Elucidating Mechanisms of Recombination
In meiotic recombination, two parental chromosomes, one from the father and one from the mother, exchange parts to give rise to the next generation. This process creates new genetic variation in the progeny, which facilitates adaptation and purges detrimental mutations. Thus, meiotic recombination is one of the main forces behind evolution and an unparalleled instrument of plant and animal breeding.
In stark contrast to its importance, little is known about mechanisms controlling recombination, particularly in plants. Mechanisms of recombination appear to be different in each major group of eukaryotes and are also highly dependent on genome size and complexity. Researchers do know that recombination events are not evenly distributed throughout the genome. They predominantly take place at distinct sites called recombination hotspots.
Wojtek Pawlowski, School of Integrative Plant Science, in collaboration with Jaroslaw Pillardy, director of the Cornell Bioinformatics Facility, is working to understand why and how specific sites in the genome become recombination hotspots in maize. Maize is a major crop worldwide and an excellent model system for all eukaryotes.
Pawlowski and his team are elucidating how the recombination machinery recognizes the sites that become hotspots and how the locations of these sites are affected by genetic and epigenetic factors. They are also uncovering the mechanisms that prevent formation of carbon monoxides in heterochromatin, the dense region of the chromosome where recombination takes place. This work will further the understanding of how recombination is controlled in plants and how it affects the structure of large and complex plant genomes. The findings will be useful to breeders who are continuously looking for new ways to increase the efficiency of breeding crop plants.