Dzień DNA

Szanowni Państwo, Członkowie Oddziału Poznańskiego PTBioch,

W imieniu zarządu oddziału i sekcji kwasów nukleinowych PTBioch oraz lokalnych organizatorów zapraszamy do udziału w Dniu DNA (DNA Day).

W piątek 24. kwietnia 2026r. od godz. 12.00 do godz. 15.00 w Instytucie Chemii Bioorganicznej PAN w Poznaniu (różne sale).

Wykłady otwarte prowadzone będą w języku angielskim. Zdecydowanych do udziału w grach integracyjnych i spotkaniu PTBioch prosimy o rejestrację w formularzach (linki poniżej) celem oszacowania frekwencji.

Plan wydarzenia:

12:00 – 12:05 Welcome by the Organizers

12:05 – 12:20 Preface by prof. dr hab. Jan Barciszewski (Institute of Bioorganic Chemistry PAS) on “DNA at 2026”

12:15 – 13:10 Lecture by prof. dr hab. Piotr Ziółkowski (Institute of Molecular Biology and Biotechnology, Faculty of Biology, AMU) on „Crossing over in plants: the DNA shuffle behind diversity” in Hall 312 (ul. Wieniawskiego 17/19, level/ piętro 2, main IBCh PAS building)

13:15 – 14:00 lunch (Journal Club Hall, main IBCh PAS building)

14:00 – 16:00 Integration games, discussion and Quiz organized by the Dept. of Cancer Genetics IBCh PAS (Journal Club Hall, main IBCh PAS building)

14:00 – 15:00 Meeting of the Poznan branch and the Nucleic Acids section of the Polish Biochemical Society (CIES, ul. Wieniawskiego 21/23, hall 021)

Linki do rejestracji

Gry integracyjne: https://forms.gle/8ZiuosGRAzhJ7E238

Spotkanie PTBioch: https://docs.google.com/forms/d/e/1FAIpQLSfnUP30m6O5VaRksvbhUEsKuUrU4P2A7FBxQFrINbOBHG1S4Q/viewform?usp=dialog

Lecture abstract

During meiosis, crossovers reshuffle parental chromosomes and create new combinations of genetic variants, making them a major source of diversity in sexually reproducing organisms. In many eukaryotes, however, crossover numbers are surprisingly low and tightly controlled. In Arabidopsis thaliana, only about eight crossovers are typically formed per meiosis, most of them through the main class I pathway, which depends on a group of conserved pro-crossover factors known as ZMM proteins, while alternative recombination routes are actively suppressed.

In this lecture, I will discuss how crossover formation is regulated in plants and how this control can be relaxed. Our work shows that disrupting genes that normally limit recombination can dramatically increase crossover frequency. Unexpectedly, combining mutations in RECQ4 and ZIP4 leads to a much stronger increase in crossovers than expected, even without increasing the number of DNA double-strand breaks. This reveals an unanticipated role of ZMM proteins not only in promoting class I crossovers, but also in limiting alternative class II events. Additional increases can be achieved by removing other layers of recombination suppression, such as the mismatch repair factor MSH2, ultimately resulting in an approximately tenfold increase in crossover number compared with the wild type.

These findings show that meiotic recombination is far more flexible than previously thought. Understanding how crossovers are controlled opens new possibilities for plant breeding and genetic mapping by expanding genetic diversity beyond its natural limits.

On Prof. Piotr Ziółkowski

Piotr completed his PhD at the Institute of Plant Genetics of the Polish Academy of Sciences in Poznań, where he studied the evolution of Brassicaceae genome architecture. He joined Adam Mickiewicz University in 2005 and later held research positions at the University of Manchester and the University of Cambridge. His work at Cambridge contributed to the discovery of the heterozygosity juxtaposition effect and the identification of HEI10 as a limiting crossover factor.

In 2016, he returned to Adam Mickiewicz University to establish his own research group, which became the Laboratory of Genome Biology in 2019. As a young principal investigator, he studied the role of the histone variant H2A.Z in transcriptional regulation and plant stress responses. His team now investigates the molecular mechanisms of meiotic recombination in plants, with particular emphasis on factors shaping crossover frequency and chromosomal distribution, including interhomolog polymorphism and chromatin state. The group’s applied research aims to control crossover number and targeting during meiosis to develop new strategies for modern plant breeding, and their work is regularly published in high-ranking journals including Nature Communications, Science Advances, PNAS, The EMBO Journal, and Nature Plants.

He was awarded the title of Professor of Biological Sciences in 2022 and has served as Director of the Institute of Molecular Biology and Biotechnology since 2025. Research in Piotr’s team is supported by EMBO, the Foundation for Polish Science, and numerous grants from the National Science Centre.