The host‐associated microbiome is increasingly recognized as a critical player in health and immunity. Recent studies have shown that disruption of commensal microbial communities can contribute to ...disease pathogenesis and severity. Santa Catalina Island foxes (Urocyon littoralis catalinae) present a compelling system in which to examine microbial dynamics in wildlife due to their depauperate genomic structure and extremely high prevalence of ceruminous gland tumors. Although the precise cause is yet unknown, infection with ear mites (Otodectes cynotis) has been linked to chronic inflammation, which is associated with abnormal cell growth and tumor development. Given the paucity of genomic variation in these foxes, other dimensions of molecular diversity, such as commensal microbes, may be critical to host response and disease pathology. We characterized the host‐associated microbiome across six body sites of Santa Catalina Island foxes, and performed differential abundance testing between healthy and mite‐infected ear canals. We found that mite infection was significantly associated with reduced microbial diversity and evenness, with the opportunistic pathogen Staphylococcus pseudintermedius dominating the ear canal community. These results suggest that secondary bacterial infection may contribute to the sustained inflammation associated with tumor development. As the emergence of antibiotic resistant strains remains a concern of the medical, veterinary, and conservation communities, uncovering high relative abundance of S. pseudintermedius provides critical insight into the pathogenesis of this complex system. Through use of culture‐independent sequencing techniques, this study contributes to the broader effort of applying a more inclusive understanding of molecular diversity to questions within wildlife disease ecology.
see also the Perspective by Trevelline et al
While most wildlife researchers and managers agree that human tolerance is critical in determining the success and persistence of wildlife populations, the concept of tolerance has lacked ...definitional precision and operational consistency in the literature. This inconsistency has opened the door to a multiplicity of human-wildlife tolerance studies that present tolerance as either an attitude, a normative belief, or a behavioral intention, making it difficult to compare results across study systems. We drew upon foundational human dimensions of wildlife, sociology, and animal behavior studies to propose an integrated framework of human-wildlife tolerance, defined here as "accepting wildlife and/or wildlife behaviors that one dislikes." This definition clarifies the term "tolerance" by incorporating attitudes and acceptability (antecedents of behavior) as two distinct but interrelated axes. We also develop a typology framework that will provide insight into changing responses to human-wildlife conflict, and help evaluate future tolerance-boosting policy or educational interventions.
Ceruminous gland tumours are highly prevalent in the ear canals of Santa Catalina Island foxes (Urocyon littoralis catalinae). Previous work suggests that tumours may result from a combination of ...ectoparasites, disruption of the host‐associated microbiome, and host immunopathology. More specifically, ear mite infection has been associated with broad‐scale microbial dysbiosis marked by secondary bacterial infection with the opportunistic pathogen Staphylococcus pseudintermedius. Together, ear mites and S. pseudintermedius probably sustain chronic inflammation and promote conditions suitable for tumour development. In the present study, we expanded upon this framework by constructing otic microbial community networks for mite‐infected and uninfected foxes sampled in 2017–2019. Across sampling years, we observed consistent signatures of microbial dysbiosis in mite‐infected ear canals, including reduced microbial diversity and shifted abundance towards S. pseudintermedius. Network analysis further revealed that mite infection disrupts overall community structure. In mite‐infected networks, interaction strengths between taxa were generally weaker, and numerous subnetworks disappeared altogether. We also found that two strains of S. pseudintermedius connected to the main network, suggesting that multistrain biofilm formation may be occurring. In contrast, S. pseudintermedius is peripheral in the uninfected network, with its only connections including a second strain of S. pseudintermedius and the possible competitor Acinetobacter rhizosphaerae. Finally, the lineup of potential keystone taxa shifted across disease states. Fusobacteria spp., a carcinogenesis‐promoting microbe, assumed a keystone role in the mite‐infected community. Considered together, these findings provide insights into how mite infection may destabilize the microbiome and ultimately contribute to tumour development in this island endemic species.
Abstract
Animals vary considerably in the amount of behavioral plasticity they exhibit in daily activity timing and temporal niche switching. It is not well understood how environmental factors drive ...changes in temporal activity or how interspecific differences in the plasticity of activity timing ultimately manifest in free-living animals. Here, we investigated the temporal structure and organization of activity patterns of two insular mammalian carnivores living in sympatry, the island fox (Urocyon littoralis) and island spotted skunk (Spilogale gracilis amphiala). Using collar-mounted accelerometers, we assessed the plasticity of behavioral activity rhythms in foxes and skunks by investigating how environmental factors drive the distribution of locomotor activity across the day and year, and subsequently examined the dynamics of temporal niche overlap between the two species. We documented that foxes express phenotypic plasticity in daily activity timing across the year, ranging from nocturnal to diurnal to crepuscular rhythms depending on the individual and time of year. Most notably, foxes increased the proportion of daytime activity as seasonal temperatures decreased. Overall, activity patterns of foxes were consistent with the circadian thermoenergetics hypothesis, which posits that animals that switch their patterns of activity do so to coincide with the most energetically favorable time of day. In contrast to foxes, skunks exhibited little behavioral plasticity, appearing strictly nocturnal across the year. While the duration of skunk activity bouts increased with the duration of night, timing of activity onset and offset extended into daytime hours during summer when the duration of darkness was shortest. Analysis of temporal niche overlap between foxes and skunks suggested that niche overlap was highest during summer and lowest during winter and was dictated primarily by temporal niche switching in foxes, rather than skunks. Collectively, our results highlight how interspecific asymmetries in behavioral plasticity drive dynamic patterns of temporal niche overlap within an island carnivore community.
California's Channel Islands are home to two endemic mammalian carnivores: island foxes (Urocyon littoralis) and island spotted skunks (Spilogale gracilis amphiala). Although it is rare for two ...insular terrestrial carnivores to coexist, these known competitors persist on both Santa Cruz Island and Santa Rosa Island. We hypothesized that examination of their gut microbial communities would provide insight into the factors that enable this coexistence, as microbial symbionts often reflect host evolutionary history and contemporary ecology. Using rectal swabs collected from island foxes and island spotted skunks sampled across both islands, we generated 16S rRNA amplicon sequencing data to characterize their gut microbiomes. While island foxes and island spotted skunks both harbored the core mammalian microbiome, host species explained the largest proportion of variation in the dataset. We further identified intraspecific variation between island populations, with greater differentiation observed between more specialist island spotted skunk populations compared to more generalist island fox populations. This pattern may reflect differences in resource utilization following fine‐scale niche differentiation. It may further reflect evolutionary differences regarding the timing of intraspecific separation. Considered together, this study contributes to the growing catalog of wildlife microbiome studies, with important implications for understanding how eco‐evolutionary processes enable the coexistence of terrestrial carnivores–and their microbiomes–in island environments.
We examined the host‐associated microbiome of Channel Island foxes and island spotted skunks in the context of fine‐scale niche differentiation, as it is rare for two endemic, insular mesocarnivores to coexist. We found intraspecific variation between island populations, with greater differentiation observed between more specialist island spotted skunk populations compared to more generalist island fox populations. This pattern may reflect differences in resource utilization following fine‐scale niche differentiation, as well as evolutionary differences regarding the timing of intraspecific separation.
The clinical manufacture of antigen-specific cytotoxic T lymphocytes (CTLs) for adoptive immunotherapy is limited by the complexity and time required to produce large numbers with the desired ...function and specificity. The culture conditions required are rigorous, and in some cases only achieved in 2-cm wells in which cell growth is limited by gas exchange, nutrients, and waste accumulation. Bioreactors developed to overcome these issues tend to be complex, expensive, and not always conducive to CTL growth. We observed that antigen-specific CTLs undergo 7 to 10 divisions poststimulation. However, the expected CTL numbers were achieved only in the first week of culture. By recreating the culture conditions present during this first week-low frequency of antigen-specific T cells and high frequency of feeder cells-we were able to increase CTL expansion to expected levels that could be sustained for several weeks without affecting phenotype or function. However, the number of 24-well plates needed was excessive and cultures required frequent media changes, increasing complexity and manufacturing costs. Therefore, we evaluated novel gas-permeable culture devices (G-Rex) with a silicone membrane at the base allowing gas exchange to occur uninhibited by the depth of the medium above. This system effectively supports the expansion of CTL and actually increases output by up to 20-fold while decreasing the required technician time. Importantly, this amplified cell expansion is not because of more cell divisions but because of reduced cell death. This bioprocess optimization increased T-cell output while decreasing the complexity and cost of CTL manufacture, making cell therapy more accessible.
Molecular alterations in cancer can cause phenotypic changes in tumor cells and their micro-environment. Routine histopathology tissue slides - which are ubiquitously available - can reflect such ...morphological changes. Here, we show that deep learning can consistently infer a wide range of genetic mutations, molecular tumor subtypes, gene expression signatures and standard pathology biomarkers directly from routine histology. We developed, optimized, validated and publicly released a one-stop-shop workflow and applied it to tissue slides of more than 5000 patients across multiple solid tumors. Our findings show that a single deep learning algorithm can be trained to predict a wide range of molecular alterations from routine, paraffin-embedded histology slides stained with hematoxylin and eosin. These predictions generalize to other populations and are spatially resolved. Our method can be implemented on mobile hardware, potentially enabling point-of-care diagnostics for personalized cancer treatment. More generally, this approach could elucidate and quantify genotype-phenotype links in cancer.
Increased oxidative stress is a major contributor to the development and progression of heart failure, however, our knowledge on the role of the distinct NADPH oxidase (NOX) isoenzymes, especially on ...NOX4 is controversial. Therefore, we aimed to characterize NOX4 expression in human samples from healthy and failing hearts. Explanted human heart samples (left and right ventricular, and septal regions) were obtained from patients suffering from heart failure of ischemic or dilated origin. Control samples were obtained from donor hearts that were not used for transplantation. Deep RNA sequencing of the cardiac transcriptome indicated extensive alternative splicing of the NOX4 gene in heart failure as compared to samples from healthy donor hearts. Long distance PCR analysis with a universal 5'-3' end primer pair, allowing amplification of different splice variants, confirmed the presence of the splice variants. To assess translation of the alternatively spliced transcripts we determined protein expression of NOX4 by using a specific antibody recognizing a conserved region in all variants. Western blot analysis showed up-regulation of the full-length NOX4 in ischemic cardiomyopathy samples and confirmed presence of shorter isoforms both in control and failing samples with disease-associated expression pattern. We describe here for the first time that NOX4 undergoes extensive alternative splicing in human hearts which gives rise to the expression of different enzyme isoforms. The full length NOX4 is significantly upregulated in ischemic cardiomyopathy suggesting a role for NOX4 in ROS production during heart failure.
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