Biology subjects

Wanelik, K. M.

Publications and source records attributed to Wanelik, K. M..

8 recordsLinked to original sources

bioRxiv2025

The gut microbiota of two rodents varies over fine spatial scales yet is minimally influenced by the environmental microbiota

The gut microbiota of animals varies considerably between individuals within the same population. Given the importance of gut microbiota composition for animal biology and ultimately fitness (e.g., via effects on physiology, immunity and even behaviour), there is considerable interest in understanding which factors shape its variation. Here, we tested whether local environments are an important source of microbial diversity for mammalian guts, by sampling the faecal microbiota of wood mice (Apodemus sylvaticus) and bank voles (Myodes glareolus), as well as environmental microbiotas, across Wytham Woods. We first find that both species share a low proportion of their microbiotas with local environments and that most shared microbes are aerotolerant. We then detect that microgeographic patterns (namely soil chemistry) are associated with variation in the microbiota of local environments but this does not translate to microbiota variation between animals. Nevertheless, between-individual gut microbiota variation is strongly associated with where animals are sampled, suggesting that other local factors (e.g., biotic environment, interactions between individuals) are much stronger predictors of microbiota composition than local abiotic factors. Finally, we find that wood mice (but not bank voles) are more likely to share microbes with local than non-local environments, but that local environments still contribute little to animal microbiotas. Our findings challenge the prevailing view that mammalian microbiotas are strongly affected by local soil chemistry or the abiotic environment, while further supporting the prediction that biotic and/or other intrinsic factors (which can also act on a local scale) contribute more to microbiota composition.

ecology↗

bioRxiv2024

Superspreaders have lower gut microbial alpha-diversity and distinct gut microbial composition in a natural rodent population

The microbiome is well-known to drive variation in host states (e.g., behaviour, or immunity) that would be expected to modulate the spread of infectious disease - but the role of microbiotal interactions in promoting superspreading by individuals is poorly understood. Superspreaders are individuals with a strongly disproportionate contribution to pathogen transmission, and they come in two forms. Supershedders transmit infection to more individuals because they shed higher levels of a pathogen. Supercontacters transmit infection to more individuals because they have a larger number of social contacts. We explore associations between the gut microbiota and these two forms of superspreading in a wild rodent model - Bartonella spp. bacteraemia in the field vole (Microtus agrestis). We find evidence that, first, individuals fall into distinct shedding and contacting clusters, and second, that higher-contacters have lower and more variable gut microbial alpha-diversity than lower-contacters. We also show evidence that both higher-shedders and higher-contacters have distinct gut microbial composition, and identify OTUs which are differentially abundant in the gut microbiota of these two classes of individuals when compared to lower-shedders and lower-contacters respectively. We find that the Muribaculaceae are associated with differences in both shedding and contacting, and discuss potential mechanisms by which they may be acting on these host traits.

ecology↗

bioRxiv2022

Maternal transmission gives way to social transmission during gut microbiota assembly in wild mice

The mammalian gut microbiota influences a wide array of phenotypes and is considered a key determinant of fitness, yet knowledge about the transmission routes by which gut microbes colonise hosts in natural populations remains limited. Here, we use an intensively studied wild population of wood mice (Apodemus sylvaticus) to examine how vertical (maternal) and horizontal (social) transmission routes influence gut microbiota composition throughout life. We identify independent signals of maternal transmission (sharing of taxa between a mother and her offspring) and social transmission (sharing of taxa predicted by the social network), whose relative magnitudes shift as hosts age. In early life, gut microbiota composition is predicted to a similar extent by both maternal and social relationships, but by adulthood the impact of maternal transmission becomes undetectable, leaving only a signal of social transmission. By exploring which taxa drive the maternal transmission signal, we further identify a candidate maternally-transmitted bacterial family in wood mice, the Lactobacillaceae. Overall, our findings suggest a shifting transmission landscape for wild mice, with a mothers influence on microbiota composition waning as offspring age, while the impact of social contacts remains strong and consistent.

microbiology↗

bioRxiv2021

Early-life immune expression profiles predict later life health and fitness in a wild rodent

Individuals differ in the nature of the immune responses they produce, affecting disease susceptibility and ultimately health and fitness. These differences have been hypothesised to have an origin in events experienced early in life that then affect trajectories of immune development and responsiveness. Here we investigate early life influences on immune expression profiles using a natural population of field voles, Microtus agrestis, in which we are able to monitor variation between and within individuals though time by repeat (longitudinal) sampling of individually marked animals. We analysed the co-expression of 20 immune genes in early life to create a correlational network consisting of three main clusters, one of which (containing Gata3, Il10 and Il17) was associated with later life reproductive success and susceptibility to chronic bacterial (Bartonella) infection. More detailed analyses supported associations between early life expression of Il17 and reproductive success later in life, and of increased Il10 expression early in life and later infection with Bartonella. We also found significant association between an Il17 genotype and the early life expression of Il10. Our results demonstrate that immune expression profiles can be manifested during early life with effects that persist through adulthood and that shape the variability among individuals in susceptibility to infection and fitness widely seen in natural populations.

ecology↗

bioRxiv2019

IgE receptor polymorphism predicts divergent, sex-specific inflammatory modes and fitness costs in a wild rodent

The genotype of an individual is an important predictor of their immune function, and subsequently, their ability to control or avoid infection and ultimately contribute offspring to the next generation. However, the same genotype, subjected to different intrinsic and/or extrinsic environments can also result in different phenotypic outcomes, which can be missed in controlled laboratory studies. Natural wildlife populations, which capture both genotypic and environmental variability, provide an opportunity to more fully understand the phenotypic expression of genetic variation. We identified a synonymous polymorphism in the high-affinity Immunoglobulin E (IgE) receptor (GC and non-GC haplotypes) that has sex-dependent effects on immune gene expression, susceptibility to infection and reproductive success of individuals in a natural population of field voles (Microtus agrestis). We found that the effect of the GC haplotype on the expression of immune genes differed between sexes. While males with the GC haplotype had upregulated more pro-inflammatory genes, including the cytokine Il33, females had upregulated more anti-inflammatory genes, including the cytokine inhibitor Socs3. Furthermore we found an effect of the GC haplotype on the probability of infection with a common microparasite, Babesia microti, in females - with females carrying the GC haplotype being more likely to be infected. Finally, we found an effect of the GC haplotype on reproductive success in males - with males carrying the GC haplotype having a lower reproductive success. This is a rare example of a polymorphism whose consequences we are able to follow across immunity, infection and reproduction for both males and females in a natural population.

ecology↗

bioRxiv2019

How to characterise shared space use networks

Studying the social behaviour of small or cryptic species often relies on constructing networks from sparse point-based observations of individuals (e.g. live trapping data). Such an approach assumes that individuals that have been asynchronously detected in the same trapping location will also be more likely to have interacted. However, there is very little guidance on how much data are required for making robust co-trapping networks. In this study, we propose that co-trapping networks broadly assume that co-trapping captures shared space use (and, subsequently, likelihood of interacting), and that it may be more parsimonious to directly model shared space use. We first use empirical data to highlight that characteristics of how animals use space can help us to establish new ways to model the potential for individuals to co-occur. We then show that a method that explicitly models individuals home ranges and subsequent overlap in space among individuals (spatial overlap networks) requires fewer data for inferring observed networks that are correlated with the true shared space use network (relative to co-trapping networks constructed from space sharing events). Further, we show that shared space use networks based on estimating spatial overlap are also more powerful for detecting biological effects present in the true shared space use network. Finally, we discuss when it is appropriate to make inferences about social interactions from shared space use. Our study confirms the potential for using sparse trapping data from cryptic species to address a range of important questions in ecology and evolution. Significance statementCharacterising animal social networks requires repeated (co-)observations of individuals. Collecting sufficient data to characterise the connections among individuals represents a major challenge when studying cryptic organisms--such as small rodents. This study draws from existing spatial mark-recapture data to inspire an approach that constructs networks by estimating space use overlap (representing the potential for interactions) from observations of individuals in the same location (e.g. a trap). We then use simulations to demonstrate that the method provides consistently higher correlations between inferred (or observed) networks and the true underlying network compared to current approaches, and requires fewer observations to reach higher correlations. We further demonstrate that these improvements translate to greater network accuracy and to more power for statistical hypothesis testing.

ecology↗

bioRxiv2019

Decomposing variation in immune response in a wild rodent population

Individuals vary in their immune response and, as a result, some are more susceptible to infectious disease than others. Little is known about which components of immune pathways are responsible for this variation, but understanding these underlying processes could allow us to predict the outcome of infection for an individual, and to manage their health more effectively. In this study, we describe transcriptome-wide variation in immune response (to a standardised challenge) in a wild population of field voles (Microtus agrestis). We find that this variation can be categorised into three main types. We also identify markers, across these three categories, which display particularly strong individual variation in response. This work shows how a simple standardised challenge performed on a natural population can reveal complex patterns of natural variation in immune response.

ecology↗

bioRxiv2019

Breaking barriers: The effect of protected characteristics and their intersectionality on career transition in academics

Lay summaryIn the past decade the scientific community has been trying to tackle the historical underrepresentation of women in science and the fact that gender can constitute a barrier to career success. However, other characteristics, such as being of an ethnic minority or coming from an under-privileged background, have received less attention. In this study we find that ethnicity and socioeconomic status impact detrimentally on career progression in early career scientists, despite the fact that gender is more likely to be reported as a barrier. Our data suggest we need to widen the discussion regarding diversity and equality in science to incorporate potential barriers to career success in addition to gender.\n\nAbstractThe academic disciplines of Science Technology Engineering and Mathematics (STEM) have long suffered from a lack of diversity. While in recent years there has been some progress in addressing the underrepresentation of women in STEM subjects, other protected characteristics have received less attention. In this study, we survey early career scientists in the fields of ecology, evolutionary biology, behaviour, and related disciplines. We (i) quantitatively examine the effect of protected characteristics and their intersectionality on career transition, and (ii) provide practical suggestions, based on the qualitative responses of those surveyed, for overcoming some of the barriers we identified. We found that socioeconomic background and ethnicity impacted negatively on the quantitative measures of career progression we examined. Respondents that were female, LGBT, and from a lower socioeconomic background were more likely to report having faced a barrier, and the most frequent barrier named was related to gender. Our results suggest that respondents may have felt more confident discussing the experiences they have had related to their gender, potentially because there is now widespread discourse on this subject. However, respondents were less likely to discuss barriers they have faced in relation to ethnicity and socioeconomic status, despite the fact that the data indicates these are more detrimental to career progression. This may reflect the fact that these characteristics have received less attention, and are therefore deemed more sensitive. We hope that this study will stimulate wider discussion, and help to inform strategies to address the underrepresentation of minority groups in STEM subjects.

scientific communication and education↗