The variation observed between parents and their offspring is due to meiotic recombination called crossover. The crossover takes place during gamete formation and is based on exchange of chromosomal segments between parental chromosomes. In consequence, novel combinations of alleles are generated. We are interested in how crossovers are formed and how they are regulated.
Recently, we identified a new crossover modifier, SNI1, which is a component of the cohesin/condensin-related SMC5/6 complex. The sni1 mutants exhibit a modified pattern of recombination across the genome and affects mostly noninterfering crossovers. Our study reveals the importance of the SMC5/6 complex in ensuring the proper progress of meiotic recombination in plants (Zhu et al. PNAS 2021).
The initial step in crossover (CO) is double strand break (DSB) formation. However, only a small portion of DSBs will be repaired by crossover with majority being repaired by non-crossover (NCO) pathways. We seek to find how the CO/NCO decision is made and how it affects chromosomal distribution of crossover. In particular, we investigate how DNA polymorphisms affect crossover formation. Recently, we documented an unexpected pro-crossover role of mismatch repair factor MSH2 in regions of higher sequence diversity in Arabidopsis (Blackwell & Dluzewska et al. EMBO J. 2020).
In addition, we are interested in chromatin modifications, which affect genetic recombination as well as gene expression. In particular, we are studying the role of histone variant H2A.Z in plants. We found that H2A.Z may adopt both promoting and repressing roles in regulating gene expression, dependently on its location (Sura et al. Plant Cell 2017).
Another extensive research in our group focuses on histone acetylation, especially by histone acetyltransferase NuA4. We recently identified key components of this complex in Arabidopsis and found that by controlling both the acetylation and deposition of H2A.Z, NuA4 contributes to the switch between the stress response and autotrophic growth (Bieluszewski, Sura & Dziegielewski et al. Nat Commun 2022).
Our primary research model is Arabidopsis thaliana - favoured species of plant scientists.
Selected papers
Bieluszewski T*, Sura W*, Dziegielewski W*, Bieluszewska A, Lachance C, Kabza M, Szymanska-Lejman M, Abram M, Wlodzimierz P, De Winne N, De Jaeger G, Sadowski J, Côté J & Ziolkowski PA (2022) NuA4 and H2A.Z control environmental responses and autotrophic growth in Arabidopsis. Nat Commun 13, 277.
Zhu L, Fernández-Jiménez N, Szymanska-Lejman M, Pelé A, Underwood CJ, Serra H, Lambing C, Dluzewska J, Bieluszewski T, Pradillo M, Henderson IR, Ziolkowski PA (2021) Natural variation identifies SNI1, the SMC5/6 component, as a modifier of meiotic crossover in Arabidopsis. Proc Natl Acad Sci U S A 118: e2021970118.
Blackwell AR, Dluzewska J, Szymanska-Lejman M, Desjardins S, Tock AJ, Kbiri N, Lambing C, Lawrence EJ, Bieluszewski T, Rowan B, Higgins JD, Ziolkowski PA, Henderson IR (2020) MSH2 shapes the meiotic crossover landscape in relation to interhomolog polymorphism in Arabidopsis. EMBO J 39: e104858.
Sura W, Kabza M, Karlowski WM, Bieluszewski T, Kus-Slowinska M, Pawełoszek Ł, Sadowski J, Ziolkowski PA (2017) Dual role of the histone variant H2A.Z in transcriptional regulation of stress-response genes. Plant Cell 29: 791-807.
Ziolkowski PA, Underwood CJ, Lambing C, Martinez-Garcia M, Lawrence EJ, Ziolkowska L, Griffin C, Choi K, Franklin FC, Martienssen RA, Henderson IR. (2017) Natural variation and dosage of the HEI10 meiotic E3 ligase control Arabidopsis crossover recombination. Genes Dev 31: 306-317.
Our funding:
Contact us:
pzio@amu.edu.pl tel. +48 61 829 5966
Laboratory of Genome Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznan, Poland
Credits:
Cover picture by Piotr Ziolkowski