Biology subjects

Imrie, R. M.

Publications and source records attributed to Imrie, R. M..

3 recordsLinked to original sources

bioRxiv2022

Investigating the outcomes of virus coinfection within and across host species

Interactions between coinfecting pathogens have the potential to alter the course of infection and can act as a source of phenotypic variation in susceptibility between hosts. This phenotypic variation may influence the evolution of host-pathogen interactions within host species and interfere with patterns in the outcomes of infection across host species. Here, we examine experimental coinfections of two Cripaviruses - Cricket Paralysis Virus (CrPV), and Drosophila C Virus (DCV) -across a panel of 25 Drosophila melanogaster inbred lines and 47 Drosophilidae host species. We find that interactions between these viruses alter viral loads across D. melanogaster genotypes, with a ~3 fold increase in the viral load of DCV and a ~2.5 fold decrease in CrPV in coinfection compared to single infection, but we find little evidence of a host genetic basis for these effects. Across host species, we find no evidence of systematic changes in susceptibility during coinfection, with no interaction between DCV and CrPV detected in the majority of host species. These results suggest that phenotypic variation in coinfection interactions within host species can occur independently of natural host genetic variation in susceptibility, and that patterns of susceptibility across host species to single infections can be robust to the added complexity of coinfection.

evolutionary biology↗

bioRxiv2022

The host phylogeny determines viral infectivity and replication across Staphylococcus host species

Genetic similarity between eukaryotic host species is an important determinant of the outcome of virus host shifts, where a pathogen infects a novel host species. However, it is less clear if this is the case for prokaryotes where anti-virus defences can be transmitted by horizontal gene transfer and evolve rapidly. Understanding the patterns and determinants of cross-species transmissions may provide insights into the processes underlying pathogen emergence. Here, we measure the susceptibility of 64 strains of Staphylococcus bacteria (48 strains of S. aureus and 16 non-aureus species) to the bacteriophage ISP, which is currently under investigation for use in phage therapy. Using three methods - plaque assays, optical density (OD) assays, and quantitative (q)PCR - we find that the host phylogeny explains a large proportion of the variation in susceptibility to ISP across the host panel. These patterns were consistent in models of only S. aureus strains and models with a single representative from each Staphylococcus species, suggesting that these phylogenetic effects are conserved both within and among host species. We find positive correlations between susceptibility assessed using a binary measure of plaque assay, OD, and qPCR, but not between the continuous component of plaque assay and any other method, suggesting that plaque assays alone may be inadequate to assess host range. Together, our results demonstrate the ability of bacterial host evolutionary relatedness to explain differences in susceptibility to phage infection, with implications for the development of ISP both as a phage therapy treatment and as an experimental system for the study of virus host shifts.

evolutionary biology↗

bioRxiv2022

Earl Grey: a fully automated user-friendly transposable element annotation and analysis pipeline

Transposable elements (TEs) are major components of eukaryotic genomes and are implicated in a range of evolutionary processes. Yet, TE annotation and characterisation remains challenging, particularly for non-specialists, since existing pipelines are typically complicated to install, run, and extract data from. Current methods of automated TE annotation are also subject to issues that reduce overall quality, particularly: (i) fragmented and overlapping TE annotations, leading to erroneous estimates of TE count and coverage; (ii) repeat models represented by short sections of total TE length, with poor capture of 5 and 3 ends. To address these issues, we present Earl Grey, a fully automated TE annotation pipeline designed for user-friendly curation and annotation of TEs in eukaryotic genome assemblies. Using nine simulated genomes and an annotation of Drosophila melanogaster, we show that Earl Grey outperforms current widely-used TE annotation methodologies in ameliorating the issues mentioned above, whilst scoring highly in benchmarking for TE annotation and classification, and being robust across genomic contexts. Earl Grey provides a comprehensive and fully automated TE annotation toolkit that provides researchers with paper-ready summary figures and outputs in standard formats compatible with other bioinformatics tools. Earl Grey has a modular format, with great scope for the inclusion of additional modules focussed on further quality control and tailored analyses in future releases.

bioinformatics↗