52 research outputs found

    Purging of deleterious burden in the endangered Iberian lynx

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    Deleterious mutations continuously accumulate in populations, building up a burden that can threaten their survival, particularly in small populations when inbreeding exposes recessive deleterious effects. Notwithstanding, this process also triggers genetic purging, which can reduce the deleterious burden and mitigate fitness inbreeding depression. Here, we analyzed 20 whole genomes from the endangered Iberian lynx and 28 from the widespread Eurasian lynx, sister species which constitute a good model to study the dynamics of deleterious mutation burden under contrasting demographies, manifested in the consistently smaller population size and distribution area of the Iberian lynx. We also derived analytical predictions for the evolution of the deleterious burden following a bottleneck. We found 11% fewer derived alleles for the more putatively deleterious missense category in the Iberian lynx than in the Eurasian lynx, which, in light of our theoretical predictions, should be ascribed to historical purging. No signs of purging were found in centromeres nor in the X chromosome, where selection against recessive deleterious alleles is less affected by demography. The similar deleterious burden levels for conspecific populations despite their contrasting recent demographies also point to sustained differences in historical population sizes since species divergence as the main driver of the augmented purging in the Iberian lynx. Beyond adding to the ongoing debate on the relationship between deleterious burden and population size, and on the impact of genetic factors in endangered species viability, this work contributes a whole-genome catalog of deleterious variants, which may become a valuable resource for future conservation efforts

    Mitochondrial Genetic Diversity and Phylogenetic Relationships of Siberian Flying Squirrel (Pteromys volans) Populations

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    Siberian flying squirrel, an endangered species in South Korea, is distributed through major mountain regions of South Korea. The number of Siberian flying squirrel (Pteromys volans) in South Korea has decreased and their habitats are fragmented and isolated because of anthropogenic activities. So far no molecular genetic data has, however, been available for their conservation and management. To obtain better information concerning genetic diversity and phylogenetic relationships of the Siberian flying squirrel in South Korea, we examined 14 individuals from South Korea, 7 individuals from Russia, and 5 individuals from northeastern China along with previously published 29 haplotypes for 1,140 bp of the mtDNA cytochrome b gene. The 14 new individuals from South Korea had 7 haplotypes which were not observed in the regions of Russia and Hokkaido. The level of genetic diversity (0.616%) in the South Korean population was lower than that in eastern Russia (0.950%). The geographical distribution of mtDNA haplotypes and reduced median network confirmed that there are three major lineages of Siberian flying squirrel, occupying; Far Eastern, northern Eurasia, and the island of Hokkaido. The South Korean population only slightly distinct from the Eurasia, and eastern Russian population, and is part of the lineage Far Eastern. Based on these, we suggest that the South Korean population could be considered to belong to one partial ESU (Far Eastern) of three partial ESUs but a different management unit. However, the conservation priorities should be reconfirmed by nuclear genetic marker and ecological data.We would like to express special thanks to everyone who kindly provided samples to Conservation Genome Resource Bank for Korean wildlife. The manuscript was greatly improved by the comments of Warren E. Johnson at National Cancer Institute, USA and Tatduo Oshida at Obihiro University of Agriculture and Veterinary Medicine, Japan. This study was partially supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD; KRF-2007-C00193-I00755), BK21 program for Veterinary Science, Seoul National University and National Institute of Biological Resources, Korea and a year-2008 grant of National Institute of Biological Resources (Research title: The genetic evaluation of important biological resources; No. 074-1800-1844-304)

    Coat Polymorphism in Eurasian Lynx: Adaptation to Environment or Phylogeographic Legacy?

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    We studied the relationship between the variability and contemporary distribution of pelage phenotypes in one of most widely distributed felid species and an array of environmental and demographic conditions. We collected 672 photographic georeferenced records of the Eurasian lynx throughout Eurasia. We assigned each lynx coat to one of five phenotypes. Then we fitted the coat patterns to different environmental and anthropogenic variables, as well as the effective geographic distances from inferred glacial refugia. A majority of lynx were either of the large spotted (41.5%) or unspotted (uniform, 36.2%) phenotype. The remaining patterns (rosettes, small spots and pseudo-rosettes) were represented in 11.0%, 7.4%, and 3.9% of samples, respectively. Although various environmental variables greatly affected lynx distribution and habitat suitability, it was the effect of least-cost distances from locations of the inferred refugia during the Last Glacial Maximum that explained the distribution of lynx coat patterns the best. Whereas the occurrence of lynx phenotypes with large spots was explained by the proximity to refugia located in the Caucasus/Middle East, the uniform phenotype was associated with refugia in the Far East and Central Asia. Despite the widely accepted hypothesis of adaptive functionality of coat patterns in mammals and exceptionally high phenotypic polymorphism in Eurasian lynx, we did not find well-defined signs of habitat matching in the coat pattern of this species. Instead, we showed how the global patterns of morphological variability in this large mammal and its environmental adaptations may have been shaped by past climatic change.publishedVersio

    Brown bear attacks on humans : a worldwide perspective

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    The increasing trend of large carnivore attacks on humans not only raises human safety concerns but may also undermine large carnivore conservation efforts. Although rare, attacks by brown bears Ursus arctos are also on the rise and, although several studies have addressed this issue at local scales, information is lacking on a worldwide scale. Here, we investigated brown bear attacks (n = 664) on humans between 2000 and 2015 across most of the range inhabited by the species: North America (n = 183), Europe (n = 291), and East (n = 190). When the attacks occurred, half of the people were engaged in leisure activities and the main scenario was an encounter with a female with cubs. Attacks have increased significantly over time and were more frequent at high bear and low human population densities. There was no significant difference in the number of attacks between continents or between countries with different hunting practices. Understanding global patterns of bear attacks can help reduce dangerous encounters and, consequently, is crucial for informing wildlife managers and the public about appropriate measures to reduce this kind of conflicts in bear country.Peer reviewe

    Population and distribution of beavers Castor fiber and Castor canadensis in Eurasia

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    1. A century ago, overhunting had reduced Eurasian beaver Castor fiber populations to c. 1200 animals in scattered refugia from France to Mongolia. Reintroductions and natural spread have since restored the species to large areas of its original range. Population has more than tripled since the first modern estimate in 1998; the minimum estimate is now c. 1.5 million. 2. Range expansion 2000–2020 has been rapid, with large extensions in western and south-central Europe, southern Russia, and west and central Siberia. Beavers are now re-established in all countries of their former European range except for Portugal, Italy, and the southern Balkans; they occur broadly across Siberia to Mongolia, with scattered populations father east. About half of the world population lives in Russia. Populations appear to be mature in much of European Russia, Belarus, the Baltic States, and Poland. 3. There is a significant population of North American beaver Castor canadensis in Finland and north-west Russia. Most other 20th-Century introductions of this species have become extinct or been removed. 4. Recent DNA studies have improved understanding of Castor fiber population prehistory and history. Two clades, east and west, are extant; a third ‘Danube’ clade is extinct. Refugial populations were strongly bottlenecked, with loss of genetic diversity through genetic drift. 5. Future range extension, and large increases in populations and in impacts on freshwater systems, can be expected. Beavers are now recolonising densely populated, intensely modified, low-relief regions, such as England, the Netherlands, Belgium, and north-west Germany. They will become much more common and widespread there in coming decades. As beavers are ecosystem engineers with profound effects on riparian habitats, attention to integrating beaver management into these landscapes using experience gained in other areas – before the rapid increase in population densities and impacts occurs – is recommended. beaver, Castor fiber, Castor canadensis, distribution, Eurasia, population, reintroductionpublishedVersio

    Population and distribution of beavers Castor fiber and Castor canadensis in Eurasia

    No full text
    1. A century ago, overhunting had reduced Eurasian beaver Castor fiber populations to c. 1200 animals in scattered refugia from France to Mongolia. Reintroductions and natural spread have since restored the species to large areas of its original range. Population has more than tripled since the first modern estimate in 1998; the minimum estimate is now c. 1.5 million. 2. Range expansion 2000–2020 has been rapid, with large extensions in western and south-central Europe, southern Russia, and west and central Siberia. Beavers are now re-established in all countries of their former European range except for Portugal, Italy, and the southern Balkans; they occur broadly across Siberia to Mongolia, with scattered populations father east. About half of the world population lives in Russia. Populations appear to be mature in much of European Russia, Belarus, the Baltic States, and Poland. 3. There is a significant population of North American beaver Castor canadensis in Finland and north-west Russia. Most other 20th-Century introductions of this species have become extinct or been removed. 4. Recent DNA studies have improved understanding of Castor fiber population prehistory and history. Two clades, east and west, are extant; a third ‘Danube’ clade is extinct. Refugial populations were strongly bottlenecked, with loss of genetic diversity through genetic drift. 5. Future range extension, and large increases in populations and in impacts on freshwater systems, can be expected. Beavers are now recolonising densely populated, intensely modified, low-relief regions, such as England, the Netherlands, Belgium, and north-west Germany. They will become much more common and widespread there in coming decades. As beavers are ecosystem engineers with profound effects on riparian habitats, attention to integrating beaver management into these landscapes using experience gained in other areas – before the rapid increase in population densities and impacts occurs – is recommended. beaver, Castor fiber, Castor canadensis, distribution, Eurasia, population, reintroductio

    Population and distribution of beavers Castor fiber and Castor canadensis in Eurasia

    No full text
    1. A century ago, overhunting had reduced Eurasian beaver Castor fiber populations to c. 1200 animals in scattered refugia from France to Mongolia. Reintroductions and natural spread have since restored the species to large areas of its original range. Population has more than tripled since the first modern estimate in 1998; the minimum estimate is now c. 1.5 million. 2. Range expansion 2000–2020 has been rapid, with large extensions in western and south-central Europe, southern Russia, and west and central Siberia. Beavers are now re-established in all countries of their former European range except for Portugal, Italy, and the southern Balkans; they occur broadly across Siberia to Mongolia, with scattered populations father east. About half of the world population lives in Russia. Populations appear to be mature in much of European Russia, Belarus, the Baltic States, and Poland. 3. There is a significant population of North American beaver Castor canadensis in Finland and north-west Russia. Most other 20th-Century introductions of this species have become extinct or been removed. 4. Recent DNA studies have improved understanding of Castor fiber population prehistory and history. Two clades, east and west, are extant; a third ‘Danube’ clade is extinct. Refugial populations were strongly bottlenecked, with loss of genetic diversity through genetic drift. 5. Future range extension, and large increases in populations and in impacts on freshwater systems, can be expected. Beavers are now recolonising densely populated, intensely modified, low-relief regions, such as England, the Netherlands, Belgium, and north-west Germany. They will become much more common and widespread there in coming decades. As beavers are ecosystem engineers with profound effects on riparian habitats, attention to integrating beaver management into these landscapes using experience gained in other areas – before the rapid increase in population densities and impacts occurs – is recommended. beaver, Castor fiber, Castor canadensis, distribution, Eurasia, population, reintroductio

    Identification and molecular variations of CAN-SINEs from the ZFY gene final intron of the Eurasian badgers (genus Meles)

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    The short interspersed nucleotide elements (SINEs) are specific to the taxa and thought to be one of powerful phylogenetic gene markers. Especially, the SINE sequences, which exist uniquely in genome of order Carnivora, are named CAN-SINEs. Among the Eurasian badgers (genus Meles), a member of the family Mustelidae in order Carnivora, the Japanese badger (M. anakuma) was previously reported to have an insertion of CAN-SINE in the final intron of the zinc finger protein gene on Y chromosome (ZFY). In the present study, we examined occurrence of the CAN-SINE of the ZFY final intron in the Eurasian badgers, and three continental and four Japanese haplotypes were identified from a total of 40 male badgers. Among the Eurasian badger CAN-SINEs, a 12-bp deletion specific to the Japanese haplotypes was found, whereas the 12-bp region (non-deletion) in the continental haplotypes consisted of one 6-bp direct repeat and 6-bp microsatellite-like sequences. Moreover, the continental haplotypes were phylogenetically divided into three lineages: eastern Eurasia, Caucasus and western Eurasia. These genetic differentiations supported the classification recently proposing that genus Meles are grouped into the European badger (M. meles), the Southwest Asian badger (M canescens), the Northwest & Central Asian badger (M. leucurus) and the Japanese badger (M. anakuna). In addition, the number of adenines in the poly A/T rich tails was polymorphic among all lineages of Eurasian badgers, and geographically variable within the Japanese badgers
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