description
- Meiotic recombination creates genetic diversity in the progeny of sexually reproducing species. For example, reciprocal exchange between homologous chromosomes (known as crossover) creates novel combinations of genetic variation. The variation-generating processes acting during meiosis remain a major tool for crop improvement, whereby useful characteristics from different backgrounds can be combined. Bread wheat is a major crop in the UK and globally, where meiotic recombination during breeding remains an essential tool for variety improvement. However, the wheat genome is extremely large (17 gigabases) and shows highly skewed recombination distributions, with most crossovers occurring in the distal regions of the chromosomes. This severely limits the ability of breeders to utilise variation located in the central regions of the chromosomes. Therefore, developing tools and technologies to control recombination in wheat has direct relevance for food security. In this project the student will use chromatin immunoprecipitation (ChIP) followed by high throughput sequencing to profile the distribution of euchromatic and heterochromatic chromatin modifications throughout the wheat genome. These distributions will be related to highresolution genetic maps generated by KWS and genotypes that differ in their genetic map lengths. These experiments will be conducted in backgrounds of interest to KWS and the student will identify chromatin patterns that correlate with altered frequencies and patterns of recombination. The recent public release of a high quality reference genome assembly for wheat makes this project feasible and timely. New reverse genetic resources (e.g. TILLING, CRISPR-Cas9) are available that allow genes of interest to be disrupted in bread wheat. To functionally investigate the role of chromatin on recombination the student will isolate mutations in epigenetic regulators. These mutants will be profiled using ChIP-seq in order to characterise how chromatin is altered genome-wide. Finally, these mutants will be used to measure effects on number and distribution of recombination events during meiosis. This project will provide the student with advanced training in wheat genetics and genomics. They will generate data of basic importance for understanding wheat genome function and evolution. They will gain experience in wheat genetics relevant to both academic and industrial scientific contexts.