Somatic mutation rates scale with lifespan across mammals.

The rates and patterns of somatic mutation in normal tissues are largely unknown outside of humans1-7. Comparative analyses can shed light on the diversity of mutagenesis across species, and on long-standing hypotheses about the evolution of somatic mutation rates and their role in cancer and ageing. Here we performed whole-genome sequencing of 208 intestinal crypts from 56 individuals to study the landscape of somatic mutation across 16 mammalian species. We found that somatic mutagenesis was dominated by seemingly endogenous mutational processes in all species, including 5-methylcytosine deamination and oxidative damage. With some differences, mutational signatures in other species resembled those described in humans8, although the relative contribution of each signature varied across species. Notably, the somatic mutation rate per year varied greatly across species and exhibited a strong inverse relationship with species lifespan, with no other life-history trait studied showing a comparable association. Despite widely different life histories among the species we examined-including variation of around 30-fold in lifespan and around 40,000-fold in body mass-the somatic mutation burden at the end of lifespan varied only by a factor of around 3. These data unveil common mutational processes across mammals, and suggest that somatic mutation rates are evolutionarily constrained and may be a contributing factor in ageing.

Presumed hemocytic neoplasms in scorpions.

Although neoplasia has been documented in invertebrates, it has not been reported in scorpions. This report describes presumed hemocytic neoplasia in 2 scorpions: a >3-year-old, female emperor scorpion (Pandinus imperator) and a >4-year-old, male, Asian forest scorpion (Heterometrus sp.). The emperor scorpion had a 1-month history of body wall swelling separating the exoskeleton of the caudal opisthosoma. At necropsy, this corresponded to a white mass in the caudal coelom. The forest scorpion was found dead and processed whole for histology, at which point multiple masses were identified in the coelom and invading skeletal muscle. Histologically, both masses were composed of sheets of hemocytes with round to oval nuclei; eosinophilic, periodic acid Schiff-positive, cytoplasmic granules; mild cellular atypia; and low mitotic rates. Features of inflammation (e.g., melanization and nodulation) were not observed. These masses were diagnosed as a hemocytoma (emperor scorpion) and a hemocytic sarcoma (forest scorpion), possibly of plasmatocyte origin.

Insights into the formation and diversification of a novel chiropteran wing membrane from embryonic development.

BACKGROUND: Through the evolution of novel wing structures, bats (Order Chiroptera) became the only mammalian group to achieve powered flight. This achievement preceded the massive adaptive radiation of bats into diverse ecological niches. We investigate some of the developmental processes that underlie the origin and subsequent diversification of one of the novel membranes of the bat wing: the plagiopatagium, which connects the fore- and hind limb in all bat species. RESULTS: Our results suggest that the plagiopatagium initially arises through novel outgrowths from the body flank that subsequently merge with the limbs to generate the wing airfoil. Our findings further suggest that this merging process, which is highly conserved across bats, occurs through modulation of the programs controlling the development of the periderm of the epidermal epithelium. Finally, our results suggest that the shape of the plagiopatagium begins to diversify in bats only after this merging has occurred. CONCLUSIONS: This study demonstrates how focusing on the evolution of cellular processes can inform an understanding of the developmental factors shaping the evolution of novel, highly adaptive structures.

A SYSTEMATIC REVIEW OF RETROSPECTIVE MORBIDITY AND MORTALITY STUDIES ON CAPTIVE WILDLIFE SPECIES.

Zoological institutions manage animals for conservation, education, entertainment, and research purposes. Zoological staff have a responsibility to safeguard the welfare of animals in their care. Retrospective morbidity and/or mortality studies (MMSs) can be useful tools to highlight common diseases in captive wildlife populations. There is currently no standardized methodology for conducting MMSs. Variation in the methodology of MMSs, particularly the categorization of diseases, can make comparisons between studies challenging and may limit the applicability of the results. A Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) compliant systematic review was performed, which identified 67 MMSs describing 146 species of captive wildlife. These MMSs are becoming more common and were predominantly performed on mammals (76/146). Prospective authors are encouraged to perform MMSs on amphibians, birds, reptiles, fish, and invertebrates. The studied animals were mostly managed at institutions in the United States of America (28/67, 41.2%) and Europe (14/67, 20.9%). Classifying individuals into age groups facilitates the identification of disease trends within age classes. Only 22/67 (32.8%) studies cited justification for their age classification; classifications should be based on a referenced source on the breeding biology of the studied species. There is variation in the body systems used by authors and into which system a disease is categorized, which makes study comparisons challenging. Diseases were predominantly categorized by etiology and body system (28/77, 36.4%). Because of its ubiquity, the use of the categorization system employed by the pathology module of the Zoological Information Management System is recommended as a useful standard. This system is imperfect, and amendments to it are suggested. The results and recommendations of this study were discussed with a panel of zoo and wildlife experts; guidelines have been formulated for prospective authors aiming to conduct MMSs in captive wildlife.

FIVE YEARS OF PARTULA SNAIL PRE-EXPORT HEALTH SCREENING.

Between 2015 and 2019, a health screening was carried out annually on captive-bred Partula snails prior to export for reintroduction as part of an international effort to repopulate areas of French Polynesia, where the snails were extinct or critically endangered. In total, 129 separate tank populations of 12 different species were screened at ZSL London Zoo. Wet mounts and smears stained with modified Ziehl-Neelsen (MZN) of 535 fecal samples were examined, and 45% contained flagellated protozoa, and 35.5% had MZN-positive oocysts, measuring 3-5 µm in diameter. Smaller (2 µm) presumptive spores, MZN-positive bacilli, ciliated protozoa and nematodes were recorded less frequently. Fecal bacterial culture yielded mixed species, with a clear predominance of Myroides species (88.9% of samples). The MZN-positive oocysts (3-5 µm) were present in 6.5% of impression smears from the apices of 432 snails examined postmortem, plus acid-fast bacilli in a few cases, but no 2 µm spores. Mixed bacteria were cultured from coelomic swabs, with Myroides species again the most common (63.5%). Histologic examination was carried out on 292 snails. Autolysis affected almost 90% of those found dead but only 3.4% of euthanized snails. Histology commonly identified microsporidial sporocysts in the digestive gland and midgut epithelium of all but two species. Intracellular, extracytoplasmic Cryptosporidium-like organisms were also common in the midgut but were only observed when snails were fixed in 10% formalin (2017-2019), not ethanol. There were no clear pathologic changes associated with either organism. Pigmented hemocytic nodules were commonly observed, most frequently in the foot process; these were either age related or evidence of prior chronic inflammatory reaction and of low clinical significance. With no evidence of poor health and no significant organisms found, a total of 4,978 individuals representing 12 species were exported for reintroduction.

Adaptation and Cryptic Pseudogenization in Penguin Toll-Like Receptors.

Penguins (Sphenisciformes) are an iconic order of flightless, diving seabirds distributed across a large latitudinal range in the Southern Hemisphere. The extensive area over which penguins are endemic is likely to have fostered variation in pathogen pressure, which in turn will have imposed differential selective pressures on the penguin immune system. At the front line of pathogen detection and response, the Toll-like receptors (TLRs) provide insight into host evolution in the face of microbial challenge. TLRs respond to conserved pathogen-associated molecular patterns and are frequently found to be under positive selection, despite retaining specificity for defined agonist classes. We undertook a comparative immunogenetics analysis of TLRs for all penguin species and found evidence of adaptive evolution that was largely restricted to the cell surface-expressed TLRs, with evidence of positive selection at, or near, key agonist-binding sites in TLR1B, TLR4, and TLR5. Intriguingly, TLR15, which is activated by fungal products, appeared to have been pseudogenized multiple times in the Eudyptes spp., but a full-length form was present as a rare haplotype at the population level. However, in vitro analysis revealed that even the full-length form of Eudyptes TLR15 was nonfunctional, indicating an ancestral cryptic pseudogenization prior to its eventual disruption multiple times in the Eudyptes lineage. This unusual pseudogenization event could provide an insight into immune adaptation to fungal pathogens such as Aspergillus, which is responsible for significant mortality in wild and captive bird populations.

Spatiotemporal Trends Spanning Three Decades Show Toxic Levels of Chemical Contaminants in Marine Mammals.

Despite their ban and restriction under the 2001 Stockholm Convention, persistent organic pollutants (POPs) are still widespread and pervasive in the environment. Releases of these toxic and bioaccumulative chemicals are ongoing, and their contribution to population declines of marine mammals is of global concern. To safeguard their survival, it is of paramount importance to understand the effectiveness of mitigation measures. Using one of the world's largest marine mammals strandings data sets, we combine published and unpublished data to examine pollutant concentrations in 11 species that stranded along the coast of Great Britain to quantify spatiotemporal trends over three decades and identify species and regions where pollutants pose the greatest threat. We find that although levels of pollutants have decreased overall, there is significant spatial and taxonomic heterogeneity such that pollutants remain a threat to biodiversity in several species and regions. Of individuals sampled within the most recent five years (2014-2018), 48% of individuals exhibited a concentration known to exceed toxic thresholds. Notably, pollutant concentrations are highest in long-lived, apex odontocetes (e.g., killer whales (Orcinus orca), bottlenose dolphins (Tursiops truncatus), and white-beaked dolphins (Lagenorhynchus albirostris)) and were significantly higher in animals that stranded on more industrialized coastlines. At the present concentrations, POPs are likely to be significantly impacting marine mammal health. We conclude that more effective international elimination and mitigation strategies are urgently needed to address this critical issue for the global ocean health.

Northerly range expansion and first confirmed records of the smalltooth sand tiger shark, Odontaspis ferox, in the United Kingdom and Ireland.

Three Odontaspis ferox (confirmed by mtDNA barcoding) were found in the English Channel and Celtic Sea in 2023 at Lepe, UK (50.7846, -1.3508), Kilmore Quay, Ireland (52.1714, -6.5937), and Lyme Bay, UK (50.6448, -2.9302). These are the first records of O. ferox in either country, and extend the species' range by over three degrees of latitude, to >52° N. They were ~275 (female), 433 (female), and 293 cm (male) total length, respectively. These continue a series of new records, possibly indicative of a climate change-induced shift in the species' range.

A RETROSPECTIVE ANALYSIS OF THE MORBIDITY AND MORTALITY OF CAPTIVE NORTHERN BALD IBIS (GERONTICUS EREMITA), AFRICAN SACRED IBIS (THRESKIORNIS AETHIOPICUS), AND SCARLET IBIS (EUDOCIMUS RUBER) HOUSED AT THE LONDON ZOO FROM 2000 TO 2020.

Necropsy (n = 144) and medical (n = 121) records of captive northern bald ibis (NBI; Geronticus eremita), African sacred ibis (ASI; Threskiornis aethiopicus), and scarlet ibis (SCI; Eudocimus ruber) housed at the Zoological Society of London's London Zoo (LZ) from 2000 to 2020 were reviewed. Pododermatitis was a common cause of morbidity in all species (79 cases in 247 examinations). Trauma (58 of 144), the majority being caused by suspected collisions with stationary objects in the zoo's habitats, infectious diseases (32 of 144), predominantly valvular endocarditis (10 of 32), and aspergillosis (9 of 32) were major causes of mortality. The odds of a morbidity being related to toxicosis were 4.4 times greater in NBI than for ASI (95% CI, 1.5-13.3; P < 0.05); all cases in the NBI were plumbism. Overall, females of all species had 3.4 times greater odds of undetermined morbidity than males (95% CI, 1.5-7.9; P < 0.05), and the majority (16 of 25) were birds that were thin without an apparent cause. Nestlings had 11.3 times greater odds of nutritional morbidity than adults (95% CI, 1.7-73.0) and 5.5 times greater than juveniles (95% CI, 0.7-41.0; P < 0.05). These data have identified areas that require further study in the population of NBI, ASI, and SCI held at LZ.

RETROSPECTIVE STUDY OF MORBIDITY AND MORTALITY OF CAPTIVE AFRICAN WILD DOGS (LYCAON PICTUS) HELD WITHIN UNITED KINGDOM ZOOLOGICAL INSTITUTIONS BETWEEN 2000 AND 2020.

The African wild dog (Lycaon pictus) is listed as Endangered by the International Union for Conservation of Nature and is part of captive breeding programs designed to support free-living populations and genetic diversity. This study's aim was to identify common causes of morbidity and mortality objectively in United Kingdom captive African wild dogs to inform management recommendations that will improve health and welfare and reduce disease prevalence. Data were gathered from 140 individual dogs housed in 10 institutions, with morbidity records for 122 individuals and 70 postmortem reports. Descriptive statistics including the Mann-Whitney U test and odds ratios were used to analyze morbidity and mortality across age and sex. The most common cause of death for African wild dogs, excluding those,< 7 d old, was trauma (23%), followed by geriatric (18%), degenerative (15%), and neoplastic (14%) conditions. The most common morbidity was also trauma (62%), of which 76% was caused by intraspecific aggression. Integumentary disease secondary to trauma was the most common morbidity by body system. Eight independent incidents of barbiturate toxicosis from consumption of contaminated carcasses, affecting 18 animals, were identified. Records for neonatal deaths were incomplete and conclusions limited; neonatal loss was estimated at 20.5%. Recommendations include research into factors affecting intraspecific aggression in captivity, operant conditioning for hand injection, provision of dietary carcasses from reputable sources, and improved record-keeping.

CHOLELITHIASIS IN CAPTIVE MOUNTAIN CHICKEN FROGS (LEPTODACTYLUS FALLAX): DIAGNOSTIC IMAGING AND HISTOPATHOLOGICAL FEATURES.

The mountain chicken frog (Leptodactylus fallax) is a critically endangered species highly reliant on ex situ conservation programs. In captivity, cholelithiasis has been reported during clinical examinations using diagnostic imaging and observed during postmortem examinations. Some individuals have presented with nonspecific clinical signs potentially associated with this condition, but little is known about its clinical relevance. A retrospective evaluation of ultrasonographic (n = 139) and radiographic (n = 156) images and histopathology samples (n = 32) obtained between 2014 and 2020 from 133 individuals was performed. An ultrasound scoring system was developed to evaluate changes in the gallbladder, with 38% (53/139) of the images showing abnormal contents. Gallbladder distension appeared associated with these findings (generalized estimating equation model, P < 0.001). In contrast, radiography proved to have low overall sensitivity (48%) when compared to ultrasonography for identifying abnormal gallbladder contents. A weak level of agreement (Cohen's kappa = 0.535) was observed between the imaging modalities. Histologically, cholecystitis was present in 86% (12/14) of the individuals, thickening of the gallbladder wall in 71% (10/14), and intrahepatic cholangitis in 90% (18/20). There was no evidence of cholestasis in any of the affected individuals. A significant difference was observed in the hepatic melanomacrophage density between animals with and without cholelithiasis (Welch two-sample t test, P < 0.001). This study provides an overview on the use of diagnostic imaging modalities to evaluate cholelithiasis and proposes a convenient ultrasound score to standardize monitoring of the condition in L. fallax. It is also the first systematic review of histopathological changes associated with cholelithiasis in this species.

A RETROSPECTIVE STUDY OF MORBIDITY AND MORTALITY IDENTIFIED AT POSTMORTEM EXAMINATION OF CAPTIVE LANGURS (TRACHYPITHECUS SPP) FROM SIX UNITED KINGDOM ZOOLOGICAL INSTITUTIONS: A 19-YEAR REVIEW.

Langurs are Asian primates belonging to the Colobinae subfamily. Langur populations are declining, with most species categorized as threatened by the International Union for Conservation of Nature. Investigation into the threats to population viability and sustainability would be beneficial but there is limited literature available on common diseases or causes of death in these species, either in captive or free-ranging settings. This study aimed to evaluate the most common causes of morbidity and mortality in Trachypithecus species submitted for postmortem examination by six United Kingdom zoological institutions between 2001 and 2020, to inform best practice husbandry guidelines. Necropsy and histopathology reports from 88 individuals of Trachypithecus species from six zoological organizations in the United Kingdom were analyzed. Species included Javan langurs (Trachypithecus auratus; n = 35), dusky langurs (Trachypithecus obscurus; n = 28), François' langurs (Trachypithecus francoisi; n = 16), purple-faced langurs (Trachypithecus vetulus; n = 4), silvered langurs (Trachypithecus cristatus; n = 4), and Phayre's langur (Trachypithecus phayrei; n = 1). Morbidities and causes of death were recorded. Gastrointestinal diseases and systemic infections were the leading causes of death (27.4% and 21.0% of cases where cause of death was known, respectively); linear foreign bodies were the most common cause of death. Interstitial pneumonia was frequently observed secondary to systemic infection. Heart abnormalities, anthracosis, and hemosiderosis were common but not directly associated with mortality. Further investigation is necessary to assess the importance of these conditions and whether they predispose to other diseases. This study provides a baseline for future research evaluating captive and free-ranging langur health and highlights husbandry practices that may decrease morbidity in these species.

RISK FACTORS ASSOCIATED WITH YOLK SAC RETENTION IN CAPTIVE-BRED HUMBOLDT PENGUIN (SPHENISCUS HUMBOLDTI) CHICKS.

Multiple occurrences of yolk sac retention prompted a retrospective investigation in a recently formed colony of captive Humboldt penguins (Spheniscus humboldti). Necropsy reports of 141 parent-reared penguin chicks that died between January 2014 and December 2018 were reviewed for evidence of yolk sac retention, defined as the presence of a yolk sac at postmortem examination of a chick aged 7 d or greater, and analyzed by demographic and pathological variables for identification of risk factors. Fifty-nine (65%) chicks that died at age 7 d or greater had a retained yolk sac at postmortem examination, revealing that this was a common condition in penguins in this population. Chicks that retained their yolk sac were also more likely to present with minimal gut contents (P = 0.02), have a prominent bursa of Fabricius (P < 0.01), and be the first chick hatched of their clutch (P = 0.02). Parental experience and age were not predictive of yolk sac retention, but there was a trend for chicks with retained yolk sacs to present with a poorer body condition, reduced weight, and reduced crown-rump length compared to chicks without a retained yolk sac. Histopathological and bacteriological findings of retained yolk sacs were not significantly different from those of chicks under 7 d of age. Although likely to be multifactorial, the association between yolk sac retention and indicators of suboptimal feed intake and growth (empty gastrointestinal tract, poor body condition score, decreased crown-rump length, and decreased weight at death) is hypothesized to be a result of parental neglect, leading to starvation and absorption arrest of the yolk, as previously indicated in broiler chicks.

Detection of Usutu virus infection in wild birds in the United Kingdom, 2020.

In August 2020, as part of a long-term disease surveillance programme, Usutu virus was detected in five Eurasian blackbirds (Turdus merula) and one house sparrow (Passer domesticus) from Greater London, England. This was initially detected by reverse transcription-PCR and was confirmed by virus isolation and by immunohistochemical detection of flavivirus in tissues. Phylogenetic analysis identified Usutu virus African 3.2 lineage, which is prevalent in the Netherlands and Belgium, suggesting a potential incursion from mainland Europe.

YERSINIA PSEUDOTUBERCULOSIS INFECTIONS IN PRIMATES, ARTIODACTYLS, AND BIRDS WITHIN A ZOOLOGICAL FACILITY IN THE UNITED KINGDOM.

Infection with Yersinia pseudotuberculosis can be difficult to diagnose and treat successfully. Twenty-four cases from the Zoological Society of London (ZSL) London Zoo and ZSL Whipsnade Zoo were identified between 2001 and 2019. Husbandry, medical, and postmortem records for six primates, 10 artiodactyls, and eight birds were reviewed to identify common clinical signs and gross lesions. Most cases occurred during the winter; however, an outbreak in four primates occurred during the summer following a period of stress associated with increased ambient noise and activity. Common clinical signs included lethargy (6/6 primates, 4/10 artiodactyls, 4/8 birds) or death without premonitory signs (3/10 artiodactyls, 4/8 birds). Once clinical signs were observed, disease progressed quickly. Poor condition was common in mammals (6/6 primates, 9/10 artiodactyls), but often went undetected until postmortem examination. Neurological signs occurred in three of six primates. Diarrhea and anorexia were uncommon in all animals. Hepatitis was observed in all groups (4/6 primates, 2/10 artiodactyls, 4/8 birds), mesenteric lymphadenomegaly was common in mammals (4/6 primates, 8/10 artiodactyls), and gastroenteritis was common in artiodactyls (7/10). Erythematous, punctate rashes, which have only been reported with yersiniosis in humans, were present in three of six primates. Bacterial cultures from the liver in primates and birds or enlarged mesenteric lymph nodes in artiodactyls were often diagnostic. All isolates were susceptible to marbofloxacin, oxytetracycline, streptomycin, ceftazidime, amoxicillin clavulanic acid, trimethoprim sulfamethoxazole, azithromycin, and doxycycline, and resistant to clindamycin. Histopathology and Perl's Prussian blue stains were performed on available liver samples (n = 18). Intracellular hemosiderin was present in 17 of 18 cases. Additional research is needed to determine if there is a relationship between hemosiderosis and yersiniosis.

Histopathological characterization and grading of chronic enterocolitis in Sulawesi crested macaques (Macaca nigra).

Sulawesi crested macaques (Macaca nigra) (SCMs) are critically endangered and frequently suffer from chronic intestinal disease in captivity. Often, despite routine diagnostic investigations and confirmation of intestinal inflammation, an aetiology cannot be identified, leading to a non-specific categorization as chronic enterocolitis rather than an aetiological diagnosis. This study evaluates the histological features of gastrointestinal tissues from 23 SCMs, comparing animals with a clinical history suggestive of chronic enterocolitis (n = 14) with those without gastrointestinal clinical signs (n = 9). Tissues were graded according to the Nancy index (NI), a scoring system used in human medicine to evaluate disease activity in ulcerative colitis, a common form of human inflammatory bowel disease (IBD). Additionally, inflammatory cells in the colonic lamina propria were visually identified by type, counted and subsequently compared between diseased and control animals. Moderate to severe lymphoplasmacytic inflammation and structural changes were most common in the colons of affected SCMs, whereas histopathological changes were absent or mild in all examined small intestine (n = 17) and stomach (n = 11) tissues. The colonic NI had a significant positive correlation with clinical disease severity and 57% (n = 8) of animals with clinical signs had a NI grade of ≥2, consistent with moderate to severe, active IBD. Half of SCMs with recurrent rectal prolapse (n = 6) had a NI grade of 0, suggesting that intestinal inflammation is not always part of this condition's pathogenesis. The numbers of colonic lymphocytes, plasma cells, neutrophils, macrophages and total leucocytes were significantly higher in diseased animals. This study validated the use of the NI in SCMs, enabling a more standardized histopathological evaluation of the colon in this species.

Prevalence and Molecular Analysis of Encephalomyocarditis Virus-2 in the Hazel Dormouse.

The hazel dormouse (Muscardinus avellanarius) population in the UK continues to decline due to habitat loss, despite reintroductions of captive-bred individuals being conducted nationally for over 30 years. Disease surveillance of captive-bred and wild dormice is performed to identify novel and existing disease threats which could impact populations. In this study, we firstly investigated cause of death in seven hazel dormice found dead in England, through next-generation sequencing identifying a virus closely related to a wood mouse encephalomyocarditis virus-2 (EMCV-2). Subsequently, lung tissue samples from 35 out of 44 hazel dormice tested positive for EMCV-2 RNA using a reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and Sanger sequencing methods developed in this study. Formalin-fixed tissues available for nine hazel dormice which tested positive for EMCV-2 RNA were examined microscopically. Three cases showed moderate interstitial pneumonia with minimal to mild lymphoplasmacytic myocarditis, but no evidence of encephalitis. However, the presence of possible alternative causes of death in these cases means that the lesions cannot be definitively attributed to EMCV-2. Here, we report the first detection of EMCV-2 in hazel dormice and conclude that EMCV-2 is likely to be endemic in the hazel dormouse population in England and may be associated with clinical disease.

Isolation and molecular identification of nematode surface mutants with resistance to bacterial pathogens.

Numerous mutants of the nematode Caenorhabditis elegans with surface abnormalities have been isolated by utilizing their resistance to a variety of bacterial pathogens (Microbacterium nematophilum, Yersinia pseudotuberculosis, and 2 Leucobacter strains), all of which are able to cause disease or death when worms are grown on bacterial lawns containing these pathogens. Previous work led to the identification of 9 srf or bus genes; here, we report molecular identification and characterization of a further 10 surface-affecting genes. Three of these were found to encode factors implicated in glycosylation (srf-2, bus-5, and bus-22), like several of those previously reported; srf-2 belongs to the GT92 family of putative galactosyltransferases, and bus-5 is homologous to human dTDP-D-glucose 4,6-dehydratase, which is implicated in Catel-Manzke syndrome. Other genes encoded proteins with sequence similarity to phosphatidylinositol phosphatases (bus-6), Patched-related receptors (ptr-15/bus-13), steroid dehydrogenases (dhs-5/bus-21), or glypiation factors (bus-24). Three genes appeared to be nematode-specific (srf-5, bus-10, and bus-28). Many mutants exhibited cuticle fragility as revealed by bleach and detergent sensitivity; this fragility was correlated with increased drug sensitivity, as well as with abnormal skiddy locomotion. Most of the genes examined were found to be expressed in epidermal seam cells, which appear to be important for synthesizing nematode surface coat. The results reveal the genetic and biochemical complexity of this critical surface layer, and provide new tools for its analysis.

The genomic epidemiology of Escherichia albertii infecting humans and birds in Great Britain.

Escherichia albertii is a recently identified gastrointestinal bacterial pathogen of humans and animals which is typically misidentified as pathotypes of diarrhoeagenic Escherichia coli or Shigella species and is generally only detected during genomic surveillance of other Enterobacteriaceae. The incidence of E. albertii is likely underestimated, and its epidemiology and clinical relevance are poorly characterised. Here, we whole genome sequenced E. albertii isolates from humans (n = 83) and birds (n = 79) isolated in Great Britain between 2000 and 2021 and analysed these alongside a broader public dataset (n = 475) to address these gaps. We found human and avian isolates typically (90%; 148/164) belonged to host-associated monophyletic groups with distinct virulence and antimicrobial resistance profiles. Overlaid patient epidemiological data suggested that human infection was likely related to travel and possibly foodborne transmission. The Shiga toxin encoding stx2f gene was associated with clinical disease (OR = 10.27, 95% CI = 2.98-35.45 p = 0.0002) in finches. Our results suggest that improved future surveillance will further elucidate disease ecology and public and animal health risks associated with E. albertii.

Bridging clinic and wildlife care with AI-powered pan-species computational pathology.

Cancers occur across species. Understanding what is consistent and varies across species can provide new insights into cancer initiation and evolution, with significant implications for animal welfare and wildlife conservation. We build a pan-species cancer digital pathology atlas (panspecies.ai) and conduct a pan-species study of computational comparative pathology using a supervised convolutional neural network algorithm trained on human samples. The artificial intelligence algorithm achieves high accuracy in measuring immune response through single-cell classification for two transmissible cancers (canine transmissible venereal tumour, 0.94; Tasmanian devil facial tumour disease, 0.88). In 18 other vertebrate species (mammalia = 11, reptilia = 4, aves = 2, and amphibia = 1), accuracy (range 0.57-0.94) is influenced by cell morphological similarity preserved across different taxonomic groups, tumour sites, and variations in the immune compartment. Furthermore, a spatial immune score based on artificial intelligence and spatial statistics is associated with prognosis in canine melanoma and prostate tumours. A metric, named morphospace overlap, is developed to guide veterinary pathologists towards rational deployment of this technology on new samples. This study provides the foundation and guidelines for transferring artificial intelligence technologies to veterinary pathology based on understanding of morphological conservation, which could vastly accelerate developments in veterinary medicine and comparative oncology.