Seminar Dr Stefan Heckmann

Genetic variation used in plant breeding largely arises during meiosis, when crossovers (COs) reshuffle parental DNA. COs arise during prophase I through homologous recombination along proteinaceous chromosome axes and within the synaptonemal complex (SC), a structure that links homologous chromosomes during pachytene. In many crops, such as barley and wheat, COs are few and clustered near chromosome ends, leaving large genome regions genetically “locked” and underutilized. New strategies are therefore needed to understand and re-distribute meiotic recombination.
We combine work in Arabidopsis thaliana and Hordeum vulgare (barley).

In Arabidopsis, using TurboID-based proximity proteomics, we mapped proteins on meiotic chromosome structures, leading to the discovery of SCEP3, a previously unknown central element protein of the SC. Loss of SCEP3 disrupts SC formation, abolishes CO assurance and interference, and increases CO frequency (mainly female COs), thereby eliminating sex‑specific differences in recombination (heterochiasmy). We also developed FeM‑ID, a method that enables robust cytological analysis of female meiotic chromosome behavior.

In barley, we established BSMV-induced gene editing (BSMVIGE) in Cas9-expressing lines and single-pollen nucleus genotyping (SPNG) using digital PCR. BSMVIGE allows rapid generation of meiotic mutants, while SPNG provides high‑throughput CO measurements without growing offspring populations. By manipulating key meiotic genes, we show that the number and distribution of COs in barley can be modified, demonstrating that its recombination landscape is plastic and can be engineered to unlock hidden genetic diversity for crop improvement. Notably, despite the high conservation of meiosis, the requirements for conserved meiotic players in CO formation differ between these plants, possibly reflecting differences in genome organization.


Stefan Heckmann, Leibniz Institute of Plant Genetics and Crop Plant Research IPK, Gatersleben, Germany

Invitation: Rajeev Kumar
"Meiosis Mechanisms" MeioMe team


In connection with the research developed at the Institute Jean-Pierre Bourgin for Plant Sciences.