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Biology subjects

Wilkinson, D. A.

Publications and source records attributed to Wilkinson, D. A..

4 recordsLinked to original sources

Urban bats change the menu: dietary plasticity across human-modified landscapes of a tropical island

In a rapidly urbanizing world, research on dietary habits of wildlife is essential to understand how plastic behaviors may guide evolutionary trajectories of endangered animal species. Bats are very sensitive to habitat destruction and land-use change, although some species have shown the capacity for adaptation to urban life. In this study, we tested to what extent urban insectivorous bats modify their feeding strategies in a recently human-modified tropical insular ecosystem. Using a DNA metabarcoding approach on fecal samples collected in seven roosts, we analyzed the dietary niche of free-tailed bats (Mormopterus francoismoutoui) endemic to Reunion Island. Our results revealed a wide dietary niche, including 174 arthropod species in 12 orders, among which lepidopterans were predominant. We identified several crop pests and disease vectors, highlighting the central role of this bat species for agroecology and epidemiology concerns. Our study also highlighted potential sex- and reproduction-related dietary strategies. Moreover, we found that agriculture areas, inferred from land cover surrounding bat roosts, were associated with higher relative abundance of Lepidoptera in the diet of bats. In contrast, bats roosting in urban areas increased their consumption of Blattodea. As Reunion free-tailed bats roost and thrive in human-modified landscapes, understanding the consequences of this dietary plasticity for bat health and fitness will be necessary for urban evolutionary research and conservation actions.

ecology↗

Transboundary hotspots associated with SARS-like coronavirus spillover risk: implications for mitigation

The emergence of SARS-like coronaviruses is a multi-stage process from wildlife reservoirs to people. Here we characterize multiple drivers--landscape change, host distribution, and human exposure--associated with the risk of spillover of SARS-like coronaviruses to help inform surveillance and mitigation activities. We consider direct and indirect transmission pathways by modeling four scenarios with livestock and mammalian wildlife as potential and known reservoirs before examining how access to healthcare varies within clusters and scenarios. We found 19 clusters with differing risk factor contributions within a single country (N=9) or transboundary (N=10). High-risk areas were mainly closer (11-20%) rather than far (<1%) from healthcare. Areas far from healthcare reveal healthcare access inequalities, especially Scenario 3, which includes wild mammals as secondary hosts. China (N=2) and Indonesia (N=1) had clusters with the highest risk. Our findings can help stakeholders in land use planning integrating healthcare implementation and One Health actions.

ecology↗

Partial RdRp sequences offer a robust method for Coronavirus subgenus classification

The recent reclassification of the Riboviria, and the introduction of multiple new taxonomic categories including both subfamilies and subgenera for coronaviruses (family Coronaviridae, subfamily Orthocoronavirinae) represents a major shift in how official classifications are used to designate specific viral lineages. While the newly defined subgenera provide much-needed standardisation for commonly cited viruses of public health importance, no method has been proposed for the assignment of subgenus based on partial sequence data, or for sequences that are divergent from the designated holotype reference genomes. Here, we describe the genetic variation of a partial region of the coronavirus RNA-dependent RNA polymerase (RdRp), which is one of the most used partial sequence loci for both detection and classification of coronaviruses in molecular epidemiology. We infer Bayesian phylogenies from more than 7000 publicly available coronavirus sequences and examine clade groupings relative to all subgenus holotype sequences. Our phylogenetic analyses are largely coherent with genome-scale analyses based on designated holotype members for each subgenus. Distance measures between sequences form discrete clusters between taxa, offering logical threshold boundaries that can attribute subgenus or indicate sequences that are likely to belong to unclassified subgenera both accurately and robustly. We thus propose that partial RdRp sequence data of coronaviruses is sufficient for the attribution of subgenus-level taxonomic classifications and we supply the R package, "MyCoV", which provides a method for attributing subgenus and assessing the reliability of the attribution. Importance StatementThe analysis of polymerase chain reaction amplicons derived from biological samples is the most common modern method for detection and classification of infecting viral agents, such as Coronaviruses. Recent updates to the official standard for taxonomic classification of Coronaviruses, however, may leave researchers unsure as to whether the viral sequences they obtain by these methods can be classified into specific viral taxa due to variations in the sequences when compared to type strains. Here, we present a plausible method for defining genetic dissimilarity cut-offs that will allow researchers to state which taxon their virus belongs to and with what level of certainty. To assist in this, we also provide the R package MyCoV which classifies user generated sequences.

evolutionary biology↗

Bat coronavirus phylogeography in the western Indian Ocean

Bats provide key ecosystem services such as crop pest regulation, pollination, seed dispersal, and soil fertilization. Bats are also major hosts for biological agents responsible for zoonoses, such as coronaviruses (CoVs). The islands of the Western Indian Ocean are identified as a major biodiversity hotspot, with more than 50 bat species. In this study, we tested 1,013 bats belonging to 36 species from Mozambique, Madagascar, Mauritius, Mayotte, Reunion Island and Seychelles, based on molecular screening and partial sequencing of the RNA-dependent RNA polymerase gene. In total, 88 bats (8.7%) tested positive for coronaviruses, with higher prevalence in Mozambican bats (20.5% {+/-} 4.9%) as compared to those sampled on islands (4.5% {+/-} 1.5%). Phylogenetic analyses revealed a large diversity of - and {beta}-CoVs and a strong signal of co-evolution between CoVs and their bat host species, with limited evidence for host-switching, except for bat species sharing day roost sites. ImportanceThis is the first study to report the presence of coronaviruses (CoVs) in bats in Mayotte, Mozambique and Reunion Island, and in insectivorous bats in Madagascar. Eight percent of the tested bats were positive for CoVs, with higher prevalence in continental Africa than on islands. A high genetic diversity of - and {beta}-CoVs was found, with strong association between bat host and virus phylogenies, supporting a long history of co-evolution between bats and their associated CoVs in the Western Indian Ocean. These results highlight that strong variation between islands does exist and is associated with the composition of the bat species community on each island. Future studies should investigate whether CoVs detected in these bats have a potential for spillover in other hosts.

evolutionary biology↗