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Sophie Laurence - One of the best experts on this subject based on the ideXlab platform.
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Genetic Structure of Muskrat (Ondatra zibethicus) and Its Concordance with Taxonomy in North America
2016Co-Authors: Sophie Laurence, Jamieson C Gorrell, David W Coltman, I. Schulte-hosteddeAbstract:Extrinsic factors such as physical barriers play an important role in shaping population genetic structure. A reduction in gene flow leading to population structuring may ultimately lead to population divergence. These divergent populations are often considered subspecies. Because genetic differentiation may represent differences between subspecies, patterns of genetic structure should reflect subspecies groupings. In this study, we examine the contemporary population genetic structure of muskrat (n 5 331) and assess the relevance of 4 geographically distinct subspecies designations across northern North America using 9 microsatellite loci. We predicted that patterns of gene flow and genetic structure would reflect the described subspecies. We found evidence of genetic differentiation between western and eastern regions, and muskrats from Newfoundland (NF) showed significantly lower genetic diversity than central regions. A strong isolation by distance pattern was also detected within the eastern cluster. Our results did not differentiate Ondatra zibethicus spatulus (northwest) from O. z. albus (central), but they suggest a distinction between O. z. obscurus (NF) and O. z. zibethicus (east). This study highlights the need for more phylogenetic studies in order to better understand intraspecific divergence and the genetic characterization of subspecies. Key words: genetic structure, isolation by distance, microsatellite loci, Ondatra zibethicus, subspecies The population genetic structure of contemporary popula
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genetic structure of muskrat Ondatra zibethicus and its concordance with taxonomy in north america
Journal of Heredity, 2011Co-Authors: Sophie Laurence, Jamieson C Gorrell, David W Coltman, Albrecht I SchultehosteddeAbstract:Extrinsic factors such as physical barriers play an important role in shaping population genetic structure. A reduction in gene flow leading to population structuring may ultimately lead to population divergence. These divergent populations are often considered subspecies. Because genetic differentiation may represent differences between subspecies, patterns of genetic structure should reflect subspecies groupings. In this study, we examine the contemporary population genetic structure of muskrat (n 5 331) and assess the relevance of 4 geographically distinct subspecies designations across northern North America using 9 microsatellite loci. We predicted that patterns of gene flow and genetic structure would reflect the described subspecies. We found evidence of genetic differentiation between western and eastern regions, and muskrats from Newfoundland (NF) showed significantly lower genetic diversity than central regions. A strong isolation by distance pattern was also detected within the eastern cluster. Our results did not differentiate Ondatra zibethicus spatulus (northwest) from O. z. albus (central), but they suggest a distinction between O. z. obscurus (NF) and O. z. zibethicus (east). This study highlights the need for more phylogenetic studies in order to better understand intraspecific divergence and the genetic characterization of subspecies.
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Baculum variation and allometry in the muskrat (Ondatra zibethicus): a case for sexual selection
Evolutionary Ecology, 2009Co-Authors: Diana E. Tasikas, Evan R. Fairn, Sophie Laurence, Albrecht I. Schulte-hosteddeAbstract:Sexual selection is a powerful force that influences the evolution of a variety of traits associated with female mate choice and male–male competition. Although other factors have been implicated, sexual selection may be particularly important in the evolution of the genitalia. Traits under sexual selection typically have high phenotypic variance and positive allometry relative to non-sexual traits. Here, we test the hypothesis that the baculum (os penis) of the muskrat ( Ondatra zibethicus ) is under sexual selection by examining phenotypic variance and allometry relative to non-sexual traits. Muskrats were sampled from Ontario, Canada, and a variety of traits measured. Measurements included baculum length and width, and three non-sexual traits (skull length, skull width, hind foot length). We used coefficient of variation (CV) and allometric slopes calculated using reduced major axis regression to test our hypotheses. Baculum traits had significantly higher CV’s relative to non-sexual traits. Baculum traits also showed positive allometry, whereas all non-sexual traits had negative allometric relationships. In addition, baculum width had higher CV’s and steeper allometric slopes than baculum length, indicating that, in muskrat, baculum width may be more influenced by sexual selection than baculum length. Positive allometry of the baculum is consistent with other examples of mammalian genitalia, but contrasts with negative allometry found in many insects. Other examples of positive allometry and high phenotypic variance of the baculum have suggested that females may use the baculum as an indicator of male quality. “Good genes” indicator traits may be particularly important in species that mate in an environmental context that prohibits female assessment of male quality. Muskrats mate aquatically, and thus females may be unable to properly assess males prior to copulation.
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isolation and characterization of polymorphic microsatellite loci in muskrat Ondatra zibethicus
Molecular Ecology Resources, 2009Co-Authors: Sophie Laurence, Sarah C Elsasser, A G Kidd, David Lesbarreres, Corey S. Davis, Adam J Bewick, David W Coltman, Albrecht I SchultehosteddeAbstract:We describe the isolation and characterization of 12 highly polymorphic microsatellite loci for the muskrat, Ondatra zibethicus. Microsatellite markers from three other rodent species were cross-amplified in muskrat and one of them was polymorphic. We observed moderate to high levels of genetic variability in these 13 polymorphic loci (five to 22 alleles per locus) with observed heterozygosity ranging from 0.48 to 0.96. These markers will be useful for further studies on population genetic structure in muskrat and potentially in other rodent species.
Albrecht I Schultehostedde - One of the best experts on this subject based on the ideXlab platform.
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genetic structure of muskrat Ondatra zibethicus and its concordance with taxonomy in north america
Journal of Heredity, 2011Co-Authors: Sophie Laurence, Jamieson C Gorrell, David W Coltman, Albrecht I SchultehosteddeAbstract:Extrinsic factors such as physical barriers play an important role in shaping population genetic structure. A reduction in gene flow leading to population structuring may ultimately lead to population divergence. These divergent populations are often considered subspecies. Because genetic differentiation may represent differences between subspecies, patterns of genetic structure should reflect subspecies groupings. In this study, we examine the contemporary population genetic structure of muskrat (n 5 331) and assess the relevance of 4 geographically distinct subspecies designations across northern North America using 9 microsatellite loci. We predicted that patterns of gene flow and genetic structure would reflect the described subspecies. We found evidence of genetic differentiation between western and eastern regions, and muskrats from Newfoundland (NF) showed significantly lower genetic diversity than central regions. A strong isolation by distance pattern was also detected within the eastern cluster. Our results did not differentiate Ondatra zibethicus spatulus (northwest) from O. z. albus (central), but they suggest a distinction between O. z. obscurus (NF) and O. z. zibethicus (east). This study highlights the need for more phylogenetic studies in order to better understand intraspecific divergence and the genetic characterization of subspecies.
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isolation and characterization of polymorphic microsatellite loci in muskrat Ondatra zibethicus
Molecular Ecology Resources, 2009Co-Authors: Sophie Laurence, Sarah C Elsasser, A G Kidd, David Lesbarreres, Corey S. Davis, Adam J Bewick, David W Coltman, Albrecht I SchultehosteddeAbstract:We describe the isolation and characterization of 12 highly polymorphic microsatellite loci for the muskrat, Ondatra zibethicus. Microsatellite markers from three other rodent species were cross-amplified in muskrat and one of them was polymorphic. We observed moderate to high levels of genetic variability in these 13 polymorphic loci (five to 22 alleles per locus) with observed heterozygosity ranging from 0.48 to 0.96. These markers will be useful for further studies on population genetic structure in muskrat and potentially in other rodent species.
Paulauskas Algimantas - One of the best experts on this subject based on the ideXlab platform.
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New data on the helminths of the muskrat (Ondatra zibethicus) in Lithuania
2016Co-Authors: Mažeika Vytautas, Kontenytė Rima, Paulauskas AlgimantasAbstract:Thirty-four muskrats, hunted in 2006 2007 on Rusnė Island, Lithuania, were examined for helminths. Eight helminth species were found: five trematodes (Echinostoma sp., Plagiorchis elegans, Skrjabinoplagiorchis Ondatrae, Psilotrema spiculigerum, Psilotrema simillimum) and three cestodes (Hydatigera taeniaeformis, Tetratirotaenia polyacantha, Echinococcus multilocularis). All the species found are widely spread or are indigenous to Europe. The helminth fauna in the muskrat consisted of helminths hosted by a wide range of waterfowl and mammals. This was only the second time the cestode E. multilocularis, the causative agent of the serious zoonosis alveolar echinococcosis, was found in the muskrat in LithuaniaBiologijos katedraGamtos mokslų fakultetasKlaipėdos universitetasVytauto Didžiojo universiteta
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Ondatros (Ondatra zibethicus) invazinis paplitimas ir poveikis ekosistemai
2016Co-Authors: Skyrienė Gintarė, Paulauskas AlgimantasAbstract:Ondatros (Ondatra zibethicus) greitai paplito naujuose biotopuose po to, kai buvo introdukuotos į Europą ir užėmė jos šiaurinę, rytinę ir vidurinę dalis. Viena sėkmingos invazijos priežasčių – greita reprodukcija ir sėkmingas savarankiškas plitimas naujose vietose. Ondatros yra pusiau vandens graužikai, neigiamai veikiantys ekosistemas. Ši rūšis, ženkliai veikianti aplinką, gali būti pakankamai svarbi ekonomikos požiūriu. Šiuo metu ondatrų labai sumažėjo, ypač Lietuvoje, Lenkijoje, ir tai gali būti ekologinių veiksnių, tokių kaip maisto prieinamumas, ligos, parazitai, plėšrūnai, poveikis. Be to, ondatrų mirtingumą nemažai lemia ir žmogaus veikla: jos intensyviai gaudomos dėl kailio, kurio ekonominė vertė yra išaugusi visame pasaulyje. Straipsnyje apžvelgiama ondatros (Ondatra zibethicus) introdukcijos į Europą istorija, paplitimas visoje Eurazijoje, veiksniai, nulėmę populiacijos didėjimą, o vėliau ir mažėjimą, genetiniai tyrimai ir šios invazinės rūšies poveikis ekosistemaiThe muskrat (Ondatra zibethicus L.) after being introduced to Europe quickly colonized new areas. They occupied Northern, Eastern and Central Europe. One of the reasons for their successful invasion into new areas was the release of animals in numerous places and their subsequent successful self-spreading from these places. However, this semi-aquatic rodent negatively impacts the ecosystem (causes damages of watercourse embankment through burrowing, consumes crops). The species possesses a high potential for both environmental and economic impact. Nowadays, following the successful widespread of this species, abundance of its population is reduced in some countries, e. g. Lithuania and Poland. The reasons for that can be ecological factors: availability of food, diseases, parasites and carnivore predators. Moreover, humans cause significant mortality of muskrats. The rodents are extensively trapped for fur, which is of increasing economic value around the world. The paper presents a review of the muskrat introduction history into Europe and whole Eurasia, distribution of the species, the factors important for population abundance increase and reduction, on genetics as well as muskrat invasion impact on non-native ecosystems for this speciesBiologijos katedraGamtos mokslų fakultetasVytauto Didžiojo universiteta
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The microsatellite markers for genetic structure of muskrat (Ondatra zibethicus)
2015Co-Authors: Skyrienė Gintarė, Paulauskas Algimantas, Belkin Vladimir, Fyodorov FyodorAbstract:The muskrat (Ondatra zibethicus) is one of the semi-aquatic mammals which were introduced from North America in various regions around the world (Danell, 1996; Musser ir Carleton, 2005). The microsatellites markers were used only for the Canadian muskrat populations (Laurence et al. 2009) and there are no genetics studies (using microsatellite) of muskrat in Europe or Russia. The aim of this study was to evaluate genetic structure (using microsatellite markers) of muskrat populations in Lithuania and South Karelia, Russia. A total of 179 samples of muskrat were investigated genetically: 71 muskrat from Lithuania and 108 – Russia. The genetic variability was compared using 7 polymorphic microsatellite loci (Oz08, Oz17, Oz22, Oz30, Oz41, Oz43, Oz44). Population analysis revealed moderate to high levels of genetic variability (in Lithuania: He = 0.35- 0.88, Ho = 0.29-0.94; In Russia: He = 0.74-0.90, Ho = 0.44-0.80). The numbers of polymorphic loci were 100 % and size ranged from 183 to 272 base pairs in Lithuania and Russia. The numbers of alleles per locus ranging from 5 to 15 in Lithuania (in a total of 67 alleles) and from 8 to 19 – Russia (in a total of 91 alleles). Each locus was tested for departure from Hardy-Weinberg equilibrium (HWE) and all loci exhibited significant in Russia populations and 6 loci in Lithuania. The results of principal coordinate analysis (PCA) by genetic similarity showed that the two populations separated and formed two different groups – Lithuanian and Russian. The results showed that the genetic diversity was higher in Russia population of muskrat than in Lithuania, but lower if to compare with muskrat population from Canada (Laurence et al. 2009; Laurence et el., 2013). The study was supported by the Research Council of Lithuania (grant No. LEK-14/2012)Biologijos katedraGamtos mokslų fakultetasVytauto Didžiojo universiteta
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Assessment of invasive muskrat Ondatra zibethicus distribution and impacts on ecosystems in Lithuania
2015Co-Authors: Butautytė-skyrienė Gintarė, Paulauskas Algimantas, Ulevičius AliusAbstract:After acclimatization muskrats spread over almost all Lithuania and increased to about 40 000 individuals in the 1980s. But since then the number of muskrats has decreased to about 2000 individuals. We used BINPAS (Bioinvasion Impact/Biopollution Assessment System) for terrestrial ecosystems, which is usually using for water ecosystems, to assess the impact of Ondatra zibethicus on native species and communities, on habitats, on ecosystems and the biopollution level (BPL). The impact of muskrats varied between different regions of Lithuania. Widespread and high numbers of muskrats, and strong biopollution of ecosystem functioning were identified in four regions of Lithuania – Nevėžis and Nemunas Rivers, Šalčia River, Varėnė river, Vištytis Regional ParkBiologijos katedraGamtos mokslų fakultetasVytauto Didžiojo universiteta
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Population structure of muskrat (Ondatra zibethicus) in Lithuania
2014Co-Authors: Skyrienė Gintarė, Paulauskas AlgimantasAbstract:The muskrat (Ondatra zibethicus) is a semi-aquatic rodent and it is listed as the most successfully acclimatized alien species in Europe with a wide distribution, fast increase of abundance, short colonisation time, massive spread into various ecosystems and significant ecological impact. Lithuania is no exception; after introducing, the muskrat rapidly inhabited a wide spectrum of waters throughout the whole country. The analysis of the variation in body dimensions and other characteristics of muskrats is important for assessing the effect of environmental factors on muskrat populations. The aim of this reasearch was to examine invasive species muskrat population demographic status, sex structure and ratio, weight and to count the embryons and placental scars. Population structure of muskrat were studied using muskrat population (n꞊129) hunted during 2001 – 2012 throughout Lithuania. Males predominant over females in catch numbers – 67% of all hunted males and 33 % of all hunted females. Male dominance in numbers has been attributed either to different mortality of the sexes or the differences in activity resulting in a greater proportion of males being hunted (Pankakoski, 1983). The biggest differences of caught muskrat in different years were in 2006 and 2007 (65% males and 35% females, 77% and 23%, respectively). The male and female ratio of the muskrat population was 2:1 and effective population size (Ne) 113 and it is being less than an absolute population size (N) 129. The literature on the sex ratios in muskrat populations is extensive and usually there is a clear prepoderance of males in spring (Pankakoski, 1983). Mean weight of muskrat was 936 g. Males showed slighlty higher weight in comparison to females (980 g and 900g, respectively) because of intraspecific competition. There was significant difference between weight of females and males (t = 1.682, p = 0.031). [...]Biologijos katedraVytauto Didžiojo universiteta
David W Coltman - One of the best experts on this subject based on the ideXlab platform.
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Genetic Structure of Muskrat (Ondatra zibethicus) and Its Concordance with Taxonomy in North America
2016Co-Authors: Sophie Laurence, Jamieson C Gorrell, David W Coltman, I. Schulte-hosteddeAbstract:Extrinsic factors such as physical barriers play an important role in shaping population genetic structure. A reduction in gene flow leading to population structuring may ultimately lead to population divergence. These divergent populations are often considered subspecies. Because genetic differentiation may represent differences between subspecies, patterns of genetic structure should reflect subspecies groupings. In this study, we examine the contemporary population genetic structure of muskrat (n 5 331) and assess the relevance of 4 geographically distinct subspecies designations across northern North America using 9 microsatellite loci. We predicted that patterns of gene flow and genetic structure would reflect the described subspecies. We found evidence of genetic differentiation between western and eastern regions, and muskrats from Newfoundland (NF) showed significantly lower genetic diversity than central regions. A strong isolation by distance pattern was also detected within the eastern cluster. Our results did not differentiate Ondatra zibethicus spatulus (northwest) from O. z. albus (central), but they suggest a distinction between O. z. obscurus (NF) and O. z. zibethicus (east). This study highlights the need for more phylogenetic studies in order to better understand intraspecific divergence and the genetic characterization of subspecies. Key words: genetic structure, isolation by distance, microsatellite loci, Ondatra zibethicus, subspecies The population genetic structure of contemporary popula
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genetic structure of muskrat Ondatra zibethicus and its concordance with taxonomy in north america
Journal of Heredity, 2011Co-Authors: Sophie Laurence, Jamieson C Gorrell, David W Coltman, Albrecht I SchultehosteddeAbstract:Extrinsic factors such as physical barriers play an important role in shaping population genetic structure. A reduction in gene flow leading to population structuring may ultimately lead to population divergence. These divergent populations are often considered subspecies. Because genetic differentiation may represent differences between subspecies, patterns of genetic structure should reflect subspecies groupings. In this study, we examine the contemporary population genetic structure of muskrat (n 5 331) and assess the relevance of 4 geographically distinct subspecies designations across northern North America using 9 microsatellite loci. We predicted that patterns of gene flow and genetic structure would reflect the described subspecies. We found evidence of genetic differentiation between western and eastern regions, and muskrats from Newfoundland (NF) showed significantly lower genetic diversity than central regions. A strong isolation by distance pattern was also detected within the eastern cluster. Our results did not differentiate Ondatra zibethicus spatulus (northwest) from O. z. albus (central), but they suggest a distinction between O. z. obscurus (NF) and O. z. zibethicus (east). This study highlights the need for more phylogenetic studies in order to better understand intraspecific divergence and the genetic characterization of subspecies.
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isolation and characterization of polymorphic microsatellite loci in muskrat Ondatra zibethicus
Molecular Ecology Resources, 2009Co-Authors: Sophie Laurence, Sarah C Elsasser, A G Kidd, David Lesbarreres, Corey S. Davis, Adam J Bewick, David W Coltman, Albrecht I SchultehosteddeAbstract:We describe the isolation and characterization of 12 highly polymorphic microsatellite loci for the muskrat, Ondatra zibethicus. Microsatellite markers from three other rodent species were cross-amplified in muskrat and one of them was polymorphic. We observed moderate to high levels of genetic variability in these 13 polymorphic loci (five to 22 alleles per locus) with observed heterozygosity ranging from 0.48 to 0.96. These markers will be useful for further studies on population genetic structure in muskrat and potentially in other rodent species.
Skyrienė Gintarė - One of the best experts on this subject based on the ideXlab platform.
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Ondatros (Ondatra zibethicus) invazinis paplitimas ir poveikis ekosistemai
2016Co-Authors: Skyrienė Gintarė, Paulauskas AlgimantasAbstract:Ondatros (Ondatra zibethicus) greitai paplito naujuose biotopuose po to, kai buvo introdukuotos į Europą ir užėmė jos šiaurinę, rytinę ir vidurinę dalis. Viena sėkmingos invazijos priežasčių – greita reprodukcija ir sėkmingas savarankiškas plitimas naujose vietose. Ondatros yra pusiau vandens graužikai, neigiamai veikiantys ekosistemas. Ši rūšis, ženkliai veikianti aplinką, gali būti pakankamai svarbi ekonomikos požiūriu. Šiuo metu ondatrų labai sumažėjo, ypač Lietuvoje, Lenkijoje, ir tai gali būti ekologinių veiksnių, tokių kaip maisto prieinamumas, ligos, parazitai, plėšrūnai, poveikis. Be to, ondatrų mirtingumą nemažai lemia ir žmogaus veikla: jos intensyviai gaudomos dėl kailio, kurio ekonominė vertė yra išaugusi visame pasaulyje. Straipsnyje apžvelgiama ondatros (Ondatra zibethicus) introdukcijos į Europą istorija, paplitimas visoje Eurazijoje, veiksniai, nulėmę populiacijos didėjimą, o vėliau ir mažėjimą, genetiniai tyrimai ir šios invazinės rūšies poveikis ekosistemaiThe muskrat (Ondatra zibethicus L.) after being introduced to Europe quickly colonized new areas. They occupied Northern, Eastern and Central Europe. One of the reasons for their successful invasion into new areas was the release of animals in numerous places and their subsequent successful self-spreading from these places. However, this semi-aquatic rodent negatively impacts the ecosystem (causes damages of watercourse embankment through burrowing, consumes crops). The species possesses a high potential for both environmental and economic impact. Nowadays, following the successful widespread of this species, abundance of its population is reduced in some countries, e. g. Lithuania and Poland. The reasons for that can be ecological factors: availability of food, diseases, parasites and carnivore predators. Moreover, humans cause significant mortality of muskrats. The rodents are extensively trapped for fur, which is of increasing economic value around the world. The paper presents a review of the muskrat introduction history into Europe and whole Eurasia, distribution of the species, the factors important for population abundance increase and reduction, on genetics as well as muskrat invasion impact on non-native ecosystems for this speciesBiologijos katedraGamtos mokslų fakultetasVytauto Didžiojo universiteta
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The microsatellite markers for genetic structure of muskrat (Ondatra zibethicus)
2015Co-Authors: Skyrienė Gintarė, Paulauskas Algimantas, Belkin Vladimir, Fyodorov FyodorAbstract:The muskrat (Ondatra zibethicus) is one of the semi-aquatic mammals which were introduced from North America in various regions around the world (Danell, 1996; Musser ir Carleton, 2005). The microsatellites markers were used only for the Canadian muskrat populations (Laurence et al. 2009) and there are no genetics studies (using microsatellite) of muskrat in Europe or Russia. The aim of this study was to evaluate genetic structure (using microsatellite markers) of muskrat populations in Lithuania and South Karelia, Russia. A total of 179 samples of muskrat were investigated genetically: 71 muskrat from Lithuania and 108 – Russia. The genetic variability was compared using 7 polymorphic microsatellite loci (Oz08, Oz17, Oz22, Oz30, Oz41, Oz43, Oz44). Population analysis revealed moderate to high levels of genetic variability (in Lithuania: He = 0.35- 0.88, Ho = 0.29-0.94; In Russia: He = 0.74-0.90, Ho = 0.44-0.80). The numbers of polymorphic loci were 100 % and size ranged from 183 to 272 base pairs in Lithuania and Russia. The numbers of alleles per locus ranging from 5 to 15 in Lithuania (in a total of 67 alleles) and from 8 to 19 – Russia (in a total of 91 alleles). Each locus was tested for departure from Hardy-Weinberg equilibrium (HWE) and all loci exhibited significant in Russia populations and 6 loci in Lithuania. The results of principal coordinate analysis (PCA) by genetic similarity showed that the two populations separated and formed two different groups – Lithuanian and Russian. The results showed that the genetic diversity was higher in Russia population of muskrat than in Lithuania, but lower if to compare with muskrat population from Canada (Laurence et al. 2009; Laurence et el., 2013). The study was supported by the Research Council of Lithuania (grant No. LEK-14/2012)Biologijos katedraGamtos mokslų fakultetasVytauto Didžiojo universiteta
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The distribution, genetic diversity and helminths of alien mammal muskrat (Ondatra zibethicus)
2014Co-Authors: Skyrienė GintarėAbstract:Ondatra yra svetimkraštis pusiau-vandens žinduolis, kuris buvo introdukuotas iš Šiaurės Amerikos į įvairius regionus visame pasaulyje. Šio darbo tikslas – ištirti svetimkraščio žinduolio ondatros (Ondatra zibethicus) paplitimą, genetinę įvairovę ir helmintus. Šiame moksliniame darbe įvertintas ondatros paplitimas ir gausumas Lietuvoje parodė, kad jie skirtinguose Lietuvos regionuose yra nevienodi, skirtingais metais svyruoja, įvairiuose vandens telkiniuose ženkliai krenta. Todėl ondatros poveikis vietinėms rūšims ir bendrijai, buveinių ir ekosistemų funkcionavimui yra nežymus ir lokalus. Iki šiol invazinio gyvūno genetinei struktūrai dėmesio buvo skirta labai mažai, todėl panaudojant DNR mikrosatelitinius žymenis ištirta genetinė įvairovė. Pirmą kartą įvertinta Lietuvos ondatrų populiacijų genetinė analizė ir genetinė įvairovė, kuri buvo mažesnė antrinėje (Lietuvos) introdukcijos vietovėje, nei pirminėje (Karelijos (Rusijos)), ar aborigeninėse Kanados populiacijose. Ondatrų helmintų ištirtumas, leido įvertinti, kad veikiant aklimatizacijai Ondatra neteko amerikinės kilmės parazitų. O palyginus helmintų fauną ir helmintų užsikrėtimo rodiklius buvo nustatyta, kad jie didesni didžiausio ondatros skaitlingumo metais (1973-1975 m.) negu smarkiai sumažėjusio (2001-2014 m.). Ištirtas ondatrų skaičius leidžia daryti prielaidą, kad jos helmintologinis poveikis žmonėms ir aplinkai yra mažas.The muskrat is an alien semi-aquatic mammal which was introduced to various regions around the world from North America. The aim of the study – to investigate the distribution, genetic diversity and helminths of alien mammal muskrat (Ondatra zibethicus). The evaluated distribution and the abundance of muskrats showed that it are not the same, very varying in different years and falling significantly in the various water bodies in Lithuania. Therefore, the impact of muskrats on native species and communities, habitats and ecosystems are insignificant and localized. Until now, the attention to the genetic structure of this invasive animal was very little. The genetic analysis and genetic diversity of the population of muskrats was assessed for the first time in Lithuania. The genetic diversity was studied using the microsatellite DNA markers. This allowed for the evaluation that the genetic diversity was lower in Lithuania than Karelia (Russia) or native Canadian populations of muskrat. After the evaluation of helminthological analysis were determined that the muskrat has lost American origin parasites after the period of acclimatization. The comparison of the helminth community structure and infection rates of muskrat were determined that it were higher in the highest numerosity of muskrat’s abundance (in 1973-1975) to comparing the period than it significantly reduced (in 2001-2014). Investigated number of muskrats suggests that the helminthological impact of muskrat to humans and the environment is low.Vytauto Didžiojo universiteta
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Svetimkraščio žinduolio ondatros (Ondatra zibethicus) paplitimas, genetinė įvairovė ir helmintai
2014Co-Authors: Skyrienė GintarėAbstract:The muskrat is an alien semi-aquatic mammal which was introduced to various regions around the world from North America. The aim of the study – to investigate the distribution, genetic diversity and helminths of alien mammal muskrat (Ondatra zibethicus). The evaluated distribution and the abundance of muskrats showed that it are not the same, very varying in different years and falling significantly in the various water bodies in Lithuania. Therefore, the impact of muskrats on native species and communities, habitats and ecosystems are insignificant and localized. Until now, the attention to the genetic structure of this invasive animal was very little. The genetic analysis and genetic diversity of the population of muskrats was assessed for the first time in Lithuania. The genetic diversity was studied using the microsatellite DNA markers. This allowed for the evaluation that the genetic diversity was lower in Lithuania than Karelia (Russia) or native Canadian populations of muskrat. After the evaluation of helminthological analysis were determined that the muskrat has lost American origin parasites after the period of acclimatization. The comparison of the helminth community structure and infection rates of muskrat were determined that it were higher in the highest numerosity of muskrat’s abundance (in 1973-1975) to comparing the period than it significantly reduced (in 2001-2014). Investigated number of muskrats suggests that the helminthological impact of muskrat to humans and the environment is low.Ondatra yra svetimkraštis pusiau-vandens žinduolis, kuris buvo introdukuotas iš Šiaurės Amerikos į įvairius regionus visame pasaulyje. Šio darbo tikslas – ištirti svetimkraščio žinduolio ondatros (Ondatra zibethicus) paplitimą, genetinę įvairovę ir helmintus. Šiame moksliniame darbe įvertintas ondatros paplitimas ir gausumas Lietuvoje parodė, kad jie skirtinguose Lietuvos regionuose yra nevienodi, skirtingais metais svyruoja, įvairiuose vandens telkiniuose ženkliai krenta. Todėl ondatros poveikis vietinėms rūšims ir bendrijai, buveinių ir ekosistemų funkcionavimui yra nežymus ir lokalus. Iki šiol invazinio gyvūno genetinei struktūrai dėmesio buvo skirta labai mažai, todėl panaudojant DNR mikrosatelitinius žymenis ištirta genetinė įvairovė. Pirmą kartą įvertinta Lietuvos ondatrų populiacijų genetinė analizė ir genetinė įvairovė, kuri buvo mažesnė antrinėje (Lietuvos) introdukcijos vietovėje, nei pirminėje (Karelijos (Rusijos)), ar aborigeninėse Kanados populiacijose. Ondatrų helmintų ištirtumas, leido įvertinti, kad veikiant aklimatizacijai Ondatra neteko amerikinės kilmės parazitų. O palyginus helmintų fauną ir helmintų užsikrėtimo rodiklius buvo nustatyta, kad jie didesni didžiausio ondatros skaitlingumo metais (1973-1975 m.) negu smarkiai sumažėjusio (2001-2014 m.). Ištirtas ondatrų skaičius leidžia daryti prielaidą, kad jos helmintologinis poveikis žmonėms ir aplinkai yra mažas.Vytauto Didžiojo universiteta
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Population structure of muskrat (Ondatra zibethicus) in Lithuania
2014Co-Authors: Skyrienė Gintarė, Paulauskas AlgimantasAbstract:The muskrat (Ondatra zibethicus) is a semi-aquatic rodent and it is listed as the most successfully acclimatized alien species in Europe with a wide distribution, fast increase of abundance, short colonisation time, massive spread into various ecosystems and significant ecological impact. Lithuania is no exception; after introducing, the muskrat rapidly inhabited a wide spectrum of waters throughout the whole country. The analysis of the variation in body dimensions and other characteristics of muskrats is important for assessing the effect of environmental factors on muskrat populations. The aim of this reasearch was to examine invasive species muskrat population demographic status, sex structure and ratio, weight and to count the embryons and placental scars. Population structure of muskrat were studied using muskrat population (n꞊129) hunted during 2001 – 2012 throughout Lithuania. Males predominant over females in catch numbers – 67% of all hunted males and 33 % of all hunted females. Male dominance in numbers has been attributed either to different mortality of the sexes or the differences in activity resulting in a greater proportion of males being hunted (Pankakoski, 1983). The biggest differences of caught muskrat in different years were in 2006 and 2007 (65% males and 35% females, 77% and 23%, respectively). The male and female ratio of the muskrat population was 2:1 and effective population size (Ne) 113 and it is being less than an absolute population size (N) 129. The literature on the sex ratios in muskrat populations is extensive and usually there is a clear prepoderance of males in spring (Pankakoski, 1983). Mean weight of muskrat was 936 g. Males showed slighlty higher weight in comparison to females (980 g and 900g, respectively) because of intraspecific competition. There was significant difference between weight of females and males (t = 1.682, p = 0.031). [...]Biologijos katedraVytauto Didžiojo universiteta
