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dc.contributor.advisorStokkan, Karl-Arne
dc.contributor.advisorFolkow, Lars
dc.contributor.authorSiefken, Sandra Katharina Christiane
dc.date.accessioned2010-08-10T11:10:19Z
dc.date.available2010-08-10T11:10:19Z
dc.date.issued2010-05-15
dc.description.abstractReindeer (Rangifer tarandus tarandus) live at high latitudes and are therefore exposed to extreme changes in environmental illumination. In winter they spend months in relative darkness, in summer they are exposed to months of continuous brightness. Previous investigations have revealed a shift in the wavelength of the light being reflected by the tapetum lucidum (TL) between winter and summer. Since no seasonal changes in the TL have ever been documented in any species before, this finding raised several questions. In the present study the following issues have been dealt with: Is this chromatic shift triggered by changing light conditions between summer and winter or regulated by an endogenous clock? Are there other parts of the visual system that undergo seasonal changes? What are the physical mechanisms behind this shift? To find out what is regulating the change in reflected light eyes from animals killed in summer and from animals killed in winter were compared to each other and to eyes from animals kept in altered light conditions.en
dc.format.extent3552257 bytes
dc.format.mimetypeapplication/pdf
dc.identifier.urihttps://hdl.handle.net/10037/2610
dc.identifier.urnURN:NBN:no-uit_munin_2356
dc.language.isoengen
dc.publisherUniversitetet i Tromsøen
dc.publisherUniversity of Tromsøen
dc.rights.accessRightsopenAccess
dc.rights.holderCopyright 2010 The Author(s)
dc.subject.courseIDBIO-3910nor
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Zoofysiologi og komparativ fysiologi: 483en
dc.subjectVDP::Mathematics and natural science: 400::Zoology and botany: 480::Zoophysiology and comparative physiology: 483en
dc.titleSeasonal changes in the Tapetum lucidum as an adaptation to winter darkness in reindeeren
dc.typeMaster thesisen
dc.typeMastergradsoppgaveen


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