BIOINFORMATICS SEMINAR SERIES
https://bioinformatics.udel.edu/seminar
Phylogenetic Analysis of Global Isolates of the Avian Malaria Parasite Plasmodium relictum
Esther Weyer
PhD student, Bioinformatics Data Science
CBCB
University of Delaware
Abstract:
Establishing species limits is a difficult objective that has been both improved and complicated by an increase in available genomic data. Individual genes can be under different selective pressures, resulting in discordance between gene and overall species trees. It is particularly challenging to determine boundaries for pathogens that need to be sequenced against high levels of background host DNA and can be subjected to additional evolutionary considerations such as recombination events. One pathogen that provides an opportunity to investigate these possibilities is Plasmodium relictum, an avian malaria pathogen that is well-characterized, globally distributed, and has several distinct lineages, including GRW4 which has had a devastating effect on the native avifauna of Hawaii. In this study, we aimed to establish a robust phylogeny for the lineages within the P. relictum species as well as test for potential gene flow events and positive selection by incorporating more gene sequences than previous studies. Phylogenetic trees were generated by both a maximum likelihood search and multi-species coalescence model using aligned orthologous sequences captured by SWGA from 52 infections across multiple geographic regions. We saw consistent tree structure between methods as well as the separation of lineages in two cryptic species, and support for introgression between branches. Including more loci improved robustness of the lineage phylogeny and increased the capacity to test for complex evolutionary events in pathogens.
Bio:
Esther Weyer is currently pursuing a PhD in Bioinformatics Data Science. She completed her undergraduate training at Rensselaer Polytechnic Institute, having double-majored in biochemistry and mathematics. Using this combined background, she currently works on research studying evolution and phylogenetics of avian malaria under the supervision of Dr. Vincenzo Ellis.
