The power of synteny : deep evolutionary insights from comparative genomics

Abstract

Synteny, or the order of genes in a given genome, is an emergent property of individuals and species that has only, with the implementation of next gen-sequencing, become available for evolutionary consideration. In this dissertation, I leverage syntenic information in concert with sequence data to draw connections between evolutionary mechanisms, species divergence, and trait innovation. In Chapter I, I review the major themes that ties my dissertation research together, highlighting important mechanisms at work in evolutionary complexity and introducing the system of which it will be a part. In Chapter II, I use a phylogenomic approach to better understand species relationships within the tribe. I utilize transcriptome sequences and genome derived synteny information to improve orthology detection over standard sequence similarity approaches and gain greater insight into the relationships of the tribe. I also implement differential fractionation rate orthology inference information to address gene tree-species tree incongruence. In Chapter III, as published in Abrahams et al., 2020, I utilize a microsynteny network and phylogenetic inference to investigate the origin and diversification of the MAM/IPMS gene family. I uncover unique MAM-like genes found at the orthologous locus in the Cleomaceae that shed light on the transition from IPMS to MAM. In the Brassicaceae, I identify six distinct MAM clades across Lineages I, II, and III. I characterize the evolutionary impact and consequences of local duplications, transpositions, whole genome duplications, and gene fusion events, generating several new hypotheses on the function and diversity of the MAM locus.