BTT EAGER: Mitotic Recombination between Homologous Chromosomes

University Of California-Davis, Davis CA

Investigators

Abstract

All the individuals of a given species carry the same genes. What makes one individual different from another is its unique combination of alleles (versions) of those genes. By crossing plants carrying different sets of alleles, crop breeders can create new crop varieties, with new combinations of alleles. However, because genes are clustered together on chromosomes, a desirable allele of one gene may be located very close to an undesirable allele of another gene on the same chromosome. The close clustering, or linkage of genes means that both the desirable and undesirable alleles are inherited together. This research provides tools that allow the plant breeder to separate or replace alleles of linked genes. This technology accelerates the rate at which new and improved crop varieties can be produced. This is an important goal, as the development of new crop varieties is an ongoing race with the evolution of new varieties of pathogens, increasing demand from an expanding world population, unpredictable climate, and the degradation of existing farmland. Food security -worldwide, not just at home- is an essential aspect of our national security. CRISPR technologies provide a remarkably specific and efficient means for the generation of targeted DNA double strand breaks (DSBs) in plants. Error-prone end-to-end joining of CRISPR induced breaks can generate targeted mutations and translocations; repair via homologous recombination (HR) can create new alleles or new combinations of alleles. CRISPR-induced HR events are relatively rare in plants. Tools developed here proposal improve the efficiency of HR. While this technology applies to any HR-dependent event, specifically interest is in the facilitation of recombination between endogenous preexisting alleles. This technology greatly enhances the speed and specificity of the development of new plant lines, both for breeding and for research. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.