Dissecting the mechanism of meiotic crossover patterning in plants

Sex cells (e.g. sperm and eggs in humans) are produced by a special cell division called meiosis, during which chromosomes exchange large DNA segments. These DNA exchanges (called crossovers) are essential for generating genetic diversity, the driving force for evolution, and their frequency and position along chromosomes are tightly controlled. Despite over a century’s research, the cellular mechanism that determines where, and how many, crossovers form has remained mostly mysterious.

In this project, the student will build on recent discoveries by performing key experiments in plants to test a new mechanistic model for meiotic crossover patterning (the coarsening model), pursuing new hypotheses unlocked by this novel way of thinking. They will use a multidisciplinary approach, encompassing live-imaging/super-resolution microscopy, proteomics, genomics and mathematical modelling to comprehensively investigate the mechanism of meiotic crossover patterning in the model plant species, Arabidopsis thaliana. The interdisciplinary project will take place in the laboratory of Dr Chris Morgan, located in the Department of Cell and Developmental Biology at the John Innes Centre. Applications are welcomed from students across the biological sciences and that are interested in fundamental genetics and chromosome biology. The overall aim of this project is to address a critical knowledge gap in the field of genetics, generating insight and stimulating further work that will ultimately have practical applications in feeding Earth’s ever-growing population in the face of climate change.

References

Morgan C, Howard M, Henderson IR (2024) HEI10 coarsening, chromatin and sequence polymorphism shape the plant meiotic recombination landscape. Curr Opin Plant Biol 81:102570. https://doi.org/https://doi.org/10.1016/j.pbi.2024.102570

Girard C, Zwicker D, Mercier R (2023) The regulation of meiotic crossover distribution: a coarse solution to a century-old mystery? Biochem Soc Trans 51:1179–1190. https://doi.org/10.1042/BST20221329

Fozard JA, Morgan C, Howard M (2023) Coarsening dynamics can explain meiotic crossover patterning in both the presence and absence of the synaptonemal complex. Elife 12:e79408. https://doi.org/10.7554/eLife.79408

Morgan C, Fozard JA, Hartley M, Henderson IR, Bomblies K, Howard M (2021) Diffusion-mediated HEI10 coarsening can explain meiotic crossover positioning in Arabidopsis. Nat Commun 12:4674. https://doi.org/10.1038/s41467-021-24827-w