Files
Abstract
Septins are a class of cytoskeletal GTPase used in cytokinesis and conserved in most eukaryotes. Septins form hetero-hexamers or hetero-octamers in a predetermined order strictly based on their ancestry. When comparing fungal and animal septin monomer order within polymers, some septins are seated in the same relative position as their cross-kingdom septin with the most recent common ancestor while others do not. Many attempts and revisions to classify the evolutionary history of septins and group them according to their functions have been made. The first study documents the history of septin classification and compares the septins within the most commonly researched model organisms used for septin research. The second study expands the collection of non-opisthokont (non-animal or fungal species) septins and revises septin group memberships. Using ancestral sequence reconstruction, secondary structure prediction, and sequence alignment, the mechanism for the origins of heteropolymerization from an ancestral homodimer is hypothesized. The final study began while studying the techniques used in the above studies. This study shows intra-species contamination can be detected using B-allele frequency visualization, and documents that low levels of contamination are sufficient to disrupts phylogenetic and population genomic analyses.