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dc.contributor.advisorWalter, Ronald
dc.contributor.authorContreras, Adam
dc.date.accessioned2013-06-20T17:08:44Z
dc.date.available2013-06-20T17:08:44Z
dc.date.issued2013-05-20
dc.identifier.urihttps://digital.library.txstate.edu/handle/10877/4650
dc.descriptionPresented to the Honors Committee of Texas State University-San Marcos In Partial Fulfillment of the Requirements For Graduation in the Honors College, May 2013.en_US
dc.description.abstractXiphophorus fish have been used as experimental models for UV-inducible melanoma for over 85 years. The aim of this study was to characterize the stress response (i.e., cortisol production) in Xiphophorus fish in skin after UV exposure. The primary stress response was characterized in X. maculatus Jp 163 B, X. couchianus, and F1 interspecies hybrids (Xm-Xh) produced from the cross X. maculatus Jp 163 B (x) X. couchianus. The stress response in treated fish suggests experimental handling of the animals was the primary stressor and that UVB exposure effectively suppressed cortisol production rates. In Xm-Xh hybrids cortisol production rates were intermediate between parental species, but more similar to X. maculatus Jp 163 B. Thus, the cortisol stress responses appeared to be more species specific than treatment specific. To eliminate species specific effects, we tested albino and wild type X. hellerii that only differed in pigment expression (i.e. were tyrosinase deficient). Although wild type fish exhibited a primary stress response to experimental handling the albino fish did not. This may suggest a role for tyrosinase in synthesizing catecholamines that provide substrate for the overall stress response. Analysis of stress recovery showed the fish returned to baseline cortisol production by 6 h, except for the albinos. This suggests albino skin is still repairing UV induced damage whereas wild type have repaired it by 6 h. Understanding the effects of stress and cortisol are important for elucidating the genetic interactions that lead to reduced immune function and/or increased susceptibility to tumorigenesis.
dc.formatText
dc.format.extent81 pages
dc.format.medium1 file (.pdf)
dc.language.isoen_US
dc.subjectCortisolen_US
dc.subjectStressen_US
dc.subjectXiphophorusen_US
dc.subjectUVBen_US
dc.subjectTyrosinaseen_US
dc.subjectHandlingen_US
dc.subjectConfinementen_US
dc.subjectRadiationen_US
dc.subjectFishen_US
dc.titleCortisol Released Due to Experimental Handling and UVB Radiation in Xiphophorus Speciesen_US
txstate.documenttypeThesis
dc.contributor.committeeMemberBooth, Rachell
thesis.degree.departmentHonors College
thesis.degree.disciplineChemistry and Biochemistry
thesis.degree.grantorTexas State University
txstate.departmentHonors College


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