The Dynamics of Centromere Evolution in the Brassicaceae Family

University Of Chicago, Chicago IL

Investigators

Abstract

Flowering plants have genomes that range over 1000-fold in size. One of the major factors contributing to changes in genome size is the ability of plants to survive increases in the number of chromosomes (polyploidization); most plant species are thought to have undergone whole genome duplications (autopolyploidization) or hybridizations between different species (allopolyploidization). These events are often accompanied by chromosome rearrangements, fusions and loss. Nonetheless, the resulting chromosomes must contain a single centromere that ensures their inheritance during cell division. This project aims to understand how chromosomes maintain a single centromere, while preserving essential genes - using genomics technology, it will explore how plants eliminate extra centromeres and how they create new centromeres. The research will be performed by comparing the genome of the model plant Arabidopsis thaliana to the genomes of its closest relatives. A. thaliana has undergone several polyploidization, genome rearrangement and DNA loss events, producing a species with only 5 chromosomes and an extremely compact genome. The information gained from this project will broadly impact the understanding of plant genomes and their evolution. It will also clarify the changes associated with the formation of new centromeres (neocentromeres), which can lead to cancer in mammalian cells and genomic instability in crops. This program will also provide research opportunities for minority undergraduate students and will provide a senior postdoctoral associate experience in mentoring graduate students. The results of this work will be published and will also be presented in venues that educate the public and policy makers in plant genetic engineering.