title: RAD51B plays an essential role during somatic and meiotic recombination in Physcomitrella.
abstract: The eukaryotic RecA homologue Rad51 is a key factor in homologous recombination and recombinational repair. Rad51-like proteins have been identified in yeast (Rad55, Rad57 and Dmc1), plants and vertebrates (RAD51B, RAD51C, RAD51D, XRCC2, XRCC3 and DMC1). RAD51 and DMC1 are the strand-exchange proteins forming a nucleofilament for strand invasion, however, the function of the paralogues in the process of homologous recombination is less clear. In yeast the two Rad51 paralogues, Rad55 and Rad57, have been shown to be involved in somatic and meiotic HR and they are essential to the formation of the Rad51/DNA nucleofilament counterbalancing the anti-recombinase activity of the SRS2 helicase. Here, we examined the role of RAD51B in the model bryophyte Physcomitrella patens. Mutant analysis shows that RAD51B is essential for the maintenance of genome integrity, for resistance to DNA damaging agents and for gene targeting. Furthermore, we set up methods to investigate meiosis in Physcomitrella and we demonstrate that the RAD51B protein is essential for meiotic homologous recombination. Finally, we show that all these functions are independent of the SRS2 anti-recombinase protein, which is in striking contrast to what is found in budding yeast where the RAD51 paralogues are fully dependent on the SRS2 anti-recombinase function.
authors.affiliation: INRA, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Charlot
authors.affiliation: INRA, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France.
authors.forename: Liudmila
authors.initials: L
authors.lastname: Chelysheva
authors.affiliation: Centre for Plant Sciences, Faculty of Biological Sciences, Leeds University, Leeds LS2 9JT, UK.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Kamisugi
authors.affiliation: INRA, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Vrielynck
authors.affiliation: INRA, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France.
authors.forename: Anouchka
authors.initials: A
authors.lastname: Guyon
authors.affiliation: INRA, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France.
authors.forename: Aline
authors.initials: A
authors.lastname: Epert
authors.affiliation: INRA, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Le Guin
authors.affiliation: Laboratoire de Biologie Moleculaire et Cellulaire, Institut de Biologie, Universite de Neuchatel, rue Emile-Argand 11, CH-2007 Neuchatel, Switzerland.
authors.forename: Didier G
authors.initials: DG
authors.lastname: Schaefer
authors.affiliation: Centre for Plant Sciences, Faculty of Biological Sciences, Leeds University, Leeds LS2 9JT, UK.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Cuming
authors.affiliation: INRA, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Grelon
authors.affiliation: INRA, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France AgroParisTech, Institut Jean-Pierre Bourgin UMR1318, Saclay Plant Sciences, Versailles, France fabien.nogue@versailles.inra.fr.
authors.forename: Fabien
authors.initials: F
authors.lastname: Nogué
mesh_terms: D019068:Bryopsida / Q000033:anatomy & histology / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics / Q000502:physiology; D017353:Gene Deletion; D059765:Homologous Recombination; D008540:Meiosis / Q000235:genetics*; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D051135:Rad51 Recombinase / Q000235:genetics / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D051135:Rad51 Recombinase; D004265:DNA Helicases