280; Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599-3280;
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Copenhaver
authors.affiliation: State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plants Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200438, China; Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China Hongma@fudan.edu.cn yx_wang@fudan.edu.cn.
authors.forename: Hong
authors.initials: H
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plants Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200438, China; Hongma@fudan.edu.cn yx_wang@fudan.edu.cn.
authors.forename: Yingxiang
authors.initials: Y
authors.lastname: Wang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D020090:Chromosome Segregation / Q000235:genetics; D032461:Chromosomes, Plant / Q000235:genetics; D003434:Crossing Over, Genetic / Q000235:genetics*; D004257:DNA Polymerase II / Q000235:genetics* / Q000378:metabolism; D018744:DNA, Plant / Q000235:genetics* / Q000378:metabolism; D005298:Fertility / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D008540:Meiosis / Q000235:genetics*; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D009154:Mutation; D030821:Plants, Genetically Modified; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D018744:DNA, Plant; D021122:Protein Subunits; C507136:POL2a protein, Arabidopsis; D004257:DNA Polymerase II
keywords: Arabidopsis; DNA polymerase-ε; DNA synthesis; meiotic recombination