8 research outputs found

    Genome-wide analyses suggest parallel selection for universal traits may eclipse local environmental selection in a highly mobile carnivore

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    Ecological and environmental heterogeneity can produce genetic differentiation in highly mobile species. Accordingly, local adaptation may be expected across comparatively short distances in the presence of marked environmental gradients. Within the European continent, wolves (Canis lupus) exhibit distinct north-south population differentiation. We investigated more than 67-K single nucleotide polymorphism (SNP) loci for signatures of local adaptation in 59 unrelated wolves from four previously identified population clusters (northcentral Europe n=32, Carpathian Mountains n=7, Dinaric-Balkan n=9, Ukrainian Steppe n=11). Our analyses combined identification of outlier loci with findings from genome-wide association study of individual genomic profiles and 12 environmental variables. We identified 353 candidate SNP loci. We examined the SNP position and neighboring megabase (1Mb, one million bases) regions in the dog (C. lupus familiaris) genome for genes potentially under selection, including homologue genes in other vertebrates. These regions included functional genes for, for example, temperature regulation that may indicate local adaptation and genes controlling for functions universally important for wolves, including olfaction, hearing, vision, and cognitive functions. We also observed strong outliers not associated with any of the investigated variables, which could suggest selective pressures associated with other unmeasured environmental variables and/or demographic factors. These patterns are further supported by the examination of spatial distributions of the SNPs associated with universally important traits, which typically show marked differences in allele frequencies among population clusters. Accordingly, parallel selection for features important to all wolves may eclipse local environmental selection and implies long-term separation among population clusters.201

    Genetic characterization and population bottleneck in the Hucul horse based on microsatellite and mitochondrial data

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    The aim of this work was to gather information about the origin and genetic characterization of the Central European Hucul horse based on 71 horses using 17 microsatellites and the D-loop region of mtDNA. Their genetic relationship to the Polish Konik (N = 7), German (N = 4) and Hungarian wild Przewalski horses (N = 4) and 200 horse sequences from GenBank was also analysed. Both microsatellite and mtDNA analysis showed a high genetic variation in the Hucul. A total of 130 alleles were detected, the mean number of observed alleles per microsatellite was 7.647, and the number of effective alleles was 4.401. The average observed and expected heterozygosity were 0.706 and 0.747, respectively. The high heterozygosity values and Wright's fixation index (FIS) (−0.128) indicated a low level of inbreeding, low or no selection pressure, and large number of alleles. mtDNA analysis revealed 18 haplotypes for the Hucul population with a total of 23 variable sites. Haplotype and nucleotide diversities were 0.935 ± 0.011 and 0.022 ± 0.012, respectively. Neutrality tests (Tajima's D and Fu's Fs) were non-significant, and mismatch distribution was ragged, indicating that the Hucul population is in genetic equilibrium. The most frequent mtDNA D-loop region belonged to haplogroup A (48%), which was also present in Przewalski Wild horse samples, while Polish Konik samples belonged to three haplotypes and C, F, and G haplogroups. Large and significant pairwise ΊST values along with a small number of common haplotypes indicated a low level of gene flow and lack of genetic structure among the three studied breeds (Hucul, Konik, and Przewalski Wild horse). The present work contributes to our knowledge of the genetic diversity of the Hucul horse and helps to define its genetic conservation. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 54–65

    Unregulated hunting and genetic recovery from a severe population decline: the cautionary case of Bulgarian wolves

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    European wolf (Canis lupus) populations have suffered extensive decline and range contraction due to anthropogenic culling. In Bulgaria, although wolves are still recovering from a severe demographic bottleneck in the 1970s, hunting is allowed with few constraints. A recent increase in hunting pressure has raised concerns regarding long-term viability. We thus carried out a comprehensive conservation genetic analysis using microsatellite and mtDNA markers. Our results showed high heterozygosity levels (0.654, SE 0.031) and weak genetic bottleneck signals, suggesting good recovery since the 1970s decline. However, we found high levels of inbreeding (FIS = 0.113, SE 0.019) and a Ne/N ratio lower than expected for an undisturbed wolf population (0.11, 95 % CI 0.08-0.29). We also found evidence for hybridisation and introgression from feral dogs (C. familiaris) in 10 out of 92 wolves (9.8 %). Our results also suggest admixture between wolves and local populations of golden jackals (C. aureus), but less extensive as compared with the admixture with dogs. We detected local population structure that may be explained by fragmentation patterns during the 1970s decline and differences in local ecological characteristics, with more extensive sampling needed to assess further population substructure. We conclude that high levels of inbreeding and hybridisation with other canid species, which likely result from unregulated hunting, may compromise long-term viability of this population despite its current high genetic diversity. The existence of population subdivision warrants an assessment of whether separate management units are needed for different subpopulations. Our study highlights conservation threats for populations with growing numbers but subject to unregulated hunting. © 2013 The Author(s)

    A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids

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    High-throughput genotyping technologies developed for model species can potentially increase the resolution of demographic history and ancestry in wild relatives. We use a SNP genotyping microarray developed for the domestic dog to assay variation in over 48K loci in wolf-like species worldwide. Despite the high mobility of these large carnivores, we find distinct hierarchical population units within gray wolves and coyotes that correspond with geographic and ecologic differences among populations. Further, we test controversial theories about the ancestry of the Great Lakes wolf and red wolf using an analysis of haplotype blocks across all 38 canid autosomes. We find that these enigmatic canids are highly admixed varieties derived from gray wolves and coyotes, respectively. This divergent genomic history suggests that they do not have a shared recent ancestry as proposed by previous researchers. Interspecific hybridization, as well as the process of evolutionary divergence, may be responsible for the observed phenotypic distinction of both forms. Such admixture complicates decisions regarding endangered species restoration and protection

    Winter temperature and forest cover have shaped red deer distribution in Europe and the Ural Mountains since the Late Pleistocene

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    Aim The Expansion-Contraction model has been used to explain the responses of species to climatic changes. During periods of unfavourable climatic conditions, species retreat to refugia from where they may later expand. This paper focuses on the palaeoecology of red deer over the past 54 ka across Europe and the Urals, to reveal patterns of change in their range and explore the role of environmental conditions in determining their distribution. Location Europe and western Asia to 63 degrees E. Taxon Red deer (Cervus elaphus). Methods We collected 984 records of radiocarbon-dated red deer subfossils from the Late Pleistocene and the Holocene, including 93 original dates. For each deer sample we compiled climatic and biome type data for the corresponding time intervals. Results During the last 54 ka changes in red deer range in Europe and the Urals were asynchronous and differed between western and eastern Europe and western Asia due to different environmental conditions in those regions. The range of suitable areas for deer during the Last Glacial Maximum (LGM) was larger than previously thought and covered vast regions not only in southern but also in western and eastern Europe. Throughout the period investigated the majority of specimens inhabited forests in the temperate climatic zone. The contribution of forests in deer localities significantly decreased during the last 4 ka, due to deforestation of Europe caused by humans. Mean January temperature was the main limiting factor for species distribution. Over 90% of the samples were found in areas where mean January temperature was above -10 degrees C. Main conclusions Red deer response to climatic oscillations are in agreement with the Expansion-Contraction model but in contradiction to the statement of only the southernmost LGM refugia of the species. During the last 54 ka red deer occurred mostly in forests of the temperate climatic zone
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