skip to content

Department of Plant Sciences

 

Supervisor

Dr Natasha Yelina

Brief summary

The project aims to gain further mechanistic insight into meiotic crossover formation in plants.

Importance of Research

Crossover recombination underlies genetic diversity, evolution and crop breeding. The proposed research aims to gain essential knowledge to enable crossover engineering for accelerated crop improvement.

Project Summary

During meiosis parental chromosomes physically exchange parts or undergo crossover recombination. This fundamental process in all sexually reproducing eukaryotes creates genetic diversity and underlies evolution and crop breeding.

To form a crossover, nuclear DNA is first cut and then repaired in a multistep process. In plants, majority of DNA cuts are repaired as a non-crossover, or without parental chromosome exchange, resulting in minimal genetic diversity. This project aims to combine molecular, genetic, and biochemistry approaches to gain a deeper insight into how a group of proteins, termed, pro-crossover factors, ensure a crossover outcome of meiotic DNA repair. This knowledge will lead to a fundamental advance of how meiotic crossovers are formed and will be an important step towards engineering recombination in chromosome locations of breeders’ choice.

What will the successful applicant do?

Pro-crossover factors work together to promote crossovers; however, the hierarchy of their action is unknown. The first part of the project will be to test whether any pro-crossover factors can initiate recruitment others to the DNA and thus ensure crossover formation.  Pro-crossover factors can be regulated via post-translational modifications (PTM). The second part of the project will be to test whether and how PTMs are involved in crossover control.

References

Nataliya E Yelina, Daniel Holland, Sabrina Gonzalez-Jorge, Dominique Hirsz, Ziyi Yang, Ian R Henderson, Coexpression of MEIOTIC-TOPOISOMERASE VIB-dCas9 with guide RNAs specific to a recombination hotspot is insufficient to increase crossover frequency in Arabidopsis, G3 Genes|Genomes|Genetics, Volume 12, Issue 7, July 2022, jkac105, doi.org/10.1093/g3journal/jkac105

H. B. D. Prasada Rao et al. A SUMO-ubiquitin relay recruits proteasomes to chromosome axes to regulate meiotic recombination. Science355,403-407(2017). DOI:10.1126/science.aaf6407

Pyatnitskaya, A., Borde, V. & De Muyt, A. Crossing and zipping: molecular duties of the ZMM proteins in meiosis. Chromosoma 128, 181–198 (2019). doi.org/10.1007/s00412-019-00714-8