Ad Hoc Seminar - John Weir, Friedrich Miescher Laboratory, Germany John Weir is at the Friedrich Miescher Laboratory, Max-Planck, Tübingen, Germany, where his lab investigate the structural biochemistry of meiosis.The seminar is open to all.Breaks and Crosses: Insights into the molecular mechanisms of meiotic recombinationAbstractMeiotic recombination begins with hundreds of programmed DNA double-strand breaks and ends with a few crossovers that link homologous chromosomes. Both steps depend on transient protein assemblies that are hard to capture in cells. We have begun to understand some these protein complexes using biochemical reconstitution, hybrid structural biology and biophysics. I will first describe how the mammalian meiotic chromosome axis is built on cohesin complexes, and how the axis engages with the SPO11 associated machinery. I will then turn to crossover formation. I will show how RPA maintains the processivity of the ZMM helicase Mer3/HFM1 to ensure normal crossover levels, and how Mer3 engages Rad52 decamers during second-end capture to regulate DNA repair outcome and how, ultimately, the ZMM proteins may associate with the axis. Nov 26 2026 3:00pm - 4:00pm Ad Hoc Seminar - John Weir, Friedrich Miescher Laboratory, Germany Breaks and Crosses: Insights into the molecular mechanisms of meiotic recombination. Room 7.20 Michael Swann Building, King's Buildings This article was published on Friday 6 November 2026
Ad Hoc Seminar - John Weir, Friedrich Miescher Laboratory, Germany John Weir is at the Friedrich Miescher Laboratory, Max-Planck, Tübingen, Germany, where his lab investigate the structural biochemistry of meiosis.The seminar is open to all.Breaks and Crosses: Insights into the molecular mechanisms of meiotic recombinationAbstractMeiotic recombination begins with hundreds of programmed DNA double-strand breaks and ends with a few crossovers that link homologous chromosomes. Both steps depend on transient protein assemblies that are hard to capture in cells. We have begun to understand some these protein complexes using biochemical reconstitution, hybrid structural biology and biophysics. I will first describe how the mammalian meiotic chromosome axis is built on cohesin complexes, and how the axis engages with the SPO11 associated machinery. I will then turn to crossover formation. I will show how RPA maintains the processivity of the ZMM helicase Mer3/HFM1 to ensure normal crossover levels, and how Mer3 engages Rad52 decamers during second-end capture to regulate DNA repair outcome and how, ultimately, the ZMM proteins may associate with the axis. Nov 26 2026 3:00pm - 4:00pm Ad Hoc Seminar - John Weir, Friedrich Miescher Laboratory, Germany Breaks and Crosses: Insights into the molecular mechanisms of meiotic recombination. Room 7.20 Michael Swann Building, King's Buildings This article was published on Friday 6 November 2026
Nov 26 2026 3:00pm - 4:00pm Ad Hoc Seminar - John Weir, Friedrich Miescher Laboratory, Germany Breaks and Crosses: Insights into the molecular mechanisms of meiotic recombination.
