Biology subjects

Toshkova, N.

Publications and source records attributed to Toshkova, N..

5 recordsLinked to original sources

bioRxiv2025

How do urban-dwelling bats cope with urbanisation? Sex-dependent plasticity of stress, microbiome and pathogen shedding

Understanding wildlifes stress and infection response patterns is crucial, especially for species like bats that are ecologically important and potential zoonotic reservoirs. While highly sensitive to habitat destruction and land use change, bats have shown adaptability in human-modified landscapes. This study investigates the impact of urbanisation on the endemic Reunion free-tailed bat (Mormopterus francoismoutoui), which roosts in a variety of rapidly urbanised habitats. We analysed 412 urine samples from 11 roosts across Reunion Island, covering a gradient of urban and agricultural land use. We measured urinary cortisol, microbiome diversity and the shedding of Leptospira bacteria and paramyxovirus. After accounting for natural cortisol level variations due to circadian rhythm, age, sex, reproduction and capture-induced stress, we found that bats roosting in agricultural and urban areas were in better condition and had lower cortisol levels, suggesting adaptation to human-modified landscapes. Less-stressed bats had more diverse urinary microbiomes and reduced pathogen shedding, suggesting that landscape modifications may indirectly alter the natural epidemiology of bat-borne infectious agents. These patterns were particularly pronounced in females, supporting sex-dependent plasticity to urbanisation in bats. Our study highlights how rapid urbanisation may elicit plastic responses in bats, with potential cascading effects on zoonotic risk of transmission.

ecology↗

bioRxiv2024

An integrative approach for profiling antibody responses in bats to human pathogens

Serological analyses are a fundamental tool for identifying infections by a wide range of pathogens. They offer a current overview of pathogen prevalence and insight into past infections. This is particularly relevant for bats, given their high capacity to tolerate pathogens and their role as reservoirs of zoonotic diseases. At present, serological studies in bats have predominantly employed traditional techniques such as enzyme-linked immunosorbent assay (ELISA). However, these techniques have several limitations, including low throughput and the lack of bat-specific detection antibodies. To address these limitations, we developed an integrative approach for systemic serological analyses based on microarray technology, which enables the simultaneous detection of bat IgG antibodies against >190 human pathogens (viruses, bacteria, protists). The results of our analyses demonstrated an antibody response in bats targeting multiple epitopes from different pathogens, thereby proving the methods high-throughput capability. Furthermore, this approach does not rely on the use of IgG detection reagents, thereby allowing for its application to a diverse range of bat species. This assay offers insights into the infections of bats with pathogens, thereby enhancing our comprehension of zoonotic disease dynamics and facilitating targeted pathogen surveillance.

immunology↗

bioRxiv2024

The best of two worlds: using stacked generalization for integrating expert range maps in species distribution models

Species distribution models (SDMs) are powerful tools for assessing suitable habitat across large areas and at fine spatial resolution. Yet, the usefulness of SDMs for mapping species realized distributions is often limited, since data biases or missing information on dispersal barriers or biotic interactions hinder them from accurately delineating species range limits. One way to overcome this limitation is to integrate SDMs with expert range maps, which provide coarse-scale information on the extent of species ranges that is complementary to information offered by SDMs. Here, we propose a new approach for integrating expert range maps in SDMs based on an ensemble method called stacked generalization. Specifically, our approach relies on training a meta-learner regression model using predictions from one or more SDM algorithms alongside the distance of training points to expert-defined ranges as predictor variables. We demonstrate our approach with an occurrence dataset for 49 bat species covering four biodiversity hotspots in the Eastern Mediterranean, Western Asia, and Central Asia. Our approach offers a flexible method to integrate expert range maps with any combination of SDM modeling algorithms, thus facilitating the use of algorithm ensembles. In addition, it provides a novel, data-driven way to account for uncertainty in expert-defined ranges not requiring prior knowledge about their accuracy, which is often lacking. Our approach holds considerable promise for better understanding species distributions, and thus for biogeographical research and conservation planning. In addition, our work highlights the overlooked potential of stacked generalization as an ensemble method in species distribution modeling.

ecology↗

bioRxiv2023

Temperature sensitivity of bat antibodies links metabolic state with antigen-recognition diversity

Bat immune system features multiple unique properties such as dampened inflammatory responses and increased tissue protection, explaining their long lifespan and tolerance to viral infections. Here, we demonstrated that body temperature fluctuations corresponding to different physiological states in bats exert a dramatic impact on their antibody repertoires. At elevated temperatures typical for flight, IgG from Myotis myotis and Nyctalus noctula showed elevated antigen binding strength and diversity, recognizing both pathogen-derived antigens and autoantigens. The opposite was observed at temperatures reflecting inactive physiological states. This behavior was not observed for IgG antibodies of human and other mammals, or antibodies of birds. Importantly, diversification of bat antibody specificities resulted in preferential recognition of damaged endothelial and epithelial cells, indicating an anti-inflammatory function. The temperature-sensitivity of bat antibodies was mediated by the variable regions of immunoglobulin molecules. Additionally, we revealed specific molecular features of bat IgG such as low thermodynamic stability and implication of hydrophobic interactions in antigen binding as well as high prevalence of polyreactivity. Overall, our results extend the understanding of bat tolerance to disease and inflammation and highlight the link between metabolism and immunity. This might have important repercussions for human health in the future.

immunology↗

bioRxiv2019

Differential oxidative costs of locomotory and genital damage in an orb-weaving spider

In animals that regularly experience tissue loss, physiological responses may have evolved to overcome the related costs. Changes in oxidative status may reflect such self-maintenance mechanisms. Here, we investigated how markers of oxidative status varied in female orb-weaving spiders (Larinia jeskovi) by mimicking two distinct types of tissue loss they may naturally encounter: damage to their locomotory system and damage to their external genital structure, as inflicted by males to females during copulation (external female genital mutilation). Damage to the locomotory system resulted in a significant shift in the oxidative status reflecting investment into self-maintenance. In contrast, the loss of the genital structure did not result in quantitative changes of oxidative markers. The lack of response to genital mutilation suggests that genital mutilation is physiologically not costly for female spiders. The cost incurred to females rather arises from genital mutilation preventing the females from remating with another male.

evolutionary biology↗