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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Genetická struktura mediteránních populací kaloně Rousettus aegyptiacus / Genetická struktura mediteránních populací kaloně Rousettus aegyptiacus

Marešová, Tereza January 2012 (has links)
5 Abstract The genus Rousettus represents the only fruit bat genus distributed both in Asia and Africa reaching northern distributional limits of the Pteropodidae family. This unusual distribution pattern is related to the ability of echolocation, subsequent cave dwelling and probably other thermoregulatory and behavioural adaptations to relatively cold and dry climate. Methods for identification of genetically discrete populations were used in the presented study to acquire better comprehension of historical ways of colonization along with current dispersal and migratory patterns of the Egyptian fruit bat (Rousettus aegyptiacus) in the Mediterranean basin and adjacent range patches. Modern approaches to population and landscape genetics were applied on a dataset comprising 553 individuals from 72 localities using 20 nuclear microsatellites. Our results revealed a significant genetic distance of East African individuals and certain substructure in the northern part of the range. Cypriot population is clearly separated, and - for higher K - the isolation of colonies from Egyptian oases is highly supported. Genetic proximity of south Arabian and Sinai populations contradict current taxonomy of the species. Our findings highlight the role of seas and deserts as barriers restricting gene flow and the evolution...
2

Fylogeografie of Rousettus aegyptiacus ve Středomoří / Phylogeography of Rousettus aegyptiacus in the Mediterranean region

Dundarova, Cheliana January 2011 (has links)
The genus Rousettus has distributional pattern unique among fruitbats comprising both Asia and Africa and reaching northern distributional limits of the family in Persia, Arabia and Mediterranean basin. This could be ascribed to the ability of echolocation, consequent cave dwelling, and presumably other site-specific adaptations, which enabled dispersal independent of forest block and surviving in Mediterranean type of climate. Using fastly evolving mitochondrial marker, we aimed to assess genetic variability, its geographic distribution and demography of northern populations of the Egyptian fruitbat (Rousettus aegyptiacus). Mitochondrial network indicates deep genetic divergence between disjunct Mediterranean and eastern African parts of the range. Basal position of Sinaic and Jordanian haplotypes within northern clade indicate important role of these regions in colonization of eastern Mediterranean. Generally, the northern haplogroup is moderately diversified with partial geographic localization of particular haplotypes. Significant isolation by distance pattern suggests relatively pronounced site fidelity of particular colonies, at least in terms of maternal gene flow. Landscape genetics analyses indicate discontinuities in distribution of mitochondrial genetic variability, in some cases correlating with...
3

The Role of Hepcidin in Regulation of Iron Balance in Bats

Stasiak, Iga 17 September 2012 (has links)
Iron storage disease is a significant cause of liver disease and mortality in captive Egyptian fruit bats (Rousettus aegyptiacus). The nature of the susceptibility in this and other captive exotic species to iron storage disease is not clear. Hepcidin, a key iron regulatory hormone, is involved in the regulation of iron absorption in humans and other mammalian species and a deficiency in hepcidin has been associated with a number of genetic mutations resulting in hemochromatosis in humans. The objectives of this thesis were to identify whether there is a functional mutation in the hepcidin gene in the Egyptian fruit bat that may increase the susceptibility of this species to iron storage disease, and whether there is a functional deficiency in hepcidin gene expression in the Egyptian fruit bat in response to iron challenge. We compared the coding region of the hepcidin gene amongst several species of bats and investigated hepcidin response to intramuscular injection of iron dextran amongst three species of bats with variable susceptibility to iron storage disease; the Egyptian fruit bat, the straw-colored fruit bat (Eidolon helvum), and the common vampire bat (Desmodus rotundus). While a number of genetic differences were identified amongst species, a functional mutation that could result in decreased hepcidin activity was not identified in the Egyptian fruit bat. Bats exhibited marked variation in hepcidin gene expression, with the highest level of hepcidin response to iron challenge in the common vampire bat. While the Egyptian fruit bat exhibited significant hepcidin response to iron challenge, the magnitude of response was lower than that in the common vampire bat and lower than expected based on findings in healthy humans. The straw-colored fruit bat did not exhibit any hepcidin response despite a significant increase in iron stores, which suggests this species may have evolved an alternate mechanism for coping with excessive iron or may be more susceptible to iron overload than previously recognized. / Toronto Zoo Scholarship Fund

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