title: The cyclin-A CYCA1;2/TAM is required for the meiosis I to meiosis II transition and cooperates with OSD1 for the prophase to first meiotic division transition.
abstract: Meiosis halves the chromosome number because its two divisions follow a single round of DNA replication. This process involves two cell transitions, the transition from prophase to the first meiotic division (meiosis I) and the unique meiosis I to meiosis II transition. We show here that the A-type cyclin CYCA1;2/TAM plays a major role in both transitions in Arabidopsis. A series of tam mutants failed to enter meiosis II and thus produced diploid spores and functional diploid gametes. These diploid gametes had a recombined genotype produced through the single meiosis I division. In addition, by combining the tam-2 mutation with AtSpo11-1 and Atrec8, we obtained plants producing diploid gametes through a mitotic-like division that were genetically identical to their parents. Thus tam alleles displayed phenotypes very similar to that of the previously described osd1 mutant. Combining tam and osd1 mutations leads to a failure in the prophase to meiosis I transition during male meiosis and to the production of tetraploid spores and gametes. This suggests that TAM and OSD1 are involved in the control of both meiotic transitions.
authors.affiliation: Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, Versailles, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: d'Erfurth
authors.forename: Laurence
authors.initials: L
authors.lastname: Cromer
authors.forename: Sylvie
authors.initials: S
authors.lastname: Jolivet
authors.forename: Chloé
authors.initials: C
authors.lastname: Girard
authors.forename: Christine
authors.initials: C
authors.lastname: Horlow
authors.forename: Yujin
authors.initials: Y
authors.lastname: Sun
authors.forename: Jennifer P C
authors.initials: JP
authors.lastname: To
authors.forename: Luke E
authors.initials: LE
authors.lastname: Berchowitz
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Copenhaver
authors.forename: Raphael
authors.initials: R
authors.lastname: Mercier
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D020090:Chromosome Segregation; D056750:Cyclin A1 / Q000235:genetics / Q000378:metabolism*; D004171:Diploidy; D018506:Gene Expression Regulation, Plant; D008540:Meiosis; D009154:Mutation; D011058:Pollen / Q000166:cytology / Q000235:genetics; D011418:Prophase
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D056750:Cyclin A1; C577069:OSD1 protein, Arabidopsis