Lisa Bono, Texas Tech University

Enoch Ghosh1, Austen Rowell1 & Lisa M. Bono1 1 Department of Biological Sciences, Lubbock TX

Epidemiology, Evolution, and Diversity

Characterizing viruses that are only known from sequencing-based approaches remains challenging, especially identifying ecologically relevant information like niche and host range. Existing approaches can predict host from viral sequence alone but only at the genus level. Furthermore, these are only designed for DNA phages, and no comparable approach exists for RNA phages. We used publicly available genome sequences and host range data of recognized members of the dsRNA phage family Cystoviridae, which are a model system for host range evolution. We used all known cystovirus sequences and their host data to infer phylogenetic trees. We compared three sets of phylogenetic trees: one based on the sequence of the cystoviruses alone, one for their hosts, and one for the cystoviruses constrained by host range. We found that the unconstrained trees were better supported than the constrained trees, suggesting that host range is not well predicted by phage sequence similarity. However, the host information of many cystoviruses is incomplete, reducing the resolution of our analysis. Consequently, we are expanding our collection of cystoviruses isolated both on typical and a broader range of hosts. While cystoviruses have typically been isolated on Pseudomonas savastanoi, recently identified cystoviruses infect a broader range of hosts. After sequencing these novel cystoviruses and assessing their host range, we will assess if this additional data improves our phylogenetic inferences. This will help us predict the host of cystoviruses known only from sequences and more broadly fill the gap in knowledge about RNA phages.