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Nausea is an uncomfortable sensation that accompanies many therapeutics, especially diabetes treatments involving glucagon-like peptide-1 receptor (GLP1R) agonists. Recent studies in mice have revealed that GLP1R-expressing neurons in the area postrema play critical roles in nausea. Here, we characterized a ligand-conjugated saporin that can efficiently ablate GLP1R+ cells from humans, mice, and the Suncus murinus, a small animal model capable of emesis. This new tool provides a strategy to manipulate specific neural pathways in the area postrema in the Suncus murinus and may help elucidate roles of area postrema GLP1R+ neurons in emesis during therapeutics involving GLP1R agonists.

The genus Notiosorex is the only group of shrews in North America with adaptations to arid or semiarid zones. The genus was described with a single variable species, Notiosorex crawfordi , from which 5 new species have since been distinguished. To date, the phylogenetic relationships of Notiosorex species have only been partially analyzed and it is possible that there are still distinct species included within the catch-all of N. crawfordi. Here, we use geometric morphometrics on cranial and mandibular characters of the described extant species, 3 fossil species, and a distinctive population of N. crawfordi as a proxy for an integrated assessment of phylogenetic relationships of all Notiosorex species. Our results indicate that the population from the Altiplano Mexicano is more similar to, yet distinct from, N. villai than it is to N. crawfordi —we describe it as a new species. We also used the resulting tree to reconstruct phylogeographic history within the genus, which suggests that Notiosorex sp. nov. N. villai , N. evotis , and N. tataticuli all diverged allopatrically as populations from the ancestral area that is currently occupied by N. crawfordi (and in the deeper past by the fossil species N. harrisi), and pushed south into the Gulf Coast, the Altiplano, and Baja California within the last 5 million years following the end of the Miocene. [ABSTRACT FROM AUTHOR]

Interspecific competition, environmental filtering, or spatial variation in productivity can contribute to positive or negative spatial covariance in the abundances of species across ensembles (i.e. groups of interacting species defined by geography, resource use, and taxonomy). In contrast, density compensation should give rise to a negative relationship between ecomorphological similarity and abundance of species within ensembles. We evaluated (1) whether positive or negative covariances characterized the pairwise relationships of 21 species of Congolese shrew, and (2) whether density compensation characterized the structure of each of 36 Congolese shrew ensembles, and did so based on the abundances or biomasses of species. In general, positive covariance is more common than negative covariance based on considerations of abundance or biomass, suggesting dominant roles for environmental filtering and productivity. Nonetheless, negative covariance is more common for ecomorphologically similar species, suggesting a dominant role for competition within functional groups. Effects of abundance or biomass compensation, via pairwise or diffuse competitive interactions, were detected less often than expected by chance, suggesting that interspecific competition is not the dominant mechanism structuring these ensembles. Effects of competition may be balanced by responses to variation in resource abundance among sites in a landscape or among niche spaces within sites. Future studies of compensatory effects should incorporate considerations of heterogeneity in the abundance and distribution of resources in ecological space to better isolate the effects of competition and resource abundance, which can have opposing effects on community structure. [ABSTRACT FROM AUTHOR]

Endotherms vary widely in their capacity to defend sublethal body temperature (Tb) during acute heat exposure. Interspecific variation in the upper thermal limits of small mammals remains poorly studied, particularly in taxa other than bats. We hypothesised that rupicolous elephant shrews (Macroscelidae), on account of their occupancy of above-ground rock crevices in hot habitats and rapid cursorial locomotion, have evolved pronounced heat tolerance capacities. To test this hypothesis, we quantified relationships between Tb, resting metabolic rate (RMR) and evaporative water loss (EWL) in western rock elephant shrews (Elephantulus rupestris) exposed to air temperature (Tair) approaching or exceeding Tb under conditions of low humidity representative of the study population's arid, winter-rainfall habitat in western South Africa. Our data revealed a pronounced capacity to tolerate Tair > Tb, with E. rupestris tolerating Tair up to 48.0 ± 0.1 °C while defending Tb > 7 °C below Tair (maximum Tb = 41.64 ± 0.16 °C). Three behavioural pathways were employed to dissipate heat: open mouth panting, flattening their body posture, and nose-licking. At the highest experimental Tair values achieved, EWL increased 15.05-fold relative to normothermic levels and heat was dissipated evaporatively at rates equivalent to 174%—240% of metabolic heat production. The heat tolerance limit of Tair = 48 °C in E. rupestris is one of the highest yet recorded in a non-volant small mammal, and our data support the notion that elephant shrews possess a pronounced capacity to avoid lethal hyperthermia during acute heat exposure. [ABSTRACT FROM AUTHOR]

Background: This database compiles comprehensive occurrence information, based on voucher specimens of small-eared shrews, genus Cryptotis, that occur from México to Peru. The database integrates the information obtained from four main sources: natural history museums, public databases, fieldwork and scientific literature. It contains 3,639 records from 53 species in 12 countries. Of the total, 83.54% have collecting dates, 51.36% of the specimens are sexed and 84.56% have decimal degrees coordinates. By generating this database and making it publicly available, we hope to improve the biological knowledge of this group of small mammals still poorly studied in the region. It aims to be a valuable resource for students, researchers, conservationists and decision-makers. New information: The dataset contains information on all species of the genus Cryptotis in the Neotropical Region (namely from México to Peru), incorporating the most updated taxonomic and nomenclatural changes. The database includes records in regions and countries that are poorly represented in currently available data repositories. Most records have verified temporal and spatial information. [ABSTRACT FROM AUTHOR]

Mammalian cardiac troponin I (cTnI) contains a highly conserved amino-terminal extension harboring protein kinase A targets [serine-23 and -24 (Ser23/24)] that are phosphorylated during β-adrenergic stimulation to defend diastolic filling by means of an increased cardiomyocyte relaxation rate. In this work, we show that the Ser23/24-encoding exon 3 of TNNI3 was pseudoexonized multiple times in shrews and moles to mimic Ser23/24 phosphorylation without adrenergic stimulation, facilitating the evolution of exceptionally high resting heart rates (~1000 beats per minute). We further reveal alternative exon 3 splicing in distantly related bat families and confirm that both cTnI splice variants are incorporated into cardiac myofibrils. Because exon 3 of human TNNI3 exhibits a relatively low splice strength score, our findings offer an evolutionarily informed strategy to excise this exon to improve diastolic function during heart failure. [ABSTRACT FROM AUTHOR]

Borna disease virus 1 (BoDV-1) is the causative agent of Borna disease, a fatal neurologic disorder of domestic mammals and humans, resulting from spill-over infection from its natural reservoir host, the bicolored white-toothed shrew (Crocidura leucodon). The known BoDV-1-endemic area is remarkably restricted to parts of Germany, Austria, Switzerland and Liechtenstein. To gain comprehensive data on its occurrence, we analysed diagnostic material from suspected BoDV-1-induced encephalitis cases based on clinical and/or histopathological diagnosis. BoDV-1 infection was confirmed by RT-qPCR in 207 domestic mammals, 28 humans and seven wild shrews. Thereby, this study markedly raises the number of published laboratory-confirmed human BoDV-1 infections and provides a first comprehensive summary. Generation of 136 new BoDV-1 genome sequences from animals and humans facilitated an in-depth phylogeographic analysis, allowing for the definition of risk areas for zoonotic BoDV-1 transmission and facilitating the assessment of geographical infection sources. Consistent with the low mobility of its reservoir host, BoDV-1 sequences showed a remarkable geographic association, with individual phylogenetic clades occupying distinct areas. The closest genetic relatives of most human-derived BoDV-1 sequences were located at distances of less than 40 km, indicating that spill-over transmission from the natural reservoir usually occurs in the patient´s home region. Borna disease virus 1 (BoDV-1) is a zoonotic pathogen endemic in bicoloured white-toothed shrews in Central Europe that can cause fatal encephalitis in humans and other mammals. Here, the authors investigate the molecular epidemiology and phylogeography of BoDV-1 using newly collected and archived samples. [ABSTRACT FROM AUTHOR]

Baseline information on species diversity is lacking in many parts of the world. To address this gap, we conducted the first assessment of small mammal diversity in the Cantanhez National Park, Guinea‐Bissau, West Africa. We used live‐ and pitfall‐trapping to sample small mammals and identified them molecularly. We recorded 183 individuals from 11 species (eight rodents and three shrews). Half of the captures were made up of the forest soft‐furred mouse Praomys rostratus (48.1%), followed by the multimammate mouses Mastomys huberti (18.0%) and Mastomys erythroleucus (7.7%). Our surveys extended the geographic distribution of Matthey's mouse, Mus mattheyi, by 250 km into Guinea‐Bissau. [ABSTRACT FROM AUTHOR]

Abstract This work proposes a functional data analysis approach for morphometrics in classifying three shrew species (S. murinus, C. monticola, and C. malayana) from Peninsular Malaysia. Functional data geometric morphometrics (FDGM) for 2D landmark data is introduced and its performance is compared with classical geometric morphometrics (GM). The FDGM approach converts 2D landmark data into continuous curves, which are then represented as linear combinations of basis functions. The landmark data was obtained from 89 crania of shrew specimens based on three craniodental views (dorsal, jaw, and lateral). Principal component analysis and linear discriminant analysis were applied to both GM and FDGM methods to classify the three shrew species. This study also compared four machine learning approaches (naïve Bayes, support vector machine, random forest, and generalised linear model) using predicted PC scores obtained from both methods (a combination of all three craniodental views and individual views). The analyses favoured FDGM and the dorsal view was the best view for distinguishing the three species.

We report on a small collection of shrews from the central part of the Democratic Republic of Congo. Three taxa are recognized, of which a long-tailed and a middle-sized species of Crocidura are described as C. salonga sp. nov. and C. binco sp. nov. Crocidura lwiroensis is recorded for the first time since its description from near Lake Tanganyika in 2013. [ABSTRACT FROM AUTHOR]

Humans and other animals readily transition from externally to internally focused attention, and these transitions are accompanied by activation of the default mode network (DMN). The DMN was considered a cortical network, yet recent evidence suggests subcortical structures are also involved. We investigated the role of ventral pallidum (VP) and mediodorsal thalamus (MD) in DMN regulation in tree shrew, a close relative of primates. Electrophysiology and deep learning-based classification of behavioral states revealed gamma oscillations in VP and MD coordinated with gamma in anterior cingulate (AC) cortex during DMN states. Cross-frequency coupling between gamma and delta oscillations was higher during DMN than other behaviors, underscoring the engagement of MD, VP and AC. Our findings highlight the importance of VP and MD in DMN regulation, extend homologies in DMN regulation among mammals, and underline the importance of thalamus and basal forebrain to the regulation of DMN. A study using electrophysiology, behavioral methods and modelling demonstrates the importance of the ventral pallidum and mediodorsal thalamus in DMN regulation in tree shrews. [ABSTRACT FROM AUTHOR]

The Guadix-Baza Basin (southern Spain) displays one of the best continental records from the Late Miocene to the Middle Pleistocene in western Europe, with many localities of fossil small mammals in a quite complete and continuous stratigraphic sequence. The Late Miocene continentalization of the Guadix-Baza Basin was firstly mentioned in the 1980s based on the presumed presence of Hipparion gromovae granatensis at the site of Abla (Almería province). Subsequent discoveries of late Turolian deposits confirmed the Late Miocene continentalization of the basin. The interest in the Abla site led to a second sampling campaign to look for microvertebrate fossils, which proved successful. In this paper, a complete taxonomic study of the novel microvertebrate fauna from Abla is presented, providing updated information on the age of the locality. Representatives of the vertebrate families Cyprinidae, Alytidae, Anguidae, Soricidae, Cricetidae, and Muridae have been identified. The presence of Stephanomys specimens exceeding the size of latest Miocene-earliest Pliocene species allows us to correlate the Abla site with the Early Pliocene (Ruscinian), a younger age than initially stated. A qualitative paleoecological interpretation based on the herpetofauna suggests the dominance of open environments with presence of permanent water bodies during the deposition of the Abla site, under warmer and more humid climate conditions than today in the Guadix-Baza Basin. A revision of the Hipparion remains from this locality showed that the sample is closer to Hipparion fissurae than to the initially assigned species. [ABSTRACT FROM AUTHOR]

The body condition index (BCI) values in small mammals are important in understanding their survival and reproduction. The upper values could be related to the Chitty effect (presence of very heavy individuals), while the minimum ones are little known. In this study, we analyzed extremes of BCI in 12 small mammal species, snap-trapped in Lithuania between 1980 and 2023, with respect to species, animal age, sex, and participation in reproduction. The proportion of small mammals with extreme body condition indices was negligible (1.33% with a BCI < 2 and 0.52% with a BCI > 5) when considering the total number of individuals processed (n = 27,073). When compared to the expected proportions, insectivores and herbivores were overrepresented, while granivores and omnivores were underrepresented among underfit animals. The proportions of granivores and insectivores were higher, while those of omnivores and herbivores were lower than expected in overfit animals. In several species, the proportions of age groups in underfit and overfit individuals differed from that expected. The male–female ratio was not expressed, with the exception of Sorex araneus. The highest proportion of overfit and absence of underfit individuals was found in Micromys minutus. The observation that individuals with the highest body mass are not among those with the highest BCI contributes to the interpretation of the Chitty effect. For the first time in mid-latitudes, we report individuals of very high body mass in three shrew species. [ABSTRACT FROM AUTHOR]

Habitat type and habitat change are very important factors in the body condition of small mammals that inhabit them. The response can be positive, increasing, or the opposite, decreasing body condition. We analyzed outliers of the body condition indices (BCIs) of 12 species trapped in nine different habitats during 1980–2023 in Lithuania, a mid-latitude country. Mixed and fragmented habitats, as well as commensal habitats, could be considered the least suitable for small mammals, based on the highest proportions of underfit and low proportions of best-fit individuals. On the contrary, meadows and disturbed habitats (landfills and cormorant colonies) had the highest proportions of best-fit individuals, while the proportion of under-fit individuals was much lower than expected. We found outliers in the BCI in all species, except for the under-fit harvest mice (Micromys minutus), and in all habitats, though not numerous. The presence of the highest BCI in yellow-necked mice (Apodemus flavicollis) and bank voles (Clethrionomys glareolus) in the disturbed habitats studied and in house mice (Mus musculus) in commensal habitats may be related to the resources provided by these habitats. Our results demonstrate the feasibility of using retrospective small mammal morphometric data to analyze their relationship with habitat. [ABSTRACT FROM AUTHOR]

The relationship between the body condition of different small mammal species and the habitat they occupy is poorly analyzed. We analyzed the body condition index, BCI, of 18 small mammal species trapped in forest, shrub, wetland, meadow, riparian, mixed and fragmented, disturbed, agricultural, and commensal habitats of Lithuania during the span of 1980–2023. The composition of small mammal communities was habitat-dependent, being richest in meadows, with eighteen species, and poorest in riparian habitats, with nine species. A significant variation in the BCI with respect to habitat was observed in eight small mammal species (Sorex araneus, S. minutus, Apodemus agrarius, A. flavicollis, Clethrionomys glareolus, Alexandromys oeconomus, Microtus agrestis, and M. arvalis). The highest average BCI for most of these species was found in disturbed habitats, with S. minutus and M. arvalis showing the highest BCI in agricultural habitats. The lowest average BCI for most species was found in mixed habitats, while C. glareolus and M. arvalis exhibited the lowest BCI in shrub habitats. In general, species dominating certain habitats did not have the highest BCI. This is the first multi-species, multi-habitat study of body condition in small mammals at mid-latitudes. [ABSTRACT FROM AUTHOR]

Venom production has evolved independently many times in the animal kingdom, although it is rare among mammals. Venomous shrews produce venom in their submandibular salivary glands and use it for food acquisition. Only a few toxins have been identified in shrew venoms thus far, and their modes of action require investigation. The biological and molecular processes relating to venom production and gland functioning also remain unknown. To address this gap, we investigated protein content in extracts from venom glands of two shrew species, Neomys fodiens and Sorex araneus, and interpreted their biological functions. Applying a proteomic approach coupled with Gene Ontology enrichment analysis, we identified 313 and 187 putative proteins in venom glands of N. fodiens and S. araneus, respectively. A search of the UniProt database revealed that most of the proteins found in both shrew species were involved in metabolic processes and stress response, while GO enrichment analysis revealed more stress-related proteins in the glands of S. araneus. Molecules that regulate molecule synthesis, cell cycles, and cell divisions are necessary to enable venom regeneration and ensure its effectiveness in predation and food hoarding. The presence of proteins involved in stress response may be the result of shrews' high metabolic rate and the costs of venom replenishment. Some proteins are likely to promote toxin spreading during envenomation and, due to their proteolytic action, reinforce venom toxicity. Finally, finding numerous proteins involved in immune response suggests a potential role of shrew venom gland secretions in protection against pathogens. These findings open up new perspectives for studying biological functions of molecules from shrew venom glands and extend our knowledge on the functioning of eulipotyphlan venom systems. Because the majority of existing and putative venomous mammals use oral venom systems to inject venom into target species, the methods presented here provide a promising avenue for confirming or discovering new taxa of venomous mammals. [ABSTRACT FROM AUTHOR]

Introduction: Globally, rodents and shrew populations constitute crucial elements of diverse environments and animal communities. It is imperative to study their population dynamics to mitigate any potential negative impact on humans, as they can be involved in the transmission of critical zoonotic agents, such as Blastocystis. Therefore, this study aimed to identify the prevalence and genetic composition of Blastocystis in wild rodents and shrews residing in the Zhejiang provinces of China. Methods: A total of 652 wild rodents and and shrews were captured from three different regions in Zhejiang Province from April 1st to October 31, 2023. The DNA was isolated by collecting fresh feces from the intestines of each rodent or and shrew. Rodent and shrew species were examined by vertebrate cytochrome b (cytb) analysis and PCR amplification. Blastocystis was also found in all fecal samples using PCR analysis and sequencing of the partial small subunit of ribosomal RNA (SSU rRNA) gene. Results: Among all the samples, 6.6% (43/652) showed a positive result for Blastocystis. In the results, 6 species of rodent and shrew were identified with Blastocystis, including Apodemusagrarius (n = 36) (2.8%), Niviventer confucianus (n = 75) (17.3%), Rattus losea (n = 18) (5.6%), R. norvegicus (n = 155) (2.6%), R. tanezumi (n = 86) (3.5%), and Suncus murinus (n = 282) (7.4%). The existence of 6 Blastocystis subtypes, ST4 (n = 33), ST1 (4), ST7 (n = 3), ST2 (n = 1), ST3 (n = 1), and ST5 (n = 1), were confirmed by sequence analysis. Discussion: Based on the molecular data obtained, the wild rodents and shrews under investigation were found to be concurrently infected with zoonotic subtypes of Blastocystis, including ST1 to ST5 and ST7. This suggests that these animals could potentially pose a zoonotic threat to humans and other animals susceptible to Blastocystis infection. [ABSTRACT FROM AUTHOR]

The Fingui white-toothed shrew Crocidura fingui , categorized as Data Deficient on the IUCN Red List, is endemic to Príncipe Island, Central Africa. It is currently known from < 10 sites and its ecology and any threats are largely unknown. We review its distribution and ecology, and any potential threats, based on camera-trap data, field observations and previously published and unpublished sightings. Crocidura fingui appears to have an island-wide distribution and to use a range of ecosystems, from native forests to urban areas. It is largely nocturnal and exhibits considerable spatiotemporal overlap with introduced mammals such as the African civet Civettictis civetta , domestic cat Felis catus and rats Rattus spp. The species has an area of occupancy < 500 km2 and is known from fewer than five locations, and its population is inferred to be affected by several introduced mammals. We recommend that it is recategorized as Endangered on the IUCN Red List. [ABSTRACT FROM AUTHOR]

Using univariate and multivariate statistics, I conducted a detailed morphological analysis on the dentition and skull of long-tailed shrews of the Sorex cinereus species group from east-central US. Based on the examination of 109 shrews, by use of 24 measurements, I identified 3 distinct morphological groups. These groups are referrable to: (1) Sorex cinereus cinereus (Masked Shrew) from southeastern New York, northern New Jersey, and northeastern Pennsylvania; (2) S. c. fontinalis (= S. fontinalis of some authors) (Maryland Shrew) from southeastern Pennsylvania, northeastern Maryland, and the Delmarva Peninsula of Maryland, Delaware, and Virginia; and (3) Sorex c. nigriculus (Tuckahoe Masked Shrew) endemic to southern New Jersey. The lower Delaware River and Bay may be a barrier that prevents intergradation between S. c. nigriculus and S. c. fontinalis or they could be 2 distinct species. Intergradation between S. c. nigriculus and S. c. cinereus in central New Jersey likely is occurring, although targeted sampling is needed to verify this. Intergradation between S. c. cinereus and S. c. fontinalis in east-central Pennsylvania is uncertain. [ABSTRACT FROM AUTHOR]

Alternative splicing is the process of generating different mRNAs from the same primary transcript, which contributes to increase the transcriptome and proteome diversity. Abnormal splicing has been associated with the development of several diseases including cancer. Given that mutations and abnormal levels of the RIPK2 transcript and RIP-2 protein are frequent in tumors, and that RIP-2 modulates immune and inflammatory responses, we investigated alternative splicing events that result in partial deletions of the kinase domain at the N-terminus of RIP-2. We also investigated the structure and expression of the RIPK2 truncated variants and isoforms in different environments. In addition, we searched data throughout Supraprimates evolution that could support the biological importance of RIPK2 alternatively spliced products. We observed that human variants and isoforms were differentially regulated following temperature stress, and that the truncated transcript was more expressed than the long transcript in tumor samples. The inverse was found for the longer protein isoform. The truncated variant was also detected in chimpanzee, gorilla, hare, pika, mouse, rat, and tree shrew. The fact that the same variant has been preserved in mammals with divergence times up to 70 million years raises the hypothesis that it may have a functional significance. [ABSTRACT FROM AUTHOR]

Plant–animal interactions play a crucial role in ecosystem functioning, especially through seed dispersal mechanisms. Understanding how small mammal populations respond to seed availability is essential for ecosystem management and biodiversity conservation, especially in the context of habitat loss and climate change. We conducted a 10-year study in mixed Mediterranean oak–beech forests to investigate the population dynamics of common small mammal species in response to seed availability. Our findings revealed distinct responses among species, influenced by life history traits, foraging behaviour, and diet. Wood mice (Apodemus sylvaticus) showed a rapid population increase with seed availability both in the same year of seed fall and the following year, suggesting a flexible foraging strategy and a dependence on arboreal seed producers. Yellow-necked mice (Apodemus flavicollis) revealed immediate population increases in response to seed availability in the autumn, probably because of their arboreal habits and preference for exploiting seeds prior to maturation. Bank voles (Clethrionomys glareolus) showed responses with population peaks in years following high seed availability, indicating a slower demographic response to resource abundance. Surprisingly, the greater white-toothed shrew (Crocidura russula) responded indirectly to seed availability in Mediterranean forests, suggesting complex interactions with seed-associated invertebrates or dependence on other variables not considered. Our findings highlight the importance of understanding how changes in seed availability influence the population ecology of small mammals, with significant implications for the conservation and management of Mediterranean forest ecosystems in the context of climate change and recurrent droughts. These results emphasise the need to consider species interactions, resource availability, and climate change in the conservation and management of evolving ecosystems. [ABSTRACT FROM AUTHOR]

There are two types of distributed denial of service (DDoS) attacks: high-rate DDoS (HRDDoS) attacks and low-rate DDoS (LRDDoS) attacks. A shrew attack is an LRDDoS attack that can prove to be more harmful than an HRDDoS attack since it is not easily noticeable and is stealthy. It can cause TCP flows to attain near-zero throughput by sending attack pulses of short bursts synchronized with the TCP retransmission timeout (RTO) value. As a result, each time it attempts to retransmit after the timeout, it forces the TCP packets to be dropped. Thus, if it is not detected for a long time, it may endanger the victim systems and reduce the overall quality of services. In this paper, we conduct a statistical analysis of network traffic, where we analyze the deviations in flow behavior based on packets sent under normal and attack conditions. In order to achieve this, we use a priority determiner D to determine the participation of a flow in congestion and its adherence to legitimate TCP compliance under attack conditions. Shrew attack flows exhibit higher values of D as they do not adhere to TCP compliance and tend to contribute to more congestion to disrupt a server. This nature of attack flows enables us to filter them based on the values of D and mitigate them by blocking these flows. The experimental results on various scenarios demonstrated high accuracy to substantiate the efficacy of the proposed method. [ABSTRACT FROM AUTHOR]

The tree shrew (Tupaia belangeri) has long been proposed as a suitable alternative to non-human primates (NHPs) in biomedical and laboratory research due to its close evolutionary relationship with primates. In recent years, significant advances have facilitated tree shrew studies, including the determination of the tree shrew genome, genetic manipulation using spermatogonial stem cells, viral vector-mediated gene delivery, and mapping of the tree shrew brain atlas. However, the limited availability of tree shrews globally remains a substantial challenge in the field. Additionally, determining the key questions best answered using tree shrews constitutes another difficulty. Tree shrew models have historically been used to study hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, myopia, and psychosocial stress-induced depression, with more recent studies focusing on developing animal models for infectious and neurodegenerative diseases. Despite these efforts, the impact of tree shrew models has not yet matched that of rodent or NHP models in biomedical research. This review summarizes the prominent advancements in tree shrew research and reflects on the key biological questions addressed using this model. We emphasize that intensive dedication and robust international collaboration are essential for achieving breakthroughs in tree shrew studies. The use of tree shrews as a unique resource is expected to gain considerable attention with the application of advanced techniques and the development of viable animal models, meeting the increasing demands of life science and biomedical research. [ABSTRACT FROM AUTHOR]

Simple Summary: The genus Crocidura has ~200 species, which accounts for roughly half of the Soricidae family's diversity. The "pergrisea" species group, which comprises at least four species—Crocidura arispa, Crocidura pergrisea, Crocidura ramona, and Crocidura serezkyensis—is especially interesting among Crocidura endemics of central and western Asian regions. The taxonomic value of a fifth species, Crocidura armenica, has been unclear for a long time owing to the poor condition of the skulls of both type specimens. Using a microcomputed-tomography-based cybertaxonomic (CTtax) approach and a newly developed pipeline, "AProMaDesU", we re-evaluated the type material of the Armenian shrew and expanded the hypodigm of this species using three additional specimens. A morphospace analysis based on three-dimensional craniomandibular datasets revealed the uniqueness of C. armenica and C. arispa. The extraction of museum DNA from a unique collection of samples of the "Crocidura pergrisea" species complex, which comprises local endemics of Central and West Asia, allowed us to determine their inter- and intragroup relationships. The first step of this study was the re-evaluation of heavily damaged type specimens of C. armenica via a microcomputed-tomography-based cybertaxonomic approach (CTtax), which enabled a precise description of the species' morphology; three-dimensional models of the cybertypes were made available through the MorphoBank Repository. We developed the "AProMaDesU" pipeline on the basis of five requirements for micro-CT-based cyber-datasets in relation to mammalian collections. Our second step was a combination of several meticulous approaches to morphological investigation against a background of a cytb-based phylogeny, which helped us to make a taxonomic decision about the status of species of the "pergrisea" group, e.g., C. arispa, C. armenica, and C. serezkyensis, when the morphological results were partly incongruent with the molecular phylogeny. Nevertheless, under two assumptions, our findings preserved a separate species-level status of C. serezkyensis and C. arispa. In addition, we restored the species-level status of C. armenica. This taxonomic decision is based on our morphospace analysis, which revealed unique craniomandibular shape transformations within the rocky shrews that helped them with the transition to a new area of morphospace/trophic niches and consequently separated them from the other analyzed Crocidura groups. [ABSTRACT FROM AUTHOR]

Hepatitis A virus (HAV), a member of the genus Hepatovirus (Picornaviridae HepV), remains a significant viral pathogen, frequently causing enterically transmitted hepatitis worldwide. In this study, we conducted an epidemiological survey of HepVs carried by small terrestrial mammals in the wild in Yunnan Province, China. Utilizing HepV-specific broad-spectrum RT-PCR, next-generation sequencing (NGS), and QNome nanopore sequencing (QNS) techniques, we identified and characterized two novel HepVs provisionally named EpMa-HAV and EpLe-HAV, discovered in the long-tailed mountain shrew (Episoriculus macrurus) and long-tailed brown-toothed shrew (Episoriculus leucops), respectively. Our sequence and phylogenetic analyses of EpMa-HAV and EpLe-HAV indicated that they belong to the species Hepatovirus I (HepV-I) clade II, also known as the Chinese shrew HepV clade. Notably, the codon usage bias pattern of novel shrew HepVs is consistent with that of previously identified Chinese shrew HepV. Furthermore, our structural analysis demonstrated that shrew HepVs differ from other mammalian HepVs in RNA secondary structure and exhibit variances in key protein sites. Overall, the discovery of two novel HepVs in shrews expands the host range of HepV and underscores the existence of genetically diverse animal homologs of human HAV within the genus HepV. [ABSTRACT FROM AUTHOR]

The genus Soriculus is currently recognized as monotypic, containing only one species, Soriculus nigrescens , which is distributed mainly in the Himalayas and the southern Hengduan Mountains. The taxonomy of Soriculus is ambiguous due to insufficient taxonomic sampling. We conducted extensive surveys of Soriculus across the Himalayas and Hengduan Mountains. We sequenced two mitochondrial and three nuclear genes, and the complete mitochondrial genomes of several selected specimens to infer the phylogenetic relationships of Soriculus and also analysed their morphological and morphometric variations. Our results indicate monophyly of Soriculus , and the diversity of the genus is greatly underestimated. We described two new species, Soriculus nivatus sp. nov. and Soriculus medogensis sp. nov. , and elevated S. minor as a distinct species. Additionally, we found another putative new species of Soriculus in Medog County; however, we did not formally describe it because only one specimen was collected. Divergence time estimates suggest that the global cooling and desiccating events around the Miocene/Pliocene and Pliocene/Pleistocene boundaries and the Pleistocene climatic oscillations may have played major roles in the diversification of Soriculus. Our results highlight the overlooked diversity of small mammals in the eastern Himalayas, which warrants further surveys and taxonomic studies. [ABSTRACT FROM AUTHOR]

Background: Biological traits are mainly determined by genotype and are also influenced by environmental factors, especially in the process of adapting to different environments, corresponding phenotypic variations may occur. Even for the same animal, there may be some morphological differences due to its long-term adaptation to different habitat environments. Molar teeth are the direct contact point between animals and the environment, which are of great significance in the study of animal adaptability to different environments. Methods: To explore the relationship between the morphology of the molars (upper molars and lower molars) of tree shrews (Tupaia belangeri) and environmental variations in different regions, we applied geometric morphometric methods to measure the morphological characteristics of the molars of T. belangeri in 12 different regions of China (Hainan, Daxin, Leye, Xingyi, Xichang, Hekou, Kunming, Mengla, Dali, Tengchong, Pianma, Laboratory bred F1 generation). Result: The results showed that the morphological variations of the lower molars of T. belangeri in 12 different regions were larger, which was more suitable and reference valuable for studying the morphological differences among different geographical populations. The Principal component analysis showed that T. belangeri from 12 regions were clustered into 4 branches: Hainan was clustered into one branch, Daxin was clustered into one branch, Pianma and Tengchong were clustered into one branch and Leye, Xingyi, Hekou, Kunming, Xichang, Mengla, Dali and laboratory bred F1 generation were clustered into one branch. The thin plate spline analysis showed that deformations in the upper molars were mostly concentrated in the alveolar and dental margins. The deformations of the lower molars were mainly concentrated in the alveolar, marginal and occlusal surfaces. Multidimensional scaling showed that there were differences in molars morphology among the 12 locations, with significant variations in Hainan, Daxin, Pianma and Tengchong regions, reflecting the adaptive variation of T. belangeri to different ecological environments. The present results can provide a certain basis for the study of phenotypic adaptation in T. belangeri. [ABSTRACT FROM AUTHOR]

In 2010–2023, the dynamics of the population abundance and changes in the proportion of species in the community of small mammals (insectivores and rodents) inhabiting a slope larch forest in the vicinity of the city of Magadan (northern coast of the Sea of Okhotsk) was traced. The census of animals was carried out using Gero traps and cone traps (trap-line methods). In total, we analyzed 4700 trap-nights and 15 720 cone-nights. Altogether, 3384 individuals of 9 species belonging to the families of shrews (Soricidae), squirrels (Sciuridae), mice (Muridae), and hamsters (Cricetidae) were trapped. During the considered period, the relative abundance and the amplitude of its interannual fluctuations decreased in the populations of even-toothed shrews (Sorex isodon) and grey red-backed voles (Craseomys rufocanus). The proportion of Laxmann's shrews (S. caecutiens) and Korean field mice (Apodemus peninsulae) in the community increased 2.6 and 2.5 times, respectively, while the proportion of even-toothed shrew and grey red-backed vole decreased 2.8 times and 3 times, respectively. As a result, about 50% of the individuals in the samples were Laxmann's shrews and about 30% were northern red-backed voles (Clethrionomys rutilus). This, in turn, led to an increase in the dominance (the Simpson index increased from 0.21 to 0.34), a decrease in evenness (the Pielou index decreased from 0.87 to 0.61), and a significant decrease in the species diversity of the small mammal community (the Shannon index decreased from 1.7 to 1.3; t = 10.90, p < 0.001). [ABSTRACT FROM AUTHOR]

When evolution leads to differences in body size, organs generally scale along. A well-known example of the tight relationship between organ and body size is the scaling of mammalian molar teeth. To investigate how teeth scale during development and evolution, we compared molar development from initiation through final size in the mouse and the rat. Whereas the linear dimensions of the rat molars are twice that of the mouse molars, their shapes are largely the same. Here, we focus on the first lower molars that are considered the most reliable dental proxy for size-related patterns due to their low within-species variability. We found that scaling of the molars starts early, and that the rat molar is patterned equally as fast but in a larger size than the mouse molar. Using transcriptomics, we discovered that a known regulator of body size, insulin-like growth factor 1 (Igf1), is more highly expressed in the rat molars compared to the mouse molars. Ex vivo and in vivo mouse models demonstrated that modulation of the IGF pathway reproduces several aspects of the observed scaling process. Furthermore, analysis of IGF1-treated mouse molars and computational modeling indicate that IGF signaling scales teeth by simultaneously enhancing growth and by inhibiting the cusp-patterning program, thereby providing a relatively simple mechanism for scaling teeth during development and evolution. Finally, comparative data from shrews to elephants suggest that this scaling mechanism regulates the minimum tooth size possible, as well as the patterning potential of large teeth.

We collected shrews using pitfall traps in a forest area in Kvam, Hordaland, Western Norway in 1997- 98. Altogether, 205 individuals of pygmy shrew, Sorex minutus and 129 individuals of common shrew, Sorex araneus were collected. Both shrew species occurred over a wide range of forest types. Common shrew was absent in bogs and pygmy shrew apparently was absent in alder forest. Common shrew was relatively evenly distributed among forest types while the catches of pygmy shrew was significantly lower in deciduous forest than in pine forest, and this may suggest that the pygmy shrew is partially excluded from these areas by the common shrew. Catches of shrews showed no unambiguous correlation with catches of arthropods. Shrew catches were only weakly related to variation in forest productivity, humidity and tree cover. For both species the number of animals caught was highest in June and July, with rather few specimens caught in early spring and late autumn/winter.

Objectives: Mpox is a neglected viral endemic tropical disease in Central and Western African countries transmitted to humans by an animal. However, the natural reservoir of the virus remains elusive. In this study, we looked for potential reservoirs of the mpox virus (MPXV) in Gabonese wildlife to prevent future outbreaks and enrich the literature with additional data on animal reservoirs. Methods: DNA was extracted from the livers and spleens from 2549 animals (bats [859], bushmeats [356], rodents [1309], and shrews [25]) collected between 2012 and 2021. DNA was analyzed by real-time and conventional polymerase chain reaction, targeting the 14 kD protein and the rpo subunit RNA polymerase of orthopoxviruses. Results: No MPXV DNA was detected despite the presence of potential host reservoirs such as Critcetomys, Crocidura, Praomys, and Atherurus africanus. This absence could be due to (i) the low number of animals collected for some species, (ii) the acute nature of mpox infection but also (iii) the lack of the potential reservoir Funisciurus anerythrus among collected animals, and (iv) the fact that the samplings are not included in the probable ecological niche of MPXV. Conclusion: Longitudinal studies including potential ecological niches of F. anerythrus and MPXV in Gabon may be useful to get more information on MPXV circulation.

Previously we proposed a new reconnaissance method for estimating the total abundance of small mammals in urban areas. The method includes placing plastic bottles with bait inside equal distances apart. In this research we examined two ways to improve the method: using bottles of smaller volume (0,25 liters instead of 0,5 liters) to increase the ergonomics and using opaque bottles to make them more attractive for animals. Bigger and smaller bottles with neck diameter of 38 mm were fastened in pairs which were set in a transect with a fi ve-meter spacing. The same was done with pairs of opaque and transparent bottles. A bait (rye bread with unrefi ned sunfl ower oil) was put into all the bottles. During the following days we recorded animals’ visits into the bottles. It was found out that there are no signifi cant diff erences in how often animals attend bottles of 0,25 liters and 0,5 liters, the same results were received for both transparent and opaque bottles. Thus, the simple method for estimating abundance of small mammals may be optimized by using smaller bottles, the colour of which is not important.

The common shrew (Sorex araneus) is one of the most studied shrew species of the Western Palaearctic. Despite this, the general drivers underlying morphological variation still remain unclear. Here we provide evidence for contradictory effects of climatic and geographical factors on the mandible of the common shrew. At the continental scale there is a negative correlation between body- and skull-size and latitude and longitude but at regional scales such an association is often not apparent; in fact, in some cases body size and skull size follow the opposite trend and observations at various scales yielded contradictory results. We studied shrew mandibles using geometric morphometrics and tested for correlations of their size and shape with selected geographical and climatic variables. We examined 1155 mandibles from 29 European localities and found significant interpopulation differences in both size and shape. Centroid size negatively correlated with latitude. We also found that centroid size was significantly correlated with altitude and annual precipitation. Our results confirmed an inverse Bergmann's rule relationship in S. araneus along the transect from the Baltic to the Adriatic Sea. Regarding mandible shape, Slovenian shrews were the most distant from all other studied populations. We discuss how altitude and precipitation can influence the morphology of the common shrew. [ABSTRACT FROM AUTHOR]

In contrast to cats and dogs, here we report that the α2-adrenergic receptor antagonist yohimbine is emetic and corresponding agonists clonidine and dexmedetomidine behave as antiemetics in the least shrew model of vomiting. Yohimbine (0, 0.5, 0.75, 1, 1.5, 2, and 3 mg/kg, i.p.) caused vomiting in shrews in a bell-shaped and dose-dependent manner, with a maximum frequency (0.85 ± 0.22) at 1 mg/kg, which was accompanied by a key central contribution as indicated by increased expression of c-fos, serotonin and substance P release in the shrew brainstem emetic nuclei. Our comparative study in shrews demonstrates that clonidine (0, 0.1, 1, 5, and 10 mg/kg, i.p.) and dexmedetomidine (0, 0.01, 0.05, and 0.1 mg/kg, i.p.) not only suppress yohimbine (1 mg/kg, i.p.)-evoked vomiting in a dose-dependent manner, but also display broad-spectrum antiemetic effects against diverse well-known emetogens, including 2-Methyl-5-HT, GR73632, McN-A-343, quinpirole, FPL64176, SR141716A, thapsigargin, rolipram, and ZD7288. The antiemetic inhibitory ID50 values of dexmedetomidine against the evoked emetogens are much lower than those of clonidine. At its antiemetic doses, clonidine decreased shrews' locomotor activity parameters (distance moved and rearing), whereas dexmedetomidine did not do so. The results suggest that dexmedetomidine represents a better candidate for antiemetic potential with advantages over clonidine. [ABSTRACT FROM AUTHOR]

Insectivores (Eulypotiphla) are a substantial component of Russian forest ecosystems. The parasites of these animals also form an important part of natural biocenoses and act as one of the factors in the formation of biodiversity. The Mordovia Nature Reserve and National Park "Smolny" are large, forested areas located in the center of European Russia. We studied the helminth fauna of insectivores in these protected areas in 2018–2022. In total, using the method of complete helminthological necropsy, we examined 478 individuals of shrews, moles, and hedgehogs and recorded 34 species of parasitic worms, i.e., 8 trematode, 7 cestode, 1 acanthocephalan, and 18 nematode species. The most diverse helminth fauna was found in Sorex araneus (22 species). The composition of helminths in S. isodon (12), Neomys fodiens (9), Sorex minutus, and Erinaceus roumanicus (8 species each) turned out to be less diverse. The lowest species diversity of helminths was observed in Neomys milleri (3) and Talpae europaea (2 species). Taking into account the newly obtained data, we conducted a review of the helminth diversity in shrews, hedgehogs, and moles in the Middle Volga region. According to our literature data, the helminth fauna of insectivores in this region consists of 52 species, including 14 cestodes, 13 trematodes, 22 nematodes, and 3 acanthocephalans. Most of them belong to the Palearctic faunal complex (36 species). The helminth fauna of insectivores in the studied protected areas was compared with the helminth fauna of micromammals in other areas of the Middle Volga region. Our comparative analysis showed a high and average degree of similarity in the helminth fauna within individual species and genera of Eulipotyphla. [ABSTRACT FROM AUTHOR]

Nucleotide sequence polymorphism and haplotypic diversity of the cytochrome b gene were studied in samples of the Laxmann's Shrew subspecies-Sorex caecutiens koreni from the populations of the Kolyma River basin and Chukotka Peninsula. Fifty-six cytb haplotypes differing among themselves by 87 mutations in 84 sites were found. The cytb haplotypes of individuals of the subspecies S. c. koreni and S. c. macropygmaeus were shown to belong to the same maternal mtDNA lineage; their monophyletic origin from the same ancestral haplotype Scb1 and the presence of identical cytb haplotypes in both subspecies were revealed. The mutual isolation of the shrew populations in the upper basin of the Kolyma River and Chukotka is shown. The proportion of intrapopulation genetic variability is 95.74%, intergroup variability is 5.74%, and intragroup variability is 1.48%, which reflects a very high level of intrapopulation variability of cytb haplotypes in the studied groups of S. c. koreni, their monophyletic origin, and the genetic unity of the Chukchi samples. The values of molecular diversity indices testify to the stability of populations that have had a high value of effective abundance for a long time. [ABSTRACT FROM AUTHOR]

The Chinese tree shrew (Tupaia belangeri chinensis) has emerged as a promising model for investigating adrenal steroid synthesis, but it is unclear whether the same cells produce steroid hormones and whether their production is regulated in the same way as in humans. Here, we comprehensively mapped the cell types and pathways of steroid metabolism in the adrenal gland of Chinese tree shrews using single-cell RNA sequencing, spatial transcriptome analysis, mass spectrometry, and immunohistochemistry. We compared the transcriptomes of various adrenal cell types across tree shrews, humans, macaques, and mice. Results showed that tree shrew adrenal glands expressed many of the same key enzymes for steroid synthesis as humans, including CYP11B2, CYP11B1, CYB5A, and CHGA. Biochemical analysis confirmed the production of aldosterone, cortisol, and dehydroepiandrosterone but not dehydroepiandrosterone sulfate in the tree shrew adrenal glands. Furthermore, genes in adrenal cell types in tree shrews were correlated with genetic risk factors for polycystic ovary syndrome, primary aldosteronism, hypertension, and related disorders in humans based on genome-wide association studies. Overall, this study suggests that the adrenal glands of Chinese tree shrews may consist of closely related cell populations with functional similarity to those of the human adrenal gland. [ABSTRACT FROM AUTHOR]

We describe 3 new species of shrews (Eulipotyphla, Soricidae, Crocidura) from West Sumatra, Indonesia. Two of these taxa were found above 1,800 m on Mt. Singgalang. The third taxon was found above 1,660 m on Mt. Talamau, 65 km northwest of Mt. Singgalang. We also resurrect Crocidura aequicauda based on 2 specimens from Mts. Tujuh and Kerinci, which lie near the border between West Sumatra and Jambi provinces. Several methodological approaches support our findings: linear cranial morphometrics, landmark-based 2D geometric morphometrics, and molecular phylogenetics using both mtDNA and 6 nuclear exons. A multilocus species-tree analysis places the 3 new species and C. aequicauda in a clade with the Javan endemics C. monticola and C. umbra. Although the 2 taxa from Mt. Singgalang are recovered as sister species, 1 is nearly twice the size of the other, and they are divergent in several other morphological characters, such as tail length, cranium size, and pelage color and texture. Recently diverged yet morphologically disparate sister taxa living syntopically in an isolated habitat "island," like the montane forests of Mt. Singgalang, is unusual in mammals but documented in other Crocidura on neighboring Java and Borneo; these 2 new taxa represent the first known case of this phenomenon on Sumatra. Our results bring the number of Sumatran Crocidura to 10, 9 of which are endemic to the island. All 3 of the new species appear to be endemic to a single mountain and were not detected in similar surveys of nearby mountains. If this local endemism pattern is common, it would indicate that Sumatra's mammal diversity may be severely underestimated, largely due to the paucity of small-mammal surveys and museum specimens. [ABSTRACT FROM AUTHOR]

Simple Summary: Parasitic protozoa are a common cause of vector-borne disease outbreaks and have been identified in different groups of wild animal species. Small mammals, such as rodents and shrews, play an important role in the transmission and maintenance of parasites. To understand the risk of parasitic protozoa, it is essential to have a good understanding of the status of transmitting vectors. This study aimed to investigate the diversity and current status of parasitic protozoa, including Trypanosoma, Babesia, and Theileria, from small mammals in the Republic of Korea. We found that the prevalence of Trypanosoma grosi was 23.9% (79/331) and Babesia microti was 10% (33/331), while Theileria was not detected in small mammals. These results can be used to raise awareness of parasite infection in the Republic of Korea. Small mammals, such as rodents and shrews, are natural reservoir hosts of zoonotic diseases, including parasitic protozoa. To assess the risk of rodent-borne parasitic protozoa in the Republic of Korea (ROK), this study investigated the status of parasitic protozoa, namely Trypanosoma, Babesia, and Theileria, in small mammals. In total, 331 blood samples from small mammals were analyzed for parasites using PCR and sequenced. Samples were positive for Trypanosoma grosi (23.9%; n = 79) and Babesia microti (10%; n = 33) but not Theileria. Small mammals from Seogwipo-si showed the highest infection rate of T. grosi (48.4%), while the highest B. microti infection rate was observed in those from Gangneung-si (25.6%). Sequence data revealed T. grosi to be of the AKHA strain. Phylogenetic analysis of B. microti revealed the US and Kobe genotypes. B. microti US-type–infected small mammals were detected throughout the country, but the Kobe type was only detected in Seogwipo-si. To our knowledge, this is the first nationwide survey that confirmed T. grosi and B. microti infections at the species level in small mammals in the ROK and identified the Kobe type of B. microti. These results provide valuable information for further molecular epidemiological studies on these parasites. [ABSTRACT FROM AUTHOR]

Background: Many pathogens and parasites can infect multiple host species, and the competence of different hosts as pathogen reservoirs is key to understanding their epidemiology. Small mammals are important hosts for the instar stages of Ixodes ricinus ticks, the principal vector of Lyme disease in Europe. Small mammals also act as reservoirs of Borrelia afzelii, the most common genospecies of the Borrelia burgdorferi sensu lato (s.l.) spirochetes causing Lyme disease in Europe. However, we lack quantitative estimates on whether different small mammal species are equally suitable hosts for feeding I. ricinus and whether they show differences in pathogen transmission from host to tick. Methods: Here, we analysed the feeding success and prevalence of B. burgdorferi s.l. infections in 12,987 instar I. ricinus found on captured small mammals with known infection status in Norway (2018–2022). Results: We found that larvae were more likely to acquire a blood meal from common shrews (Sorex araneus, 46%) compared to bank voles (Myodes glareolus, 31%) and wood mice (Apodemus sylvaticus, 36%). Nymphs tended to be more likely to acquire a blood meal from wood mice (66%) compared to bank voles (54%). Common shrews harboured few nymphs (n=19). Furthermore, we found that larvae feeding on infected bank voles (11%) were more likely to be infected with B. burgdorferi s.l. than larvae on infected common shrews (7%) or wood mice (4%). Conclusions: Our study provides quantitative evidence of differences in suitability for the instar stages of I. ricinus across taxa of small mammals and highlights how even known small mammal host species can differ in their ability to feed ticks and infect larval ticks with the pathogen causing Lyme disease. [ABSTRACT FROM AUTHOR]

Globally, Enterocytozoon bieneusi has been detected in humans and various animal hosts. Wild rats and shrews have the potential to act as carriers of E. bieneusi, facilitating the parasite's transmission to humans and domestic animals. We aimed to investigate the prevalence of E. bieneusi in 652 wild rats and shrews from Zhejiang Province, China, by amplifying the internal transcribed spacer (ITS) region of rDNA through polymerase chain reaction (PCR). To determine animal species, we amplified the Cytochrome b (Cyt-b) gene in their fecal DNA using PCR. Furthermore, we determined the genotype of E. bieneusi by amplifying the ITS region of rDNA through PCR. Genetic traits and zoonotic potential were evaluated using similarity and phylogenetic analyses. Suncus murinus (n = 282) and five rat species, Rattus losea (n = 18), Apodemus agrarius (n = 36), Rattus tanezumi (n = 86), Rattus norvegicus (n = 155), and Niviventer niviventer (n = 75), were identified. The average infection rate of E. bieneusi was 14.1% (92/652) with 18.1% (51/282) in S. murinus and 11.1% (41/370) in rats (27.8% in R. losea, 22.2% in A. agrarius, 10.5% in R. tanezumi, 8.4% in R. norvegicus, and 8.0% in N. niviventer). Thirty-three genotypes were identified, including 16 known genotypes. The most commonly known genotypes were HNR-VI (n = 47) and Peru11 (n = 6). Type IV, KIN-1, SHW7, and HNPL-II were each found in two samples, while Macaque4, CH5, K, Henan-III, Henan-V, HNP-II, HNPL-I, HNPL-III, HNHZ-II, and HNHZ-III were each found in one sample. Additionally, 17 novel genotypes were discovered: WZR-VIII (n = 5), WZR-I to WZR-VII, WZR-IX to WZR-XII, and WZSH-I to WZSH-V (n = 1 each). Those 33 genotypes were divided into three groups: Group 1 (n = 25), Group 2 (n = 3), and Group 13 (n = 5). The initial report underscores the extensive occurrence and notable genetic diversity of E. bieneusi in wild rats and shrews from Zhejiang province, China. These results suggest that these animals play a pivotal role in the transmission of E. bieneusi. Furthermore, animals carrying the zoonotic genotypes of E. bieneusi pose a serious threat to residents. [ABSTRACT FROM AUTHOR]

Scrub typhus is a re-emerging disease caused by Orientia tsutsugamushi, transmitted by mites belonging to the family Trombiculidae. Humans and rodents acquire the infection by the bite of larval mites/chiggers. Suncus murinus, the Asian house shrew, has been reported to harbor the vector mites and has been naturally infected with O. tsutsugamushi. The present study aimed to localize and record O. tsutsugamushi in the tissues and the host response in shrews naturally infected with O. tsutsugamushi. Sheehan's modified May–Grunwald Giemsa staining was carried out in 365 tissues from 87 animals, and rickettsiae were documented in 87 tissues from 20 animals. Immunohistochemical (IHC) staining, using polyclonal antibodies raised against selected epitopes of the 56-kDa antigen, was carried out, and 81/87 tissue sections were tested positive for O. tsutsugamushi. By IHC, in addition to the endothelium, the pathogen was also demonstrated by IHC in cardiomyocytes, the bronchiolar epithelium, stroma of the lungs, hepatocytes, the bile duct epithelium, the epithelium and goblet cells of intestine, the tubular epithelium of the kidney, and splenic macrophages. Furthermore, the pathogen was confirmed by real-time PCR using blood (n = 20) and tissues (n = 81) of the IHC-positive animals. None of the blood samples and only 22 out of 81 IHC-positive tissues were tested positive by PCR. By nucleotide sequencing of the 56-kDa gene, Gilliam and Karp strains were found circulating among these animals. Although these bacterial strains are highly virulent and cause a wide range of pathological alterations, hence exploring their adaptive mechanisms of survival in shrews will be of significance. Given that the pathogen localizes in various organs following a transient bacteremia, we recommend the inclusion of tissues from the heart, lung, intestine, and kidney of reservoir animals, in addition to blood samples, for future molecular surveillance of scrub typhus. [ABSTRACT FROM AUTHOR]

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An analysis of the community of rodents and insectivores in five biotopes of the southern forest steppe of Northern Kulunda has been carried out. High biodiversity is typical for the coastal strip with dense herbage near the lake, and low biodiversity is typical for the feather grass–forb steppe. At the beginning of the 21st century, there was a change in dominants of the community of small mammals, and the species richness increased. Of the five shrew species, only the common, tundra, and Eurasian pygmy shrews inhabit all biotopes. Their total proportion in each biotope varied between 16 to 38%. Among the 11 rodent species, the narrow-headed vole is the dominant species. Its total proportion in the community of small mammals was 38.3%. This species is characterized by a peculiar cycle of abundance. The reduction of steppe habitats has led to a decrease in the number of steppe lemming and a change in its population cycle. The proportion of other rodent species in the community of small mammals is low. [ABSTRACT FROM AUTHOR]

Semi-fossorial Sorex unguiculatus is a common shrew species in the central part of Northeast Asia, and this paper is devoted to elucidating its status in shrew taxocenes within the entire specified range. The configuration of the modern range of the long-clawed shrew differs from the generally accepted one, and its formation occurred through distribution from two Late Pleistocene refugiums—mainland and island. According to the status of the long-clawed shrew in the taxocenes, three areas were distinguished: this species is a dominant in low-species insular taxocenes, a subdominant in multispecies taxocenes of coniferous–broad-leaved forests of the Ussuri Territory, and a minor one in the zone of interpenetration of nemoral and taiga vegetation of the left-bank part of the Lower Amur Region. The further northwestern expansion of the long-clawed shrew is unlikely due to the specific requirements of this species for the type and structure of soils, which change significantly under the conditions of the appearance of permafrost, and coexistence with an ecologically similar species—the flat-skulled shrew. [ABSTRACT FROM AUTHOR]

Despite its biogeographical uniqueness, where two vast savanna regions are separated by the Afromontane mosaic vegetation, there is a significant lack of small mammal sampling in the Tigray region of Ethiopia. Leveraging all our available data on rodents and shrews in the region, we tested the hypothesis that the Afromontane mosaic vegetation in the highlands acts as a barrier to gene flow between taxa found in the Somali-Masai and Sudanian savanna in the southeast and western lowland parts of the region, respectively. Morphological and DNA sequence analysis confirmed the presence of 23 species of small rodents and shrews in the region. We recorded 18 of these species in the Afromontane mosaic vegetation, seven species in the Sudanian savanna, and four species in the Somali-Masai savanna. Notably, the fauna of the Sudanian savanna was strikingly different from that of the Somali-Masai savanna at both intraspecific and interspecific levels, suggesting the northern Ethiopian highlands as a very strong biogeographic barrier for taxa adapted to arid lowlands. However, the reported species diversity remains provisional, and additional sampling from unexplored areas is needed. Furthermore, some of the reported taxa, in this study, such as Mus cf. tenellus, Crocidura cf. fuscomurina, Dendromus sp. indet. 2, and Otomys cf. cheesmani, require detailed taxonomic investigation and may represent new species. A robust understanding of the taxonomic diversity and distribution of the small mammals in the region is crucial for effective conservation planning as well as for addressing practical questions related to rodents, such as in public health and pest management. [ABSTRACT FROM AUTHOR]

Phylogenetically, the tribosphenic molars—prototypes of multi-cusped cheek teeth in marsupial and placental mammals—are derived from the single-cusped conical teeth of reptiles through the addition of cusps. Ontogenetically, mammalian molars are formed through the interface between the dental epithelium and mesenchyme (future enamel–dentin junction), becoming geometrically complex by adding epithelial signaling centers, called enamel knots, which determine future cusp positions. To reevaluate cusp homologies in Mesozoic mammals from an ontogenetic perspective, this study tracked molar development in a living placental mammal species, the house shrew (Suncus murinus), whose molars are morphologically the least derived from tribosphenic prototypes. The development of shrew molars proceeded as if it replayed the evolutionary process of tribosphenic molars. The first formed enamel knots gave rise to the evolutionarily oldest cusps—upper paracone and lower protoconid. The order of formation of other enamel knots and their location in development seemed to trace the order of cusp appearance in evolution. The parallel relationship between ontogeny and phylogeny of mammalian molars, if any, suggests that a change in the timing between developmental events rather than a change in the morphogenetic mechanism itself, should have been a major causal factor for the evolutionary transformation of tooth morphology. [ABSTRACT FROM AUTHOR]

Aim: Mountains are geographic features that provide sharp elevational gradients which can accommodate a diversity of terrestrial flora and fauna. In the face of climate change, many of these species are being pushed higher to escape ever‐increasing temperatures. Despite this, we have little understanding of how species distribute themselves across mountains. African mountains in particular are less studied than mountains elsewhere and the small mammal groups that inhabit them are also poorly studied when compared to other groups. In this study, we examined the responses of three functionally distinct small mammal taxonomic groups to changes in elevation across Africa. Location: Africa. Methods: We calculated four functional diversity metrics for 166, 97 and 153 communities of rodents, bats and shrews comprising 225, 183 and 109 species, respectively. We employed RLQ and fourth‐corner analyses to identify any associations between the functional traits of the small mammals and elevation and other climatic variables. Results: We show that the species richness of the three taxa responded differently to increases in elevation, with only rodents showing a mid‐elevational hump. The composition of rodent and bat communities differed significantly in upland versus lowland sites, but bat communities showed far more overlap across the elevational gradient. Functional diversity metrics responded differently for each taxon highlighting the importance of using different taxonomic groups when studying elevational patterns of functional diversity. Main Conclusions: Our study shows that functional divergence increases with elevation in all three taxa, indicating a pervasive and broadly applicable strong environmental filtering at higher elevations. Our findings suggest that species at higher elevations may be at higher risk due to specialization. These species are losing habitat due to ongoing climate change that will force them up the elevational gradient. At the same time, the human population in Africa is predicted to triple in size by the year 2100, which will also likely contribute to further habitat loss and fragmentation. As small mammals often play essential roles in ecosystems, from seed dispersal to soil aeration and predation, understanding the susceptibility of the specialization of species at higher elevations is crucial for the effective conservation and management of mountain ecosystems, especially in light of climatic change and human expansion. [ABSTRACT FROM AUTHOR]

Sorex maritimensis (Maritime Shrew) is endemic to Canada and found only in Nova Scotia and New Brunswick. The Maritime Shrew has been identified as one of the vertebrate species in Nova Scotia that is most susceptible to the effects of climate change and global warming, and it is listed by NatureServe as vulnerable (category G3). While generally regarded as a wetland specialist, relatively little is known about its specific habitat preferences. Non-invasive methods of sampling have proven valuable in identifying and monitoring such rare species. The objective of this study was to optimize a non-invasive method to document presence of Maritime Shrews using collected fecal DNA and to develop a PCR-based protocol to amplify a short, ∼120 base-pair section of the cox1 gene using shrew-specific primers. We used baited feeding tubes to collect shrew feces. We designed cox1 PCR primers to preferentially amplify this mini-DNA barcode for shrews in samples that may contain feces from rodents as well. We designed the primers to amplify a small amplicon to increase the likelihood of successful amplification from degraded DNA. This technique is likely to be effective for documenting the distribution and habitat preferences of this relatively rare shrew in Nova Scotia and New Brunswick. [ABSTRACT FROM AUTHOR]

The rate of hydropower dam construction on rivers is increasing in emerging economies in South Asia, to achieve economic development goals. These large infrastructure projects are likely to have many negative consequences on freshwater species but have not yet received much consideration. Among freshwater small mammalian species, water shrews are seriously impacted by these large structures. This paper aims to determine if water shrews have been considered during the Environmental Impact Assessment (EIA) of these hydro dam project sites, as well as present the sightings of the water shrews from Nepalese rivers with hydropower potential. We reviewed 44 EIA reports of such projects in Nepal using a set of four criteria and 15 questions to analyze the methods of impact assessment for mammals and the reports on the presence of water shrews in each built area. The study found that the number of mammal species reported during the EIA varied from five to 55 species but no relationships between the hydropower structure's size and any water shrew species were considered in the studies. In almost all EIA reports, the term aquatic ecosystem was prioritized over the term aquatic small mammals, and the latter was not considered in the assessment. The major reason for not considering these species is probably due to the lack of robust methods to capture small mammals such as shrews, or due to survey methods focused only on terrestrial mammals. The Aquatic Animal Protection Act was fully reviewed and assured to be followed in a majority of the reports, yet the monitoring parameters and indicators were not available for aquatic small mammals. Ignoring the presence of these mammals while constructing hydropower plants is a serious threat to their persistence. We also reported the Himalayan water shrew in the Barun River and the elegant water shrew in the Upper Tamakoshi River of Nepal. Therefore, a better understanding of these species among hydropower developers, and all concerned agencies, is essential. [ABSTRACT FROM AUTHOR]