Biology subjects

Lilley, T. M.

Publications and source records attributed to Lilley, T. M..

5 recordsLinked to original sources

bioRxiv2023

When the host's away, the pathogen will play: the protective role of the skin microbiome during hibernation

The skin of animals is enveloped by a symbiotic microscopic ecosystem known as the microbiome. The host and microbiome exhibit a mutualistic relationship, collectively forming a single evolutionary unit sometimes referred to as a holobiont. Although the holobiome theory highlights the importance of the microbiome, little is known about how the skin microbiome contributes to protecting the host. Existing studies focus on humans or captive animals, but research in wild animals is in its infancy. Specifically, the protective role of the skin microbiome in hibernating animals remains almost entirely overlooked. This is surprising, considering the massive population declines in hibernating North American bats caused by the fungal pathogen Pseudogymnoascus destructans, which causes white-nose syndrome. Hibernation offers a unique setting in which to study the function of the microbiome because, during torpor, the hosts immune system becomes suppressed, making it susceptible to infection. We conducted a systematic review of peer-reviewed literature on the protective role of the skin microbiome in non-human animals. We selected 230 publications that mentioned pathogen inhibition by microbes residing on the skin of the host animal. We found that the majority of studies were conducted in North America and focused on the bacterial microbiome of amphibians infected by the chytrid fungus. Despite mentioning pathogen inhibition by the skin microbiome, only 30,4 % of studies experimentally tested the actual antimicrobial activity of symbionts. Additionally, only 7,8 % of all publications studied defensive cutaneous symbionts during hibernation. With this review, we want to highlight the knowledge gap surrounding skin microbiome research in hibernating animals. For instance, research looking to mitigate the effects of white-nose syndrome in bats should focus on the antifungal microbiome of Palearctic bats, as they survive exposure to the Pseudogymnoascus destructans -pathogen during hibernation. We also recommend future studies prioritize lesser-known microbial symbionts, such as fungi, and investigate the effects of a combination of anti-pathogen microbes, as both areas of research show promise as probiotic treatments. By incorporating the protective skin microbiome into disease mitigation strategies, conservation efforts can be made more effective.

evolutionary biology↗

bioRxiv2023

Reference genome for the Northern bat (Eptesicus nilssonii), a most northern bat species

The northern bat (Eptesicus nilssonii) is the most northern bat species in the world. Its distribution covers whole Eurasia, and the species is thus well adapted to different habitat types. However, recent population declines have been reported and rapid conservation efforts are needed. Here we present a high-quality de novo genome assembly of a female northern bat from Finland (BLF_Eptnil_asm_v1.0). The assembly was generated using a combination of Pacbio and Omni-C technologies. The primary assembly comprises 726 scaffolds spanning 2.0 Gb, represented by a scaffold N50 of 102 Mb, a contig N50 of 66.2 Mb, and a BUSCO completeness score of 93.73%. Annotation of the assembly identified 20,250 genes. This genome will be an important resource for the conservation and evolutionary genomic studies especially in understanding how rapid environmental changes affect northern species.

genomics↗

bioRxiv2023

Climatic factors and host species composition at hibernation sites drive the incidence of bat fungal disease

Emerging infectious diseases pose a serious threat to wildlife, and their occurrence will likely be further exacerbated due to climate change. The aim of our study was to investigate whether the occurrence of White-nose disease (WND), a fungal disease of hibernating bats, can be predicted using local climatic conditions and host species abundance at hibernation sites. In addition, we used our model to predict areas potentially at risk if the pathogen is introduced and investigated how the potential distribution of WND may shift in the future due to climate change. We employed logistic regression as part of our ecological niche modelling approach, integrating climate and census data as explanatory variables, along with WND status (the response variable) obtained from 448 hibernacula. This approach allowed us to predict regions at elevated risk of WND by applying these climatic variables to current global climatic conditions and a climate change scenario. A model incorporating data on mean annual surface temperature, precipitation, and three host species reliably predicted WND occurrence in Europe. This model demonstrated robust transferability beyond Europe, as confirmed by both theoretical and empirical assessments (e.g., accurately predicting the observed mortality events in North America). We identified several high-risk areas in the southern hemisphere and demonstrate that climate change may cause a remarkable shift in the distribution range of WND. Our results highlight the importance of environmental factors in controlling the manifestation of disease in localities where both the pathogen and suitable hosts are present. We pinpoint several areas requiring increased surveillance and precautions to avoid the introduction of the pathogen, and show that climate change has massive potential to reshape and expand these areas, putting new populations at risk.

ecology↗

bioRxiv2020

Ten-year projection of white-nose syndrome disease dynamics at the southern leading-edge of infection in North America

Predicting the emergence and spread of infectious diseases is critical for effective conservation of biodiversity. White-nose syndrome (WNS), an emerging infectious disease of bats, has resulted in high mortality in eastern North America. Because the fungal causative agent Pseudogymnoascus destructans is constrained by temperature and humidity, spread dynamics may vary greatly by geography. Environmental conditions in the southern part of the continent, where disease dynamics are typically studied, making it difficult to predict how the disease will manifest. Herein, we modeled the spread of WNS in Texas based on available cave densities and average dispersal distances of species occupying these sites, and projected these results out to 10 years. We parameterized a predictive model of WNS epidemiology and its effects on hibernatory bat populations with observed environmental data from bat hibernation sites in Texas. Our model suggests that bat populations in northern Texas will be more affected by WNS mortality than southern Texas. As such, we recommend prioritizing the preservation of large overwintering colonies of bats in north Texas through management actions. Our model further illustrates that infectious disease spread and infectious disease severity can become uncoupled over a gradient of environmental variation. Finally, our results highlight the importance of understanding host, pathogen and environmental conditions in various settings to elucidate what may happen across a breadth of environments.

ecology↗

bioRxiv2020

First record of a Nathusius' pipistrelle (Pipistrellus nathusii) overwintering at a latitude above 60°N

Highly mobile species are considered to be the first to respond to climate change by transforming their ranges of distribution. There is evidence suggesting that Pipistrellus nathusii, a long-distance migrant, is expanding both its reproduction and overwintering ranges to the North. We recorded the echolocation calls of bats at 16 sites in South-Western Finland on two consecutive winters, and detected calls of P. nathusii at one of the sites throughout the latter winter. To our knowledge, this is the northernmost observation of an overwintering P. nathusii, and further evidence that the species is already responding to climate change.

ecology↗