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This is the case of a specimen of Didelphis albiventris with signs of respiratory difficulty after a dog attack. Thoracic radiographic examination revealed pneumothorax, pulmonary contusion, and rib fracture, but no alteration compatible with diaphragmatic hernia was observed. Pneumothorax was reduced and the other alterations were treated. However, clinical manifestations persisted, and thus a contrast-gastrointestinal radiographic study was performed, showing abdominal organs in the thoracic cavity and loss of diaphragmatic line. The surgical approach was instituted, with access to the diaphragm through median laparotomy. Through the diaphragmatic rupture, present in the left antimere, there were herniated liver and gastric portions, intestinal segments, and omentum. After inspection and repositioning of the abdominal organs, the diaphragm raffia was performed with single sutures interrupted with 3-0 Nylon thread. The patient’s complete recovery occurred 14 days after the surgical procedure, with remission of clinical manifestations and normality of thoracic images in radiographic studies.

There are many different forms of nutrient provision in viviparous (live-bearing) species. The formation of a placenta is one method where the placenta functions to transfer nutrients from mother to fetus (placentotrophy), to transfer waste from the fetus to the mother, and to perform respiratory gas exchange. Despite having the same overarching function, there are different types of placentation within placentotrophic vertebrates, and many morphological changes occur in the uterus during pregnancy to facilitate formation of the placenta. These changes are regulated in complex ways but are controlled by similar hormonal mechanisms across species. This review describes current knowledge of the morphological and molecular changes to the uterine epithelium preceding implantation among mammals. Our aim is to identify the commonalities and constraints of these cellular changes to understand the evolution of placentation in mammals and to propose directions for future research. We compare and discuss the complex modifications to the ultrastructure of uterine epithelial cells (UEC) and show that there are similarities in the changes to the cytoskeleton and gross morphology of the UEC, especially of the apical and lateral plasma membrane of the cells during the formation of a placenta in all eutherians and marsupials studied to date. We conclude that further research is needed to understand the evolution of placentation among viviparous mammals, particularly concerning the level of placental invasiveness, hormonal control, and genetic underpinnings of pregnancy in marsupial taxa.

Three versions of syncytiotrophoblast exist in the human placenta: an invasive type associated with the implanting conceptus, non-invasive villous type of definitive placenta, and placental bed giant cells. Syncytins are encoded by modified env genes of endogenous retroviruses (ERV), but how they contribute functionally to placental syncytial structures is unclear. A minimum of eight genes (ERVW1, ERVFRD-1, ERVV-1, ERVV-2, ERVH48-1, ERVMER34-1, ERV3-1, & ERVK13-1) encoding syncytin family members are expressed in human trophoblast, the majority from implantation to term. ERVW1 (Syncytin 1) and ERVFRD-1 (Syncytin 2) are considered the major fusogens, but, when the expression of their genes is analyzed by single cell RNAseq in first trimester placenta, their transcripts are distinctly patterned and also differ from those of their proposed binding partners, SLC1A5 and MFSD2A, respectively. ERVRH48-1 (suppressyn or SUPYN) and ERVMER34-1 are probable negative regulators of fusion and co-expressed, primarily in cytotrophoblast. The remaining genes and their products have been little studied. Syncytin expression is a feature of placental development in almost all eutherian mammals studied, in at least one marsupial, and in viviparous lizards, which lack the trophoblast lineage. Their expression has been inferred to be essential for pregnancy success in the mouse. All the main human ERV genes arose following independent retroviral insertion events, none of which trace back to the divergence of eutherians and metatherians (marsupials). While syncytins may be crucial for placental development, it seems unlikely that they helped orchestrate the divergence of eutherians and marsupials.

A short gestation, low birth weight and presence of cutaneous exchange of O2 and CO2 comprise altricial features of newborn marsupials and that collectively implies a highly immature respiratory system. In the present study, we investigated various respiratory characteristics of the neonatal/postnatal tammar wallaby, a species of marsupial in which > 30% of the newborn’s total O2 demands are supported by cutaneous rather than pulmonary gas exchange. The ventilatory response (HVR) to acute hypoxia (10% inspired O2) was absent in the newborn (1 day old) pouch young; a hypoxic hypometabolism contributed entirely to the hyperventilation (increased pulmonary convection requirement). A high (compared to older animals) resting metabolic cost to breathe and an inefficient respiratory system suggest the lack of a HVR might be due to an energetic constraint that impinges on their ability to sustain an increase in ventilation. The latter was supported by the inability of the newborn to tolerate metabolic-ventilatory stimulation following administration of the metabolic uncoupler, 2,4-dinitrophenol (2,4-DNP). At 1 week of age, the cost of breathing was reduced, which coincided with the expression of a significant ventilatory response to hypoxia, a more energetically efficient respiratory system, and tolerance to 2,4-DNP. These data suggest this species of marsupial is born with major respiratory insufficiency, and that their pronounced dependence on the skin for metabolic gas exchange is of critical importance for survival.

The increased availability of genomic resources for many species has expanded perspectives on problems in conservation by helping to design management strategies for threatened species. Tasmanian devils (Sarcophilus harrisii) are an iconic and endangered marsupial with an intensively managed breeding program aimed at preventing extinction in the wild caused by devil facial tumour disease. Between 2015 and 2017, 85 devils from this program were released to three sites in Tasmania to support wild populations. Of these, 26 were known to have been killed by vehicles shortly after release. A previous analysis indicated that increased generations in captivity was a positive predictor of vehicle strike, with possible behavioural change hypothesised. Here we use 39 resequenced devil genomes to characterise diversity at 35 behaviour-associated genes, which contained 826 single nucleotide polymorphisms (24 were non-synonymous). We tested for a predictor of survival by examining three genes (AVPR1B, OXT and SLC6A4) in 62 released devils with known fates (survived, N = 39; died, N = 23), and genome-wide associations via reduced-representation sequencing (1727 single nucleotide polymorphisms [SNPs]), in 55 devils with known fates (survived, N = 38; died, N = 17). Overall, there was little evidence of an association between genetic profile and probability of being struck by a vehicle. Despite previous evidence of low genetic diversity in devils, the 35 behaviour-associated genes contained variation that may influence their functions. Our dataset can be used for future research into devil behavioural ecology, and adds to the increasing body of research applying genomics to conservation problems.

Little is known about how the large brains of mammals are accommodated into the dazzling diversity of their skulls. It has been suggested that brain shape is influenced by relative brain size, that it evolves or develops according to extrinsic or intrinsic mechanical constraints, and that its shape can provide insights into its proportions and function. Here, we characterise the shape variation among 84 marsupial cranial endocasts of 57 species including fossils, using 3D geometric morphometrics and virtual dissections. Statistical shape analysis revealed four main patterns: over half of endocast shape variation ranges between elongate and straight to globular and inclined; little allometric variation with respect to centroid size, and none for relative volume; no association between locomotion and endocast shape; limited association between endocast shape and previously published histological cortex volumes. Fossil species tend to have smaller cerebral hemispheres. We find divergent endocast shapes in closely related species and within species, and diverse morphologies superimposed over the main variation. An evolutionarily and individually malleable brain with a fundamental tendency to arrange into a spectrum of elongate-to-globular shapes – possibly mostly independent of brain function - may explain the accommodation of brains within the enormous diversity of mammalian skull form.

Biofluorescence has been detected in several nocturnal-crepuscular organisms from invertebrates to birds and mammals. Biofluorescence in mammals has been detected across the phylogeny, including the monotreme duck-billed platypus (Ornithorhyncus anatinus), marsupial opossums (Didelphidae), and New World placental flying squirrels (Gluacomys spp.). Here, we document vivid biofluorescence of springhare (Pedetidae) in both museum specimens and captive individuals—the first documented biofluorescence of an Old World placental mammal. We explore the variation in biofluorescence across our sample and characterize its physical and chemical properties. The striking visual patterning and intensity of color shift was unique relative to biofluorescence found in other mammals. We establish that biofluorescence in springhare likely originates within the cuticle of the hair fiber and emanates, at least partially, from several fluorescent porphyrins and potentially one unassigned molecule absent from our standard porphyrin mixture. This discovery further supports the hypothesis that biofluorescence may be ecologically important for nocturnal-crepuscular mammals and suggests that it may be more broadly distributed throughout Mammalia than previously thought.

Wombats suffer from sarcoptic mange, a mite infection that ultimately leads to their death from secondary infections. In 2017, wildlife carers were granted legal approval to treat bare-nosed wombats (Vombatus ursinus) for sarcoptic mange in the field using 4 mL of topical Cydectin® per adult wombat. However, (limited) scientific field trials suggest approved protocols are inadequate which has been supported anecdotally by wildlife carers. Elucidating carer experience is key to holistically advancing understandings of sarcoptic mange treatment. We interviewed 18 wildlife carers regarding the use of Cydectin® to treat free-ranging adult wombats infected with sarcoptic mange which uncovered 43 detailed case studies for examination. Case studies revealed that wildlife carers have used 10–200-mL doses of topical Cydectin® to treat wombats to recovery. These results suggest there is no best-fit for treating wombats in the field, due to individual differences in observed levels of sarcoptic mange severity and differences in wombat behavior. Furthermore, wildlife carers suggested pour-on Cydectin® appeared non-toxic to wombats at rates as high as 200 mL per treatment. We recommend scientific trials should be undertaken to determine the impact and efficacy of the varying treatment regimens, including low and high doses of topical Cydectin® on bare-nosed wombats. This information is required for regulating authorities, and subsequently wildlife carers, and managers, to make fully informed decisions about wombat sarcoptic mange treatment.

Ross River virus (RRV) is a mosquito-borne zoonotic arbovirus associated with high public health and economic burdens across Australia, but particularly in South East Queensland (SEQ). Despite this high burden, humans are considered incidental hosts. Transmission of RRV is maintained among mosquitoes and many nonhuman vertebrate reservoir hosts, although the relative contributions of each of these hosts are unclear. To clarify the importance of a range of vertebrates in RRV transmission in SEQ, a total of 595 serum samples from 31 species were examined for RRV exposure using a gold-standard plaque reduction neutralization test. Data were analyzed statistically using generalized linear models and a coefficient inference tree, and spatially. RRV exposure was highly variable between and within species groups. Critically, species group ("placental mammal," "marsupial," and "bird"), which has previously been used as a proxy for reservoir hosts, was a poor correlate for exposure. Instead, we found that generalized "diet" and greater "body mass" were most strongly correlated with seropositivity. We also identified significant differences in seropositivity between the two major possum species (ringtail possums and brushtail possums), which are ecologically and taxonomically different. Finally, we identified distinct hotspots and coldspots of seropositivity in nonhuman vertebrates, which correlated with human notification data. This is the largest diversity of species tested for RRV in a single study to date. The analysis methods within this study provide a framework for analyzing serological data in combination with species traits for other zoonotic disease, but more specifically for RRV highlight areas to target further public health research and surveillance effort.

Background Ticks are obligate haematophagous ectoparasites of vertebrate hosts and transmit the widest range of pathogenic organisms of any arthropod vector. Seven tick species are known to feed on bare-nosed wombats (Vombatus ursinus), in addition to the highly prevalent Sarcoptes scabiei mite which causes fatal sarcoptic mange in most bare-nosed wombat populations. Little is known about the pathogens carried by most wombat ticks or how they may impact wombats and wombat handlers. Methods Wombat ticks were sourced from wildlife hospitals and sanctuaries across Australia and identified to species level using taxonomic keys. Genomic DNA was extracted from a subsample, and following the amplification of the bacterial 16S rRNA gene V3–V4 hypervariable region, next-generation sequencing (NGS) on the Illumina MiSeq platform was used to assess the microbial composition. Results A total of 447 tick specimens were collected from 47 bare-nosed wombats between January 2019 and January 2020. Five species of ticks were identified comprising wombat tick Bothriocroton auruginans (n = 420), wallaby tick Haemaphysalis bancrofti (n = 8), bush tick Haemaphysalis longicornis (n = 3), common marsupial tick Ixodes tasmani (n = 12), and Australian paralysis tick Ixodes holocyclus (n = 4). Tick infestations ranged from one to 73 ticks per wombat. The wombat tick was the most prevalent tick species comprising 94% of the total number of samples and was present on 97.9% (46/47) of wombat hosts. NGS results revealed the 16S rRNA gene diversity profile was predominantly Proteobacteria (55.1%) followed by Firmicutes (21.9%) and Actinobacteria (18.4%). A species of Coxiella sharing closest sequence identity to Coxiella burnetii (99.07%), was detected in 72% of B. auruginans and a Rickettsiella endosymbiont dominated the bacterial profile for I. tasmani. Conclusions A new host record for H. longicornis is the bare-nosed wombat. One adult male and two engorged adult female specimens were found on an adult male wombat from Coolagolite in New South Wales, and more specimens should be collected to confirm this host record. The most prevalent tick found on bare-nosed wombats was B. auruginans, confirming previous records. Analysis of alpha-diversity showed high variability across both sample locations and instars, similar to previous studies. The detection of various Proteobacteria in this study highlights the high bacterial diversity in native Australian ticks. Graphical Abstract

We report a human case of ocular filariasis, caused by a species of Breinlia nematode, from Queensland, Australia. Morphological and molecular evidence indicated that the nematode Breinlia (Johnstonema) annulipapillata, or a closely related taxon, likely transmitted from a macropodid marsupial host was involved, which might represent an accidental finding or an emerging zoonosis.

Mammalian pregnancy evolved in the therian stem lineage, that is, before the common ancestor of marsupials and eutherian (placental) mammals. Ancestral therian pregnancy likely involved a brief phase of attachment between the fetal and maternal tissues followed by parturition—similar to the situation in most marsupials including the opossum. In all eutherians, however, embryo attachment is followed by implantation, allowing for a stable fetal–maternal interface and an extended gestation. Embryo attachment induces an attachment reaction in the uterus that is homologous to an inflammatory response. Here, we elucidate the evolutionary mechanism by which the ancestral inflammatory response was transformed into embryo implantation in the eutherian lineage. We performed a comparative uterine transcriptomic and immunohistochemical study of three eutherians, armadillo (Dasypus novemcinctus), hyrax (Procavia capensis), and rabbit (Oryctolagus cuniculus); and one marsupial, opossum (Monodelphis domestica). Our results suggest that in the eutherian lineage, the ancestral inflammatory response was domesticated by suppressing one of its modules detrimental to pregnancy, namely, neutrophil recruitment by cytokine IL17A. Further, we propose that this suppression was mediated by decidual stromal cells, a novel cell type in eutherian mammals. We tested a prediction of this model in vitro and showed that decidual stromal cells can suppress the production of IL17A from helper T cells. Together, these results provide a mechanistic understanding of early stages in the evolution of eutherian pregnancy.

Traumatic injury, including bone fracture, is, to date, one of the leading causes of koala mortality in the South East Queensland region of Australia. Further, the specialist diet of koalas, which is restricted to certain Eucalyptus spp., may impact their normal bone physiology. Considering the dramatic koala population decline and high incidence of trauma, a greater understanding of koala bone physiology may support conservation. We retrieved from GenBank the protein sequences of parathyroid hormone (PTH), osteocalcin (OCN), and tissue-nonspecific alkaline phosphatase (TNALP) in human, dog, cattle, horse, koala, and gray short-tailed opossum. After homology was determined, plasma samples from 13 koalas were analyzed with human PTH, OCN, and bone-specific ALP (BALP) assay kits. Although koala PTH exhibited relatively low sequence homology with placental mammals, high sequence homology between humans and koalas was observed for both OCN and TNALP, and successful cross-reactivity was achieved using human enzyme immunoassay kits for detection of OCN and BALP biomarkers in koala plasma. However, we identified no correlation between OCN and BALP concentrations of healthy and trauma-affected koalas ( p = 0.66 and p = 0.79, respectively). Further analysis of OCN and BALP in healthy and diseased koalas will allow a better understanding of bone physiology in this unique marsupial.

Made available in DSpace on 2020-12-12T02:20:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 The white-eared opossum present a higher roadkill number in Brazil, and the vertebral column is often affected when some type of trauma occurs. Thus, this study describes the osteology and radiology of the vertebral column in white-eared opossum to serve as a basis for support in the veterinary clinical care, since the casuistry of care of this marsupial has increased every year. Radiographs of the cervical (C), thoracic (T), lumbar (L), sacral (S) and caudal (Cd) segments of the vertebral column were taken in thirty-five white-eared opossums (Didelphis albiventris). Furthermore, ten opossums without evident vertebral acquired or congenital abnormalities at the radiographic study were selected for anatomical study. Osteology was correlated with the radiographic images. The use of radiographs allowed the identification of congenital and acquired vertebral changes, as well as the identification of anatomical structures, their distribution and morphology and the number of vertebrae. The vertebral formula varied in the white-eared opossum. In 27 of 35 white-eared opossums (77.2%) with normal vertebral morphology, three vertebral formulas were observed: C7/T13/L6/S2 (62.9%), C7/T13/L5/S2 (5.7%) and C7/T13/L7/S2 (8.6%). Most of the specimens presented 27 caudal vertebrae. The anticlinal vertebra was identified as T10 in 77.2% and T11 in 22.8% of opossums. Cervical block vertebra was observed in two animals and sacrocaudal block vertebra in one animal. The haemal arches could be seen from Cd3–Cd4 in 80% and Cd2–Cd3 in 20% of opossums. The white-eared opossum showed a slender vertebral column with a relatively short thoracic region, a relatively long lumbar region and a highly flexible lumbosacral transition, suggesting that this animal is a fast-running and agile opossum. Therefore, these findings may serve as a basis for further research and support the veterinary clinical care, since the casuistry of care for this marsupial has increased every year. School of Veterinary Medicine and Animal Science Graduate Program in Wild Animals São Paulo State University (UNESP) Department of Anatomy Institute of Biosciences São Paulo State University (UNESP) Department of Animal Reproduction and Veterinary Radiology School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science Graduate Program in Wild Animals São Paulo State University (UNESP) Department of Anatomy Institute of Biosciences São Paulo State University (UNESP) Department of Animal Reproduction and Veterinary Radiology School of Veterinary Medicine and Animal Science São Paulo State University (UNESP)

Sympatric species can minimise interspecific competition by spatial avoidance or by altering their temporal activity to reduce encounter rates. The Tasmanian devil (Sarcophilus harrisii), the largest carnivorous marsupial, coexists with the smaller spotted‐tailed quoll (Dasyurus maculatus) in Tasmania, Australia. Quolls may be susceptible to interspecific competition from devils, because they utilise similar habitats, consume similar prey species and are displaced by devils at food sources. Such competition might cause quolls to spatially or temporally avoid devils. To investigate whether spatial or temporal avoidance occurred, we deployed GPS collars on sympatric devils and quolls and conducted a camera survey at a site in northwest Tasmania where the devil population was not affected by devil facial tumour disease. GPS tracking coincided with the lactation period when devils and quolls had young in dens and continued until weaning occurred. We found little spatial segregation of home range and core area placement between devils and quolls and among devils. Quolls showed more spatial segregation within the sexes than between them. Devils had larger home ranges than quolls. Male devils had larger home ranges than females, but there was no difference in home range size between the sexes of quolls. Females of both species travelled significantly further per night than did males. There was moderate temporal partitioning between the two species: devil activity peaked after dusk and devils remained active until the early morning, while quoll activity showed distinct peaks around dusk and dawn. In conclusion, quolls did not spatially avoid devils but moderate temporal partitioning occurred. It is plausible that quolls are active at different times of the diel cycle to reduce encountering devils, but further studies are needed to resolve the cause of this temporal partitioning.

Prominent ontogenetic changes of the gastrointestinal tract (GIT) should occur in mammals whose neonatal diet of milk differs from that of adults, and especially in herbivores (as vegetation is particularly distinct from milk), and even more so in foregut fermenters, whose forestomach only becomes functionally relevant with vegetation intake. Due to the protracted lactation in marsupials, ontogenetic differences can be particularly well investigated in this group. Here, we report body mass (BM) scaling relationships of wet GIT content mass in 28 in-pouch young (50 g to 3 kg) and 15 adult (16–70 kg) western grey kangaroos Macropus fuliginosus melanops. Apart from the small intestinal contents, in-pouch young and adults did not differ in the scaling exponents (‘slope’ in log-log plots) but did differ in the scaling factor (‘intercept’), with an implied substantial increase in wet GIT content mass during the out-of-pouch juvenile period. In contrast to forestomach contents, caecum contents were elevated in juveniles still in the pouch, suggestive of fermentative digestion of milk and intestinal secretion residues, particularly in the caecum. The substantial increase in GIT contents (from less than 1 to 10–20% of BM) was associated mainly with the increase in forestomach contents (from 25 to 80% of total GIT contents) and a concomitant decrease in small intestine contents (from 50 to 8%), emphasizing the shifting relevance of auto-enzymatic and allo-enzymatic (microbial) digestion. There was a concomitant increase in the contents-to-tissue ratio of the fermentation chambers (forestomach and caecum), but this ratio generally did not change for the small intestine. Our study not only documents significant ontogenetic changes in digestive morpho-physiology, but also exemplifies the usefulness of intraspecific allometric analyses for quantifying these changes.

Functionalized nanostructured systems can be used for imaging and drug delivery for anti-tumor therapy, including breast tumors. This is a more efficient approach that offers reduced systemic side effects compared to conventional diagnostic and chemotherapy methods. Multifunctional nanoparticles are potential tools in the diagnosis, location tracing and kill tumor cells through a less invasive manner. Functionalized phosphate-based nanoparticles are capable of encapsulating, or may be associated, with fluorescent probes. In this study, we synthesize a nanoparticle phosphate-based composite (NPC) and functionalize it with poly-ethylene glycol (PEG), hyaluronic acid (HA), the fluorescent probe rhodamin 6G (R6G) and the antimitotic doxorubicin (DOX). We focused on targeting human breast cancer cells reporting the biological effects of functionalized NPC on them. NPC and NPC formulations containing PEG, HA, and R6G did not cause cell viability reduction on MCF-7 and MDA-MB-231 cell lines. The cellular internalization of NPC was quantified by real-time in vitro observation, and confirmed by electron microscopy techniques. Intracellular NPC distribution is detected in the cytoplasm and nucleus of tumor cells by confocal fluorescent images. The percent association of doxorubicin to NPC matrix was approximately 18% and NPC formulations associated with doxorubicin led to a significant reduction in cell viability in MDA-MB-231 and MCF-7 cells. This data suggest the potential use of NPC as a non-cytotoxic platform for association with functional ligands to selective targeting breast cancer cells. NPC use can be also explored in drug delivery to cancer cells.

Koalas (Phascolarctos cinereus) are one of Australia’s most charismatic native small marsupial species. Unfortunately, populations of koalas are rapidly declining throughout Australia as they continue to face increasing pressure from a changing ecosystem. All wildlife species to some degree will use their hypothalamic–pituitary–adrenal (HPA) axis in response to stress. Depending on the duration of activation, the stress response can lead to either acute or chronic side effects and is modulated through the neuroendocrine stress system with the release of catecholamines and glucocorticoids (e.g., cortisol). It is well known that rehabilitation sanctuaries are inherently stressful for all animals, in particular for rescued wild koalas, as it is an unfamiliar environment where the animals cannot predict or control what will happen to them. In this pilot study, we set out to quantify faecal and fur cortisol metabolites in wild rescued koalas undergoing wildlife rehabilitation. Absolute levels of acute and chronic stress were indexed non-invasively, with faecal samples taken to evaluate acute stress, and fur samples taken to evaluate chronic stress. Sampling occurred sporadically over four months (the start of September 2018 to the end of December 2018), and was performed on three rescued koalas (Maree, Tai, and Solstice) being held at the rehabilitation centre. Results of this study show that between the three koalas, the highest recorded faecal cortisol result was 241 ng/g, and the lowest recorded faecal cortisol result was 4 ng/g, whereas the highest recorded fur cortisol result was 1.75 ng/g, and the lowest recorded fur cortisol result was 0.10 ng/g. Statistically, there was a significant difference between all three koalas and their faecal cortisol responses, as well as their fur cortisol responses. Statistically for Maree and Solstice, there was a significant difference in their faecal cortisol response between days when a stressor was recorded, and days when a stressor was not recorded. However, statistically for Tai, this was not the case, as there was no significant difference in his faecal cortisol response between days when a stressor was recorded, and days when a stressor was not recorded. In summary, the hypothesis that faecal glucocorticoids and fur glucocorticoids between koalas will differ based on individual responses to stressors was true as a whole, but individually, this hypothesis was true for Maree and Solstice, but untrue for Tai. The use of biological samples such as faeces and fur to obtain readings of glucocorticoids is a method of measuring absolute levels of physiological stress that is still evolving for koalas, and there is no current glucocorticoid baseline with which to compare the results of this study; although, measuring faecal and fur glucocorticoids is the first step in understanding how koalas undergoing wildlife rehabilitation respond to stressors.

Background Ross River virus (RRV) is a zoonotic alphavirus transmitted by several mosquito species. Until recently, endemic transmission was only considered possible in the presence of marsupial reservoirs. Methods RRV seroprevalence was investigated in placental mammals (including horses, cows, goats, pigs, dogs, rats, and mice) in Fiji, where there are no marsupials. A total of 302 vertebrate serum samples were collected from 86 households from 10 communities in Western Fiji. Results Neutralizing antibodies against RRV were detected in 28% to 100% of sera depending on the species, and neutralization was strong even at high dilutions. Conclusions These results are unlikely to be due to cross-reactions. Chikungunya is the only other alphavirus known to be present in the Pacific Islands, but it rarely spills over into non-humans, even during epidemics. The study findings, together with a recent report of high RRV seroprevalence in humans, strongly suggest that RRV is circulating in Fiji in the absence of marsupial reservoirs. Considering that all non-human vertebrates present in Fiji are pan-global in distribution, RRV has the potential to further expand its geographic range. Further surveillance of RRV and access to RRV diagnostics will be critical for the early detection of emergence and outbreaks.

Fauna translocations play an integral role in the management of threatened wildlife, though we are limited by our understanding of how the host-parasite community changes during translocation. During this longitudinal field-based study, we monitored gastrointestinal, blood-borne and ectoparasite taxa infecting woylies (Bettongia penicillata) for up to 12 months following two fauna translocations to supplement existing wild woylie populations in three different sites (Dryandra, Walcott and Warrup East) within the south-west of Western Australia. We aimed to (a) identify changes in parasite community structure of both translocated and resident woylies following translocation; and (b) evaluate the efficacy of ivermectin treatment in translocated hosts. Destination site and time since translocation had the strongest effects on parasite prevalence and mean faecal egg counts following translocation. Ivermectin treatment did not significantly reduce parasite prevalence or mean faecal egg counts in treated hosts. Prior to translocation, parasite community composition differed significantly between woylies selected for translocation and resident woylies within each release site. Following translocation, the parasite communities of translocated and resident hosts converged to become more similar over time, with loss of parasite taxa and novel host-parasite associations emerging. This is the first study to examine changes to the broader parasite community in translocated and resident animals following translocation. The dominant site-specific response of parasites following translocation reinforces the importance of incorporating parasite studies to enhance our fundamental understanding of perturbations in host-parasite systems during translocation, in particular the site-level drivers of parasite dynamics., Graphical abstract Image 1, Highlights • Perturbations to host-parasite systems during translocation are poorly understood. • Parasite dynamics were strongly impacted by site and time since translocation. • The parasite communities of translocated and resident hosts converged over time. • Ivermectin treatment had no significant impact on target parasites. • Translocation protocols should consider the intrinsic biodiversity value of parasites.

We have used a quantitative statistical approach to compare the pace of development in the cerebellum and precerebellar systems relative to body size in monotremes and metatherians with that in eutherians (rodents and humans). Embryos, fetuses, and early postnatal mammals were scored on whether key structural events had been reached in the development of the cerebellum itself (CC-corpus cerebelli; 10 milestones), or the pontine and inferior olivary precerebellar nuclear groups (PC; 4 milestones). We found that many early cerebellar and precerebellar milestones (e.g., formation of Purkinje cell layer and deep cerebellar nuclei) were reached at a smaller absolute body length in both metatherians and eutherians together, compared to monotremes. Some later milestones (e.g., formation of the external granular layer and primary fissuration) were reached at a smaller body length in metatherians than eutherians. When the analysis was performed with proportional body length expressed as a natural log-transformed ratio of length at birth, milestones were reached at a much smaller proportional body length in rodents and humans than in the metatherians or monotremes. The findings are consistent with the slower pace of metabolic activity and embryonic development in monotremes. They also indicate slightly advanced maturation of some early features of the cerebellum in some metatherians (i.e., early cerebellar development in dasyurids relative to body size), but do not support the notion of an accelerated development of the cerebellum to cope with the demands of early birth. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1998-2013, 2020. © 2019 American Association for Anatomy.

Malocclusions are a misalignment or incorrect positioning of the teeth when the upper and lower jaws close. These are poorly described in the koala and can result in irregular mastication which can have lifelong effects on body condition and oral health. A total of 370 koalas from two populations in Queensland (295) and one in South Australia (75) were examined for malocclusions. The prevalence of malocclusions in South Australian free-ranging koalas, captive Queensland koalas and Queensland free-ranging koalas was 39% (44), 30% (29) and 22% (29) respectively. Four types of malocclusion were identified based on severity of misalignment of the incisor/canine region, types 1, 2, 3 and 4. Maxillary overbite measurements of the molariform teeth were determined and these anisognathic values were then used to describe malocclusions within familial relationships in captive colonies. Captive koalas with a malocclusion had narrower mandibular width that ranged between 0.5 and 1% less than the normal measurements. The specific malocclusions reported in this study affected individuals by leading to tooth rotation, mobility and erosion with inefficient mastication of food and vegetation compaction. These changes increased the oral cavity pathology, by placing animals at risk of periodontal disease. There was evidence of familial links to malocclusion types in captive animals. Therefore captive breeding recommendations should consider known koala malocclusion traits to minimise their effect on future generations.

A red-necked wallaby (Macropus rufogriseus) in the Republic of Korea, introduced from Australia, died in 12 d after exhibiting anorexia and diarrhea. Postmortem examination revealed that the wallaby died due to coccidiosis by Eimeria sp. Morphologically, Eimeria sp. identified closely resembled E. mykytowyczi. The 18S rRNA sequence analysis showed that Eimeria sp. identified in this study has a 98.5% identity with that in Australian red kangaroo (M. rufus). However, owing to insufficient molecular information on marsupial-specific Eimeria, exact species could not be determined. Phylogenetically, Eimeria sp. identified in this study belonged to clade five of the marsupial group.

“Sparassocynids” are small, carnivorously-adapted marsupials known from the late\ud Miocene and Pliocene of South America, thought to be relatives of living didelphid\ud opossums but of otherwise uncertain phylogenetic relationships. Here, we describe a\ud nearly complete juvenile skull of the “sparassocynid” Sparassocynus derivatus, from the Pliocene (~5-3 million years old) Chapadmalal Formation, Argentina. It provides new information on the morphology of Sparassocynus, including the deciduous dentition, and (together with previously collected specimens) allows reinterpretation of the derived auditory region of “sparassocynids.” The new specimen also exhibits several distinctive apomorphies characteristic of Didelphidae and of subclades within the family. Undated Bayesian phylogenetic analysis of a total evidence dataset (132 craniodental characters, 7.3 kb of DNA sequence data from five nuclear genes) places “sparassocynids” within the didelphid genus Monodelphis, whereas “tip-andnode” dating analysis of the same dataset with an Independent Gamma Rates (IGR) clock model places them as sister to Monodelphis, showing that temporal information influenced the resultant topology. We conclude that “sparassocynids” warrant tribal separation only, as Sparassocynini new rank. Based on our dated phylogeny, we also provide a revised scenario for didelphid diversification. Crown-clade didelphids probably originated close to the Oligocene-Miocene boundary. We agree with previous proposals that the appearance of carnivorously-adapted didelphids in South America during the late Miocene, including sparassocynins, is likely related to a decline in diversity of the sparassodonts at this time, and that the disappearance of these carnivorously-adapted didelphids at the end of the Pliocene may have been due to the arrival of placental carnivorans, such as mustelids, from North America.

Milk provides mammalian neonates with nutritional support and passive immunity. This is particularly true in marsupials where young are born highly altricial and lacking many components of a fully functional adaptive immune system. Here we investigated the T cell populations in the mammaries of a lactating marsupial, the gray short-tailed opossum Monodelphis domestica. Immunohistochemistry confirmed the presence of T cells within the opossum mammaries throughout lactation. Results of quantifying transcript abundance for lymphocyte markers are consistent with γδ T cells being the most common T cell type within lactating mammaries. Numbers of γδ T cells appear to peak early during the first postnatal week, and then decline throughout lactation until weaning. In contrast, numbers of αβ T cells and γμ T cells appear to be low to non-existent in the lactating mammaries. The results support an ancient and conserved role of immune cells in the evolution and function of mammalian mammary tissue.

The fluid that surrounds the embryo in the uterus contains important nourishing factors and secretions. To maintain the distinct microenvironment in the uterine lumen, the tight junctions between uterine epithelial cells are remodeled to decrease paracellular movement of molecules and solutes. Modifications to tight junctions between uterine epithelial cells is a common feature of pregnancy in eutherian mammals, regardless of placental type. Here we used immunofluorescence microscopy and western blot analysis to describe distributional changes to tight junctional proteins, claudin-1, -3, -4, and -5, in the uterine epithelial cells of a marsupial species, Sminthopsis crassicaudata. Immunofluorescence microscopy revealed claudin-1, -3, and -5 in the tight junctions of the uterine epithelium of S. crassicaudata during pregnancy. These specific claudins are associated with restricting passive movement of fluid between epithelial cells in eutherians. Hence, their function during pregnancy in S. crassicaudata may be to maintain the uterine luminal content surrounding developing embryos. Claudin-4 disappears from all uterine regions of S. crassicaudata at the time of implantation, in contrast with the distribution of this claudin in some eutherian mammals. We conclude that like eutherian mammals, distributional changes to claudins in the uterine epithelial cells of S. crassicaudata are necessary to support pregnancy. However, the combination of individual claudin isoforms in the tight junctions of the uterine epithelium of S. crassicaudata differs from that of eutherian mammals. Our findings suggest that the precise permeability of the paracellular pathway of the uterine epithelium is species-specific.

Considered ecologically generalist, Didelphis albiventris is reported as reservoir for different species of parasites, especially Trypanosoma cruzi. However, the knowledge about the influence of T. cruzi on hematological parameters of free-living opossum remains scarce. The present study aimed to evaluate the influence of T. cruzi on hematological parameters of white-ear opossums (D. albiventris) from Campo Grande, Mato Grosso do Sul, Brazil. The blood samples and biometric data were collected from 40 opossums captured by Tomahawk and Sherman traps in six urban forest fragments located in the city. The health of these animals was inferred, mainly, by means of blood parameters (PCV, RBC, WBC, MCV and WBC differential). Molecular detection of T. cruzi infection was performed by nested polymerase chain reaction (nPCR), using 18S and 24Sα rDNA region as target. Paired-t-test and simple linear regression were used for statistical analysis. No significant difference was observed between the averages of hematological variables in relation to gender and body condition. The molecular diagnosis showed that 32.5% (13/40) of the opossums were infected by T. cruzi, which presented lymphocytosis (3.4 ± 1.5) and eosinophilia (0.09 ± 0.13). Path analysis showed that T. cruzi infection resulted in increased numbers of lymphocytes and indirectly decreased the body condition of opossums. Moreover T. cruzi infection resulted in a direct effect on decrease of MCV. Overall, our results suggest that T. cruzi infection may represent a risk to health of opossums since the lymphocytosis may cause a secondary damage on body condition of infected animals., Graphical abstract Image 1, Highlights • Trypanosoma cruzi infection may pose a risk to health of opossums. • Lymphocytosis may cause a secondary damage on body condition of infected animals. • D. albiventris is an important host of T. cruzi in the Campo Grande city.

Mammals are vertebrates with hair and mammary glands, which produce milk for nursing their young. Mammals may be divided into two groups Prototheria and Theria. Prototherian are oviparous and Therian are viviparous. Theria is a subclass of mammals. It includes Eutherians (placental mammals) and metatherians (marsupial mammals). Mammals have a wide variety of skin glands, but all seem to be variations of two major glands, Sudoriferous (sweat) and Sebaceous (oil) glands. Mammary glands appear to be modified sebaceous glands. A teat is the projection from the breast or dug or udder or mammary glands of mammals. A litter is the live birth of multiple offspring at one time in animals from the same mother and usually from one set of parents. In this research we test the hypothesis of Gilbert’s ''one-half rule''. According to one half-rule, the average number of young in a litter is one half the typical numbers of teats and the maximum litter size is equal to the total number of teats. To find relationship between number of teats and litter size, various examples of mammalian species are considered and a comparison and correlation was drawn. In this research we also introduced teat formula (Tf) in mammals for the first time.

BackgroundToxoplasma gondiiinfections are common in humans and animals worldwide. Among all intermediate hosts ofT. gondii, captive marsupials from Australia and New Zealand are highly susceptible to clinical toxoplasmosis. However, most free-range marsupials establish chronicT. gondiiinfection. Infected marsupial meat may serve as a source ofT. gondiiinfection for humans. Differences in mortality patterns in different species of kangaroos and other marsupials are not fully understood. Lifestyle, habitat, and the genotype ofT. gondiiare predicted to be risk factors. For example, koalas are rarely exposed toT. gondiibecause they live on treetops whereas wallabies on land are frequently exposed to infection.MethodsThe present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, and genetic diversity ofT. gondiiinfecting Australasian marsupials in their native habitat and among exported animals over the past decade. The role of genetic types ofT. gondiiand clinical disease is discussed.ResultsFatal toxoplasmosis has been diagnosed in captive Australasian marsupials in Argentina, Chile, China, Germany, Hungary, Japan, Spain, Turkey, and the USA. Most deaths occurred because of disseminated toxoplasmosis. Genetic characterization ofT. gondiistrains isolated from fatal marsupial infections identified Type III as well as atypical, nonclonal genotypes. Fatal toxoplasmosis was also diagnosed in free-ranging wombats (Vombatus ursinus) in Australia. Genetic characterization of DNA amplified directly from host tissues of subclinical culled kangaroos at slaughter identified many mixed-strain infections with both atypical and recombinant genotypes ofT. gondii.ConclusionsMost Australasian marsupials in their native land, Australia and New Zealand, have high prevalence ofT. gondii, and kangaroo meat can be a source of infection for humans if consumed uncooked/undercooked. The genotypes prevalent in kangaroos in Australia and New Zealand were genetically distinct from those isolated or genotyped from most macropods in the USA and other countries. Thus, clinical toxoplasmosis in marsupials imported from Australia is most likely to occur from infections acquired after importation.Graphical Abstract

Summary Transmissible cancers are malignant cells that can spread between individuals of a population, akin to both a parasite and a mobile graft. The survival of the Tasmanian devil, the largest remaining marsupial carnivore, is threatened by the remarkable emergence of two independent lineages of transmissible cancer, devil facial tumour (DFT) 1 and devil facial tumour 2 (DFT2). To aid the development of a vaccine and to interrogate how histocompatibility barriers can be overcome, we analysed the peptides bound to major histocompatibility complex class I (MHC‐I) molecules from Tasmanian devil cells and representative cell lines of each transmissible cancer. Here, we show that DFT1 + IFN‐γ and DFT2 cell lines express a restricted repertoire of MHC‐I allotypes compared with fibroblast cells, potentially reducing the breadth of peptide presentation. Comparison of the peptidomes from DFT1 + IFNγ, DFT2 and host fibroblast cells demonstrates a dominant motif, despite differences in MHC‐I allotypes between the cell lines, with preference for a hydrophobic leucine residue at position 3 and position Ω of peptides. DFT1 and DFT2 both present peptides derived from neural proteins, which reflects a shared cellular origin that could be exploited for vaccine design. These results suggest that polymorphisms in MHC‐I molecules between tumours and host can be ‘hidden’ by a common peptide motif, providing the potential for permissive passage of infectious cells and demonstrating complexity in mammalian histocompatibility barriers., The Tasmanian devil has two independent transmissible cancers that circulate in the population. We have characterized the immunopeptidomes of both cancers and host cell line. We find that the cancers and host cell lines have a common peptide motif.