Imperial College London

DrChrisWilson

Faculty of Natural SciencesDepartment of Life Sciences

Honorary Research Fellow
 
 
 
//

Contact

 

+44 (0)20 7594 2370chris.wilson Website

 
 
//

Location

 

N3.11MunroSilwood Park

//

Summary

 

Publications

Publication Type
Year
to

14 results found

Wilson CG, Pieszko T, Nowell RW, Barraclough TGet al., 2024, Recombination in bdelloid rotifer genomes: asexuality, transfer and stress., Trends Genet, ISSN: 0168-9525

Bdelloid rotifers constitute a class of microscopic animals living in freshwater habitats worldwide. Several strange features of bdelloids have drawn attention: their ability to tolerate desiccation and other stresses, a lack of reported males across the clade despite centuries of study, and unusually high numbers of horizontally acquired, non-metazoan genes. Genome sequencing is transforming our understanding of their lifestyle and its consequences, while in turn providing wider insights about recombination and genome organisation in animals. Many questions remain, not least how to reconcile apparent genomic signatures of sex with the continued absence of reported males, why bdelloids have so many horizontally acquired genes, and how their remarkable ability to survive stress interacts with recombination and other genomic processes.

Journal article

Vasilikopoulos A, Herlyn H, Fontaneto D, Wilson CG, Nowell RW, Flot JF, Barraclough TG, Van Doninck Ket al., 2024, Whole-genome analyses converge to support the Hemirotifera hypothesis within Syndermata (Gnathifera), Hydrobiologia, ISSN: 0018-8158

The clade Syndermata includes the endoparasitic Acanthocephala, the epibiotic Seisonidea, and the free-living Bdelloidea and Monogononta. The phylogeny of Syndermata is highly debated, hindering the understanding of the evolution of morphological features, reproductive modes, and lifestyles within the group. Here, we use publicly available whole-genome data to re-evaluate syndermatan phylogeny and assess the credibility of alternative hypotheses, using a new combination of phylogenomic methods. We found that the Hemirotifera and Pararotatoria hypotheses were recovered under combinations of datasets and methods with reduced possibility of systematic error in concatenation-based analyses. In contrast, the Seisonidea-sister and Lemniscea hypotheses were recovered under dataset combinations with increased possibility of systematic error. Hemirotifera was further supported by whole-genome microsynteny analyses and species-tree methods that use multi-copy orthogroups after removing distantly related outgroups. Pararotatoria was only partially supported by microsynteny-based phylogenomic reconstructions. Hence, Hemirotifera and partially Pararotatoria were supported by independent phylogenetic methods and data-evaluation approaches. These two hypotheses have important implications for the evolution of syndermatan morphological features, such as the gradual reduction of locomotory ciliation from the common ancestor of Syndermata in the stem lineage of Pararotatoria. Our study illustrates the importance of combining various types of evidence to resolve difficult phylogenetic questions.

Journal article

Fiałkowska E, Fiałkowski W, Wilson CG, Pajdak-Stós Aet al., 2022, Effects of polyaluminum chloride (PAX-18) on the relationship between predatory fungi and Lecane rotifers, Environmental Science and Pollution Research, Vol: 29, Pages: 17671-17681, ISSN: 0944-1344

<jats:title>Abstract</jats:title><jats:p>PAX-18 (polyaluminum chloride) is frequently used in WWTPs (wastewater treatment plants) to overcome sludge bulking. An alternative biological method is the usage of <jats:italic>Lecane</jats:italic> rotifers, which can be endangered by predacious fungi. We investigated the influence of different PAX-18 concentrations on the relationship between <jats:italic>Lecane inermis</jats:italic> and predacious fungi (<jats:italic>Zoophagus</jats:italic> and <jats:italic>Lecophagus</jats:italic>) differing in feeding mode. High PAX concentration (6 mg Al<jats:sup>3+</jats:sup> L<jats:sup>−1</jats:sup>) strongly limited the number of the rotifers, which in low concentration (1.2 mg Al<jats:sup>3+</jats:sup> L<jats:sup>−1</jats:sup>), after an initial decline, increased, but significantly slower than in control. Under the simultaneous influence of <jats:italic>Lecophagus</jats:italic> and PAX, rotifers were driven almost extinct at the high concentration, but survived at the lower concentration and increased in the control. When treated with <jats:italic>Zoophagus</jats:italic>, only one or two rotifers survived in treatments and control. High concentrations of PAX significantly restricted the growth of fungi, whereas in low concentrations and control conditions, their length increased, with <jats:italic>Zoophagus</jats:italic> growing much quicker than <jats:italic>Lecophagus</jats:italic>. <jats:italic>Zoophagus</jats:italic> was significantly more efficient in trapping rotifers regardless of PAX concentration. The trapping ability of mycelium following extended exposure to PAX was strongly limited at high concentrations, in comparison to control. Conidia of <jats:italic>Zoophagus</jats:italic> turned out to be considerably more re

Journal article

Nowell RW, Barraclough TG, Wilson CG, 2021, Bdelloid rotifers use hundreds of horizontally acquired genes against fungal pathogens

<jats:title>Abstract</jats:title><jats:p>Obligately asexual lineages are typically rare and short-lived. According to one hypothesis, they adapt too slowly to withstand relentlessly coevolving pathogens. Bdelloid rotifers seem to have avoided this fate, by enduring millions of years without males or sex. We investigated whether bdelloids’ unusual capacity to acquire non-metazoan genes horizontally has enhanced their resistance to pathogens. We found that horizontally transferred genes are three times more likely than native genes to be upregulated in response to a natural fungal pathogen. This enrichment was twofold stronger than that elicited by a physical stressor (desiccation), and the genes showed little overlap. Among hundreds of upregulated non-metazoan genes were RNA ligases putatively involved in resisting fungal toxins and glucanases predicted to bind to fungal cell walls, acquired from bacteria. Our results provide evidence that bdelloids mitigate a predicted challenge of long-term asexuality in part through their ability to acquire and deploy so many foreign genes.</jats:p>

Journal article

Nowell RW, Wilson CG, Almeida P, Schiffer PH, Fontaneto D, Becks L, Rodriguez F, Arkhipova IR, Barraclough TGet al., 2021, Evolutionary dynamics of transposable elements in bdelloid rotifers, eLife, Vol: 10, Pages: 1-37, ISSN: 2050-084X

Transposable elements (TEs) are selfish genomic parasites whose ability to spread autonomously is facilitated by sexual reproduction in their hosts. If hosts become obligately asexual, TE frequencies and dynamics are predicted to change dramatically, but the long-term outcome is unclear. Here, we test current theory using whole-genome sequence data from eight species of bdelloid rotifers, a class of invertebrates in which males are thus far unknown. Contrary to expectations, we find a variety of active TEs in bdelloid genomes, at an overall frequency within the range seen in sexual species. We find no evidence that TEs are spread by cryptic recombination or restrained by unusual DNA repair mechanisms. Instead, we find that that TE content evolves relatively slowly in bdelloids and that gene families involved in RNAi-mediated TE suppression have undergone significant expansion, which might mitigate the deleterious effects of active TEs and compensate for the consequences of long-term asexuality.

Journal article

Russell M, Qureshi A, Wilson C, Cator Let al., 2021, Size, not temperature, drives cyclopoid copepod predation of invasive mosquito larvae, PLoS One, Vol: 16, ISSN: 1932-6203

During range expansion, invasive species can experience new thermal regimes. Differences between the thermal performance of local and invasive species can alter species interactions, including predator-prey interactions. The Asian tiger mosquito, Aedes albopictus, is a known vector of several viral diseases of public health importance. It has successfully invaded many regions across the globe and currently threatens to invade regions of the UK where conditions would support seasonal activity. We assessed the functional response and predation efficiency (percentage of prey consumed) of the cyclopoid copepods Macrocyclops albidus and Megacyclops viridis from South East England, UK against newly-hatched French Ae. albopictus larvae across a relevant temperature range (15, 20, and 25°C). Predator-absent controls were included in all experiments to account for background prey mortality. We found that both M. albidus and M. viridis display type II functional response curves, and that both would therefore be suitable biocontrol agents in the event of an Ae. albopictus invasion in the UK. No significant effect of temperature on the predation interaction was detected by either type of analysis. However, the predation efficiency analysis did show differences due to predator species. The results suggest that M. viridis would be a superior predator against invasive Ae. albopictus larvae due to the larger size of this copepod species, relative to M. albidus. Our work highlights the importance of size relationships in predicting interactions between invading prey and local predators.

Journal article

Pathak A, Nowell RW, Wilson CG, Ryan MJ, Barraclough TGet al., 2020, Comparative genomics of Alexander Fleming's original Penicillium isolate (IMI 15378) reveals sequence divergence of penicillin synthesis genes, Scientific Reports, Vol: 10, ISSN: 2045-2322

Antibiotics were derived originally from wild organisms and therefore understanding how these compounds evolve among different lineages might help with the design of new antimicrobial drugs. We report the draft genome sequence of Alexander Fleming's original fungal isolate behind the discovery of penicillin, now classified as Penicillium rubens Biourge (1923) (IMI 15378). We compare the structure of the genome and genes involved in penicillin synthesis with those in two 'high producing' industrial strains of P. rubens and the closely related species P. nalgiovense. The main effector genes for producing penicillin G (pcbAB, pcbC and penDE) show amino acid divergence between the Fleming strain and both industrial strains, whereas a suite of regulatory genes are conserved. Homologs of penicillin N effector genes cefD1 and cefD2 were also found and the latter displayed amino acid divergence between the Fleming strain and industrial strains. The draft assemblies contain several partial duplications of penicillin-pathway genes in all three P. rubens strains, to differing degrees, which we hypothesise might be involved in regulation of the pathway. The two industrial strains are identical in sequence across all effector and regulatory genes but differ in duplication of the pcbAB-pcbC-penDE complex and partial duplication of fragments of regulatory genes. We conclude that evolution in the wild encompassed both sequence changes of the effector genes and gene duplication, whereas human-mediated changes through mutagenesis and artificial selection led to duplication of the penicillin pathway genes.

Journal article

Nowell RW, Wilson CG, Almeida P, Schiffer PH, Fontaneto D, Becks L, Rodriguez F, Arkhipova IR, Barraclough TGet al., 2020, Evolutionary dynamics of transposable elements in bdelloid rotifers

<jats:title>Abstract</jats:title><jats:p>Transposable elements (TEs) are selfish genomic parasites whose ability to spread autonomously is facilitated by sexual reproduction in their hosts. If hosts become obligately asexual, TE frequencies and dynamics are predicted to change dramatically, but the long-term outcome is unclear. Here, we test current theory using whole-genome sequence data from eight species of bdelloid rotifers, a class of invertebrates where males are thus far unknown. Contrary to expectations, we find a diverse range of active TEs in bdelloid genomes, at an overall frequency within the range seen in sexual species. We find no evidence that TEs are spread by cryptic recombination or restrained by unusual DNA repair mechanisms, but we report that bdelloids share a large and unusual expansion of genes involved in RNAi-mediated TE suppression. This suggests that enhanced cellular defence mechanisms might mitigate the deleterious effects of active TEs and compensate for the consequences of long-term asexuality.</jats:p>

Working paper

Wilson CG, Nowell R, Barraclough T, 2018, Cross-contamination explains "inter- and intraspecific horizontal genetic transfers" between asexual bdelloid rotifers, Current Biology, Vol: 28, Pages: 2436-2444.e14, ISSN: 1879-0445

A few metazoan lineages are thought to have persisted for millions of years without sexual reproduction. If so, they would offer important clues to the evolutionary paradox of sex itself [1, 2]. Most "ancient asexuals" are subject to ongoing doubt because extant populations continue to invest 17 in males [3–9]. However, males are famously unknown in bdelloid rotifers, a class of microscopic invertebrates comprising hundreds of species [10–12]. Bdelloid genomes have acquired an unusually high proportion of genes from non-metazoans via horizontal transfer [13–17]. This well-substantiated finding has invited speculation [13] that homologous horizontal transfer between bdelloid individuals also may occur, perhaps even "replacing" sex [14]. In 2016, Current Biology published an Article claiming to supply evidence for this idea. Debortoli et al. [18] sampled rotifers from natural populations and sequenced one mitochondrial and four nuclear loci. Species assignments were incongruent among loci for several samples, which was interpreted as evidence of "interspecific horizontal genetic transfers". Here, we use sequencing chromatograms supplied by the authors to demonstrate that samples treated as individuals actually contained two or more highly divergent mitoc hondrial and ribosomal sequences, revealing cross-contamination with DNA from multiple animals of different species. Other chromatograms indicate contamination with DNA from conspecific animals, explaining genetic and genomic evidence for "intraspecific horizontal exchanges" reported in the same study. Given the clear evidence of contamination, the data and findings of Debortoli et al. [18] provide no reliable support for their conclusions that DNA is transferred horizontally between or within bdelloid species.

Journal article

Barraclough TG, Nowell R, Wilson C, Smith Tet al., 2018, Comparative genomics of bdelloid rotifers: insights from desiccating and nondesiccating species, PLoS Biology, Vol: 16, ISSN: 1544-9173

Bdelloid rotifers are a Class of microscopic invertebrates that have existed for millions of years apparently without sex or meiosis. They inhabit a variety of temporary and permanent freshwater habitats globally, and many species are remarkably tolerant of desiccation. Bdelloids offer an opportunity to better understand the evolution of sex and recombination, but previous work has emphasized desiccation as the cause of several unusual genomic features in this group. Here, we present high-quality whole genome sequences of three bdelloid species: Rotaria macrura and Rotaria magnacalcarata, which are both desiccation intolerant, and Adineta ricciae, which is desiccationtolerant. In combination with the published assembly of Adineta vaga, which is also desiccation tolerant, we apply a comparative genomics approach to evaluate the potential effects of desiccation tolerance and asexuality on genome evolution in bdelloids. We find that ancestral tetraploidy is conserved among all four bdelloid species, but homologous divergence in obligately aquatic Rotaria genomes is unexpectedly low. This finding is contrary to current models regarding the role of desiccation in shaping bdelloid genomes. In addition, we find that homologous regions in A. ricciaeare largely collinear and do not form palindromic repeats as observed in the published A. vaga assembly. Consequently, several features interpreted as genomic evidence for long-term ameiotic evolution are not general to all bdelloid species, even within the same genus. Finally, we substantiate previous 50 findings of high levels of horizontally transferred non-metazoan genes in both desiccating and non-desiccating bdelloid species, and show that this unusual feature is not shared by other animal phyla, even those with desiccation-tolerant representatives. These comparisons call

Journal article

Wilson CG, Sherman PW, 2013, Spatial and temporal escape from fungal parasitism in natural communities of anciently asexual bdelloid rotifers, PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, Vol: 280, ISSN: 0962-8452

Journal article

Wilson CG, 2011, Desiccation-tolerance in bdelloid rotifers facilitates spatiotemporal escape from multiple species of parasitic fungi, BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Vol: 104, Pages: 564-574, ISSN: 0024-4066

Journal article

Wilson CG, Sherman PW, 2010, Anciently Asexual Bdelloid Rotifers Escape Lethal Fungal Parasites by Drying Up and Blowing Away, SCIENCE, Vol: 327, Pages: 574-576, ISSN: 0036-8075

Journal article

Wilson CG, 2008, Male genital mutilation: an adaptation to sexual conflict, Evolution and Human Behavior, Vol: 29, Pages: 149-164, ISSN: 1090-5138

Journal article

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://wlsprd.imperial.ac.uk:80/respub/WEB-INF/jsp/search-html.jsp Request URI: /respub/WEB-INF/jsp/search-html.jsp Query String: respub-action=search.html&id=00703317&limit=30&person=true