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To assess the susceptibility of elk (Cervus canadensis) and mule deer (Odocoileus hemionus) to SARS-CoV-2, we performed experimental infections in both species. Elk did not shed infectious virus but mounted low-level serologic responses. Mule deer shed and transmitted virus and mounted pronounced serologic responses and thus could play a role in SARS-CoV-2 epidemiology.

Interspecific pregnancies, in which mares carry horse-donkey hybrid fetuses (mule pregnancies), present physiological challenges distinct from typical horse pregnancies, especially regarding placental development and uterine hemodynamics. While doppler ultrasonography is well-established for assessing uterine artery blood flow in horses, its application in interspecific pregnancies remains limited, creating a gap in reproductive management for mule production programs. This study compared pulsatility (PI) and resistivity (RI) indices of uterine arteries in mares carrying horse (GS, n = 13) or donkey (GD, n = 13) pregnancies throughout gestation, while evaluating effects of maternal age. Using transrectal Doppler ultrasonography (SonoScape S6[R], 3-7MHz), bilateral uterine artery measurements were performed every 15 days until 150 days and monthly thereafter until parturition. Results revealed distinct hemodynamic patterns: GD pregnancies showed delayed peak PI (66-80 days vs GS: 20-35 days) and earlier stabilization (186-215 days vs GS: 306-335 days), suggesting altered placental maturation. A significant age effect was observed, with older mares exhibiting higher RI in the right uterine artery (r = 0.107, P < 0.05). While GS mares showed bilateral PI reduction, GD mares displayed unilateral (left artery) changes, indicating asymmetric adaptation. These findings provided the first reference values for uterine artery indices in interspecific equine pregnancies, demonstrating that standard horse pregnancy parameters cannot be directly applied to donkey pregnancies. The study established Doppler ultrasonography as a valuable tool for monitoring hybrid pregnancies and highlights the need for species-specific management approaches in equine reproduction, particularly for aging mares in mule breeding programs. Future research should investigate molecular mechanisms underlying these hemodynamic differences and explore targeted interventions to optimize pregnancy outcomes. Key words: breeder, donkey, stallion, hemodynamic, interspecific pregnancy. As gestacoes interespecificas, nas quais eguas carregam fetos hibridos de cruzamento entre cavalo e jumento (gestacoes de mulas), apresentam desafios fisiologicos distintos das gestacoes equinas usuais, especialmente no que se refere ao desenvolvimento placentario e a hemodinamica uterina. Embora a ultrassonografia doppler seja amplamente utilizada para avaliar o fluxo sanguineo das arterias uterinas em eguas, sua aplicacao em gestacoes interespecificas ainda e limitada, criando uma lacuna no manejo reprodutivo de programas voltados a producao de mulas. Este estudo teve como objetivo comparar os indices de pulsatilidade (IP) e resistividade (IR) das arterias uterinas em eguas gestantes de cavalos (GS, n = 13) e de jumentos (GD, n = 13) ao longo da gestacao, alem de avaliar os efeitos da idade materna. Utilizando ultrassonografia Doppler transretal (SonoScape S6[R], 3-7 MHz), foram realizadas medicoes bilaterais das arterias uterinas a cada 15 dias ate 150 dias de gestacao e, posteriormente, mensalmente ate o parto. Os resultados revelaram padroes hemodinamicos distintos: as gestacoes GD apresentaram pico de IP tardio (66-80 dias vs. GS: 20-35 dias) e estabilizacao mais precoce (186-215 dias vs. GS: 306-335 dias), sugerindo maturacao placentaria alterada. Observou-se tambem efeito significativo da idade, com eguas mais velhas apresentando maior IR na arteria uterina direita (r = 0,107; P < 0,05). Enquanto as eguas GS mostraram reducao bilateral do IP, as eguas GD exibiram alteracoes unilaterais (na arteria esquerda), indicando adaptacao assimetrica. Esses achados fornecem os primeiros valores de referencia para indices das arterias uterinas em gestacoes equinas interespecificas, demonstrando que parametros utilizados em gestacoes de eguas nao podem ser aplicados diretamente as gestacoes de jumentas. O estudo estabelece a ultrassonografia Doppler como uma ferramenta valiosa para o monitoramento de gestacoes hibridas e destaca a necessidade de abordagens de manejo especificas na reproducao equina, especialmente para eguas mais idosas empregadas em programas de producao de mulas. Pesquisas futuras devem investigar os mecanismos moleculares subjacentes a essas diferencas hemodinamicas e explorar intervencoes direcionadas para otimizar os resultados gestacionais. Palavras-chave: reprodutor, jumento, garanhao, hemodinamica, gestacao interespecifica.

The discovery of genomic imprinting through studies of manipulated mouse embryos indicated that the paternal genome has a major influence on placental development. However, previous research has not demonstrated paternal bias in imprinted genes. We applied RNA sequencing to trophoblast tissue from reciprocal hybrids of horse and donkey, where genotypic differences allowed parent-of-origin identification of most expressed genes. Using this approach, we identified a core group of 15 ancient imprinted genes, of which 10 were paternally expressed. An additional 78 candidate imprinted genes identified by RNA sequencing also showed paternal bias. Pyrosequencing was used to confirm the imprinting status of six of the genes, including the insulin receptor (INSR), which may play a role in growth regulation with its reciprocally imprinted ligand, histone acetyltransferase-1 (HAT1), a gene involved in chromatin modification, and lymphocyte antigen 6 complex, locus G6C, a newly identified imprinted gene in the major histocompatibility complex. The 78 candidate imprinted genes displayed parent-of-origin expression bias in placenta but not fetus, and most showed less than 100% silencing of the imprinted allele. Some displayed variability in imprinting status among individuals. This variability results in a unique epigenetic signature for each placenta that contributes to variation in the intrauterine environment and thus presents the opportunity for natural selection to operate on parent-of-origin differential regulation. Taken together, these features highlight the plasticity of imprinting in mammals and the central importance of the placenta as a target tissue for genomic imprinting.

Increasing ecological perturbations resulting from global change processes are altering the environmental predictability (EP) of critical forage and water resources for wildlife. While research has furthered our understanding of how EP both underlies and directs animal movement, studies have mainly focused on relationships between EP and large-scale movement behaviors (e.g. migration) at the species level, neglecting the mediating influence that environmental context has on the behavior of wide-ranging species. We address these knowledge gaps by examining how EP of forage in mule deer Odocoileus hemionus–a cosmopolitan species of the American southwest–seasonal home ranges relates to average daily movement distance, focusing on two female populations inhabiting disparate ecoregions in Utah, USA (n = 225, 2015-2022). We employed two separate metrics of EP, representing spatial and temporal constancy of vegetation productivity, and explored how home range (HR) area, forage availability, and season modulate the relationships between EP and daily movement distance. We found spatial constancy of an individual's HR significantly impacted movement during the summer and had significant interactions with HR area and forage availability. Interestingly, individuals inhabiting spatially constant HRs moved more in resource-limited seasonal environments, and less in non-limiting environments. Temporal constancy was a significant predictor of movement in non-limiting seasonal environments, resulting in shorter daily movements of deer with temporally constant HR areas. Finally, we found a significant interaction between spatial and temporal constancy, resulting in shorter daily movements of individuals inhabiting resource-limited HRs that were spatially and temporally constant. Interactions between HR area, forage availability, and constancy metrics demonstrate how the EP may become a larger driver of movement decisions as habitat quality is reduced. Understanding how EP drives movement of mule deer aids our ability to predict how global change will impact individual fitness, space use requirements and population demographics of ungulates.

For decades, mule deer Odocoileus hemionus populations have appeared to shrink across their range in North America, while white-tailed deer O. virginianus populations have increased, and their range has expanded. The underlying drivers of these patterns are unclear, and a combination of factors may be at play, including land use changes, climate change, and direct or indirect competition between the two species. Understanding how the two species differentially use the landscape and select habitat would help shed light on the underlying drivers of mule deer decline and highlight opportunities to change population trajectories through habitat management. Using an extensive GPS dataset on mule deer (n = 345) and white-tailed deer (n = 345) in their sympatric range, we used resource selection functions to investigate the relative probability of selection of different resources available to the two species. We estimated population-level relative probability of selection in winter and summer and demonstrated that a combination of factors, including nutrition, thermal cover, and human impact described resource selection better than any single factor on its own, despite annual variation in these metrics. In keeping with long-established patterns, we verified that white-tailed deer had more consistent selection than mule deer for agriculture, higher human modification, road density and tree cover. Across seasons and years, individuals of both species consistently selected for shrubs, perennial forbs and grasses, and steeper slopes. Using our large dataset, we performed out-of-sample validation and demonstrated that although the resource selection functions predicted space use well at the population level, they performed poorly at predicting resource selection between individuals or even within an individual over time. Thus, while we successfully identified key habitat characteristics that were selected differentially by individuals from the two deer species, inferring individual habitat selection and future resource use patterns proved challenging.

In Brazil, the production of gaited mules has been a prominent activity in agribusiness. The selection of gaited saddle mules with a comfortable gait for covering long distances at low speeds involves crossing marching donkeys of the Pêga breeds with horses, preferably those belonging to the Mangalarga Marchador and Campolina breeds. The reference-C and non-reference-A alleles of the DMRT3:g.22999655C>A SNP are linked with different horse gaits, including the batida gait (diagonalized) and the picada gait (lateralized) in Mangalarga Marchador and Campolina horses, respectively. Since donkeys (Equus asinus) and mules (E. asinus ♂ x E. caballus ♀) also exhibit these gaits, this study aimed to determine whether the genotype affects the gait type in these animals. The higher frequency of CA mules and the rare presence of the A allele of DMRT3 in donkeys match previous findings in Mangalarga Marchador and Campolina horses, which are crucial in creating marching mules in Brazil. This suggests that the A allele likely came from the mares used in mating with donkeys. Furthermore, our findings suggest that factors beyond this gene variant, such as other genes and genetic variations, play a role in gait characteristics in equids. In Brazil, the production of mules with a comfortable gait primarily involves the breeding of marching saddle mules. This is achieved by crossing gaited Pêga donkeys with horses from the Mangalarga Marchador and Campolina breeds. The DMRT3:g.22999655C>A SNP is implicated in regulating gait phenotypes observed in various horse breeds, including the batida (CC) and picada (CA) gaits found in these horse breeds. We aimed to determine if genotypes influenced gait type in 159 mules and 203 donkeys genotyped for the DMRT3 SNP by PCR-RFLP analysis. About 47% of mules had the CC-genotype, while 53% had the CA-genotype. Donkeys predominantly had the CC-genotype (97%), and none had AA. Both CC- and CA-genotypes were evenly distributed among mules with the batida or picada gaits. In donkeys, the CC-genotype frequencies were consistent regardless of gait type. However, the CA-genotype was more common in picada-gaited donkeys than in batida-gaited donkeys. The prevalence of CA mules and the rare presence of the non-reference allele in donkeys align with previous findings in Mangalarga Marchador and Campolina horses. This suggests that the non-reference allele likely originated from the mares involved in donkey crosses. Our results also imply that factors beyond this variant, such as other genes and polymorphisms, influence gait traits in equids.

Conserving energy of sensor nodes and ensuring balanced workloads among them are fundamental concerns in Wireless Sensor Network (WSN) design. Clustering strategies offer a promising avenue to minimize node energy consumption, thereby prolonging network lifespan. Nevertheless, numerous multi-hop routing protocols using clustering technique face the challenge of nodes nearer to the Base Station (BS) depleting their energy faster due to forwarding data from the entire network leading to premature node failure and network partitioning known as ‘hotspot problem’. The paper introduces an Energy-Efficient Mega-Cluster-Based Routing (EEMCR) protocol specially designed for expansive coverage area. The primary principle behind designing this protocol is to eliminate the hotspot problem and restrict the transmission range of nodes to the threshold distance defined by the radio energy model, thereby enhancing the overall network lifespan. The protocol adopts a centralized approach employing fixed clustering wherein the BS partitions the network into square-shaped clusters. The cluster size is determined by the threshold transmission range of the sensor radio energy model, guaranteeing that all network communication stays within this threshold distance. Four such clusters form a mega-cluster with a Mega-Cluster-Head (MCH) elected among the four Cluster Heads (CHs). The MCH role is evenly distributed among nodes of all four clusters in subsequent rounds for uniform distribution of its overhead. Implementing data aggregation at two levels (CH level as well as MCH level) leads to reduced data traffic and energy consumption throughout the network. Moreover, data collection by two data mules based on odd–even round number ensures balanced data traffic and energy distribution across the network. Analysis indicates that the proposed protocol effectively mitigates the hot-spot problem and reduces data transmission overhead of sensor nodes. In simulation, the proposed protocol on an average improves network life by 34.5%, 23.5%, 14.5% and 5.5% as compared to existing protocols FCEEC, DBSCAN, LPGCR and FBECS respectively for deployment of nodes between 600 to 1200. Also, approximately 46%, 32%, 21% and 14% of lesser sensor nodes are dead for proposed protocol in respective rounds as compared to existing protocols FCEEC, DBSCAN, LPGCR and FBECS respectively. Comparative evaluations demonstrate improved network lifetime when compared to equivalent recent routing protocols.

The migratory movements of wild animals can promote abundance and support ecosystem functioning. For large herbivores, mounting evidence suggests that migratory behaviour is an individually variable trait, where individuals can easily switch between migrant and resident tactics. The degree of migratory plasticity, including whether and where to migrate, has important implications for the ecology and conservation of large herbivores in a changing world. Mule deer (Odocoileus hemionus) are an iconic species of western North America, but are notably absent from the body of literature that suggests large herbivore migrations are highly plastic. We evaluated plasticity of migration in female mule deer using longitudinal GPS data collected from 312 individuals across nine populations in the western United States, including 882 animal‐years (801 migrants and 81 residents). We followed both resident and migratory mule deer through time to determine whether individual animals switched migratory behaviours (i.e., whether to migrate) from migratory to residency or vice versa. Additionally, we examined the fidelity of individuals to their migration routes (i.e., where to migrate) to determine whether they used the same routes year after year. We also evaluated whether age and reproductive status affected propensity to migrate or fidelity to migratory routes. Our results indicate that mule deer, unlike other large herbivores, have little or no plasticity in terms of whether or where they migrate. Resident deer remained residents, and migrant deer remained migrants, regardless of age, reproductive status or number of years monitored. Further, migratory individuals showed strong fidelity (>80%) to their migration routes year after year. Our study clearly shows that migration plasticity is not ubiquitous among large herbivores. Because of their rigid migratory behaviour, mule deer may not adapt to changing environmental conditions as readily as large herbivores with more plastic migratory behaviour (e.g., elk). The fixed migratory behaviours of mule deer make clear that conservation efforts aimed at traditional seasonal ranges and migration routes are warranted for sustaining this iconic species that continues to decline across its range. This study reveals that mule deer, unlike many other large herbivores, have little or no plasticity in terms of whether or where they migrate. The authors found resident deer remained residents, and migrant deer remained migrants, regardless of age, reproductive status or number of years monitored.

Effective mortality thresholds are critical for timely reporting and management of highly pathogenic avian influenza. Using standard modelling techniques, we evaluated the performance of different mortality thresholds in mule duck flocks. Using an eightfold increase of the mortality for two consecutive days compared to the average mortality the previous week led to a perfect classification of all flocks used for validation (12 affected and 18 non-affected flocks). A fixed daily threshold of 0.25% showed a perfect sensitivity and a good specificity (3 false positives/18). Our results fill a knowledge gap and can inform HPAI surveillance policy in non-vaccinated mule ducks.