Patterns and Processes in the Evolution of Sequence Classes and Genomic Compartments

Abstract

The content of genomes can be categorized into different sequence classes: autosomes and sex chromosomes, coding and noncoding, and repetitive and non-repetitive, to name but a few. Each of these classes of the genome has unique mechanisms that govern their evolution. In my dissertation work, I studied the evolution of the genome on three scales. My first dissertation project sought to understand the sequence class of microsatellites. For this project, I analyzed microsatellite content in all sequenced insect genomes and potential predictors of microsatellite content and rates of evolution. For my following two projects, I assessed the stability of genomes at the chromosome level. First, I assessed this stability in insects by investigating their tolerance to rearrangements dependent on the type of centromeres they possess. Next, I assessed this stability in carnivores by comparing species with small or large range sizes. For my last project, I synthesize all recorded sex chromosome systems across the tree of life and explore what we can learn from the paucity of univalent sex chromosome systems. Each of these projects adds to the understanding of genome structure and the mechanisms by which specific classes of the genome evolve.