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The shared functions of the skull are thought to result in common evolutionary patterns in mammalian cranial shape. Craniofacial evolutionary allometry (CREA) is a particularly prominent pattern where larger species display proportionally elongate facial skeletons and smaller braincases. It was recently proposed that CREA arises from biomechanical effects of cranial scaling when diets are similar. Thus, deviations from CREA should occur with changes in cranial biomechanics, for example due to dietary change. Here, we test this using 3D geometric morphometric analysis in a dataset of Australian murine crania, which are highly allometric. We contrast allometric and non‐allometric variation in the cranium by comparing evolutionary mode, allometry, ordinations, as well as allometry, integration, and modularity in functional modules. We found evidence of stabilising selection in allometry‐containing and size‐free shape, and substantial non‐allometric variation aligned with dietary specialisation in parallel with CREA. Integration among cranial modules was higher, and modularity lower, with size included, but integration between rostrum and cranial vault, which are involved in the CREA pattern, dropped dramatically after size removal. Our results thus support the hypothesis that CREA is a composite arising from selection on cranial function, with substantial non‐allometric shape variation occurring alongside CREA where dietary specialisation impacts selection on gnawing function. This emphasises the need to research mammalian cranial evolution in the context of allometric and non‐allometric selection on biomechanical function. [ABSTRACT FROM AUTHOR]

In recent years, the transmission of viruses from wildlife to humans has raised significant public health concerns, exemplified by the COVID-19 pandemic caused by the betacoronavirus SARS-CoV-2. Human activities play a substantial role in increasing the risk of zoonotic virus transmission from wildlife to humans. Rats and mice are prevalent in urban environments and may act as reservoirs for various pathogens. This study aimed to evaluate the presence of zoonotic viruses in wild rats and mice in both urban and rural areas, focusing on well-known zoonotic viruses such as betacoronavirus, hantavirus, arenavirus, kobuvirus, and monkeypox virus, along with other viruses occasionally detected in rats and mice, including rotavirus, norovirus, and astrovirus, which are known to infect humans at a high rate. A total of 128 animals were captured, including 70 brown rats (Rattus norvegicus), 45 black rats (Rattus rattus), and 13 house mice (Mus musculus), and feces, lung, and liver were collected. Among brown rats, one fecal sample tested positive for astrovirus RNA. Nucleotide sequencing revealed high sequence similarity to both human and rat astrovirus, suggesting co-presence of these viruses in the feces. Murine kobuvirus (MuKV) was detected in fecal samples from both black (n = 7) and brown (n = 6) rats, primarily from urban areas, as confirmed by sequence analysis. These findings highlight the importance of surveillance and research to understand and mitigate the risks associated with the potential transmission of pathogens by rodents. [ABSTRACT FROM AUTHOR]

The rodents of Saudi Arabia consist of twenty species and twelve genera within four families (Gliridae, Dipodidae, Muridae, and Hystricidae). Details on the past and present distribution of the rodents were included, along with available data on their habitat preference and biology. The eastern central part of Saudi Arabia, covering the Tuwiq mountains plateau, including the vicinity of Riyadh, hosts the highest number of rodent species. An analysis of the rodent fauna of Saudi Arabia revealed that they have four major zoogeographical affinities: Palaearctic–Oriental (one species), Afrotropical–Palaearctic (six species), Palaearctic (four species), endemic to Saudi Arabia and Yemen (three species), Afrotropical–Palaearctic–Oriental (three species), and three cosmopolitan species. According to the National Red List, the Euphrates Jerboa, Scarturus euphraticus, is listed as endangered, the Indian Crested Porcupine, Hystrix indica, as near threatened, three further species as data-deficient, while the rest are considered least concern. [ABSTRACT FROM AUTHOR]

The article focuses on orthohantaviruses, a group of RNA viruses found globally and hosted by native rodent species in the Americas, particularly within the Cricetidae family. Some orthohantavirus genotypes cause hantavirus cardiopulmonary syndrome (HCPS), with Argentina showing high incidence, especially in Misiones province where new reservoirs like Akodon montensis have been identified, suggesting potential underreporting due to socioeconomic factors.

Mus cypriacus is one of three small palaeoendemic mammals that have survived the Mediterranean islands' anthropization. This species, endemic to Cyprus, was described in 2006 and stands out as one of the last mammal species to have been discovered in Europe. Despite scarce data on its genetics, ecology, and life-history traits, Mus cypriacus is assessed as Least Concern LC in the IUCN Red List, partly due to its morphological similarity with the sympatric house mouse that prevented earlier identification. Our study uses mitochondrial and microsatellite markers to investigate this small rodent's population genetic structure and diversity. Our analysis did not identify any population genetic structure and suggested a high genetic diversity across Cyprus. When inferring habitat preference using sample locations, it appeared that M. cypriacus utilizes a diverse variety of habitats, covering more than 80% of the island. Although these results are encouraging for the conservation status of the species, they still need to be cautiously applied as potential threats may arise due to increasing habitat destruction and changes in land use. Consequently, our encouraging results should be applied judiciously. Additional ecological data are urgently needed to gain a more comprehensive understanding of this inconspicuous endemic species. [ABSTRACT FROM AUTHOR]

Tick-borne infectious agents (TBIAs) include several bacteria and protozoa that can infect vertebrates, including humans. Some of these agents can cause important diseases from both a public health perspective, such as Lyme disease, and from an animal health and production viewpoint, such as Texas fever. In Chile, several studies have assessed the presence of tick-borne disease agents in vectors and mammal hosts, mainly in the northern regions, but few studies have assessed the presence of these agents in Central and Southern Chile. This study aimed to assess the presence of three groups of TBIAs--Borrelia, Anaplasmataceae, and Piroplasmida--in cricetid rodents of Central and Southern Chile. A total of 207 specimens from 13 localities between the O'Higgins and Los Lagos regions were captured. DNA was extracted from the liver and spleen, and subsequently underwent polymerase chain reaction (PCR) amplification targeting the 16S rRNA, flaB, and 18S rRNA genes to detect DNA from Borrelia, Anaplasmataceae, and Piroplasmida, respectively. Although no DNA from these TBIAs was detected, the DNA extraction process was validated by optimal DNA purity ratios (an A260/A280 ratio within the 1.6-2.0 range) and successful internal control amplification in all samples. These results, in addition to findings from previous reports, suggest a very low prevalence of these TBIAs in the rodent population studied. Further research into the factors influencing the presence of these agents and their vectors will provide insight into the reasons underlying this low prevalence. [ABSTRACT FROM AUTHOR]

Anthropogenic disturbance may increase the emergence of zoonoses. Especially generalists that cope with disturbance and live in close contact with humans and livestock may become reservoirs of zoonotic pathogens. Yet, whether anthropogenic disturbance modifies host-pathogen co-evolutionary relationships in generalists is unknown. We assessed pathogen diversity, neutral genome-wide diversity (SNPs) and adaptive MHC class II diversity in a rodent generalist inhabiting three lowland rainforest landscapes with varying anthropogenic disturbance, and determined which MHC alleles co-occurred more frequently with 13 gastrointestinal nematodes, blood trypanosomes, and four viruses. Pathogen-specific selection pressures varied between landscapes. Genome-wide diversity declined with the degree of disturbance, while MHC diversity was only reduced in the most disturbed landscape. Furthermore, pristine forest landscapes had more functional important MHC–pathogen associations when compared to disturbed forests. We show co-evolutionary links between host and pathogens impoverished in human-disturbed landscapes. This underscores that parasite-mediated selection might change even in generalist species following human disturbance which in turn may facilitate host switching and the emergence of zoonoses. A study on genetic diversity and multiple pathogen infections in wild rodents and reservoir hosts shows human habitat disturbance also adversely affects generalist species by limiting their adaptive potential and facilitating pathogen spill-over. [ABSTRACT FROM AUTHOR]

The primary visual cortex (V1) is one of the most studied regions of the brain and is characterized by its specialized and laminated layer 4 in human and non-human primates. However, studies aiming to harmonize the definition of the cortical layers and borders of V1 across rodents and primates are very limited. This article attempts to identify and harmonize the molecular markers and connectional patterns that can consistently link corresponding cortical layers of V1 and borders across mammalian species and ages. V1 in primates has at least two additional and unique layers (L3b2 and L3c) and two sublayers of layer 4 (L4a and L4b) compared to rodent V1. In all species examined, layers 4 and 3b of V1 receive strong inputs from the (dorsal) lateral geniculate nucleus, and V1 is mostly surrounded by the secondary visual cortex except for one location where V1 directly abuts area prostriata. The borders of primate V1 can also be clearly identified at mid-gestational ages using gene markers. In rodents, a novel posteromedial extension of V1 is identified, which expresses V1 marker genes and receives strong inputs from the lateral geniculate nucleus. This V1 extension was labeled as the posterior retrosplenial cortex and medial secondary visual cortex in the literature and brain atlases. Layer 6 of the rodent and primate V1 originates corticothalamic projections to the lateral geniculate, lateral dorsal, and reticular thalamic nuclei and the lateroposterior–pulvinar complex with topographic organization. Finally, the direct geniculo-extrastriate (particularly the strong geniculo-prostriata) projections are probably major contributors to blindsight after V1 lesions. Taken together, compared to rodents, primates, and humans, V1 has at least two unique middle layers, while other layers are comparable across species and display conserved molecular markers and similar connections with the visual thalamus with only subtle differences. [ABSTRACT FROM AUTHOR]

Glioblastoma (GBM) is a highly aggressive human neoplasm with poor prognosis due to its malignancy and therapy resistance. To evaluate the efficacy of antitumor therapy, cell models are used most widely, but they are not as relevant to human GBMs as tissue models of gliomas, closely corresponding to human GBMs in cell heterogeneity. In this work, we compared three different tissue strains of rat GBM 101.8 (induced by DMBA), GBM 11-9-2, and GBM 14-4-5 (induced by ENU). Materials and methods: We estimated different gene expressions by qPCR-RT and conducted Western blotting and histological and morphometric analysis of three different tissue strains of rat GBM. Results: GBM 101.8 was characterized by the shortest period of tumor growth and the greatest number of necroses and mitoses; overexpression of Abcb1, Sox2, Cdkn2a, Cyclin D, and Trp53; and downregulated expression of Vegfa, Pdgfra, and Pten; as well as a high level of HIF-1α protein content. GBM 11-9-2 and GBM 14-4-5 were relevant to low-grade gliomas and characterized by downregulated Mgmt expression; furthermore, a low content of CD133 protein was found in GBM 11-9-2. Conclusions: GBM 101.8 is a reliable model for further investigation due to its similarity to high-grade human GBMs, while GBM 11-9-2 and GBM 14-4-5 correspond to Grade 2–3 gliomas. [ABSTRACT FROM AUTHOR]

Abstract The shared functions of the skull are thought to result in common evolutionary patterns in mammalian cranial shape. Craniofacial evolutionary allometry (CREA) is a particularly prominent pattern where larger species display proportionally elongate facial skeletons and smaller braincases. It was recently proposed that CREA arises from biomechanical effects of cranial scaling when diets are similar. Thus, deviations from CREA should occur with changes in cranial biomechanics, for example due to dietary change. Here, we test this using 3D geometric morphometric analysis in a dataset of Australian murine crania, which are highly allometric. We contrast allometric and non‐allometric variation in the cranium by comparing evolutionary mode, allometry, ordinations, as well as allometry, integration, and modularity in functional modules. We found evidence of stabilising selection in allometry‐containing and size‐free shape, and substantial non‐allometric variation aligned with dietary specialisation in parallel with CREA. Integration among cranial modules was higher, and modularity lower, with size included, but integration between rostrum and cranial vault, which are involved in the CREA pattern, dropped dramatically after size removal. Our results thus support the hypothesis that CREA is a composite arising from selection on cranial function, with substantial non‐allometric shape variation occurring alongside CREA where dietary specialisation impacts selection on gnawing function. This emphasises the need to research mammalian cranial evolution in the context of allometric and non‐allometric selection on biomechanical function.

In the present paper, the existence and location of the type series of the Japanese dancing mouse or waltzer, Mus wagneri variety rotans Droogleever Fortuyn, 1912, are established, and a lectotype is designated. Available type specimens are measured, and some morphological parameters, sex, and general condition of the specimens are recorded. A literature survey was conducted, and an attempt is made to clarify the position of M. wagneri variety rotans in the taxonomy of Mus. A genetic analysis suggests that the type series of the Japanese dancing mouse represent a crossbred, or derivation of a crossbred, between the original Japanese dancing mouse of Mus musculus molossinus Temminck 1844 origin and European fancy or laboratory mice of Mus musculus domesticus Schwarz & Schwarz, 1943 origin. Much of their genome was replaced and occupied by Mus musculus domesticus type genome, probably through extensive breeding with European mice. [ABSTRACT FROM AUTHOR]

The world is facing a major pulse of ecological and social changes that may favor the risk of zoonotic outbreaks. Such risk facilitation may occur through the modification of the host's community diversity and structure, leading to an increase in pathogen reservoirs and the contact rate between these reservoirs and humans. Here, we examined whether anthropization alters the relative abundance and richness of zoonotic reservoir and non-reservoir rodents in three Socio-Ecological Systems. We hypothesized that anthropization increases the relative abundance and richness of rodent reservoirs while decreasing non-reservoir species. We first developed an Anthropization index based on 15 quantitative socio-ecological variables classified into five groups: 1) Vegetation type, 2) Urbanization degree, 3) Water quality, 4) Potential contaminant sources, and 5) Others. We then monitored rodent communities in three regions of Northwestern Mexico (Baja California, Chihuahua, and Sonora). A total of 683 rodents of 14 genera and 27 species were captured, nine of which have been identified as reservoirs of zoonotic pathogens (359 individuals, 53%). In all regions, we found that as anthropization increased, the relative abundance of reservoir rodents increased; in contrast, the relative abundance of non-reservoir rodents decreased. In Sonora, reservoir richness increased with increasing anthropization, while in Baja California and Chihuahua non-reservoir richness decreased as anthropization increased. We also found a significant positive relationship between the anthropization degree and the abundance of house mice (Mus musculus) and deer mice (Peromyscus maniculatus), the most abundant reservoir species in the study. These findings support the hypothesis that reservoir species of zoonotic pathogens increase their abundance in disturbed environments, which may increase the risk of pathogen exposure to humans, while anthropization creates an environmental filtering that promotes the local extinction of non-reservoir species. [ABSTRACT FROM AUTHOR]

The family Muridae represents the largest, most diverse and successful of all groups of mammals. Here we infer the phylogenetic relationships and historical biogeography for the Iranian murid rodents, which consist in twelve species distributed in three subfamilies and seven genera. Molecular dating analyses using a relaxed Bayesian molecular clock support the monophyly of belonging to Murinae, Gerbillinae and Deomyinae and allow to set up divergence dates between them around 18.29 Ma (Million years ago). According to our results, murines may have originated approximately 12.28 Ma and the diversification of most of their evolutionary lineages may have taken place between 10 and 3 Ma, which is consistent with the fossil record. Our results provide strong support for the tribes Apodemyini and Rattini (Murinae) but the monophyly of the genus Meriones belonging to the Gerbillinae is questioned. Historical biogeographic analysis supports an area covering most of Iran, as the most likely ancestral geographic origin for gerbillines whereas that inferred for murines is restricted to the West and North of Iran. All in all, Iran seems to have acted as a corridor for faunal exchanges between the Afrotropic and Saharo-Arabian realms and the Indomalayan realm as well as between Central Asia and the Mediterranean regions. [ABSTRACT FROM AUTHOR]

Quaternary small mammals are important proxies for paleoenvironmental reconstructions. The Brazilian record, although famous and continuously growing, is hampered by poor chronological control due to the nature of most of the published assemblages. Here, we present a taphonomic analysis and paleoenvironmental reconstruction based on marsupials, bats, and rodents (480 remains) from the Gruta do Presépio archeological site (GPR, hereafter), Santa Catarina State, southern Brazil. The site is a rock shelter located in an Atlantic Forest biome, an important biodiversity hotspot. The GPR sedimentary sequence spans the Early Holocene (8330 ± 30 years 14C BP) to recent Historical time (after the arrival of Europeans). Most of the small mammal remains were deposited by strigiforms, although for the oldest units some strongly digested remains could indicate the activity of diurnal birds or carnivorous mammals. The GPR small mammal assemblages include 28 taxa (five marsupials, nine chiropterans, and 14 rodents). Most of them indicate the occurrence and persistence of forested environments during the Holocene around the site, which is in overall agreement with regional palynological data. A major community change, implying the increment of rodents allied to disturbed ecosystems (e.g. Akodon, Oligoryzomys, Mus), is very recent and reflects human forest clearance as a signature of the Anthropocene. [ABSTRACT FROM AUTHOR]

Simple Summary: Ultrastructural characters of spermiogenesis and the spermatozoon of the cestode Meggittina gerbilli, a parasite of gerbils in Tunisia, were studied using transmission electron microscopy. The type III model of spermiogenesis was observed. This model is mainly characterized by a proximodistal fusion of a single flagellum with a cytoplasmic extension. As for the sperm cell, spermatozoon type VI was observed, presenting a single axoneme, a periaxonemal sheath, crest-like bodies, twisted cortical microtubules, and a spiraled nucleus. The results show similarities between Meggittina gerbilli and other studied species within the Catenotaeniidae family. Ultrastructural characters of spermiogenesis and the mature spermatozoon of the cestode Meggittina gerbilli (Cyclophyllidea: Catenotaeniidae), a parasite of the Lesser Egyptian gerbil (Gerbillus gerbillus) and the North African gerbil (Gerbillus campestris) (Rodentia: Muridae) in the Djebel Dahar (South of Tunisia), were studied using transmission electron microscopy. The spermiogenesis of M. gerbilli is of Bâ and Marchand's type III, which is mainly characterized by a proximodistal fusion of a single flagellum with a cytoplasmic extension. In this catenotaeniid, the proximal fusion is preceded by a 90° rotation of the flagellum. The spermatozoon is a Levron et al. type VI, which presents a single axoneme with the 9 + '1' trepaxonematan pattern, a periaxonemal sheath, two crest-like bodies, twisted cortical microtubules, and a spiraled nucleus. The obtained results show similarities with the remaining studied catenotaeniids, namely Catenotaenia pusilla and Skrjabinotaenia lobata. The results are compared and discussed according to several characteristics found in the catenotaeniids and other studied cyclophyllideans. [ABSTRACT FROM AUTHOR]

Uganda’s diverse small mammalian fauna thrives due to its rich habitat diversity, which hosts a wide range of blood parasites, including trypanosomes, particularly the subgenus Herpetosoma typical for rodent hosts. We screened a total of 711 small mammals from various habitats for trypanosomes, with 253 microscopically examined blood smears and 458 tissue samples tested by nested PCR of the 18S rRNA gene. Of 51 rodent and 12 shrew species tested, microscopic screening reaches 7% overall prevalence (with four rodent species positive out of 15 and none of the shrew species out of four), while nested PCR indicated a prevalence of 13% (17 rodent and five shrew species positive out of 49 and 10, respectively). We identified 27 genotypes representing 11 trypanosome species, of which the majority (24 genotypes/9 species) belong to the Herpetosoma subgenus. Among these, we detected 15 new genotypes and two putative new species, labeled AF24 (found in Lophuromys woosnami) and AF25 (in Graphiurus murinus). Our finding of three new genotypes of the previously detected species AF01 belonging to the subgenus Ornithotrypanum in two Grammomys species and Oenomys hypoxanthus clearly indicates the consistent occurrence of this avian trypanosome in African small mammals. Additionally, in Aethomys hindei, we detected the putative new species of the subgenus Aneza. Within the T. lewisi subclade, we detected eleven genotypes, including six new; however, only the genotype AF05b from Mus and Rattus represents the invasive T. lewisi. Our study has improved our understanding of trypanosome diversity in African small mammals. The detection of T. lewisi in native small mammals expands the range of host species and highlighting the need for a broader approach to the epidemiology of T. lewisi. [ABSTRACT FROM AUTHOR]

Small mammals, including those inhabiting human-modified habitats, transmit zoonotic diseases such as cysticercosis. This disease is caused by Cysticercus fasciolaris, the larval form of species within the Hydatigera taeniaeformis s.l. group. While the life cycle of these flatworms is well understood, certain aspects of their phylogeny remain unknown. Studies in Europe, Asia, and Africa suggest that the species Hydatigera taeniaeformis s.s. exclusively infects small mammals of the family Muridae. However, no studies have been conducted in the Americas until now. In this study, small mammals were captured on 18 pig farms in the province of Buenos Aires throughout a year. Necropsies of captured individuals were performed, and the presence of cysts was recorded. The prevalence of cysticercosis was analyzed for the entire assemblage, with species as the explanatory variables. Species-specific prevalence was also modeled, considering season and type of farm as the explanatory variables. Cysts were collected from Akodon azarae, Oligoryzomys flavescens, Rattus novergicus, and Rattus rattus identified through molecular techniques, comparing their DNA sequences with those stored in GenBank for phylogenetic hypothesis. A total of 460 small mammals were analyzed, including the introduced species R. novergicus, R. rattus, and M. musculus and the native species A. azarae, O. flavescens, Oxymycterus rufus, Didelphis albiventris, and Lutreolina crassicaudata. The prevalence of cysticercosis was similar between species, and it showed a seasonal association in R. norvegicus and A. azarae. Phylogenetic analysis confirmed the presence of Hydatigera taeniaeformis s.s. in cricetids, suggesting a recent spillover event associated with European colonization in the Americas. [ABSTRACT FROM AUTHOR]

Bartonellosis is a vector-borne disease which is increasingly threatening the health of humans and animals worldwide consequent to the growing wildlife-animals-human interactions. Little is known about the epidemiology of this disease in Tanzania. In this study we investigated and characterized Bartonella species in small mammals' ectoparasites from potentially high-risk areas in the country. A total of 141 ectoparasites pools of mites, fleas, ticks, and lice were analyzed using conventional PCR and sequencing. Bartonella DNA was detected in 34.8 % of the tested ectoparasite pools, with mites at 32.9 %, fleas at 40 %, ticks at 12.5 %, and lice at 50 %. Phylogenetic analysis showed that the Bartonella spp. genotypes were closely related to those found in Uganda, Kenya, and South Africa. Different genotypes with independent haplotypes were observed, although most Bartonella spp. from fleas shared the same haplogroup. The confirmed presence of Bartonella elizabethae and Bartonella tribocorum in field and house rodents emphasizes the prevailing transmission risk of zoonotic infections in the study areas and beyond. Screening of humans, companion animals, and livestock in potentially high-risk areas in Tanzania is necessary in order to inform the development of responsive surveillance and control strategies. [ABSTRACT FROM AUTHOR]

Montemys delectorum is the only member of the genus Montemys within the family Muridae, which is an endemic rodent of the Eastern Africa Highlands. It is a threatened species due to habitat loss, and its current conservation status is uncertain. We studied the breeding pattern and population size of M. delectorum, two of the most important factors in understanding the conservation status of a species. Capture-mark-release studies were conducted from February 2021 to June 2022 in open patchy forests and dense forest habitats. Montemys delectorum showed bimodal breeding seasonality: a low rate for the short interval between December and February and a pronounced rate for May-July, following the high rainfall in April. This shows that rainfall promotes vegetation availability, which stimulates breeding activity and adds offspring to the population, resulting in increased population abundance. The population of M. delectorum is not stable in this landscape, as indicated by the significant differences in population size between the two forest types, with a significantly greater population in the patchy open forest. This indicates that the patchy open forest should be considered an essential refuge for the species. [ABSTRACT FROM AUTHOR]

The article is devoted to the ecological and faunal analysis of the family Muridae of Ternopil Region, namely, the study of species composition, relative abundance, landscape distribution, and habitat preferences of the representatives of this group. The species composition of the mammal fauna of all six landscape areas was analysed and the habitat preferences of rodents were determined. The materials were collected during 2017–2020, and 7350 trap-days were processed and 206 specimens of rodents were trapped, representing 7 species. The richest in terms of genus and species composition is the tribe Apodemurini, represented by the genera Apodemus (1 species), Micromys (1), and Sylvaemus (3). The tribe Murini is less rich and is represented by two species of two genera, Mus (1) and Rattus (1). The most abundant and widespread species of the first tribe is the yellow-necked wood mouse (Sylvaemus tauricus), the others are common species (Apodemus agrarius, S. uralensis, S. sylvaticus, and Micromys minutus). The second group includes two alien species that have the status of abundant, particularly in synanthropic habitats: the house mouse (Mus musculus) and the brown rat (Rattus norvegicus). The geographical ranges of the identified species are characterised. The described species are common in their natural zones and habitat types. The obtained results support the conclusion of I. V. Zagorodniuk (2008) on the gradation of habitat distribution of representatives of the genus Sylvaemus (S. tauricus, S. uralensis, and S. sylvaticus) by different types of forest biocoenoses. The alien species Mus musculus and Rattus norvegicus, preferring urban areas, form exantropic colonies in summer. Ruderal habitats are attractive for Apodemus agrarius and Micromys minutus. The natural habitats of mouse-like rodents in the region are quite heterogeneous, although they are represented by one ecological group, which the authors designate as ‘terrestrial-burrowing’ animals. Distribution maps of each species of the family Muridae in western Podillia are presented. The distribution cadastres were compiled on the basis of spring and summer surveys of typical habitats of mouse-like rodents in six landscape areas of western Podillia. Only the locations of exantropic settlements in the region were included in the Mus musculus and Rattus norvegicus cadastres.

The name Rattus obiensis Fabre, Portela Miguez, Holden, Fitriana, Semiadi, Musser, & Helgen, was recently applied to a newly discovered species of Rattus known to date only from the Moluccan island of Obi in Indonesia. However, this name is preoccupied by Rattus rattus obiensis Sody, 1941, a name applied to a commensal rat and currently recognized as a synonym of Rattus tanezumi Temminck, 1844. A replacement name, Rattus ombirah Fabre et al., 2024. nom. nov., is here proposed for the endemic Rattus of Obi.

The mechanisms of species dispersal and colonization that drive the process of range expansion have always been in the focus of fundamental ecology. Typically, species' ranges change slowly, but human activities through global processes (landscape transformations, climate warming, and biological invasions) have sped up changes in species distributions, thus providing opportunities to observe and study range shifts in real time. In Kalmykia, human-induced landscape transformations from desert to steppe and vice versa allowed us to study the colonization process during range expansion in a desert-dwelling rodent, the midday gerbil (Meriones meridianus). We studied the population dynamics and changes in the range of midday gerbils in the southern part of Kalmykia, their physical conditions, and infestation with fleas on the wave of colonization, as well as demographic properties of the population of colonists compared to the source population. We found that, in recent years, the species range has been rapidly expanding to the west, where gerbils have established new colonies. The colonists differed significantly from the residents of the source population in a lower average body weight, this being associated not with the poorer physical conditions but with the age structure: the fertility rates of female colonists were much higher, and the population of colonists was much younger compared to the source population. In addition, colonists were almost not infested by fleas in contrast to the residents of the source population. Our findings indicate that the population on the wave of colonization does not experience the negative effects of low numbers, and the high reproductive rates in the colonist population account for its rapid growth and expansion. [ABSTRACT FROM AUTHOR]

The large Japanese field mouse (Apodemus speciosus) is endemic to the Japanese islands and Kunashir Island in Russia. Variability in the morphology of 722 molars was studied for the first time for the population of this species from Kunashir Island, which allowed us to identify seven new traits for the species. According to data obtained when studying modern and paleontological material (recent, Holocene, Late Pleistocene, Middle Pleistocene), mice of Kunashir Island lack some traits of molars previously described for the large Japanese field mouse from Honshu Island; at the same time, stabilization of the morphology was noted for the remaining traits. Varying frequency was demonstrated for the new traits. This can be caused either by the small number of founders or the passage of the Kunashir population through sharp declines in numbers. It is possible that a change in the frequency of some molar phenes in different historical epochs could be associated with the transition of mice to another type of feed following changes in the climate and the prevailing vegetation. [ABSTRACT FROM AUTHOR]

Using the method of group biomarking with rhodamine B, new data on migratory patterns (natal dispersal and breeding dispersal) of the pygmy wood mouse (Sylvaemus uralensis (Pallas 1811)) outside its home range were obtained by studying the long-distance locomotion of small mammals on the Eastern Urals Radiation Reserve (Chelyabinsk region, Southern Urals). Long-distance locomotion (1500 m) over 14 hours in the dark part of the day was registered for two yearling males for the first time, allowing for the possible speed of movement of S. uralensis to be estimated. Taking into account that the main activities of rodents occur during evening and morning twilight, the actual time could be considerably shorter. Both dispersers were under-yearling males of different functional status. One of them was a young animal captured during spring reproduction (May 2019) in the year of birth. The other male was young, captured before leaving in winter (October 2021) and not reproducing in the year of birth. Group biomarking by rhodamine B made it possible to estimate the night-time distance and the speed of movement of S. uralensis, also allowing an episode of external contamination by the biomarkers of transient specimens (October 2021) that visited the marking plot, but that did not touch the bait, to be revealed. Our results allow us to conclude that long-distance locomotion of individuals of different functional statuses beyond the home area is normal in S. uralensis. [ABSTRACT FROM AUTHOR]

The genetic structure of the reed vole (Alexandromys fortis (Büchner 1889)) from the northern periphery of its distribution area was studied using the variability of the mtDNA control region. A high haplotype and nucleotide diversity has been shown in the northern part of the species range. The diversity is due to the presence of two lineages that form phylogenetic subclades within the NORTH lineage on dendrograms. The MAIN haplotypes have a wide geographic distribution. Basically, the distribution of the ISL haplotypes is confined to the islands of the Rimsky-Korsakov Archipelago (Bolshoy Pelis and Matveev) in the Sea of Japan and in the Barguzin Depression in Buryatia. They are also found in mainland populations, albeit with low frequencies, only in the south of the Russian Far East. The ISL haplotypes are noted to be close to those previously identified based on fossil material from cave deposits in the south of Primorsky Krai. Several alternative hypotheses concerning the ways of the formation of such a phylogeographic structure are considered. Small areas with local favorable environmental features are suggested to have persisted at the northern periphery of the reed vole distribution, where the species could have survived the Pleistocene and retained the ISL haplotypes that might have appeared earlier than the MAIN haplotypes. Those local areas can be considered as microrefugia, which could have played important roles in maintaining the high genetic diversity of the species in the southern part of the Russian Far East. Secondary colonization events by individuals with the MAIN haplotypes could have occurred already after the completion of the climatic minimum and the wide expansion of the species to the north from a southern macrorefugium. The existence of two macrorefugia, in which two subclades, MAIN and ISL, were formed, followed by random fixations of rarer ISL haplotypes in small isolated populations, is also hypothesized. [ABSTRACT FROM AUTHOR]

The variability and evenness (diversity) of the system of red blood cell parameters was assessed for the first time using multivariate and information analysis methods in the synanthropic M. musculus and the hemisynanthropic A. (S.) uralensis in the Central Caucasus Mountains (Elbrus region). This paper introduces the concept of the actual or realized "niche" of the red blood cell parameters system in the multidimensional space of the descriptive model. The niches of A. (S.) uralensis and M. musculus were clearly differentiated, the niche volume of A. (S.) uralensis significantly exceeding that of M. musculus. This paper describes interspecific differences in the seasonal regulation of blood parameters, which was more complex in A. (S.) uralensis and clearly cyclical from "winter" to "autumn." The results allowed us to conclude that, compared to M. musculus, A. (S.) uralensis implements a more flexible adaptation strategy to seasonal changes in the environment. The tested methodology of data analysis allows us to consider the results of particular studies on mammalian hematopoietic regulation in the broader context of problems of biodiversity and the dynamics and self-organization of biological systems. [ABSTRACT FROM AUTHOR]

The Ethiopian Highlands represent one of the most important centres of endemism on Earth. Six endemic species of laminate-toothed rats have been reported from Ethiopia in a previous study based mostly on morphological analyses. Largely missing genetic data for some of the species, insufficient sampling across Ethiopia, and presence of a pseudogene on cytochrome b created knowledge gaps in basic taxonomy, distribution, and phylogenetic position of the Ethiopian taxa. Here we perform an integrative taxonomic revision of the group by using the largest available sets of genomic and morphological data. We first reconstructed the mitochondrial phylogeny of the whole genus, delimited major clades, and evidenced two independent colonization events of Otomys to Ethiopia. By using genome-scale SNPs, we delimited putative Ethiopian species and analysed their phylogenetic relationships. In genetically characterized specimens we assessed morphological variation of skulls. We confirmed the presence of six previously reported species and significantly extended the known distributional range for some of them. Furthermore, we discovered a genetically and morphologically distinct lineage in northern Ethiopia, probably representing a new species. The speciation processes are similar to other Afromontane Ethiopian endemic rodent clades, with prevailing allopatric diversification combined with reticulate processes. [ABSTRACT FROM AUTHOR]

The genus Epichernes Muchmore, 1982 has three Neotropical species with specific rodent hosts. Epichernes vickeryae sp. nov. is here described from Monteverde, Puntarenas, Costa Rica: the specimens were collected from a spiny pocket mouse Heteromys nubicolens. The new species, named E. vickeryae, is closer to E. navarroi by the position of trichobothria setae ist and isb, which are adjacent and the number of teeth on the movable finger, known from Mexico. The new species is characterized by trichobothrium ist adjacent to isb, femur L/B 1.71–1.85, it has 22–31 external accessory teeth, 58 teeth on fixed finger and 62 on movable finger. The carapace ranging from 1.12 mm to 1.33 mm in length, central tergites with 21–22 setae, chelicera with five setae on the hand, sb and b denticulate. The new species represents the second known species of Epichernes from Costa Rica. [ABSTRACT FROM AUTHOR]

Rodentia is the most species-rich order among mammals. The Republic of South Africa harbours a high rodent diversity whose taxonomy and phylogeny have been extensively studied using genetic tools. Such advances have led to the establishment of new faunal lists for the country. Because rodents are frequently recovered from archaeological cave site material and owl pellets, and constitute prime material for studying both past and present environmental conditions, it is necessary to characterize their osteological remains. The skull and teeth are the most useful diagnostic skeletal elements preserved in modern and fossil accumulations. This key provides updated craniodental criteria for identifying rodent genera found in Quaternary deposits, and modern material from the Republic of South Africa, thus facilitating research on past and present rodent diversity. [ABSTRACT FROM AUTHOR]

Background: Wenzhou virus (WENV), a member of the Mammarenavirus genus in the Arenaviridae family, has been detected in wild rodents from eight provinces in China, including Zhejiang, Shandong, Hainan, Xinjiang, Hunan, Guangdong, Yunnan, and Jiangxi provinces, and some countries from Southeast Asia. The IgG-antibodies of WENV have been detected in both healthy populations and patients with unknown fever and respiratory symptoms. However, the potential harmfulness of WENV to humans has been underestimated due to mild symptoms after infection, similar to respiratory diseases. Thus, it is imperative to enhance the surveillance of WENV in wild rodents, particularly Rattus norvegicus, and continuously monitor its prevalence. Results: From 2017 to 2021, a total of 390 wild rodents were collected from six provinces in the eastern and southern coastal areas, containing nine species of rats. Samples of each tissue were collected, and PCR amplified for identification. Four R. norvegicus samples were detected to be WENV-positive. No genomic sequence of WENV was detected in Rattus flavipectus, Rattus losea, Suncus murinus, Apodemus agrarius, Mus musculus, Microtus fortis, Micromys minutus, and Niviventer niviventer from Jiangsu, Zhejiang, Fujian, Hainan, Guangdong and Guangxi provinces. Three genomic sequences were identified to be WENV by phylogenetic analysis. The full-length sequences of HAIKOU-40 were amplified in R. norvegicus from Hainan, which showed a close relationship to Wufeng/ WFS, sharing 84.5–89.4% homology at the nucleotide level and 91.6–98.9% homology at the amino acid level. Phylogenetic analysis revealed that HAIKOU-40 formed an Asia-specific cluster with all WENVs and Loie River mammarenavirus (LORV), provisionally named Asian ancestry. This cluster has diverged earlier from the remaining mammarenavirus. The sequences obtained in Xiamen, Fujian province showed more than 90% nucleotide identities with WENV, which may be a strain of WENV. Additionally, the sequence of Wuxi-87 which was a positive sequence detected in Wuxi, Jiangsu province exhibited 83% nucleotide identity with Lassa virus (LASV). Further efforts will be made to isolate and identify this virus strain, verify the relationship between Wuxi-87 and LASV, and confirm whether R. norvegicus is a new host of LASV. Conclusions: In this study, we conducted a systematic examination of the prevalence of WENV among rodents on the southeast coast of China. Additionally, we characterized the genome of a newly discovered WENV strain, that confirmed the role of R. norvegicus in the transmission of WENV. This highlights the importance of investigating the prevalence of WENV in both wild rodents and humans. [ABSTRACT FROM AUTHOR]

Background: The causative agent of plague, Yersinia pestis, is maintained in nature via a flea-rodent cycle. Western Iran is an old focus for plague, and recent data indicate that rodents and dogs in this region have serological evidence of Y. pestis infection. The purpose of this study was to conduct a large-scale investigation of Y. pestis infection in shepherd dogs, rodents, and their fleas in old foci for plague in Western Iran. Materials and methods: This study was conducted in Hamadan province from 2014 to 2020. Rodents and fleas were collected from various locations throughout this region. Y. pestis was investigated in rodent spleen samples and fleas using culture, serology, and real-time PCR methods. Additionally, sera samples were collected from carnivores and hares in this region, and the IgG antibody against the Y. pestis F1 antigen was assessed using an ELISA. Results: In this study, 927 rodents were captured, with Meriones spp. (91.8%) and Microtus qazvinensis (2.6%) being the most prevalent. A total of 6051 fleas were collected from rodents and carnivores, most of which were isolated from Meriones persicus. None of the rodents or fleas examined tested positive for Y. pestis using real-time PCR and culture methods. Meanwhile, IgG antibodies were detected in 0.32% of rodents. All serologically positive rodents belonged to M. persicus. Furthermore, none of the sera from the 138 carnivores (129 sheepdogs, five Vulpes vulpes, four Canis aureus), and nine hares tested positive in the ELISA test. Conclusion: This primary survey of rodent reservoirs shows serological evidence of Y. pestis infection. Western Iran is an endemic plague focus, and as such, it requires ongoing surveillance. Author summary: This article investigates the ongoing presence of the plague in Iran and stresses the importance of continuous monitoring in the western region, a major area for endemic plague. Rodents are the primary carriers of diseases in their natural habitats and contribute significantly to the ongoing presence of infectious cycles. The study focuses on the presence of Yersinia pestis, the bacteria responsible for the plague, in guard dogs, rodents, and fleas in the historical center of western Iran. The research confirms the presence of Y. pestis infection in rodents, specifically Meriones persicus, in western Iran through serological evidence. Given the new discoveries in Iran and the resurgence of the plague in neighboring countries, ongoing monitoring of plague infections in wildlife across various regions of the country is crucial for public health outcomes. [ABSTRACT FROM AUTHOR]

Background: During early mammalian development, DNA methylation undergoes two waves of reprogramming, enabling transitions between somatic cells, oocyte and embryo. The first wave of de novo DNA methylation establishment occurs in oocytes. Its molecular mechanisms have been studied in mouse, a classical mammalian model. Current model describes DNA methyltransferase 3A (DNMT3A) and its cofactor DNMT3L as two essential factors for oocyte DNA methylation—the ablation of either leads to nearly complete abrogation of DNA methylation. However, DNMT3L is not expressed in human oocytes, suggesting that the mechanism uncovered in mouse is not universal across mammals. Results: We analysed available RNA-seq data sets from oocytes of multiple mammals, including our novel data sets of several rodent species, and revealed that Dnmt3l is expressed only in the oocytes of mouse, rat and golden hamster, and at a low level in guinea pigs. We identified a specific promoter sequence recognised by an oocyte transcription factor complex associated with strong Dnmt3l activity and demonstrated that it emerged in the rodent clade Eumuroida, comprising the families Muridae (mice, rats, gerbils) and Cricetidae (hamsters). In addition, an evolutionarily novel promoter emerged in the guinea pig, driving weak Dnmt3l expression, likely without functional relevance. Therefore, Dnmt3l is expressed and consequently plays a role in oocyte de novo DNA methylation only in a small number of rodent species, instead of being an essential pan-mammalian factor. In contrast to somatic cells, where catalytically inactive DNMT3B interacts with DNMT3A, forming a heterotetramer, we did not find evidence for the expression of such inactive Dnmt3b isoforms in the oocytes of the tested species. Conclusions: The analysis of RNA-seq data and genomic sequences revealed that DNMT3L is likely to play a role in oocytes de novo DNA methylation only in mice, rats, gerbils and hamsters. The mechanism governing de novo DNA methylation in the oocytes of most mammalian species, including humans, occurs through a yet unknown mechanism that differs from the current model discovered in mouse. [ABSTRACT FROM AUTHOR]

The climbing mouse is a rare, small mammal listed as an endangered species on the China species red list. Molecular phylogenetic analyses and the evolutionary history of the genus remain unexplored because of the extreme difficulty in capturing individuals and their narrow distribution. Here, we collected 44 specimens, sequenced one mitochondrial and eight nuclear genes, and integrated morphological approaches to estimate phylogenetic relationships, delimit species boundaries, and explore evolutionary history. Molecular analyses and morphological results supported the validity of these four species. Here, we describe two new species, Vernaya meiguites sp. nov. and Vernaya nushanensis sp. nov., and recognize Vernaya foramena, previously considered a subspecies of Vernaya fulva, as a valid species. The estimated divergence time suggests that the climbing mouse began to diversify during the Pliocene (3.36 Ma). [ABSTRACT FROM AUTHOR]

We describe a new genus and species of large-bodied murine from archaeological deposits at Liang Bua, a limestone cave in western Flores, East Nusa Tenggara, Indonesia. Among a large assemblage of murine remains, several mandibular elements recovered from mostly Holocene sediments show a distinct anatomy, with a long and robust jaw, massive proodont incisors, and relatively small molars. These morphological features are unusual among murines but most similar to terrestrial and carnivorous species of the Indo-Pacific, colloquially referred to as shrew rats (Philippines, Sulawesi) or moss mice (New Guinea), and indicate a potential carnivorous dietary adaptation, perhaps specializing in a vermivorous diet. The size of the mandible indicates that this murine is the largest shrew rat yet known. Although presumed extinct, targeted field research is needed to determine if this rat still lives on Flores today. [ABSTRACT FROM AUTHOR]

Four new species of Rattus are described from the Moluccan islands (Maluku) of Indonesia: Rattus taliabuensis and R. feileri, both from the island of Taliabu, and R. halmaheraensis and R. obiensis from the islands of Halmahera and Obi, respectively. These descriptions are presented as part of a taxonomic review of Moluccan Rattus based on all known specimens in museum collections worldwide. Morphological characters, molecular systematics, and geographical distributions are documented for each of these species. Using both morpho-anatomical and morphometric approaches, we found that the Maluku Islands support Rattus taxa with spiny fur and two distinct morphotypes (1) species with a long tail and short rostrum (R. morotaiensis, R. halmaheraensis, R. obiensis, R. feileri) and (2) species with a short tail and long rostrum (R. taliabuensis, R. feliceus, R. ceramicus, R. elaphinus). Most of the new Moluccan species belong to a clade that includes members of the R. xanthurus species group from Sulawesi and the Australo-Papuan Rattus lineages. Their phylogenetic relationships highlight the role of Wallacea as an important area for diversification of Rattus into the Australo-Papuan region. Finally, the morphologically distinctive taxon Nesoromys ceramicus from Seram was found to be sister species to R. feliceus, and we relegate Nesoromys into the synonymy of the genus Rattus. The close affinities between R. ceramicus and R. feliceus may be an example of in situ island speciation, which has not been observed for small mammals on other Maluku Islands. [ABSTRACT FROM AUTHOR]

The article discusses the field of Wallacean mammalogy and zooarchaeology, focusing on the region of Wallacea, which includes islands in Indonesia such as Sulawesi, Borneo, and Bali. The authors highlight the importance of Alfred Russel Wallace's contributions to biogeography and his recognition of the distinct fauna in the Malay Archipelago. They also discuss the research conducted on mammals in the Wallacean region, particularly on Sulawesi, and the need for further taxonomic studies. The article emphasizes the impact of human activities and environmental changes on the mammal species in Wallacea, calling for conservation efforts to ensure their survival. The authors dedicate the special issue to the memory of two influential Indonesian scientists, Boeadi and Rokus Due Awe. [Extracted from the article]

As a group of ectoparasites, chiggers (larvae of chigger mites) are the exclusive vector of scrub typhus (tsutsugamushi disease). Rodents are the most important hosts of chiggers. The Anderson's niviventer rat, Niviventer andersoni, is an endemic species of rodent in China. However, few studies have involved this endemic rodent species and its ectoparasites including chiggers. According to the field investigation in five provincial regions of southwest China between 2001 and 2019, this paper retrospectively analysed the infestation and distribution of chiggers on the body surface of N. andersoni in southwest China for the first time. From 77 Anderson's niviventer rats captured, a total of 527 chiggers were collected and they were identified as 39 species and nine genera in two subfamilies of family Trombiculidae. Of 39 chigger species identified, Leptotrombidium deliense and L. scutellare are the most important vectors of scrub typhus in China. The overall infestation indexes were PM = 29.87%, MA = 6.84 and MI = 22.91, and the indexes of chigger mite community were Mf = 39, H' = 2.60, E = 0.71 and D = 0.12. The dominant chigger species are L. wenense, L. xiaguanense and L. fujianense with a total Cr = 51.04%, among which L. wenense is one of the six main vectors of scrub typhus in China. The dominant chigger species are of aggregated distribution among different individuals of the rats. [ABSTRACT FROM AUTHOR]

Modulation of odorant receptors mRNA induced by prolonged odor exposure is highly correlated with ligand-receptor interactions in Drosophila as well as mammals of the Muridae family. If this response feature is conserved in other organisms, this presents an intriguing initial screening tool when searching for novel receptor-ligand interactions in species with predominantly orphan olfactory receptors. We demonstrate that mRNA modulation in response to 1-octen-3-ol odor exposure occurs in a time- and concentration-dependent manner in Aedes aegypti mosquitoes. To investigate gene expression patterns at a global level, we generated an odor-evoked transcriptome associated with 1-octen-3-ol odor exposure. Transcriptomic data revealed that ORs and OBPs were transcriptionally responsive whereas other chemosensory gene families showed little to no differential expression. Alongside chemosensory gene expression changes, transcriptomic analysis found that prolonged exposure to 1-octen-3-ol modulated xenobiotic response genes, primarily members of the cytochrome P450, insect cuticle proteins, and glucuronosyltransferases families. Together, these findings suggest that mRNA transcriptional modulation of olfactory receptors caused by prolonged odor exposure is pervasive across taxa and can be accompanied by the activation of xenobiotic responses. [ABSTRACT FROM AUTHOR]

Grey voles Microtus sensu lato represent one of the youngest and most successful radiations of rodents in the Holarctic that gave rise to several genera and over 60 living species. Despite abundant fossil record encompassing up to one million years, the early stages of Microtus' evolution remain poorly understood. We describe Microtus voles from fluvial deposits (Tobolsky Horizon, the Late Middle Pleistocene) found in 2019–2020 in Gornopravdinsk 2, West Siberia. Based on linear measurements, m1 morphotypes, and configuration of mandibular masseteric crests, we identify the sample as a new taxon M. nivaloides lidiae ssp. nov. It appears more advanced than type specimens of M. nivaloides sensu stricto from West Runton Freshwater Bed (the Early Middle Pleistocene, Great Britain), and falls within the range of m1 variability of M. nivaloides sensu lato from the Middle Pleistocene of Eastern Europe. M. n. lidiae is found in a non-analogue faunal assemblage with Lemmus sibiricus, Dicrostonyx simplicior, Alexandromys oeconomus, Lasiopodomys gregalis, rare Clethrionomys cf. glareolus, Alexandromys aut Microtus cf. malei, Lagurus sp. We hypothesise that M. n. lidiae was a meadow-steppe element in the Middle Pleistocene communities and a terminal taxon in the 'nivaloides' clade that became extinct with no descendants. [ABSTRACT FROM AUTHOR]

The continental Late Miocene is relatively well represented in North Africa, but stratigraphic gaps are present in the Vallesian due to the scarcity of localities from this time. In this paper, we present the small mammal association from the section of Guefaït 1, in the Aïn Beni Mathar Basin (Jerada, eastern Morocco). This sequence contains three successive fossiliferous levels: Guefaït 1A, Guefaït 1B and Guefaït 1C. The small mammal association of the richest level, Guefaït 1A, includes insectivores (Schizogalerix sp., Lartetium cf. africanum), bats (cf. Hypsugo sp.) and rodents of the families Gerbillidae (Zramys salemi, Myocricetodon seboui, Myocricetodon aff. trerki, Myocricetodon sp.), Muridae (Progonomys cathalai), Gliridae (Microdyromys cf. chaabi) and Sciuridae (Atlantoxerus sp.). Large mammals are scarcely represented by Gazella sp. and Hipparion sp. The rodent association, characterised by the occurrence of Progonomys cathalai and Zramys salemi, indicates an early Late Miocene, latest Vallesian age for the sites of Guefaït 1. The novel small mammal combination from this site constitutes a significant finding that improves our understanding of evolution of terrestrial Late Miocene faunas from northern Africa. [ABSTRACT FROM AUTHOR]

Biogeography and the occurrence of small mammals are usually hard to investigate due to the small size and secretive habits of these mammals. Available data are particularly insufficient on minor islands and at national borders, where research efforts are usually scarce. Here we briefly updated the knowledge on murid rodents on two remote Italian small islands (Lampedusa and Pantelleria) at the southernmost Italian borders. During summer 2019, house mice and rats were sampled in Lampedusa and Pantelleria and molecular markers were sequenced for species identification. The new sequences of Mus domesticus were also compared with samples from previous works collected in Lampedusa, Pantelleria, and several localities in the Mediterranean basin. Moreover, our analyses provided the first genetic evidence of the occurrence of Rattus norvegicus in Lampedusa. To conclude, R. rattus was confirmed to be present in Pantelleria. The newly collected haplotype of M. domesticus from Pantelleria is similar to those currently known for Sicily, whereas the new haplotype from Lampedusa partially diverges from the ones previously described, and clusters with haplotypes from North Africa and the Middle East.

In recent years, the transmission of viruses from wildlife to humans has raised significant public health concerns, exemplified by the COVID-19 pandemic caused by the betacoronavirus SARS-CoV-2. Human activities play a substantial role in increasing the risk of zoonotic virus transmission from wildlife to humans. Rats and mice are prevalent in urban environments and may act as reservoirs for various pathogens. This study aimed to evaluate the presence of zoonotic viruses in wild rats and mice in both urban and rural areas, focusing on well-known zoonotic viruses such as betacoronavirus, hantavirus, arenavirus, kobuvirus, and monkeypox virus, along with other viruses occasionally detected in rats and mice, including rotavirus, norovirus, and astrovirus, which are known to infect humans at a high rate. A total of 128 animals were captured, including 70 brown rats (Rattus norvegicus), 45 black rats (Rattus rattus), and 13 house mice (Mus musculus), and feces, lung, and liver were collected. Among brown rats, one fecal sample tested positive for astrovirus RNA. Nucleotide sequencing revealed high sequence similarity to both human and rat astrovirus, suggesting co-presence of these viruses in the feces. Murine kobuvirus (MuKV) was detected in fecal samples from both black (n = 7) and brown (n = 6) rats, primarily from urban areas, as confirmed by sequence analysis. These findings highlight the importance of surveillance and research to understand and mitigate the risks associated with the potential transmission of pathogens by rodents.

In this paper, we present a detailed survey on the rodent fauna from the site of Barranco de los Conejos (Guadix-Baza Basin, southern Spain). Its rodent fauna is composed of three arvicolines (Orcemys giberti, Manchenomys oswaldoreigi, and Tibericola vandermeuleni) and two murids (Castillomys rivas and Apodemus atavus). The three arvicoline species present ever-growing molars. Orcemys giberti and Manchenomys oswaldoreigi can be considered as descendants of local Mimomys species (Mimomys medasensis and Mimomys tornensis, respectively), while Tibericola vandermeuleni is an eastern inmigrant. Loosening of roots in Orcemys giberti and Manchenomys oswaldoreigi is explained as an adaptation to a fossorial way of life, in relation to the Early Pleistocene glacial–interglacial dynamics, which led to cooler and drier conditions. This environmental change would also explain the dispersal of Tibericola from the eastern Mediterranean.

In 1885 the Geographical Society of Australasia sent the steam launch Bonito to chart the Fly and Strickland Rivers (now in Western Province, Papua New Guinea). The Expedition spent five months in New Guinea with the primary objectives of survey and biological exploration. The type locality of the murid rodent Melomys muscalis froggatti Troughton, 1937, described from a single specimen obtained during the Expedition, is localized to the region of the base camp at Observation Bend, Strickland River, based on the original Expedition maps and the unpublished diary reminiscence of the collector W. W. Froggatt. A review of the mammal collection obtained during that Expedition has not been reported previously, perhaps due to the poor surviving documentation. Several months after the Expedition returned to Sydney, Australian Museum curator E. P. Ramsay prepared a list of 22 mammal specimens received by the Museum. Twenty specimens attributed to the Expedition were not entered into the collection registers until 1913, half of which are likely to be incorrectly associated with the Expedition. Most specimens were registered with very limited data about collection date and locality. Of the 22 specimens originally received by Ramsay, eight rodents and two flying foxes (Pteropus spp.) have not been located in the Collection, but might remain unrecognized as specimens with no data. It is possible that additional mammal specimens were sent by the Geographical Society of Australasia to other institutions at the conclusion of the Expedition.

The Crested-tailed deer mouse, Habromys lophurus, is one of seven arboreal species within the genus Habromys. Species of this genus are monotypic, relatively rare, and occur in low densities. Their geographical distribution is highly fragmented due to being restricted to montane cloud forest in Mesoamerica and they are of conservation concern. All Habromys species are endemic to Mexico, except H. lophurus, which is also distributed in Guatemala and El Salvador. In this study, we obtained and characterized the first mitogenome and several thousand nuclear ultraconserved elements (UCEs) of H. lophurus to determine its phylogenetic position within neotomine-peromyscine mice. Its mitogenome sequence (16,509 bp) is only the second complete mitogenome obtained for this poorly known genus. We also obtained the first nuclear genomic data for H. lophurus, including 3,654 UCE loci, as well as a partial mitogenome of H. simulatus (6,349 bp), and 2,186 UCE for the outgroup Holochilus sciureus. Phylogenetic analyses that included our newly generated genomic data coupled with previously published data from other neotomine-peromyscine mice confirm the placement of H. lophurus, H. simulatus, and H. ixtlani within a highly supported clade. The Habromys clade was nested within a clade that also contains members of the genus Peromyscus and provides further support for the hypothesis of the paraphyly of Peromyscus. These genomic resources will contribute to future phylogenomic studies that aim to further elucidate the evolutionary history of this rare and critically endangered genus of rodents. [ABSTRACT FROM AUTHOR]

The New World porcupines of the genus Coendou comprise 16 species of arboreal nocturnal rodents. Some of these species are poorly known and have not been included in phylogenetic analyses. Based on recently collected specimens with associated tissue from the Brazilian Amazonia, we investigate the distribution and phylogenetic relationships of Roosmalens' dwarf porcupine, Coendou roosmalenorum, using an integrative approach using mitochondrial gene sequences and morphological data from new specimens and localities. Our results recovered C. roosmalenorum in the subgenus Caaporamys. However, analyses of our molecular and combined datasets produced different topologies. The new record shows the presence of C. roosmalenorum 480 km to the southeast of the Rio Madeira and 95 km away from Rio Juruena in Mato Grosso state, indicating a wider distribution in southern Amazonia than suspected. All known records of C. roosmalenorum are in the Madeira biogeographical province, to which it might be endemic. [ABSTRACT FROM AUTHOR]

Trabecular bone is modelled throughout an animal's life in response to its mechanical environment, but like other skeletal anatomy, it is also subject to evolutionary influences. Yet the relative strengths of factors that affect trabecular bone architecture are little studied. We investigated these influences across the Philippine endemic murine rodent clade Chrotomyini. These mammals have robustly established phylogenetic relationships, exhibit a range of well-documented substrate-use types, and have a body size range spanning several hundred grammes, making them ideal for a tractable study of extrinsic and intrinsic influences on trabecular bone morphology. We found slight differences in vertebral trabecular bone among different substrate-use categories, with more divergent characteristics in more ecologically specialized taxa. This suggests that the mechanical environment must be relatively extreme to affect trabecular bone morphology in small mammals. We also recovered allometric patterns that imply that selective pressures on bone may differ between small and large mammals. Finally, we found high intrataxonomic variation in trabecular bone morphology, but it is not clearly related to any variable we measured, and may represent a normal degree of variation in these animals rather than a functional trait. Future studies should address how this plasticity affects biomechanical properties and performance of the skeleton. [ABSTRACT FROM AUTHOR]

We examined the penile morphology of two murid species: Mus musculus Linnaeus, 1758 and Micromys minutus (Pallas, 1771) and discussed how the position of the baculum affects the diversity of penile morphology. The ratio of stalk length to total penis length was not significantly different between Mu. musculus and Mi. minutus; however, distal end of the stalk was more distal in Mu. musculus than in Mi. minutus. Lateral bacular mound of Mu. musculus is short but has a function in cross-sectional volume expansion of glans near the distal end of the internal prepuce with outward turning of lateral bacular mounds induced by blood flowing into the well-developed cavernous space. In contrast, lateral bacular mounds in Mi. minutus were located more proximally. The cavernous space of lateral bacular mounds was not developed. Considering that the pivot point of the anterior tip of lateral bacular mound and distal tip of the stalk is located proximally, and lateral bacular mounds are shorter and do not reach distal tip of the internal prepuce, lateral bacular mounds could not contribute to the increased cross-sectional areas of the distal portion of penis. Overall, we found that development of the cavernous space enabling the cross-sectional volume increase of penis via blood flow, possibly enhances success of fertilization; further, the position of the stalk tip functions as the pivot point for moving lateral bacular mounds, and affects the position of the increase in penile volume. These two factors are thought to have been changed during the evolutionary process. [ABSTRACT FROM AUTHOR]

Host specificity of fleas affects their biodiversity that plays a major role in determining the potential transmission routes by pathogens through vertebrate hosts, including humans. In the Biogeographic Andean region, numerous systematic and ecological studies have been conducted, revealing a high diversity of flea taxa of mammals and the presence of pathogenic organisms transmitted by fleas; however, the degree of preference with which each flea species associates with a mammal host remains poorly understood in this region. Herein, host specificity in mammal fleas from the Andean region was analysed. We employed the number of host species for each flea species and the index of host specificity STD*. Following the literature, 144 species and 13 subspecies of fleas (31 genera and 10 families) have been described in the Andean biogeographic region; 76 taxa are endemic to this region. To carry out the analyses of host specificity, we considered 1759 records of fleas collected from 124 species and 59 genera of wild and domestic mammals, mostly rodent species (85.9%). Our results indicate that typical Andean fleas are genus or family host specific (mostly STD* less than 3.0). More diverse mammal hosts are parasitized by more diverse flea genera and families and these hosts are phylogenetically related. Otherwise, these hosts are associated with different flea lineages, suggesting the interaction of ecological and evolutionary mechanisms (host‐switching, ecological adaptations and co‐evolutionary alternation). The fields of disease ecology and One Health are considering the host specificity of arthropod vectors as an important point to understand the mechanisms of emergence and re‐emergence of diseases. Our results allow us to estimate the risk of diseases involving fleas in the Andean region. [ABSTRACT FROM AUTHOR]