Search

Abstract The lion (Panthera leo) was extirpated from the Cape region of South Africa during the mid-nineteenth century. Whilst historically classified as a distinct subspecies known as the Cape lion (P. l. melanochaita), recent molecular studies challenge the distinctiveness of this population, suggesting that it represents the southernmost population of the species' Southern Clade. The Cape lion is often cited as having a distinctive skull morphology, which has justified its subspecific classification, but only a limited number of specimens have been available for examination, so that the Cape lion’s skull morphology has not been satisfactorily understood. In this study we collected morphometric data from a greatly enlarged sample of 22 Cape lion skulls, including 12 adults, constituting the largest sample size analysed for this possible subspecies. The results suggest that (1) morphological characteristics of the skull previously thought to distinguish the Cape lion are not diagnostic, and (2) nor is the skull morphology of male and female Cape lions distinct from that of males and females of other southern African lions. Our results independently support those based on molecular investigations, which suggest that the Cape lion was not distinct from other lions within the Southern Clade.

ABSTRACT Remnant populations of endangered species often have complex demographic histories associated with human impact. This can present challenges for conservation as populations modified by human activity may require bespoke management. The Eurasian red squirrel, Sciurus vulgaris (L., 1758), is endangered in the UK. Scotland represents a key stronghold, but Scottish populations have been subjected to intense anthropogenic influence, including widespread extirpations, reintroductions and competition from an invasive species. This study examined the genetic legacy of these events through low coverage whole‐genome resequencing of 106 red squirrels. Previously undetected patterns of population structure and gene flow were uncovered. One offshore island, four mainland Scottish populations, and a key east‐coast migration corridor were observed. An abrupt historical population bottleneck, related to extreme founder effects, has led to a severe and prolonged depression in genome‐wide heterozygosity, which is amongst the lowest reported for any species. Current designated red squirrel conservation stronghold locations do not encompass all existing diversity. These findings highlight the genetic legacies of past anthropogenic influence on long‐term diversity in endangered taxa. Continuing management interventions and regular genetic monitoring are recommended to safeguard and improve future diversity.

The mechanical properties of dietary items are known to influence skull morphology, either through evolution or by phenotypic plasticity. Here, we investigated the impact of supplementary feeding of peanuts on the morphology of red squirrels (Sciurus vulgaris) from five populations in Britain (North Scotland, Borders, Jersey and two temporally distinct populations from Formby (Merseyside)). Stable isotope analysis confirmed dietary ecology in 58 specimens. Geometric morphometrics were used to analyse three-dimensional and two-dimensional shape variation across 113 crania and 388 mandibles, respectively. Nitrogen isotope ratios (δ15N) were lower in the 1990s and 2010s Formby squirrels (suggesting a diet with an increased proportion of peanuts), and higher in other populations. Significant differences in cranio-mandibular shape were found between all populations, with 1990s Formby red squirrels exhibiting a morphology associated with reduced masticatory efficiency. This effect was partially reversed following a reduction in supplementary feeding of peanuts. We propose that these morphological changes are related to the reduced mechanical effort needed to process peanuts relative to naturally occurring food items. This could be an example of diet-induced plastic changes to the skeleton in non-muroid wild mammals, although further research is needed to exclude other driving factors such as genetics.

Species reintroductions are increasingly seen as important methods of biodiversity restoration. Reintroductions of red kites Milvus milvus and white-tailed eagles Halieaeetus albicilla to Britain, which were extirpated in the late 19th and early 20th centuries, represent major conservation successes. Here, we measured stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) in feather keratin and bone collagen of museum specimens of red kites and white-tailed eagles, which were collected from across Scotland between the 1800s and 2010s. Our objectives were to investigate dietary differences between species and between the pre- and post- reintroduction periods. Among reintroduced birds, δ13C values were significantly less negative and δ15N values higher in feather keratin and bone collagen of white-tailed eagles compared to red kites, likely reflecting a greater reliance on marine resources by the former. Our stable isotope data showed a wide range, confirming the dietary diversity observed in conventional diet studies of both taxa, with white-tailed eagles, in particular, having wide dietary niches and a considerable degree of inter-individual variability. Isotopic data from pre-introduction red kites mostly fell within the range of post-reintroduction birds, suggesting they had similar diets to the pre-reintroduction birds, or the prey base for modern birds is isotopically indistinguishable from that of their historic counterparts. For white-tailed eagles, several pre-reintroduction birds were isotopically distinct from the post-reintroduction population. These differences may indicate a changing prey base, although these conclusions are complicated by shifting distributions and small population samples. Overall, our study demonstrates the utility of natural history collections in examining changes in diet, environment, and interactions with humans in reintroduced species compared with pre-extirpation indigenous populations.

We report a tarsometatarsus and an associated pedal phalanx from the lower Eocene London Clay of Walton-on-the- Naze (Essex, UK). The specimen resembles the tarsometatarsus of the taxon Limnofregata (Fregatidae), but it belongs to a species that is distinctly larger than any other, extinct or extant, frigatebird, from which it also differs in some morphological features. Because of a close stratigraphical and geographical provenance, as well as a similar large size and frigatebird-like morphology, we consider it possible that the fossil belongs to Marinavis longirostris. This large seabird was initially described from the London Clay of Abbey Wood and is based on fragments of the rostrum, which likewise show a resemblance to the Fregatidae. If correctly assigned to the Fregatidae, the fossils would be among the earliest records of frigatebirds and the first fossils of this group of birds from the Paleogene of Europe, but we note that our tentative classification is still afflicted with considerable uncertainty.

Background: The aim of this study was to audit clinical and patient-reported outcomes of patients treated with [177Lu]-DOTA-octreotate (177Lu-DOTATATE) at a single Australian centre over an 11-year period. Methods: A retrospective analysis of 189 patients with metastatic or locally advanced neuroendocrine neoplasms or tumours (NENs/NETs) or other somatostatin receptor-positive tumour treated with 177Lu-DOTATATE at The Queen Elizabeth Hospital from 2011 to 2022 was carried out. Toxicity, radiological response, health-related quality of life (hr-QoL), and overall survival (OS) were summarised. Results: Gastroenteropancreatic (NET) origin accounted for 75% of cases. The median age of diagnosis was 59 years and median age at first cycle of 177Lu-DOTATATE at The Queen Elizabeth Hospital was 64.7 years (range 16.5-92.6 years). Of the 182 patients who commenced induction peptide receptor radionuclide therapy (iPRRT), 143 (79%) completed four or five induction cycles. There were 52 patients who received retreatment PRRT (rPRRT). When radiological response was assessed following completion of a full iPRRT course (≥four cycles, 131 patients), radiologically stable disease was seen in 76% of patients. A completed hr-QoL questionnaire was available for 760 cycles (92%). Significant improvements were found across multiple domains after iPRRT. Eight patients (4.2%) developed a haematological malignancy. Renal function declined at long-term but not short-term follow-up. Median duration of follow-up was 37.6 months (range 0.0-134.6 months) with a median OS from first cycle of PRRT 48.4 months (95% confidence interval 42.5-57.3 months). Conclusion: Patients with advanced NEN/NET or other somatostatin receptor-positive malignancies treated with 177Lu-DOTATATE at our centre had improved hr-QoL following iPRRT, with comparable toxicity and OS to other centres.

IntroductionElasmobranchs, such as sharks and rays, are among the world’s most endangered vertebrates, with over 70% loss in abundance over the past 50 years due to human impacts. Zooarchaeological baselines of elasmobranch diversity, distribution, and exploitation hold great promise for contributing essential historical contexts in the assessment of contemporary patterns in their taxonomic diversity and vulnerability to human-caused extinction. Yet, the historical ecology of elasmobranchs receives relatively less archaeological attention compared to that of ray-finned fishes or marine mammals, largely due to issues of taxonomic resolution across zooarchaeological identifications.MethodsWe explore the use of Zooarchaeology by Mass Spectrometry (ZooMS) for species identification in this unstudied group, using an archaeological case study from the marine environments of the Florida Keys, a marine biodiversity hotspot that is home to an array of elasmobranch species and conservation efforts. By comparison with 39 modern reference species, we could distinguish 12 taxa within the zooarchaeological assemblage from the Clupper archaeological site (Upper Matecumbe Key) that included nine sharks, two rays and a sawfish.Results and discussionThe results indicate that, through additional complexity of the collagen peptide mass fingerprint, obtained due to the presence of the cartilaginous type II collagen, ZooMS collagen peptide mass fingerprinting provides exceptionally high taxonomic resolution in this group, yielding species-level identifications in all cases where sufficient reference material was used. This case study also highlights the added value of ZooMS for taxa that are more difficult to distinguish in zooarchaeological analyses, such as vertebrae of the Atlantic sharpnose shark (Rhizoprionodon terraenovae) and the hammerhead sharks (Sphyrna spp.) in the Florida Keys. Therefore, the application of collagen peptide mass fingerprinting to elasmobranchs offers great potential to improve our understanding of their archaeological past and historical ecology.

Fossils and First Nations artifacts are both physical remains that demonstrate the deep history of the Earth and its inhabitants. Modern museums have become the places where both of these kinds of natural and cultural heritage are often stored. Yet, many museums carry baggage of institutional distrust, rooted in damaging colonial practices that rely on extractive approaches to research and collection. These practices have encouraged the separation of paleontological and cultural collections and knowledge, and have often excluded First Nations voices from their exhibitions and research practices, Here, we explore the role of museums and their relationship with paleontological objects and sites in Australia and their relationship with First Nations peoples and heritage. We analyze the results of the ‘Found a Fossil’ survey, and describe three case studies; paleontological and cultural cross-over with dinosaur tracks in the West Kimberley region of Western Australia, the digital Museum of Stone Tools initiative, and the Rola[Stone] documentary film project, both based on Anaiwan Country in New South Wales, Australia. Acknowledging the innate duality of objects and places promotes elevated complexity in the way they are understood, studied, managed, legislated and curated. It is essential that First Nations stories, places, and objects be centered with fossils and geological materials to simultaneously tell the story of life on Earth, and in Australia, the story of the oldest living cultures in the world.

Sirenia, an iconic marine taxon with a tropical and subtropical worldwide distribution, face an uncertain future. All species are designated ‘Vulnerable’ to extinction by the IUCN. Nonetheless, a comprehensive understanding of geographic structuring across the global range is lacking, impeding our ability to highlight particularly vulnerable populations for conservation priority. Here, we use ancient DNA to investigate dugong (Dugong dugon) population structure, analysing 56 mitogenomes from specimens comprising the known historical range. Our results reveal geographically structured and distinct monophyletic clades characterized by contrasting evolutionary histories. We observe deep-rooted and divergent lineages in the East (Indo-Pacific) and obtain new evidence for the relatively recent dispersal of dugongs into the western Indian Ocean. All populations are significantly differentiated from each other with western populations having approximately 10-fold lower levels of genetic variation than eastern Indo-Pacific populations. Additionally, we find a significant temporal loss of genetic diversity in western Indian Ocean dugongs since the mid-twentieth century, as well as a decline in population size beginning approximately 1000 years ago. Our results add to the growing body of evidence that dugong populations are becoming ever more susceptible to ongoing human action and global climate change.

Abstract: Although model organisms have provided insight into the earliest stages of cardiac vascularization, we know very little about this process in humans. Here we show that spatially micropatterned human pluripotent stem cells (hPSCs) enablein vitromodeling of this process, corresponding to the first three weeks ofin vivohuman development. Using four hPSC fluorescent reporter lines, we create cardiac vascular organoids (cVOs) by identifying conditions that simultaneously give rise to spatially organized and branched vascular networks within endocardial, myocardial, and epicardial cells. Using single-cell transcriptomics, we show that the cellular composition of cVOs resembles that of a 6.5 post-conception week (PCW) human heart. We find that NOTCH and BMP pathways are upregulated in cVOs, and their inhibition disrupts vascularization. Finally, using the same vascular-inducing factors to create cVOs, we produce hepatic vascular organoids (hVOs). This suggests there is a conserved developmental program for creating vasculature within different organ systems. Graphic Abstract:

Sand cats, Felis margarita, range from northern Africa and the Arabian Peninsula to Central Asia. Their apparently discontinuous distribution is recognized as comprising four subspecies. Recent genetic research found little differentiation between subspecies except for the North African form. In this study, 90 skins and 88 skulls were analyzed from the four subspecies. A discriminant function analysis of the scores, ranging from 1 to 4, of four pelage characteristics revealed differentiation between putative subspecies, except between Turkmenian and Pakistani sand cats. Northern African and Arabian sand cats tend to be spotted and striped, while Turkmenian and Pakistani sand cats are less spotted and have a dorsal crest of fur. Nonmetric multidimensional scaling (NMDS) models generated from 21 skull measurements revealed an overlap in morphospace between all subspecies, except for larger Turkmenian sand cats; northern African sand cats were smallest. Therefore, both pelage characteristics and skull morphometrics support up to three subspecies. However, considering recent genetic research, it is likely that two subspecies should be recognized, F. m. margarita from northern Africa and F. m. thinobia from the Arabian Peninsula, and Southwest and Central Asia. Widening of the dataset and nuclear DNA evidence are required to increase our understanding of geographical variation in this little studied species.

Ruffed lemurs (Varecia variegata and Varecia rubra) are categorized as Critically Endangered on the IUCN Red List, and genetic studies are needed for assessing the conservation value of captive populations. Using 280 mitochondrial DNA (mtDNA) D-loop sequences, we studied the genetic diversity and structure of captive ruffed lemurs in Madagascar, Europe and North America. We found 10 new haplotypes: one from the European captive V. rubra population, three from captive V. variegata subcincta (one from Europe and two from Madagascar) and six from other captive V. variegata in Madagascar. We found low mtDNA genetic diversity in the European and North American captive populations of V. variegata. Several founder individuals shared the same mtDNA haplotype and therefore should not be assumed to be unrelated founders when making breeding recommendations. The captive population in Madagascar has high genetic diversity, including haplotypes not yet identified in wild populations. We determined the probable geographical provenance of founders of captive populations by comparison with previous studies; all reported haplotypes from captive ruffed lemurs were identical to or clustered with haplotypes from wild populations located north of the Mangoro River in Madagascar. Effective conservation strategies for wild populations, with potentially unidentified genetic diversity, should still be considered the priority for conserving ruffed lemurs. However, our results illustrate that the captive population in Madagascar has conservation value as a source of potential release stock for reintroduction or reinforcement projects and that cross-regional transfers within the global captive population could increase the genetic diversity and therefore the conservation value of each regional population.

Abstract Sleep electroencephalogram (EEG) signals likely encode brain health information that may identify individuals at high risk for age-related brain diseases. Here, we evaluate the correlation of a previously proposed brain age biomarker, the “brain age index” (BAI), with cognitive test scores and use machine learning to develop and validate a series of new sleep EEG-based indices, termed “sleep cognitive indices” (SCIs), that are directly optimized to correlate with specific cognitive scores. Three overarching cognitive processes were examined: total, fluid (a measure of cognitive processes involved in reasoning-based problem solving and susceptible to aging and neuropathology), and crystallized cognition (a measure of cognitive processes involved in applying acquired knowledge toward problem-solving). We show that SCI decoded information about total cognition (Pearson’s r = 0.37) and fluid cognition (Pearson’s r = 0.56), while BAI correlated only with crystallized cognition (Pearson’s r = − 0.25). Overall, these sleep EEG-derived biomarkers may provide accessible and clinically meaningful indicators of neurocognitive health.

Introduction Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes encephalitis and other morbidity in Southeast Asia. Since February 2022, geographically dispersed JEV human, animal and vector detections occurred on the Australian mainland for the first time. This study will determine the prevalence of JEV-specific antibodies in human blood with a focus on populations at high risk of JEV exposure and determine risk factors associated with JEV seropositivity by location, age, occupation and other factors.Method Samples are collected using two approaches: from routine blood donors (4153 samples), and active collections targeting high-risk populations (convenience sampling). Consent-based sampling for the latter includes a participant questionnaire on demographic, vaccination and exposure data. Samples are tested for JEV-specific total antibody using a defined epitope-blocking ELISA, and total antibody to Australian endemic flaviviruses Murray Valley encephalitis and Kunjin viruses.Analysis Two analytic approaches will occur: descriptive estimates of seroprevalence and multivariable logistic regression using Bayesian hierarchical models. Descriptive analyses will include unadjusted analysis of raw data with exclusions for JEV-endemic country of birth, travel to JEV-endemic countries, prior JEV-vaccination, and sex-standardised and age-standardised analyses. Multivariable logistic regression will determine which risk factors are associated with JEV seropositivity likely due to recent transmission within Australia and the relative contribution of each factor when accounting for effects within the model.Ethics National Mutual Acceptance ethical approval was obtained from the Sydney Children’s Hospitals Network Human Research Ethics Committee (HREC). Local approvals were planned to be sought in each jurisdiction, as per local ethics processes. Ethical approval was also obtained from the Australian Red Cross Lifeblood HREC.Dissemination Findings will be communicated to participants and their communities, and human and animal health stakeholders and policy-makers iteratively and after final analyses. Understanding human infection rates will inform procurement and targeted allocation of limited JEV vaccine, and public health strategies and communication campaigns, to at-risk populations.

Beta (β)-galactosidase is a lysosomal enzyme that removes terminal galactose residues from glycolipids and glycoproteins. It is upregulated in, and used as a marker for, senescent cells. Microglia are brain macrophages implicated in neurodegeneration, and can upregulate β-galactosidase when senescent. We find that inflammatory activation of microglia induced by lipopolysaccharide results in translocation of β-galactosidase to the cell surface and release into the medium. Similarly, microglia in aged mouse brains appear to have more β-galactosidase on their surface. Addition of β-galactosidase to neuronal-glial cultures causes microglial activation and neuronal loss mediated by microglia. Inhibition of β-galactosidase in neuronal-glial cultures reduces inflammation and neuronal loss induced by lipopolysaccharide. Thus, activated microglia release β-galactosidase that promotes microglial-mediated neurodegeneration which is prevented by inhibition of β-galactosidase.