We study the nature and mechanisms of plant genome evolution. Specific research areas include determining the relationships between plant genomes, measuring diversity, understanding the role and evolutionary history of repetitive DNA, and studying three-dimensional genome modulation at meiosis and during gene expression. The focus of research will use crop species and their wild relatives, taking a comparative approach. Investigation of the role and nature of polyploidy and whole genome duplication will be a key focus, and we will study the mechanisms of chromosome and repetitive sequence evolution, measuring inter-genomic interactions and changes. Recognizing the value of whole genome sequencing approaches to address our questions, we use a range of genomic, bioinformatic and cytogenetic methods. The Genome Evolution Research Group is led by John Seymour Heslop Harrison with a five-year programme targeted at high-profile research and publications, involving collaborations, group members and both post-doctoral fellows and researchers. Much research is cross-disciplinary.
Research Objectives include:
1) Defining genome evolution in the Musaceae and wider Zingiberales. Bananas, plantains and the starch crop Ensete are important food crops, but production is threated by a range of diseases (biotic) and environmental stresses (abiotic, including climate). We aim to define the genetic, genomic and chromosomal variation in the Musaceae family and trace the modes of evolution.
2) Exploring and exploiting genome variation in Avena, oats (Qing Liu PI). The cereal oats is one of relatively few crops recognized as a ‘health food’ by regulatory authorities because of its soluble fibre helping reduce blood cholesterol level and heart disease risk. We aim to define the sequences – repetitive and single-copy – in diploid oat genomes and identify the evolutionary processes seen in the hexaploid crop. We will identify the chromosomal rearrangements and chromosome pairing features, aiming to improve the use of the Avena genepool to increase sustainability and utilization of the crop.
3) Discover the structure and features of the ancestral Poaceae genome. The plant family Poaceae (or Gramineae), the grasses, is the most economically important plant group. There are some 12,000 species, covering a third of the world’s land area, with the cereals providing about 70% of human nutrition and grasses/cereals feeding 90% of farm animals. We aim to characterize chromosomal and DNA sequence features across the grasses and identify the structure of the common ancestor and the mechanisms of evolution leading to extant species.
4) Develop improved DNA sequence analytical techniques to characterize repetitive DNA sequences and hybrid events. More than half of the DNA in plant genomes consists of repetitive motifs that are repeated hundreds up to millions of times. Most current approaches to sequence assembly ‘mask’, ‘collapse’ or otherwise ignore this component that is rapidly evolving and contributes to genome stability and recombination. Furthermore, many phylogenetic approaches assume a monophyletic origin of branches, being unable to identify recent or ancient polyploidy events. We aim to develop improved approaches, using both short-read and long-range sequencing and mapping approaches, complemented by cytogenetics, to define the contribution of repetitive DNA to plant genome evolution.
Positions are open for PhD students, post-doctoral researchers and for fellowship holders.
Principal Investigator: John Seymour Heslop Harrison (Professor/Ph.D.)
Email: phh4@le.ac.uk