MFPL - 2014 RESEARCH GROUPS
FRANZ KLEIN
Chromosome structure and meiotic recombination We study meiotic recombination and chromosome segregation in S. cerevisiae as model organism to understand the interplay between chromosome structure and recombination.
Franz Klein TEAM
Celine Brunner Laura Cimatti Emilio Cusanelli Eric Höhenwarter Mamta Jain Konstantin Licht Maja Stulic Mansoureh Tajaddod
During meiosis, the genetic content of a diploid cell is reduced to half, a prerequisite for the production of gametes and for sexual reproduction. Our experience shows that the important processes are conserved between yeast and man, so that many of our findings can be generalized. Chromosomes are organized as dynamic structures with distinct micro-domains, such as axis and loop regions, as well as macro-domains, such as recombination rich – or poor regions, centromeres, telomeres and others. In meiosis, cohesins and axial element proteins shape the chromosome and
The machine for DSB formation (three colored balls symbolize three located components) was localized to the base of DNA loops (Panizza et al., Cell, 2011). In contrast, DSBs are made on chromosome loops (Blatt et al., Cell, 2002).
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mediate recombination as well as correct chromosome segregation. We have established a highresolution map of protein-chromosome interactions by microarray-analysis, which we currently improve using deep sequencing. We also study in detail the process of chromosome synapsis, a structure that mainly exists to fine-tune recombination pathways. Eventually, these pathways decide over the integrity of the resulting gamete’s genome, and thus over the health of the new individual that originates from these gametes.
Glimpse into the nano-world – section of a chromosome with “DNA-break machines“. Loops of sister chromatids (blue and turquoise) are linked and held in shape by ring-molecules. The machines are anchored between the DNA-loops at the axis of the chromosome. The model is illustrative, but postulates unknown details, such as the way the ring-molecules hold DNA-loops.
SELECTED PUBLICATIONS Xaver M, Huang L, Chen D, Klein F. Smc5/6-Mms21 prevents and eliminates inappropriate recombination intermediates in meiosis. PLoS Genet. 2013;9(12):e1004067. PMID: 24385936 Klug H, Xaver M, Chaugule VK, Koidl S, Mittler G, Klein F, Pichler A. Ubc9 sumoylation controls SUMO chain formation and meiotic synapsis in Saccharomyces cerevisiae. Mol Cell. 2013;50(5):625-36. PMID: 23644018 Panizza S, Mendoza MA, Berlinger M, Huang L, Nicolas A, Shirahige K, Klein F. Spo11-accessory proteins link double-strand break sites to the chromosome axis in early meiotic recombination. Cell. 2011;146(3):372-83. PMID: 21816273