Biology subjects

Razgour, O.

Publications and source records attributed to Razgour, O..

5 recordsLinked to original sources

bioRxiv2026

Impact of sequencing approach on ecological inference from highly variable bat gut microbiomes

Understanding the functional potential of animal gut microbiomes requires analytical approaches that can accurately capture both taxonomic and functional diversity, particularly in hosts with samples with low and variable microbial DNA fractions, such as bats. Here, we compared 16S amplicon sequencing and genome-resolved metagenomics for characterising the gut microbiomes of three sympatric insectivorous bats (Pipistrellus kuhlii, Hypsugo ariel, and Cnephaeus bottae). Amplicon sequencing recovered 3,536 amplicon sequence variants (ASVs) spanning 29 microbial phyla, including five archaeal groups, while metagenomics yielded 135 metagenome-assembled genomes (MAGs) across 15 bacterial phyla. Alpha and beta diversity patterns differed significantly between approaches. Applying prevalence- and abundance-based filtering to amplicon data improved alpha diversity congruence with metagenomic profiles, indicating that low-abundance and rare ASVs inflate diversity estimates, while the low microbial DNA fractions in bat faeces challenge genome reconstruction of such taxa. Functional reconstructions diverged notably, with metagenomics-based functional profiles yielding consistently lower metabolic capacities than those indirectly inferred from 16S amplicon sequencing, both before and after prevalence- and abundance-based filtering, due to incompleteness of many reconstructed genomes. However, metagenome-assembled genomes harboured metabolic capacities missed by the indirect functional inference of metabarcoding, which largely rely on genomes of strains characterised in model organisms. Together, these findings highlight the influence of chosen methodology, host species, and data filtering on microbiome profiling in taxa with low microbial biomass. We propose practical guidelines to improve analytical consistency and reliability when studying gut microbiomes of bats and other hosts with similarly variable microbial communities.

microbiology↗

bioRxiv2025

Artificial light at night induces stress and affects evolutionary change in bats

Artificial light at night (ALAN), a pervasive component of urbanization, is rapidly transforming nocturnal environments and imposing novel selection pressures on wildlife. While behavioral responses to ALAN are increasingly well documented, physiological and evolutionary consequences are not well understood, limiting species conservation management. We used a multi-omics framework to investigate the ecological and evolutionary consequences of ALAN on a light sensitive species, the lesser horseshoe bat (Rhinolophus hipposideros), combining experiments with transcriptomics, population genomics and landscape ecology. Experimental light exposure resulted in 252 differentially expressed genes, enriched for functions in DNA damage repair, apoptosis regulation and oxidative stress mitigation. Whole genome sequencing identified genetic variation associated with ALAN and urbanization, including variants in genes linked to visual and neural function. Landscape analysis revealed that ALAN and distance to broadleaf woodland best explained patterns of population connectivity. These findings demonstrate the possible drivers behind behavioral responses, showing that ALAN can act both as an acute molecular stressor and contribute to evolutionary change, with possible consequences for movement ecology and local adaptation. Given the accelerating expansion of urbanization, understanding species-specific responses to ALAN across molecular, demographic and evolutionary timescales is critical for predicting outcomes for biodiversity and informing urban planning.

genomics↗

bioRxiv2023

Life on the edge: a new toolbox for population-level climate change vulnerability assessments

O_LIGlobal change is impacting biodiversity across all habitats on earth. New selection pressures from changing climatic conditions and other anthropogenic activities are creating heterogeneous ecological and evolutionary responses across many species geographic ranges. Yet we currently lack standardised and reproducible tools to effectively predict the resulting patterns in species vulnerability to declines or range changes. C_LIO_LIWe developed an informatic toolbox that integrates ecological, environmental and genomic data and analyses (environmental dissimilarity, species distribution models, landscape connectivity, neutral and adaptive genetic diversity and genotype-environment associations) to estimate population vulnerability. In our toolbox, functions and data structures are coded in a standardised way so that it is applicable to any species or geographic region where appropriate data are available, for example individual or population sampling and genomic datasets (e.g. RAD-seq, ddRAD-seq, whole genome sequencing data) representing environmental variation across the species geographic range. C_LIO_LIWe apply our toolbox to a georeferenced genomic dataset for the East African spiny reed frog (Afrixalus fornasini) to predict population vulnerability, as well as demonstrating that range loss projections based on adaptive variation can be accurately reproduced using data for two European bat species (Myotis escalerai, and M. crypticus). C_LIO_LIOur framework sets the stage for large scale, multi-species genomic datasets to be leveraged in a novel climate change vulnerability framework to quantify intraspecific differences in genetic diversity, local adaptation, range shifts and population vulnerability based on exposure, sensitivity, and range shift potential. C_LI

evolutionary biology↗

bioRxiv2023

Applying genomic approaches to identify historic population declines in European forest bats

O_LIAnthropogenically-driven environmental changes over the past two centuries have led to severe biodiversity loss, most prominently in the form of loss of populations and individuals. Better tools are needed to assess the magnitude of these wildlife population declines. Anecdotal evidence suggests European bat populations have suffered substantial declines in the past few centuries. However, there is little empirical evidence of these declines that can be used to put more recent population changes into historic context and set appropriate targets for species recovery. C_LIO_LIThis study is a collaboration between academics and conservation practitioners to develop molecular approaches capable of providing quantitative evidence of historic population changes and their drivers that can inform the assessment of conservation status and conservation management. We generated a genomic dataset for the Western barbastelle, Barbastella barbastellus, a globally Near Threatened and regionally Vulnerable bat species, including colonies from across the species British and Iberian ranges. We used a combination of landscape genetics and approximate Bayesian computation model-based inference of demographic history to identify both evidence of population size changes and possible drivers of these changes. C_LIO_LIWe found that levels of genetic diversity increased and inbreeding decreased with increasing broadleaf woodland cover around the colony location. Genetic connectivity was impeded by artificial lights and facilitated by the combination of rivers and broadleaf woodland cover. C_LIO_LIThe demographic history analysis showed that both the northern and southern British barbastelle populations have declined by 99% over the past 330-548 years. These declines may have been triggered by loss of large oak trees and native woodlands due to shipbuilding during the early colonial period. C_LIO_LISynthesis and applications. Genomic approaches can be applied to provide a better understanding of the conservation status of threatened species, within historic and contemporary context, and inform their conservation management. This study shows how we can bridge the implementation gap and promote the application of genomics in conservation management through co-designing studies with conservation practitioners and co-developing applied management targets and recommendations. C_LI

genomics↗

bioRxiv2019

Diet diversification shapes broad-scale distribution patterns in European bats

Large-scale species distributions have been traditionally attributed to physiological traits related to abiotic factors, while behavioural features linked to biotic interactions have received little attention. We tested the relationship between trophic and spatial niche breadths through combining species distribution modelling with dietary DNA metabarcoding of over 400 bats sampled across Europe belonging to seven species. Our results point to a causality cascade between hunting plasticity, trophic niche breadth and spatial niche breadth, and thus indicate that behavioral plasticity and dietary diversification can contribute to shaping broad-scale species distributions.

ecology↗