RESUMEN
Adult mammalian skin wounds heal by forming fibrotic scars. We report that full-thickness injuries of reindeer antler skin (velvet) regenerate, whereas back skin forms fibrotic scar. Single-cell multi-omics reveal that uninjured velvet fibroblasts resemble human fetal fibroblasts, whereas back skin fibroblasts express inflammatory mediators mimicking pro-fibrotic adult human and rodent fibroblasts. Consequently, injury elicits site-specific immune responses: back skin fibroblasts amplify myeloid infiltration and maturation during repair, whereas velvet fibroblasts adopt an immunosuppressive phenotype that restricts leukocyte recruitment and hastens immune resolution. Ectopic transplantation of velvet to scar-forming back skin is initially regenerative, but progressively transitions to a fibrotic phenotype akin to the scarless fetal-to-scar-forming transition reported in humans. Skin regeneration is diminished by intensifying, or enhanced by neutralizing, these pathologic fibroblast-immune interactions. Reindeer represent a powerful comparative model for interrogating divergent wound healing outcomes, and our results nominate decoupling of fibroblast-immune interactions as a promising approach to mitigate scar.
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Reno , Cicatrización de Heridas , Adulto , Animales , Humanos , Cicatriz/patología , Fibroblastos/patología , Trasplante de Piel , Piel/patología , Feto/patologíaRESUMEN
We investigated Alongshan virus infection in reindeer in northeastern China. We found that 4.8% of the animals were viral RNA-positive, 33.3% tested positive for IgG, and 19.1% displayed neutralizing antibodies. These findings suggest reindeer could serve as sentinel animal species for the epidemiologic surveillance of Alongshan virus infection.
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Anticuerpos Antivirales , Reno , Animales , Reno/virología , China/epidemiología , Anticuerpos Antivirales/sangre , Anticuerpos Neutralizantes/sangre , Infecciones por Bunyaviridae/veterinaria , Infecciones por Bunyaviridae/epidemiología , Infecciones por Bunyaviridae/virología , ARN Viral , Inmunoglobulina G/sangreRESUMEN
Overharvest can severely reduce the abundance and distribution of a species and thereby impact its genetic diversity and threaten its future viability. Overharvest remains an ongoing issue for Arctic mammals, which due to climate change now also confront one of the fastest changing environments on Earth. The high-arctic Svalbard reindeer (Rangifer tarandus platyrhynchus), endemic to Svalbard, experienced a harvest-induced demographic bottleneck that occurred during the 17-20th centuries. Here, we investigate changes in genetic diversity, population structure, and gene-specific differentiation during and after this overharvesting event. Using whole-genome shotgun sequencing, we generated the first ancient and historical nuclear (n = 11) and mitochondrial (n = 18) genomes from Svalbard reindeer (up to 4000 BP) and integrated these data with a large collection of modern genome sequences (n = 90) to infer temporal changes. We show that hunting resulted in major genetic changes and restructuring in reindeer populations. Near-extirpation followed by pronounced genetic drift has altered the allele frequencies of important genes contributing to diverse biological functions. Median heterozygosity was reduced by 26%, while the mitochondrial genetic diversity was reduced only to a limited extent, likely due to already low pre-harvest diversity and a complex post-harvest recolonization process. Such genomic erosion and genetic isolation of populations due to past anthropogenic disturbance will likely play a major role in metapopulation dynamics (i.e., extirpation, recolonization) under further climate change. Our results from a high-arctic case study therefore emphasize the need to understand the long-term interplay of past, current, and future stressors in wildlife conservation.
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Reno , Animales , Reno/genética , Animales Salvajes , Frecuencia de los Genes , Flujo Genético , SvalbardRESUMEN
Chronic wasting disease (CWD), a prion disease affecting cervids, has been known in North America (NA) since the 1960s and emerged in Norway in 2016. Surveillance and studies have revealed that there are different forms of CWD in Fennoscandia: contagious CWD in Norwegian reindeer and sporadic CWD in moose and red deer. Experimental studies have demonstrated that NA CWD prions can infect various species, but thus far, there have been no reports of natural transmission to non-cervid species. In vitro and laboratory animal studies of the Norwegian CWD strains suggest that these strains are different from the NA strains. In this work, we describe the intracerebral transmission of reindeer CWD to six scrapie-susceptible sheep. Detection methods included immunohistochemistry (IHC), western blot (WB), enzyme-linked immunosorbent assay (ELISA), real-time quaking-induced conversion (RT-QuIC) and protein misfolding cyclic amplification (PMCA). In the brain, grey matter vacuolation was limited, while all sheep exhibited vacuolation of the white matter. IHC and WB conventional detection techniques failed to detect prions; however, positive seeding activity with the RT-QuIC and PMCA amplification techniques was observed in the central nervous system of all but one sheep. Prions were robustly amplified in the lymph nodes of all animals, mainly by RT-QuIC. Additionally, two lymph nodes were positive by WB, and one was positive by ELISA. These findings suggest that sheep can propagate reindeer CWD prions after intracerebral inoculation, resulting in an unusual disease phenotype and prion distribution with a low amount of detectable prions.
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Priones , Reno , Enfermedad Debilitante Crónica , Animales , Enfermedad Debilitante Crónica/transmisión , Ovinos , Priones/metabolismo , Noruega , Encéfalo/metabolismo , Fenotipo , Enfermedades de las Ovejas/transmisiónRESUMEN
In September 2020, an outbreak of epizootic hemorrhagic disease occurred in captive reindeer (Rangifer tarandus) and was associated with neurological signs and mortality. Four reindeer died or were euthanized after acute illness over a 12-day period. Affected reindeer displayed abnormal behavior, neurologic signs, lethargy, and/or lameness. The most consistent gross finding was dark red streaks throughout the adrenal gland cortices (4/4). One animal had acute hemorrhage involving the subcutis and skeletal muscles over the ventrolateral body wall and back, and abomasal serosa. Histologically, the most common lesions were adrenal gland cortical hemorrhage (4/4) with necrosis (3/4) and lymphoplasmacytic meningoencephalitis with gliosis, glial nodules, satellitosis, and nonsuppurative perivascular cuffing (4/4). The brain lesions were most frequent in the gray matter of the cerebrum, hippocampus, and thalamus but also involved the cerebellum and brainstem. Epizootic hemorrhagic disease virus serotype 6 was detected through PCR and sequencing of the spleen in all cases.
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Reno , Animales , Hemorragia/epidemiología , Hemorragia/veterinaria , Necrosis/veterinaria , Glándulas Suprarrenales , Brotes de Enfermedades/veterinariaRESUMEN
Prion diseases, including chronic wasting disease (CWD) in cervids, are fatal neurodegenerative disorders caused by the misfolding of cellular prion proteins. CWD is known to spread among captive and free-ranging deer in North America. In 2016, an outbreak of contagious CWD was detected among wild reindeer in Norway, marking the first occurrence of the disease in Europe. Additionally, new sporadic forms of CWD have been discovered in red deer in Norway and moose in Fennoscandia. We used serial protein misfolding cyclic amplification to study the ability of Norwegian prion isolates from reindeer, red deer, and moose (two isolates), as well as experimental classical scrapie from sheep, to convert a panel of 16 brain homogenates (substrates) from six different species with various prion protein genotypes. The reindeer CWD isolate successfully converted substrates from all species except goats. The red deer isolate failed to convert sheep and goat substrates but exhibited amplification in all cervid substrates. The two moose isolates demonstrated lower conversion efficacies. The wild type isolate propagated in all moose substrates and in the wild type red deer substrate, while the other isolate only converted two of the moose substrates. The experimental classical scrapie isolate was successfully propagated in substrates from all species tested. Thus, reindeer CWD and classical sheep scrapie isolates were similarly propagated in substrates from different species, suggesting the potential for spillover of these contagious diseases. Furthermore, the roe deer substrate supported conversion of three isolates suggesting that this species may be vulnerable to prion disease.
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Ciervos , Enfermedades de las Cabras , Enfermedades por Prión , Priones , Reno , Scrapie , Enfermedades de las Ovejas , Enfermedad Debilitante Crónica , Animales , Ovinos , Priones/genética , Reno/metabolismo , Enfermedades por Prión/veterinaria , Proteínas Priónicas/genética , Proteínas Priónicas/metabolismo , Enfermedad Debilitante Crónica/genética , Noruega/epidemiología , Cabras/metabolismoRESUMEN
Wild and semidomesticated reindeer are one of the key species in Arctic and subarctic areas, and their population dynamics are closely tied to winter conditions. Difficult snow conditions have been found to decrease the calving success and survivability of reindeer, but the economic effects of variation in winter conditions on reindeer husbandry have not been studied. In this study, we combine state-of-the-art economic-ecological modeling with the analysis of annual reindeer management reports from Finland. These contain local knowledge of herding communities. We quantify the occurrence probabilities of different types of winters from annual management reports and analyze the effects of this variation in winter conditions on reindeer husbandry using an age- and sex-structured bioeconomic reindeer-lichen model. Our results show that difficult winters decrease the net revenues of reindeer husbandry. However, they also protect lichen pastures from grazing, thereby increasing future net revenues. Nonetheless, our solutions show that the variability of winter conditions overall decrease the net income of herders compared to constant winter conditions. Low lichen biomass appears to make reindeer management more sensitive to the effects of difficult winter conditions. We also found that it is economically sensible to use supplementary feeding during difficult winters, but the net revenues still decrease compared to average winters because of the high feeding costs. Overall, our analysis suggests that the increasing variability of winter conditions due to climate change will decrease net revenues in reindeer husbandry. This decrease will still occur even if the most extreme effects of climate change do not occur. This study shows that combining a state-of-the-art bioeconomic model and practitioner knowledge can bring compatible insights, ideas, results, and a bottom-up perspective to the discussion.
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Cambio Climático , Reno , Animales , Finlandia , Líquenes , Estaciones del Año , Nieve , Crianza de Animales Domésticos/economía , Crianza de Animales Domésticos/normasRESUMEN
AIMS: This study aimed to compare the concentrations of heavy metals in reindeer and cow meat and offal originating from the Nenets Autonomous Okrug, Northwestern Russia, and to assess the risk to the health of the indigenous population associated with heavy metal intake due to the consumption of reindeer and cow. METHODS: Lead, cadmium, mercury, and arsenic concentrations were measured in 39 muscle, 15 liver, and 14 kidney samples from reindeer and 33, 18, and 12 corresponding samples from cow in 2014-2016 using atomic absorption spectrometry. Estimated daily intake of investigated heavy metals, hazard quotient, hazard index and cancer risk were calculated. RESULTS: Mean cadmium and mercury concentrations in reindeer liver and kidney exceeded the maximum permissible levels for bovine animals. However, the estimated daily intakes of heavy metals through consumption of reindeer and cow meat and offal were lower than tolerable daily intakes. Hazard quotient and hazard index values for heavy metals in reindeer and cow samples were <1. Hazard index values were in descending order: reindeer kidney (0.389)>reindeer muscle (0.382)>cow muscle (0.088)>reindeer liver (0.051)>cow kidney (0.012)>cow liver (0.004). The cancer risk related to the consumption of reindeer and cow meat and offal did not exceed acceptable levels. CONCLUSIONS: There is no human health risk associated with heavy metal intake due to the consumption of reindeer and cow meat and offal originating from the Nenets Autonomous Okrug.
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Mercurio , Metales Pesados , Neoplasias , Reno , Femenino , Humanos , Bovinos , Animales , Cadmio/análisis , Metales Pesados/análisis , Mercurio/análisis , Medición de Riesgo , Carne/análisis , Contaminación de Alimentos/análisisRESUMEN
First stage larvae of an unknown lungworm (Protostrongylidae) were isolated in the feces of a wild reindeer (Rangifer tarandus) from Taimyr, Russia. Larvae were 365-366 µm long and had a tail spike lacking a dorsal spine. DNA analyses using BLAST showed that nuclear sequences obtained (LSU rDNA, 825 bp and ITS2 rDNA, 395 bp) were highly similar (99.50% and 98.88% identity, respectively) to an isolate of Orthostrongylus macrotis (GenBank: EU595592.1) from North America. It cannot be confirmed whether these larvae represent an uncharacterized species of Orthostrongylus or can be referred to O. macrotis, a species that has historically only been reported from the Nearctic. This is the first report of lungworms attributable to Protostrongylinae in R. tarandus across its vast geographic in the Holarctic.
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Metastrongyloidea , Parásitos , Reno , Animales , Reno/parasitología , Parásitos/genética , Federación de Rusia , Metastrongyloidea/genética , Larva , ADN RibosómicoRESUMEN
For the first time, information is provided on the size of the home range of Siberian forest reindeer (Rangifer tarandus valentinae) of the Altai-Sayan population of Kuznetsk Alatau, the minimum distance that the deer passes per day, their changes, and changes of habitats during the annual cycle. Possible reasons for the cyclical use of the habitat by forest reindeer are discussed.
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Ciervos , Reno , Animales , BosquesRESUMEN
Chronic wasting disease (CWD) is the transmissible spongiform encephalopathy or prion disease affecting cervids. In 2016, the first cases of CWD were reported in Europe in Norwegian wild reindeer and moose. The origin and zoonotic potential of these new prion isolates remain unknown. In this study to investigate zoonotic potential we inoculated brain tissue from CWD-infected Norwegian reindeer and moose into transgenic mice overexpressing human prion protein. After prolonged postinoculation survival periods no evidence for prion transmission was seen, suggesting that the zoonotic potential of these isolates is low.
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Ciervos , Priones , Reno , Enfermedad Debilitante Crónica , Animales , Ciervos/metabolismo , Humanos , Ratones , Ratones Transgénicos , Noruega , Priones/genética , Priones/metabolismo , Reno/metabolismo , Enfermedad Debilitante Crónica/genéticaRESUMEN
Arctic ecosystems are changing dramatically with warmer and wetter conditions resulting in complex interactions between herbivores and their forage. We investigated how Svalbard reindeer (Rangifer tarandus platyrhynchus) modify their late winter diets in response to long-term trends and interannual variation in forage availability and accessibility. By reconstructing their diets and foraging niches over a 17-year period (1995-2012) using serum δ13 C and δ15 N values, we found strong support for a temporal increase in the proportions of graminoids in the diets with a concurrent decline in the contributions of mosses. This dietary shift corresponds with graminoid abundance increases in the region and was associated with increases in population density, warmer summer temperatures and more frequent rain-on-snow (ROS) in winter. In addition, the variance in isotopic niche positions, breadths, and overlaps also supported a temporal shift in the foraging niche and a dietary response to extreme ROS events. Our long-term study highlights the mechanisms by which winter and summer climate changes cascade through vegetation shifts and herbivore population dynamics to alter the foraging niche of Svalbard reindeer. Although it has been anticipated that climate changes in the Svalbard region of the Arctic would be detrimental to this unique ungulate, our study suggests that environmental change is in a phase where conditions are improving for this subspecies at the northernmost edge of the Rangifer distribution.
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Reno , Animales , Reno/fisiología , Svalbard , Ecosistema , Especies Reactivas de Oxígeno , Estaciones del Año , Regiones Árticas , Dieta , Cambio ClimáticoRESUMEN
BACKGROUND: Mosquito-borne viruses pose a serious threat to humans worldwide. There has been an upsurge in the number of mosquito-borne viruses in Europe, mostly belonging to the families Togaviridae, genus Alphavirus (Sindbis, Chikungunya), Flaviviridae (West Nile, Usutu, Dengue), and Peribunyaviridae, genus Orthobunyavirus, California serogroup (Inkoo, Batai, Tahyna). The principal focus of this study was Inkoo (INKV) and Sindbis (SINV) virus circulating in Norway, Sweden, Finland, and some parts of Russia. These viruses are associated with morbidity in humans. However, there is a knowledge gap regarding reservoirs and transmission. Therefore, we aimed to determine the prevalence of INKV and SINV in blood sucking insects and seroprevalence for INKV in semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) in Norway. MATERIALS AND METHODS: In total, 213 pools containing about 25 blood sucking insects (BSI) each and 480 reindeer sera were collected in eight Norwegian reindeer summer pasture districts during 2013-2015. The pools were analysed by RT-PCR to detect INKV and by RT-real-time PCR for SINV. Reindeer sera were analysed for INKV-specific IgG by an Indirect Immunofluorescence Assay (n = 480, IIFA) and a Plaque Reduction Neutralization Test (n = 60, PRNT). RESULTS: Aedes spp. were the most dominant species among the collected BSI. Two of the pools were positive for INKV-RNA by RT-PCR and were confirmed by pyrosequencing. The overall estimated pool prevalence (EPP) of INKV in Norway was 0.04%. None of the analysed pools were positive for SINV. Overall IgG seroprevalence in reindeer was 62% positive for INKV by IIFA. Of the 60 reindeer sera- analysed by PRNT for INKV, 80% were confirmed positive, and there was no cross-reactivity with the closely related Tahyna virus (TAHV) and Snowshoe hare virus (SSHV). CONCLUSION: The occurrence and prevalence of INKV in BSI and the high seroprevalence against the virus among semi-domesticated reindeer in Norway indicate that further studies are required for monitoring this virus. SINV was not detected in the BSI in this study, however, human cases of SINV infection are yearly reported from other regions such as Rjukan in south-central Norway. It is therefore essential to monitor both viruses in the human population. Our findings are important to raise awareness regarding the geographical distribution of these mosquito-borne viruses in Northern Europe.
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Aedes , Virus de la Encefalitis de California , Flavivirus , Reno , Animales , Virus de la Encefalitis de California/genética , Inmunoglobulina G , Noruega/epidemiología , Estudios Seroepidemiológicos , Virus Sindbis/genética , TundraRESUMEN
The cost of reproduction on demographic rates is often assumed to operate through changing body condition. Several studies have found that reproduction depresses body mass more if the current conditions are severe, such as high population densities or adverse weather, than under benign environmental conditions. However, few studies have investigated the association between the fitness components and body mass costs of reproduction. Using 25 years of individual-based capture-recapture data from Svalbard reindeer Rangifer tarandus platyrhynchus, we built a novel Bayesian state-space model that jointly estimated interannual change in mass, annual reproductive success and survival, while accounting for incomplete observations. The model allowed us to partition the differential effects of intrinsic and extrinsic factors on both non-reproductive mass change and the body mass cost of reproduction, and to quantify their consequences on demographic rates. Contrary to our expectation, the body mass cost of reproduction (mean = -5.8 kg) varied little between years (CV = 0.08), whereas the between-year variation in body mass changes, that were independent of the previous year's reproductive state, varied substantially (CV = 0.4) in relation to autumn temperature and the amount of rain-on-snow in winter. This body mass loss led to a cost of reproduction on the next reproduction, which was amplified by the same environmental covariates, from a 10% reduction in reproductive success in benign years, to a 50% reduction in harsh years. The reproductive mass loss also resulted in a small reduction in survival. Our results show how demographic costs of reproduction, driven by interannual fluctuations in individual body condition, result from the balance between body mass costs of reproduction and body mass changes that are independent of previous reproductive state. We illustrate how a strong context-dependent fitness cost of reproduction can occur, despite a relatively fixed body mass cost of reproduction. This suggests that female reindeer display a very conservative energy allocation strategy, either aborting their reproductive attempt at an early stage or weaning at a relatively constant cost. Such a strategy might be common in species living in a highly stochastic and food limited environment.
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Herbivoria , Reno , Animales , Regiones Árticas , Teorema de Bayes , Femenino , Reproducción , Estaciones del AñoRESUMEN
Global temperatures are increasing, affecting timing and availability of vegetation along with relationships between plants and their consumers. We examined the effect of population density, herd body condition in the previous year, elevation, plant productivity and phenology, snow, and winter onset on juvenile body mass in 63 semi-domesticated populations of Rangifer tarandus throughout Norway using spatiotemporal generalized additive models (GAMs) and varying coefficient models (VCMs). Optimal climate windows were calculated at both the regional and national level using a novel nonlinear climate window algorithm optimized for prediction. Spatial and temporal variation in effects of population and environmental predictors were considered using a model including covariates decomposed into spatial, temporal, and residual components. The performance of this decomposed model was compared to spatiotemporal GAMs and VCMs. The decomposed model provided the best fit and lowest prediction errors. A positive effect of herd body condition in the previous year explained most of the deviance in calf body mass, followed by a more complex effect of population density. A negative effect of timing of spring and positive effect of winter onset on juvenile body mass suggested that a snow free season was positive for juvenile body mass growth. Our findings suggest early spring onset and later winter permanent snow cover as reinforcers of early-life conditions which support more robust reindeer populations. Our methodological improvements for climate window analyses and effect size measures for decomposed variables provide important contributions to account for, measure, and interpret nonlinear relationships between climate and animal populations at large scales.
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Cambio Climático , Reno , Animales , Regiones Árticas , Herbivoria , Plantas , Estaciones del Año , NieveRESUMEN
OBJECTIVE: To investigate the pharmacokinetics of orally and intravenously (IV) administered meloxicam in semi-domesticated reindeer (Rangifer tarandus tarandus). STUDY DESIGN: A crossover design with an 11 day washout period. ANIMALS: A total of eight young male reindeer, aged 1.5-2.5 years and weighing 74.3 ± 6.3 kg, mean ± standard deviation. METHODS: The reindeer were administered meloxicam (0.5 mg kg-1 IV or orally). Blood samples were repeatedly collected from the jugular vein for up to 72 hours post administration. Plasma samples were analysed for meloxicam concentrations with ultraperformance liquid chromatography combined with triple quadrupole mass spectrometry. Noncompartmental analysis for determination of pharmacokinetic variables was performed. RESULTS: The pharmacokinetic values, median (range), were determined. Elimination half-life (t½) with the IV route (n = 4) was 15.2 (13.2-16.8) hours, the volume of distribution at steady state was 133 (113-151) mL kg-1 and clearance was 3.98 (2.63-5.29) mL hour-1 kg-1. After oral administration (n = 7), the peak plasma concentration (Cmax) was detected at 6 hours, t½ was 19.3 (16.7-20.5) hours, Cmax 1.82 (1.17-2.78) µg mL-1 and bioavailability (n = 3) 49 (46-73)%. No evident adverse effects were detected after either administration route. CONCLUSIONS AND CLINICAL RELEVANCE: A single dose of meloxicam (0.5 mg kg-1 IV or orally) has the potential to maintain the therapeutic concentration determined in other species for up to 3 days in reindeer plasma.
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Reno , Administración Oral , Animales , Área Bajo la Curva , Disponibilidad Biológica , Semivida , Masculino , MeloxicamRESUMEN
New data on the diet of the wild reindeer (Rangifer tarandus pearsoni) on the Yuzhny Island of the Novaya Zemlya archipelago in the summer are presented. The coprological method shows the predominance of vascular plants in the studied samples of reindeer feces. The selectivity of reindeer in relation to pasture habitats and forage groups of plants indicates that the area and variety of forage lands in the summer are sufficient for the reindeer and are not limiting factors for it.
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Reno , Animales , Dieta , Estaciones del AñoRESUMEN
Founder populations are of special interest to both evolutionary and conservation biologists, but the detection of genetic signals of selection in these populations is challenging due to their demographic history. Geographically separated founder populations likely to have been subjected to similar selection pressures provide an ideal but rare opportunity to overcome these challenges. Here we take advantage of such a situation generated when small, isolated founder populations of reindeer were established on the island of South Georgia, and using this system we look for empirical evidence of selection overcoming strong genetic drift. We generated a 70 k ddRADseq single nucleotide polymorphism database for the two parallel reindeer founder populations and screened for signatures of soft sweeps. We find evidence for a genomic region under selection shared among the two populations, and support our findings with Wright-Fisher model simulations to assess the power and specificity of interpopulation selection scans-namely Bayescan, OutFLANK, PCadapt and a newly developed scan called Genome Wide Differentiation Scan (GWDS)-in the context of pairwise source-founder comparisons. Our simulations indicate that loci under selection in small founder populations are most probably detected by GWDS, and strengthen the hypothesis that the outlier region represents a true locus under selection. We explore possible, relevant functional roles for genes in linkage with the detected outlier loci.
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Genética de Población , Reno , Animales , Flujo Genético , Islas , Polimorfismo de Nucleótido Simple , Reno/genética , Selección GenéticaRESUMEN
The boreal forest consists of drier sunlit and moister-shaded habitats with varying moss abundance. Mosses control vascular plant-soil interactions, yet they all can also be altered by grazers. We determined how 2 decades of reindeer (Rangifer tarandus) exclusion affect feather moss (Pleurozium schreberi) depth, and the accompanying soil N dynamics (total and dissolvable inorganic N, δ15N), plant foliar N, and stable isotopes (δ15N, δ13C) in two contrasting habitats of an oligotrophic Scots pine forest. The study species were pine seedling (Pinus sylvestris L.), bilberry (Vaccinium myrtillus L.), lingonberry (V. vitis-idaea L.), and feather moss. Moss carpet was deeper in shaded than sunlit habitats and increased with grazer exclusion. Humus N content increased in the shade as did humus δ15N, which also increased due to exclusion in the sunlit habitats. Exclusion increased inorganic N concentration in the mineral soil. These soil responses were correlated with moss depth. Foliar chemistry varied due to habitat depending on species identity. Pine seedlings showed higher foliar N content and lower foliar δ15N in the shaded than in the sunlit habitats, while bilberry had both higher foliar N and δ15N in the shade. Thus, foliar δ15N values of co-existing species diverged in the shade indicating enhanced N partitioning. We conclude that despite strong grazing-induced shifts in mosses and subtler shifts in soil N, the N dynamics of vascular vegetation remain unchanged. These indicate that plant-soil interactions are resistant to shifts in grazing intensity, a pattern that appears to be common across boreal oligotrophic forests.
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Briófitas , Suelo , Ecosistema , Nitrógeno , TaigaRESUMEN
Forest owners and Indigenous Sami reindeer herders use the same land in northern Sweden for commercial forestry and winter grazing, respectively. Fire management has been controlled by foresters since the late-19th century, and Sami herders have had to deal with the effects of both fire suppression and prescribed burning. However, the environmental history of fire management and reindeer herding in Sweden has never been thoroughly investigated. We therefore analyzed written archives in order to understand how reindeer herding was considered in planned burning during the mid-20th century, and how the effects of prescribed burning on reindeer herding were interpreted by foresters. We supplemented the interpretation of written sources by including local Sami reindeer herders' insights about prescribed burning. Written records show that reindeer herding was increasingly integrated into the planning process during the 20th century, yet foresters failed to include important aspects of reindeer herding in their interpretation of the effects of prescribed burning. The Sami consider the effects of burning in terms of fodder availability, opportunities for reindeer to graze the fodder, and any impact on the reindeer's movement patterns and thus herd management. The Sami's historical perspective is essential in order to reconstruct a comprehensive picture of the past, and adapt forestry measures effectively in the future.