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The proportion and diversity of prey species consumed by bobcats Lynx rufus are often correlated with prey abundances, individual skill level, environmental conditions, and habitat quality. Bobcats generally consume prey species that rely on mast—the fruits of trees—for basic life-history requirements. In West Virginia forests, many mast-producing tree species have declined over the past 40 y, yet the last known study on bobcat diet in the state was in 1977. Thus, we need current data to understand the effects of forest compositional changes on bobcat dietary patterns. We evaluated stomach contents of 300 bobcats collected over the 2014–2015 (n = 150) and 2015–2016 (n = 150) hunting and trapping seasons in West Virginia. Simpson's index of diversity indicated an 87% probability that two randomly selected prey items belong to different species, supporting the idea of bobcats as generalist carnivores. White-tailed deer (hereafter deer) Odocoileus virginianus (32%), mice and rats (families Cricetidae, Dipodidae, and Muridae; 30.7%), rabbits (family Leporidae; 21.3%), Virginia opossum Didelphis virginiana (18.7%), and squirrels (family Sciuridae; 17.3%) occurred most frequently. We found 92% dietary overlap between sexes and 35% between stage classes. Deer, opossum, and raccoon Procyon lotor occurred more frequently in males, whereas rabbits occurred more frequently in females. Deer occurred more frequently in adults; raccoons in yearlings; and mice and rats in juveniles. Overall occurrence of deer (−17.1%), rodents (order Rodentia; −9.5%), opossum (+13.5%), and raccoon (+5.1%) differed significantly between the 1977 study and this study, which may allude to changes in the abundance of mast-dependent prey species over time. Similarly, hard mast (i.e., nuts) production had a significant interaction effect with study season on the overall occurrence of squirrels in bobcat diets. By improving our understanding of bobcat trophic interactions, we can better manage their populations and ecological communities by managing for the dietary requirements of their common prey species. [ABSTRACT FROM AUTHOR]

The fossil record of treeshrews, hedgehogs, and other micromammals from the Lower Siwaliks of India is sparse. Here, we report on a new genus and species of fossil treeshrew, specimens of the hedgehog Galerix, and other micromammals from the middle Miocene (Lower Siwalik) deposits surrounding Ramnagar (Udhampur District, Jammu and Kashmir), at a fossil locality known as Dehari. The treeshrew from Dehari (Sivatupaia ramnagarensis n. gen. n. sp.) currently represents the oldest record of fossil tupaiids in the Siwaliks, extending their time range by ca. 2.5–4.0 Myr in the region. Dietary analyses suggest that the new tupaiid was likely adapted for a less mechanically challenging or more frugivorous diet compared to other extant and fossil tupaiids. The occurrence of Galerix has only been recently documented from the Indian Siwaliks and the Dehari specimens help establish the likely presence of a relatively large Siwalik Galerix species in the Ramnagar region. In addition to the new treeshrew and hedgehogs, new specimens of the rodents Kanisamys indicus, Sayimys sivalensis, and Murinae indet. from Dehari help confirm that age estimates for the Ramnagar region are equivalent to the Chinji Formation in Pakistan, most likely corresponding to the middle to upper part of the Chinji Formation. UUID: http://zoobank.org/56fb160c-2df8-4cd3-be91-af4dc02d0979 [ABSTRACT FROM AUTHOR]

During oviposition trials, temperature readings on the dataloggers were noted at the 12 h check when oviposition substrate was switched. Thermostat data from some Canadian homes during the 2021 Western North America heat wave indicate internal home temperatures may reach oviposition-augmenting temperatures in extreme heat events [[29]]. Modeling used to predict sealed cabin temperatures indicate that a 30 °C day may raise internal temperatures beyond our observed limits of survival and oviposition [[34]]. Upper lethal temperatures provide information about where and when blow fly populations can persist, while upper non-lethal temperatures provide information as to where and when female blow flies can likely oviposit. [Extracted from the article]

We evaluated craniometric sexual dimorphism and ontogenetic (age) variation in invasive Rattus norvegicus and R. rattus from urban and peri-urban areas of Gauteng Province, South Africa, using univariate and multivariate analyses. Two-way analysis of variance (ANOVA), percent contribution of the sum of squares (%SSQs) of each source of variation, principal components analysis (PCA) and unweighted pair-group method with arithmetic averages (UPGMA) cluster analysis showed no sexual dimorphism in both species, however in both species, significant age variation between five age classes based on maxillary molar toothrow cusp eruption and wear was found and the age classes were pooled into juveniles (i.e., individuals of tooth-wear class I), sub-adults (II–III), and adults (IV–V). Few variables showed statistically significant sex-age interaction. The largest %SSQs to the total variance were due to error (i.e., residual), suggesting that apart from sex, age, and their interaction, there were other components that are responsible for the variation. Our approach may be useful for partitioning the effect of sexual dimorphism and ontogenetic variation in other studies, such as our stable isotope analysis-based trophic ecological studies of Rattus species from urban and peri-urban areas of Gauteng Province, South Africa. [ABSTRACT FROM AUTHOR]

Background: Bartonella are intracellular bacteria that are transmitted via animal scratches, bites and hematophagous arthropods. Rodents and their associated fleas play a key role in the maintenance of Bartonella worldwide, with > 22 species identified in rodent hosts. No studies have addressed the occurrence and diversity of Bartonella species and vectors for small mammals in Arctic and Subarctic ecosystems, which are increasingly impacted by invasive species and climate change. Methods: In this study, we characterized the diversity of rodent fleas using conventional PCR targeting the mitochondrial cytochrome c oxidase II gene (COII) and Bartonella species in rodents and shrews (n = 505) from northern Canada using conventional PCR targeting the ITS (intergenic transcribed spacer) region and gltA (citrate synthase) gene. Metagenomic sequencing of a portion of the gltA gene was completed on a subset of 42 rodents and four rodent flea pools. Results: Year, total summer precipitation the year prior to sampling, average minimum spring temperature and small mammal species were significant factors in predicting Bartonella positivity. Occurrence based on the ITS region was more than double that of the gltA gene and was 34% (n = 349) in northern red-backed voles, 35% (n = 20) in meadow voles, 37% (n = 68) in deer mice and 31% (n = 59) in shrews. Six species of Bartonella were identified with the ITS region, including B. grahamii, B. elizabethae, B. washoensis, Candidatus B. rudakovii, B. doshiae, B. vinsonii subsp. berkhoffii and subsp. arupensis. In addition, 47% (n = 49/105) of ITS amplicons had < 97% identity to sequences in GenBank, possibly due to a limited reference library or previously unreported species. An additional Bartonella species (B. heixiaziensis) was detected during metagenomic sequencing of the gltA gene in 6/11 rodents that had ITS sequences with < 97% identity in GenBank, highlighting that a limited reference library for the ITS marker likely accounted for low sequence similarity in our specimens. In addition, one flea pool from a northern red-backed vole contained multiple species (B. grahamii and B. heixiaziensis). Conclusion: Our study calls attention to the usefulness of a combined approach to determine the occurrence and diversity of Bartonella communities in hosts and vectors. [ABSTRACT FROM AUTHOR]

Rhabdomys is a genus that occupies a variety of habitats, including forest margins. Among the Rhabdomys taxa, Rhabdomys dilectus chakae has a distribution that covers the eastern seaboard of South Africa, with a poorly defined divergence date from its sister taxon Rhabdomys dilectus dilectus. Here, we study three mitochondrial markers (cytochrome b , cytochrome c oxidase I and partial control region) of R. d. chakae across the Eastern Cape and KwaZulu-Natal forests of South Africa, aiming to determine the cladogenesis (molecular dating) and effective population size of this subspecies through time, in addition to its cladogenesis in relationship to other species within the genus. A phylogenetic analysis revealed six clades within Rhabdomys , confirming that our study area is occupied solely by R. d. chakae , to the exclusion of other recognized sibling species. A fossil-calibrated Bayesian relaxed molecular clock estimated a recent split between R. d. chakae and R. d. dilectus ~1.4 ± 0.35 Mya and between two Rhabdomys pumilio groups, coastal A and B, at 1.16 ± 0.44 Mya. Coalescent Bayesian skyline plots revealed a stable population of R. d. chakae in the study area that was in slow decline until 2500 years ago, when there was an expansion in the late Holocene. Radiation within Rhabdomys dates as far back as 4.27 Mya, and subsequent demographic fluctuations primarily reflect palaeoclimatic changes. [ABSTRACT FROM AUTHOR]

Cardiovascular diseases are on the rise around the world and have become some of the leading causes of death. To enhance their chances of survival and effectively manage costs, indigenous communities in developing countries have sought natural remedies from plants and food materials within their reach. This established preference has seen Moringa oleifera garner special attention due to the praised effects of its leaves and other parts. The focus of this study was to investigate the antihypertensive activity of crude MoMLE (CME) and five solvent fractions of the same using C. gambianus and elucidate the effect of their separate interactions with atropine. Moringa oleifera (MO) leaf was collected from the University of Nigeria, Nsukka; C. gambianus was obtained from Okposi-Okwu, Ebonyi State; and antihypertensive activity was assessed using a blood pressure transducer following established methods. The result showed that CME and other fractions had a dose-dependent negative inotropic and chronotropic effect on C. gambianus as follows: N-Hexane fraction (NHF)-19.0 8.1 mmHg, chloroform fraction (CLF)-15.0 3.0 mmHg, ethyl acetate fraction (EAF)-22.3 10.7 mmHg, acetone fraction (ACF)-19.7 7.2 mmHg, and methanol fraction (MEF)-25.7 1.2 mmHg. Similar activity was observed for acetylcholine (-42 ± 4.4 mmHg) which was used as a reference drug (positive control). The study revealed that MoMLE has a hypotensive effect with methanol fraction (MEF) having the second highest hypotensive (-25.7 ± 1.2 mmHg) activity after CME with a 28.7 ± 4.2 mmHg lowering effect. Atropine interaction blocked the extracts as well as acetylcholine, suggesting a muscarinicreceptor mediated action. [ABSTRACT FROM AUTHOR]

Rodentia is the most speciose mammalian order, found across the globe, with some species occurring in close proximity to humans. Furthermore, rodents are known hosts for a variety of zoonotic pathogens. Among other animal species, rodents came into focus when the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) spread through human populations across the globe, initially as laboratory animals to study the viral pathogenesis and to test countermeasures. Under experimental conditions, some rodent species including several cricetid species are susceptible to SARS-CoV-2 infection and a few of them can transmit the virus to conspecifics. To investigate whether SARS-CoV-2 is also spreading in wild rodent populations in Germany, we serologically tested samples of free-ranging bank voles (Myodes glareolus, n = 694), common voles (Microtus arvalis, n = 2), house mice (Mus musculus, n = 27), brown or Norway rats (Rattus norvegicus, n = 97) and Apodemus species (n = 8) for antibodies against the virus. The samples were collected from 2020 to 2022 in seven German federal states. All but one sample tested negative by a multispecies ELISA based on the receptor-binding domain (RBD) of SARS-CoV-2. The remaining sample, from a common vole collected in 2021, was within the inconclusive range of the RBD-ELISA, but this result could not be confirmed by a surrogate virus neutralization test as the sample gave a negative result in this test. These results indicate that SARS-CoV-2 has not become highly prevalent in wild rodent populations in Germany. [ABSTRACT FROM AUTHOR]

Within-species morphological variation is often observed across spatial and climatic gradients. Understanding this variation is important to conservation planning, as specialised adaptations may influence a population's persistence following translocation. However, knowing whether local adaptations are prevalent within a species can be challenging when the species has undergone range contractions. Here, we used museum specimens to study size and shape variation of the greater stick-nest rat (Leporillus conditor). We aimed to determine whether intraspecific size and shape variation previously existed within the species across its historical range, and inform on possible implications for translocations of the remaining extant population. We found significantly larger skull size in the Franklin Islands and arid populations, possibly indicating a historically continuous population experiencing similar selection pressures such as high predation pressure, competition with other large arid zone rodents or climatic extremes. Conversely, skull shape variation within the species adheres to an allometric trajectory, indicating no specific local adaptations of skull shape. This absence of local skull shape adaptation suggests that the Franklin Islands population is likely suitable for mainland translocations. However, further research into the historical phylogeography of the species is recommended to identify whether large size resulted from shared ancestry or convergent evolution. [ABSTRACT FROM AUTHOR]

Australia has suffered more modern mammal extinctions than any nation. Among the list of extinct species is the blue-grey mouse (Pseudomys glaucus ), a rodent known from just three specimens (two from southern Queensland and one from northern New South Wales). We investigated circumstances of collection for the three specimens referred to this species to better illuminate optimal habitats and climatic conditions for continuing rediscovery efforts. No additional information could be found on two specimens from southern Queensland sent to the Natural History Museum, London. However, we recorded a first-hand account of how the northern New South Wales specimen was collected and have established that the collection year was 1956. We also obtained a copy of correspondence from Ellis Le G. Troughton thanking the collector for the contribution. The northern New South Wales specimen was from a pastoral property formerly dominated by woodland vegetation communities on alluvial soils. It was captured during a mouse plague following consecutive seasons of above average rainfall. Pseudomys glaucus is likely already extinct, but our results help better direct any future survey efforts. Surveys should be targeted in woodland communities on alluvial floodplains in the Darling Riverine Plains bioregion, following periods of above average rainfall conducive to the irruption of rodent populations. [ABSTRACT FROM AUTHOR]

SARS‐CoV‐2 human‐to‐animal transmission can lead to the establishment of novel reservoirs and the evolution of new variants with the potential to start new outbreaks in humans. We tested Norway rats inhabiting the sewer system of Antwerp, Belgium, for the presence of SARS‐CoV‐2 following a local COVID‐19 epidemic peak. In addition, we discuss the use and interpretation of SARS‐CoV‐2 serological tests on non‐human samples. Between November and December 2020, Norway rat oral swabs, faeces and tissues from the sewer system of Antwerp were collected to be tested by RT‐qPCR for the presence of SARS‐CoV‐2. Serum samples were screened for the presence of anti‐SARS‐CoV‐2 IgG antibodies using a Luminex microsphere immunoassay (MIA). Samples considered positive were then checked for neutralizing antibodies using a conventional viral neutralization test (cVNT). The serum of 35 rats was tested by MIA showing three potentially positive sera that were later negative by cVNT. All tissue samples of 39 rats analysed tested negative for SARS‐CoV‐2 RNA. This is the first study that evaluates SARS‐CoV‐2 infection in urban rats. We can conclude that the sample of rats analysed had never been infected with SARS‐CoV‐2. However, monitoring activities should continue due to the emergence of new variants prone to infect Muridae rodents. [ABSTRACT FROM AUTHOR]

Records on the distribution of Rickettsia spp. in their natural hosts in Central Asia are incomplete. Rodents and small mammals are potential natural reservoirs for Rickettsiae in their natural lifecycle. Studies about the maintenance of Rickettsia in wild animals are available for Western nations, but—to our knowledge—no studies and data are available in the Republic of Kazakhstan so far. The first case description of Rickettsioses in Kazakhstan was made in the 1950ies in the Almaty region and now Kyzylorda, East Kazakhstan, Pavlodar and North Kazakhstan are endemic areas. The existence of murine and endemic typhus was proven in arthropod vectors in the regions Kyzylorda and Almaty. Here we show for the first time investigations on tick-borne Rickettsia species detected by a pan-rickettsial citrate synthase gene (gltA) real-time PCR in ear lobes of small mammals (n = 624) in Kazakhstan. From all analysed small mammals 2.72% were positive for Rickettsia raoultii, R. slovaca or R. conorii. Sequencing of the rickettsial gene OmpAIV and the 23S–5S interspacer region revealed a similar heritage of identified Rickettsia species that was observed in ticks in previous studies from the region. In summary, this study proves that rodents in Kazakhstan serve as a natural reservoir of Rickettsia spp. [ABSTRACT FROM AUTHOR]

Gerbillinae is the second largest subfamily (after Murinae) in the Muridae family comprising ~16 genera and more than a hundred species. Phylogenetic relationships among the main taxa of gerbils are still not fully understood. In particular, a major issue is the phylogenetic position of the monotypic genus Ammodillus (endemic to the Horn of Africa), which according to morphological data may be one of the earliest offshoots from the gerbilline stem; however, its precise affiliations have been unknown due to the lack of genetic data. Here, by means of a multilocus dataset including one mitochondrial and five nuclear markers, we for the first time elucidated phylogenetic placement of Ammodillus and provided the most complete tribal phylogeny of Gerbillinae to date. Phylogenetic reconstructions robustly supported Ammodillus as a sister taxon to all other living gerbillines and suggested that the separation of the ammodile lineage dates back to the Middle/Late Miocene boundary (~11.7 Mya). The results are consistent with subdivision of the subfamily into four tribes: monotypic Ammodillini, Gerbillini (including Taterillus), Desmodilliscini (including Pachyuromys) and Gerbillurini. In the light of the new data, we discuss possible scenarios of Gerbillinae origin, highlight Ammodillus as a relatively ancient—albeit morphologically advanced—lineage that has never gained diversity and propose the term 'ancient singleton' for a taxon with a persistently low diversification rate. [ABSTRACT FROM AUTHOR]

Objective. To search Hantavirus and Arenavirus in small rodents and establish their spatial distribution in disturbed ecosystems in the municipality of Villavicencio, Meta, Colombia. Materials and method. A descriptive cross-sectional study was carried out from October 2018 to October 2019 in periurban and rural areas of the municipality of Villavicencio. Rodents were captured using Sherman-type traps and molecular detection of Hantavirus and Arenavirus was carried out by Polymerase chain Reaction technique. Results. A total of 50 rodents were captured belonged to 3 families and six species, the Muridae (76%) with the highest number of captured individuals, Cricetidae (22%) and Echimydae (2%). All samples were negative for the molecular markers of Hantavirus and Arenavirus. Conclusions. The study of mammalian hosts, particularly small rodents contribute to monitor diseases transmitted by these small mammals that act as reservoirs. [ABSTRACT FROM AUTHOR]

Cryptic species are prevalent among mammals, and identifying morphological methods or measurements that can effectively distinguish cryptic species has high significance in taxonomy. Three of the white-bellied rats, Niviventer confucianus, N. fulvescens and N. huang (Rodentia: Muridae), have such similar morphological characteristics that taxonomists have not been able to effectively identify them according to their morphologies. Recent studies have determined that the N. fulvescens species complex contains multiple species, indicating that previous morphological comparisons were potentially based on inaccurate species identifications, leading to false conclusions. To clarify whether the morphological differences among these three species can be used for identification, a variety of morphological methods and measurements were combined with molecular species identification to ensure accurate identifications prior to comparing morphological characteristics. The results showed that: (1) only N. confucianus has a white tail tip, distinguishing this species from the other two species but not N. fulvescens from N. huang; and (2) the tail length of N. fulvescens and ear length of N. confucianus are greater than those of the other species. Traditional morphological methods cannot differentiate these species well, with the discrimination rate reaching more than 90%; therefore, they can only be used as auxiliary methods for morphological identification. Additionally: (3) the geometric morphological results of the four skull views can be combined to distinguish the three species, among which the discrimination rate of lateral view of mandible reaches 98%, making it effective for differentiating these species; and (4) the phallic morphologies of the three species differed significantly in the presence of a dorsal groove, thickness of the distal baculum, and the positional relationship between the distal and proximal baccula; thus, this approach can completely distinguish these species. This study examines the applicability of various morphological measurements for the identification of highly morphologically similar species, provides a reference for distinguishing cryptic species produced by convergent evolution or incomplete differentiation by morphology, and suggests that phallic morphology should be the primary characteristic for differentiating such species in the future. [ABSTRACT FROM AUTHOR]

The holotype of the Tenerife (Canary Islands) giant rat, Canariomys bravoi, an almost complete cranium from the Late Pleistocene site of Cueva de las Palomas, is described for the first time. This species is characterized by its large size, robust skull with a short rostrum, dorsal inflation at the level of the infraorbital foramen, and moderately high-crowned upper molars which develop partial stephanodonty at advanced wear stages. Canariomys tamarani from Gran Canaria Island, the only other species of this genus known so far, is slightly smaller and further differs in its higher crowned molars with cusps arranged in a lamellar pattern. However, their crania are remarkedly similar and present a distinctive anatomy of the zygomatic plate, which is very high on the rostrum, so that its dorsal border is nearly on level with the zygomatic process of the maxilla instead of considerably below it as usually seen in murines. This is also observed in other insular, often large-sized, murines but certainly evolved in parallel as an adaptation to herbivory. Molar morphology is congruent with recent analyses of ancient molecular data of C. bravoi which place it in the tribe Arvicanthini (mostly African murines), more concretely within the Arvicanthis niloticus species complex. Even though genetic data indicate that both species diverged very recently, just 650,000 years ago, cranial and dental anatomy of C. bravoi are very derived. Conversely, C. tamarani presents a molar morphology reminiscent of that of A. niloticus albeit associated with a similarly highly derived cranial anatomy. [ABSTRACT FROM AUTHOR]

The diet of the Austral Pygmy Owl, Glaucidium nana, a small raptor, was studied by pellet analysis. During fall of 2020, 52 pellets were collected in a peri-urban protected area. Amongst 122 prey items, Muridae, represented exclusively by the alien species Rattus rattus and Rattus norvegicus, made up 35.24 % by number and 67.1 % of the biomass, followed by native Cricetidae, at a 37.69 % by number and 17.9 % by biomass. In the last place in relative frequency were birds and arthropods. The biomass contribution was unequal among the different prey, being the alien prey the group with the highest profit. The role of the landscape in the composition of prey in the observed trophic spectrum is discussed. [ABSTRACT FROM AUTHOR]

The Taiwan beauty snake, Elaphe taeniura friesi, has established a stable population in the central part of Okinawajima Island, and there are concerns about the negative effects of the snakes' predation on the native fauna. Thus, we examined the stomachs of 239 E. t. friesi specimens collected on Okinawajima Island from July 2018 to November 2019. Stomach contents were identified to the species level whenever possible based on morphological observations and/or DNA analyses. Of the 239 snake specimens, 39 (12 males, 16 females, and 11 juveniles) had contents in their stomach, including 67 prey items, 75% of which were mammals (Muridae and Soricidae) and the rest of which were birds (Pycnonotidae, Cisticolidae, and Columbidae). Rattus rattus occurred most frequently; 25 of the 39 snakes examined had this species in their stomachs. All avian prey items detected were nestlings and eggs. Twelve snakes had multiple prey items in their stomach, including in most cases either nestlings of passerine birds or infants or subadults of R. rattus. Therefore, E. t. friesi is an endotherm consumer that occasionally preys on nestlings and infant rats. These food habits suggested that E. t. friesi uses various habitats, from the humus layer on the ground to the branches of trees, for foraging. Several endangered endemic rodent and bird species exist in the northern area of Okinawajima Island; thus, our results provide a warning about potential negative impact on such animals when E. t. friesi expands its range to the northern part of the island. [ABSTRACT FROM AUTHOR]

The Italian peninsula represented one of the main glacial refugia during climatic oscillations of the Pleistocene, currently being a biodiversity hotspot. In this work, we analysed for the first time the genetic diversity of harvest mouse populations in Italy, and we compared them with those of the rest of Eurasia. Mitochondrial cytochrome-b gene was amplified from 12 samples from throughout the Italian range. We recorded a very low genetic diversity, in line with the rest of the harvest mouse range. In the comparative phylogenetic tree, Northern Italy samples clustered together as a sister group of the rest of Europe, whereas those from Central Italy clustered with Central Europe samples. Harvest mice have recently conquered Southern Europe, i.e., possibly at the start of the Holocene. The global genetic homogeneity might be due to accidental human-mediated introductions or to the sharp decline of the habitat of the harvest mouse, which may in turn have caused severe bottlenecks in the populations of this small rodent. [ABSTRACT FROM AUTHOR]

The cricetid rodent genus Rhipidomys belongs to the tribe Thomasomyini, subfamily Sigmodontinae, whose distribution covers high-and lowlands areas of South America. In a number of contributions to the taxonomy and systematics of the genus, 24 species of Rhipidomys were recognized by different authors until now. Here we identify 13 species of the lowland "leucodactylus" section from Brazil and named two new forms of this genus based on morphological and molecular data. One of these forms is only found at municipality of Bezerros, Pernambuco state, while the other has a more extensive distribution, being recorded in northern Goiás, west of Tocantins, southern Piauí, western portion of Bahia and northern region of Minas Gerais states. These two new species can be distinguished from the others of the genus by qualitative and quantitative characters although, like most other Brazilian species of Rhipidomys, they do not exhibit an autapomorphic characters. These species are diagnosed by unique combinations of character states that are operational and useful for species recognition. In general, the most valuable character sets to differentiate Rhipidomys species are found in the skull, external morphology being strongly variable and showing overlapping sets of characters. We compared the two new species with all Brazilian species of the "leucodactylus" section and added taxonomic comments and their phylogenetic relationships. [ABSTRACT FROM AUTHOR]

The Dahomey Gap in West Africa is a human-derived savannah-like vegetation zone interspersed by patches of moist forest, with large rainforest blocks at both West (Upper Guinean Forest) and East (Lower Guinean Forest) of its limits. Togo is a tiny country situated in the middle of the Dahomey Gap. In this paper, a biogeographic analysis of the composition of the mammalian fauna of Togo is presented, by classifying each species on the basis of five distinct ecological distribution patterns. The greatest proportion of species were Pan-African (88.0%). Excluding the Pan-African species from the analysis, the mammalian fauna appeared to be affiliated similarly to both Upper Guinean and Lower Guinean Forest blocks. Only three endemic species were observed, all of them being rodents: Cryptomys zechi (Batyergidae), Funisciurus substriatus (Sciuridae), and Leimacomys buettneri (Muridae). Considering only the multispecies genera, the great majority did not show any barrier effect by the Dahomey Gap on their own species, as all of them did occur on both sides of Togo. A barrier effect by the Dahomey Gap was uncovered in 8 genera; overall, the Dahomey Gap apparently showed a barrier effect on 28.6% of the multispecies genera. It is emphasized that the full understanding of the role of the Dahomey Gap as a biogeographic barrier and of its island forests as centers of endemism is impeded by the lack of biogeographic reviews and meta-analyses on the composition of faunal and floral groups of the entire region. [ABSTRACT FROM AUTHOR]

Cities intensely modify natural environments and impose pressures on biodiversity. In this sense, carnivorous mammals are one of the groups most affected due to their food and space requirements. The feeding and spatial behavior of the chilla fox (Lycalopex griseus, G., 1837) and dogs were studied in the vicinity of a peri-urban protected area in south-central Chile. The diet of both canids was compared seasonally, for which feces were collected along trails in three habitats: native forest, exotic plantations and scrublands. Dog feces were collected at the same site to establish whether they were avoided by foxes. Chilla fox has been highlighted for consuming a high proportion of hares followed by rodents of the Muridae family, both being exotic mammals in Chile, whereas dogs showed a predominant consumption of anthropogenic food. Significant differences were observed for chilla fox in dietary diversity, mainly in summer and fall. No spatial segregation was observed with the domestic dog, which was evidenced in a high overlap in the use of all habitats. This scenario, together with continuous human presence, are elements that must be considered in the medium-term to evaluate the effects of anthropogenic pressures on native carnivores in the study area. [ABSTRACT FROM AUTHOR]

Seed predation by rodents can strongly influence plant recruitment and establishment. The extent to which predation risk indirectly alters plant survival in tropical forests via impacts on granivory is unclear, making it difficult to assess the cascading impacts of widespread predator loss on tree recruitment and species composition. Experimental field studies that manipulate predation risk can help address these knowledge gaps and reveal whether antipredator responses among small mammals influence plant survival. We used camera traps and seed predation experiments to test the effects of perceived predation risk (via predator urine gel) on foraging behaviour of and seed removal by murid rodents in an unlogged and unhunted rainforest in Malaysian Borneo. We also explored the influence of seed traits (e.g., seed size) on removal by granivores and assessed whether granivore preferences for particular species were affected by predator urine. Murid visits to seed plots were positively related to overall seed removal, but were not affected by predator scent. Granivory was the lowest for the largest-seeded (>6 g) plant in our study, but was not influenced by predation risk. Predator urine significantly affected removal of one seed taxon (Dimoocarpus, ∼0.8 g), suggesting that removal by granivores may be affected by predation risk for some seed species but not others. This could have implications for plant species composition but may not affect the overall level of granivory. [ABSTRACT FROM AUTHOR]

A new spirurid nematode, Protospirura canariensis n. sp., a parasite of the black rat Rattus rattus Linnaeus, 1758 (Rodentia: Muridae), in El Hierro Island (Canary Archipelago, Spain), was described by means of light (LM) and scanning electron microscopy (SEM). The most discriminating characteristics between the new species and the remaining species of the genus Protospirura were observed to be the following: (a) the number of tooth-like outgrowths in the sub-median and lateral lobes of the pseudolabia, both in males and females (2 and 4, respectively); (b) the size of the right and left spicules in males (643–715 µm and 309–412 µm, respectively); and (c) the numbers and arrangements of the cloacal papillae in males. The new species has a total of 17 cloacal papillae (4 large and pedunculated pairs of precloacal papillae, an unpaired precloacal papilla and 4 pairs of postcloacal papillae). The arrangement of the postcloacal papillae are as follows: the first pair are large, pedunculated and placed near the posterior edge of cloaca; the three remaining postcloacal pairs are grouped and located near the posterior tip. In the latter group, the papillae in the first pair are large and pedunculated. The parasitized hosts and their geographical distributions were also useful criteria in distinguishing P. canariensis n. sp. from the remaining species of the genus Protospirura. In addition, the cytochrome c oxidase subunit I (cox1) sequence of the new species was obtained and compared with the available data of related species.

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. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is considered to be one of the most common female endocrine diseases with complex etiology and high incidence rate. Its diverse clinical manifestations and long-term complications seriously affect the physical and mental health and quality of life of patients. Therefore, the establishment of a practical and effective experimental model is very important to the research of PCOS. Rats and mice are one of the most commonly used experimental animals because of their small size, short reproductive cycle and stable estrous cycle. This paper reviews the research progress of mouse models of PCOS at home and abroad based on the clinical characteristics, hormone levels, endocrine and metabolic indexes of PCOS, aims to evaluate the advantages and disadvantages of various models and provide guidance for the selection of models in experiments. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the occurrence and molecular characteristics of Bartonella infections in small rodents in the Shangdang Basin, China. Small rodents were captured using snap traps, and their liver, spleen, and kidney tissues were harvested for Bartonella detection and identification using a combination of real-time PCR of the ssrA gene (296 bp) and conventional PCR and sequencing of the gltA gene (379 bp). Results showed that 55 of 147 small rodents to be positive for Bartonella, with a positivity rate of 37.41%, and 95% confidence interval of 29.50%- 45.33%. While the positivity rate across genders (42.62% in males and 33.72% in females, χ2 = 1.208, P = 0.272) and tissues (28.57% in liver, 33.59% in spleen, and 36.76% in kidney, χ2 = 2.197, P = 0.333) of small rodents was not statistically different, that in different habitats (5.13% in villages, 84.44% in forests, and 54.17% in farmlands, χ2 = 80.105, P<0.001) was statistically different. There were 42 Bartonella sequences identified in six species, including 30 B. grahamii, three B. phoceensis, two B. japonica, two B. queenslandensis, one B. fuyuanensis and four unknown Bartonella species from Niviventer confucianus, Apodemus agrarius and Tscherskia triton. In addition to habitat, Bartonella species infection could be affected by the rodent species as well. Among the Bartonella species detected in this area, B. grahamii was the dominant epidemic species (accounting for 71.43%). B. grahamii exhibited four distinct clusters, and showed a certain host specificity. In addition, 11 haplotypes of B. grahamii were observed using DNASP 6.12.03, among which nine haplotypes were novel. Overall, high occurrence and genetic diversity of Bartonella were observed among small rodents in the Shangdang Basin; this information could potentially help the prevention and control of rodent-Bartonella species in this area. Author summary: Bartonella species are recognized as emerging zoonotic pathogens that are mainly transmitted by blood-sucking arthropods, some being infectious to humans. Rodents are important natural reservoirs of Bartonella species. Bartonella infection has been detected in various countries worldwide, and their prevalence in rodents varies greatly across countries and regions. This is the first report of Bartonella prevalence and genetic diversity in Shangdang Basin of China. It revealed a high Bartonella-positivity rate in Niviventer confucianus and Apodemus agrarius in this area. Relatively higher occurrence of Bartonella species was detected in forests and farmlands. Six Bartonella species were detected, B. grahamii, B. phoceensis, B. japonica, B. queenslandensis, B. fuyuanensis and one unknown Bartonella species, of which B. grahamii was the dominant species, with high genetic diversity, and potentially pathogenicity in humans. Our study provided a better understanding of the occurrence and genetic diversity of Bartonella species in the small rodents in Shangdang Basin. [ABSTRACT FROM AUTHOR]

Mental illness modeling is still a major challenge for scientists. Animal models of schizophrenia are essential to gain a better understanding of the disease etiopathology and mechanism of action of currently used antipsychotic drugs and help in the search for new and more effective therapies. We can distinguish among pharmacological, genetic, and neurodevelopmental models offering various neuroanatomical disorders and a different spectrum of symptoms of schizophrenia. Modeling schizophrenia is based on inducing damage or changes in the activity of relevant regions in the rodent brain (mainly the prefrontal cortex and hippocampus). Such artificially induced dysfunctions approximately correspond to the lesions found in patients with schizophrenia. However, notably, animal models of mental illness have numerous limitations and never fully reflect the disease state observed in humans. [ABSTRACT FROM AUTHOR]

The Ethiopian highlands represent the largest part of the Eastern Afromontane Biodiversity Hotspot (EAMBH). Their fauna and flora are largely unique. Particularly, Afroalpine habitats on isolated mountains are known to harbour a large number of highly specialized endemic species. In contrast to intensively studied Afroalpine ecosystems, the forests in southern and southwestern parts of the Ethiopian highlands remain neglected in terms of biodiversity research, even though they represent the only remaining natural large-scale forests in this part of EAMBH. Here, we performed an integrative taxonomic revision (combining multi-locus phylogenetic analysis with classical and geometric morphometrics) and analysis of the evolutionary history of ancient lineages of the genus Mus, with a special focus on the taxon discovered in moist Ethiopian forests. We unequivocally showed that this taxon forms a very distinct gene pool separated from other taxa by the mid-Pliocene, substantially differentiated from both sympatric and sister species by external and cranial morphology. None of the available type specimens (including synonym types) can be unambiguously classified to this taxon according to both skull and body form. Therefore, we describe it as a new mammal species, narrowly endemic to two most humid forests in southern (Harenna) and southwestern (Chingawa) part of the Ethiopian highlands. The description of such paleo-endemic taxa will add incentives to embark on urgent conservation action for formal protection of these unique forests within the EAMBH. [ABSTRACT FROM AUTHOR]

Complete mitochondrial genomes of four species of Ethiopian speckled brush-furred rats Lophuromys (L. chrysopus, L. menageshae, L. melanonyx, and L. simensis) were assembled for the first time. We provide data concerning the sequencing, assembly, and annotation of the obtained mitogenomes; compare two widely used circular-genome annotation tools (MITOS and MitoZ), and discuss relevant points concerning relationships within both Ethiopian Lophuromys and the Muridae family. [ABSTRACT FROM AUTHOR]

The mesencephalic locomotor region (MLR) was discovered several decades ago in the cat. It was functionally defined based on the ability of low threshold electrical stimuli within a region comprising the cuneiform and pedunculopontine nucleus to evoke locomotion. Since then, similar regions have been found in diverse vertebrate species, including the lamprey, skate, rodent, pig, monkey, and human. The MLR, while often viewed under the lens of locomotion, is involved in diverse processes involving the autonomic nervous system, respiratory system, and the state-dependent activation of motor systems. This review will discuss the pedunculopontine nucleus and cuneiform nucleus that comprises the MLR and examine their respective connectomes from both an anatomical and functional angle. From a functional perspective, the MLR primes the cardiovascular and respiratory systems before the locomotor activity occurs. Inputs from a variety of higher structures, and direct outputs to the monoaminergic nuclei, allow the MLR to be able to respond appropriately to state-dependent locomotion. These state-dependent effects are roughly divided into escape and exploratory behavior, and the MLR also can reinforce the selection of these locomotor behaviors through projections to adjacent structures such as the periaqueductal gray or to limbic and cortical regions. Findings from the rat, mouse, pig, and cat will be discussed to highlight similarities and differences among diverse species. [ABSTRACT FROM AUTHOR]

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Autosomal dominant sleep-related hypermotor epilepsy (ADSHE; previously autosomal dominant nocturnal frontal lobe epilepsy, ADNFLE), originally reported in 1994, was the first distinct genetic epilepsy shown to be caused by CHNRA4 mutation. In the past two decades, we have identified several functional abnormalities of mutant ion channels and their associated transmissions using several experiments involving single-cell and genetic animal (rodent) models. Currently, epileptologists understand that functional abnormalities underlying epileptogenesis/ictogenesis in humans and rodents are more complicated than previously believed and that the function of mutant molecules alone cannot contribute to the development of epileptogenesis/ictogenesis but play important roles in the development of epileptogenesis/ictogenesis through formation of abnormalities in various other transmission systems before epilepsy onset. Based on our recent findings using genetic rat ADSHE models, harbouring Chrna4 mutant, corresponding to human S284L-mutant CRHNA4, this review proposes a hypothesis associated with tripartite synaptic transmission in ADSHE pathomechanisms induced by mutant ACh receptors. LINKED ARTICLES: This article is part of a themed issue on Building Bridges in Neuropharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.8/issuetoc. [ABSTRACT FROM AUTHOR]

The broad distribution of macroparasites and their thriving populations are matters of health and economic concern. Macroparasites cause damage both directly through their feeding habits, which impact host fitness, and indirectly through the transmission of various infectious diseases of relevance to human and domestic animal health and wildlife conservation. Because the impacts of macroparasites on host health and the risk of disease transmission are directly related to their abundance, understanding the drivers of macroparasite burden is of relevance. Various host traits and environmental factors have been associated with differences in macroparasite abundance. In addition to these variables, spatial scale is increasingly incorporated to understand how these drivers vary across space. However, variation in the relative importance of host traits and environmental factors as predictors of abundance at different scales is not well understood. To further clarify the relationship between scale and drivers of macroparasite abundance, we investigated the effects of host traits and environmental factors on flea abundance in rodents of the Chihuahuan Desert in northwestern Mexico on three levels: within a single site, between sampling sites with different vegetation types, and across the region. This partitioning allowed us to compare drivers at both local and regional scales. Fleas provide a natural model to assess the interplay between host and environmental variables across scales because their life cycles alternate between on‐host and off‐host environments and their hosts have varying ranges of distribution. We sampled 1311 fleas from 674 rodent individuals of 14 different species across 40 sampling plots between 2012 and 2013. Using generalized linear mixed models, we found that flea abundance was associated with different combinations of host traits such as size and sex. The specific combination of predictive variables differed across species, while the effects on flea abundance showed context and scale dependency, although this could only be tested at the full level of analysis on the most abundant species, Dipodomys merriami. Sampling season was the only variable consistently significant across scales, reflecting the far‐reaching effects of large‐scale, interannual environmental fluctuations. These results emphasize that integrating spatial scale can strengthen study design for monitoring macroparasite burden. [ABSTRACT FROM AUTHOR]

Pathogenic nematodes were collected from the gastrointestinal tract of Indian Gerbil Tatera indica Hardwicke, 1807 in Hyderabad, Sindh, Pakistan. A total of 32 nematodes were collected from 09 hosts out of 22 hosts examined. These specimens were identified as the members of genus Gongylonema Molin, 1857 (Spirurida: Spiruroidea: Gongylonematidae) based on presence of various cuticular bosses on anterior portion of the speciemens, a gubernaculum, unequal and dissimilar spicules. Previously, there is no record of genus Gongylonema from the host Tatera indica, therefore, it makes new host record from Sindh province of Pakistan. [ABSTRACT FROM AUTHOR]

This preliminary report concerns the micromammalian remains recovered from the Pleistocene strata in Excavation 1 at Wonderwerk Cave by Peter B. Beaumont during the 1980s and early 1990s. Because of the large size of the samples (170 656 specimens representing a minimum of 71 304 individuals), identification has so far only been taken to the generic level. Remains belonging to 34, and possibly 36, genera in five Orders have been identified, and there could be as many as 48 species represented. The uneven horizontal distribution of material throughout the excavation indicates probable roost or nest sites of Barn owls (Tyto alba), which is the most likely predator responsible for their accumulation. There is also considerable vertical variation in the amount of material in the different levels, which indicates that the predators were not consistently present in the area throughout the period represented by the deposits. In the majority of the samples, Gerbillinae (Gerbillis c us , gerbils) are best represented when supra-generic groupings are used. This suggests that conditions were reasonably arid during the periods represented by the samples but not necessarily throughout the entire period spanned by the deposits. When original groupings (genus and above) are considered, Otomyinae (Otomys spp., vlei rats) predominate in nearly half the samples. Secondarily important prey taxa are shrews (Soricidae), rats and mice (Murinae) and elephant shrews (Macroscelididae). This implies some variation in environmental conditions over time but more detailed interpretations must await further analysis. In particular it is imperative to identify the species of Gerbilliscus and Otomys before progress can be made. A range of techniques is now available to assist with interpreting the samples to their full potential once this has been done. [ABSTRACT FROM AUTHOR]

Anticoagulant rodenticides are commonly used in rodent control because they are economical and have great deployment versatility. However, rodents with Single Nucleotide Polymorphism (SNP) mutations within the Vkorc1 gene are resistant to the effects of anticoagulant rodenticide use and this influences the effectiveness of control strategies that rely on such rodenticides. This study examined the prevalence of rat SNP mutations in Singapore to inform the effectiveness of anticoagulant rodenticide use. A total of 130 rat tail samples, comprising 83 Rattus norvegicus (63.8%) and 47 Rattus rattus complex (36.2%) were conveniently sampled from November 2016 to December 2019 from urban settings and sequenced at exon 3 of Vkorc1. Sequencing analysis revealed 4 synonymous and 1 non-synonymous mutations in Rattus rattus complex samples. A novel synonymous mutation of L108L was identified and not previously reported in other studies. Non-synonymous SNPs were not detected in the notable codons of 120, 128 and 139 in R. norvegicus, where these regions are internationally recognised to be associated with resistance from prior studies. Our findings suggest that the prevalence of anticoagulant rodenticide resistance in Singapore is low. Continued monitoring of rodenticide resistance is important for informing rodent control strategies aimed at reducing rodent-borne disease transmission. [ABSTRACT FROM AUTHOR]

Background: Small mammals (rodents and marsupials) have been poorly explored for the occurrence of apicomplexan (genus Hepatozoon and genera of the order Piroplasmorida) and Anaplasmataceae agents in Brazil. Thus, this study investigated the occurrence of Hepatozoon spp., Piroplasmorida, and Anaplasmataceae agents in small mammals in seven forest fragments in Brazil. Methods: During 2015–2018, small mammals were captured in six forest fragments in the State of São Paulo (Cerrado and Atlantic Forest biomes) and one fragment in the State of Mato Grosso do Sul (Pantanal biome). Mammal blood, liver, spleen, and lung samples were tested molecularly for the presence of DNA of Hepatozoon, Piroplasmorida, and Anaplasmataceae agents. Results: A total of 524 mammals were captured, comprising seven species of marsupials, 14 rodents, two carnivores, and one Cingulata. Four novel haplotypes (1, 2, 3, 4) of Hepatozoon spp. were detected in small mammals from different biomes. In São Paulo state, haplotype 1 was detected in rodents from Cerrado and a transition area of Cerrado and Atlantic Forest biomes, whereas haplotype 2 was detected in rodents from the Atlantic Forest biome. On the other hand, haplotypes 3 and 4 were restricted to rodents and marsupials, respectively, from the Pantanal biome of Mato Grosso do Sul. No host species shared more than one haplotype. Despite these distinct geographical and host associations, our phylogenetic analyses indicated that the four Hepatozoon haplotypes belonged to the same clade that contained nearly all haplotypes previously reported on rodents and marsupials, in addition to several reptile-associated haplotypes from different parts of the world. No mammal samples yielded detectable DNA of Piroplasmorida agents. On the other hand, the Anaplasmataceae-targeted polymerase chain reaction (PCR) assay amplified a sequence 100% identical to the Wolbachia pipientis endosymbiont of the rodent filarid Litomosoides galizai. Conclusions: We report a variety of Hepatozoon haplotypes associated with small mammals in three Brazilian biomes: Cerrado, Atlantic Forest, and Pantanal. Through phylogenetic analyses, the Hepatozoon agents grouped in the rodent-marsupial-reptile large clade of Hepatozoon spp. from the world. The detection of a W. pipientis associated with the rodent filarid L. galizai indicates that the rodent was infected by filarial nematodes. [ABSTRACT FROM AUTHOR]

The Asian Mouse Mutagenesis Resource Association (AMMRA) is a non-profit organization consisting of major resource and research institutions with rodent expertise from within the Asia Pacific region. For more than a decade, aiming to support biomedical research and stimulate international collaboration, AMMRA has always been a friendly and passionate ally of Asian and Australian member institutions devoted to sharing knowledge, exchanging resources, and promoting biomedical research. AMMRA is also missioned to global connection by working closely with the consortiums such as the International Mouse Phenotyping Consortium and the International Mouse Strain Resource. This review discusses the emergence of AMMRA and outlines its many roles and responsibilities in promoting, assisting, enriching research, and ultimately enhancing global life science research quality. [ABSTRACT FROM AUTHOR]

Cardiac fibrosis (scarring), characterised by an increased deposition of extracellular matrix (ECM) proteins, is a hallmark of most types of cardiovascular disease and plays an essential role in heart failure progression. Inhibition of cardiac fibrosis could improve outcomes in patients with cardiovascular diseases and particularly heart failure. However, pharmacological treatment of the ECM build‐up is still lacking. In this context, preclinical models of heart disease are important tools for understanding the complex pathogenesis involved in the development of cardiac fibrosis which in turn could identify new therapeutic targets and the facilitation of antifibrotic drug discovery. Many preclinical models have been used to study cardiac fibrosis and each model provides mechanistic insights into the many factors that contribute to cardiac fibrosis. This review discusses the most frequently used rodent models of cardiac fibrosis and also provides context for the use of particular models of heart failure. LINKED ARTICLES: This article is part of a themed issue on Preclinical Models for Cardiovascular disease research (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.5/issuetoc [ABSTRACT FROM AUTHOR]

Objective: Wild animal pathogen surveillance will help to understand the next possible pandemic in advance. Rodents, which have close contact with humans, are generally regarded as a key factor for zoonotic disease control. Given the variation in rodent virus composition in diverse ecologies, we conducted a study on the viral infection of rodents of diverse species in different typical environments of Heilongjiang and Yunnan Provinces, located in northeastern and southwestern China, respectively. Methods: Viral metagenomics sequencing and bioinformatic analysis were performed to determine the different distributions of rodent-borne viruses in typical environments of Heilongjiang and Yunnan Provinces, China. After viral culture and PCR confirmation, genomic and phylogenetic quantitative analysis was performed on the detected hantaviruses (HVs) and Beilong viruses (BeiVs). Results: Nineteen rodents from three species and 35 rodents from five species of rodents were collected from Heilongjiang and Yunnan Provinces, respectively. Although the number and number of species of rodents trapped in the northeast were fewer than those in the southwest, viruses annotated from rodents in Heilongjiang were more diverse than those in Yunnan. Rodents carried 22 virus families in Heilongjiang and 13 families in Yunnan. Sequences assembled from Rattus norvegicus were annotated to the M, L, and S segments of HV, and all were clustered within the Seoul-type hantavirus (SEOV). There were 2 (R81Q, S698T) and 4 (K153R, M168I, I279S, and R1790K) amino acid site substitutions in M and L compared with the versions in the most homologous strains. Two BeiV isolates from Rattus norvegicus were closely related to BeiV from brown rats in Hong Kong, with high bootstrap values of >90% in the N segment and > 95% in the L segment. They were further clustered with Tailam virus, forming a distinct group in Paramyxoviridae. Conclusion: The rodents from Heilongjiang and Yunnan located in northeast and southwest China, respectively, had different viral spectra, and only one-third (10/32) of virus families were detected in both areas. The predominant viruses were HV and BeiV in the Hantaviridae and Paramyxoviridae families, respectively. Rodent-borne viruses in the same species were similar in different geographic disparate areas owing to their similar close contact with human habitats and human activities. Additional attention should be given to the monitoring of neglected rodent-borne viruses, especially opportunistic viruses with currently low loads. [ABSTRACT FROM AUTHOR]

The respiratory system maintains homeostatic levels of oxygen (O2) and carbon dioxide (CO2) in the body through rapid and efficient regulation of breathing frequency and depth (tidal volume). The commonly used methods of analyzing breathing data in behaving experimental animals are usually subjective, laborious, and time-consuming. To overcome these hurdles, we optimized an analysis toolkit for the unsupervised study of respiratory activities in animal subjects. Using this tool, we analyzed breathing behaviors of the common marmoset (Callithrix jacchus), a New World non-human primate model. Using whole-body plethysmography in room air as well as acute hypoxic (10% O2) and hypercapnic (6% CO2) conditions, we describe breathing behaviors in awake, freely behaving marmosets. Our data indicate that marmosets' exposure to acute hypoxia decreased metabolic rate and increased sigh rate. However, the hypoxic condition did not augment ventilation. Hypercapnia, on the other hand, increased both the frequency and depth (i.e., tidal volume) of breathing. [ABSTRACT FROM AUTHOR]

The Afar Triangle in easternmost Africa is one of biogeographically important regions, whose recent biota is virtually unknown. Here we evaluated the level of evolutionary uniqueness of biodiversity of this region in a wide regional and continental biogeographical context, using rodents as a model group. By combining our recent collections with historical records, and based on genetic data and phylogenetic approaches, we specifically tested whether and to what extent the geographical isolation of the Afar Depression is reflected in allopatric diversification of arid-adapted mammals. We documented the presence of 16 rodent species (four are reported for the first time in Ethiopia and one rediscovered there after more than 100 years) and eight additional species are likely present based on literature data. Comparative phylogeographic analysis suggests that the Afar Triangle can be considered as a part of a larger Somalian biogeographical region, but its fauna is genetically distinct, including the presence of narrow Afar endemics. To a lesser extent, there are taxa with evolutionary affinities to the eastern Sahara–Sahelian region and to the southern Arabian Peninsula. Compared to the Ethiopian Highlands, the rodent fauna of Afar is relatively poor. However, similarly to highlands, the evolutionary distinctiveness of mammals in the Afar Triangle is very high and it can be considered a unique centre of endemism. Our first comprehensive summary of Afar rodents significantly fills the gap in the knowledge of the mammalian fauna of arid regions in Ethiopia and the Horn of Africa in general and highlights the significance of the region for nature conservation. [ABSTRACT FROM AUTHOR]

Guanylate binding proteins (GBPs) are paramount in the host immunity by providing defense against invading pathogens. Multigene families related to the immune system usually show that the duplicated genes can either undergo deletion, gain new functions, or become non-functional. Here, we show that in muroids, the Gbp genes followed an unusual pattern of gain and loss of genes. Muroids present a high diversity and plasticity regarding Gbp synteny, with most species presenting two Gbp gene clusters. The phylogenetic analyses revealed seven different Gbps groups. Three of them clustered with GBP2 , GBP5 and GBP6 of primates. Four new Gbp genes that appear to be exclusive to muroids were identified as Gbpa , b , c and d. A duplication event occurred in the Gbpa group in the common ancestor of Muridae and Cricetidae (~20 Mya), but both copies were deleted from the genome of Mus musculus , M. caroli and Cricetulus griseus. The Gbpb gene emerged in the ancestor of Muridae and Cricetidae and evolved independently originating Gbpb1 in Muridae, Gbpb2 and Gbpb3 in Cricetidae. Since Gbpc appears only in three species, we hypothesize that it was present in the common ancestor and deleted from most muroid genomes. The second Gbp gene cluster, Gbp6 , is widespread across all muroids, indicating that this cluster emerged before the Muridae and Cricetidae radiation. An expansion of Gbp6 occurred in M. musculus and M. caroli probably to compensate the loss of Gbpa and b. Gbpd is divided in three groups and is present in most muroids suggesting that a duplication event occurred in the common ancestor of Muridae and Cricetidae. However, in Grammomys surdaster and Mus caroli, Gbpd2 is absent, and in Arvicanthis niloticus, Gbpd1 appears to have been deleted. Our results further demonstrated that primate GBP1 , GBP3 and GBP7 are absent from the genome of muroids and showed that the Gbp gene annotations in muroids were incorrect. We propose a new classification based on the phylogenetic analyses and the divergence between the groups. Extrapolations to humans based on functional studies of muroid Gbps should be re-evaluated. The evolutionary analyses of muroid Gbp genes provided new insights about the evolution and function of these genes. [ABSTRACT FROM AUTHOR]

Like passerines among birds, rodents among mammals have experienced an enormous radiation. Similar to songbirds, this radiation is associated with the evolution of a critical innovation in how vocal signals are produced. Recent studies on the anatomical and physiological bases of vocal production provide an opportunity to understand how proximate mechanisms shape acoustic variation to influence signal function and evolution. Acoustic variation ranges from subtle changes within individuals in different social contexts to extreme divergence among closely related species. Despite increased appreciation of this modality, relatively few studies have assessed variability of acoustic features within individuals over time and/or the consequences of such variation. Moreover, our understanding of the mechanisms that promote and constrain acoustic variation is limited. Herein, we review ontogenetic, social and endocrine factors associated with intraspecific acoustic signal variation in murid and cricetid rodents, summarize the functional consequences of such variation and describe morphological and physiological adaptations underlying vocal displays. We then suggest a framework for developing mutually informative mechanistic and functional studies to explore the evolution of signal elaboration. Clarifying the causes and consequences of interspecific and intraspecific acoustic variation is critical to understanding the evolution and function of vocalizations in the largest radiation of mammals. • Rodents exhibit extreme variation in acoustic signal structure. • Intraspecific acoustic variation is often overlooked. • Acoustic variation is associated with ontogenic, social and endocrine factors. • Anatomical and physiological bases of sound production constrain acoustic variation. • Causes and consequences of acoustic variation are important for signal evolution. [ABSTRACT FROM AUTHOR]