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dc.contributor.advisorWalter, Ronald B.
dc.contributor.authorDowns, Kevin P.
dc.date.accessioned2013-04-25T20:33:48Z
dc.date.available2013-04-25T20:33:48Z
dc.date.created2013-05
dc.date.issued2013-04-22
dc.date.submittedMay 2013
dc.identifier.urihttps://digital.library.txstate.edu/handle/10877/4539
dc.description.abstractHybrids between select Xiphophorus species have served as experimental models for UVB induced melanomagenesis. Photobiological responses observed in Xiphophorus UV inducible melanoma models support a role for DNA damage in carcinogenesis. For example, UVB induced melanomas in Xiphophorus backcross hybrids are reduced to near background levels by exposing fish to visible light, presumably to promote photoenzymatic repair (PER) of UV photoproducts. Although this biological endpoint has been well studied, little is known about the initial molecular genetic events of UVB exposure in Xiphophorus skin and how this response may be modulated by photoreactivating light (PRL). Here we report RNAseq results from adult X. maculatus exposed to UVB (6.4 kJ) or UVB plus PRL (2 hrs), where total RNA was isolated from skin after 4 hrs in the dark to allow time for gene expression. Concurrent DNA isolation allowed radioimmunoassay to quantify the major UVB photoproducts, cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone photoproducts (6-4PDs). Skin RNA was sequenced using the Illumina High-Seq platform (100 bp, PE). RNAseq reads were mapped to an X. maculatus reference transcriptome using Bowtie and relative gene expression levels compared with DESeq. Blast2GO analysis was used to assign genes functional ontology groups. In X. maculatus, genes involved in critical molecular processes such as transcription, DNA repair, and response to cellular stress displayed significantly modulated levels of expression whether PRL was present after UVB exposure or not. These expression patterns, in UVB vs. PRL exposed skin, hallmark wavelength dependent antagonistic regulatory signaling and biochemical pathways.
dc.formatText
dc.format.extent110 pages
dc.format.medium1 file (.pdf)
dc.language.isoen_US
dc.subjectXiphophorus
dc.subjectDNA repair
dc.subjectUltraviolet radiation
dc.subjectPhotoreactivating light
dc.subjectRNA sequencing
dc.subject.lcshXiphophorus--Geneticsen_US
dc.subject.lcshUltraviolet radiationen_US
dc.subject.lcshNucleotide sequenceen_US
dc.subject.lcshDNA repairen_US
dc.titleCharacterization of UVB Inducible Gene Expression in Xiphophorus Skin
txstate.documenttypeThesis
dc.contributor.committeeMemberBooth, Rachell E.
dc.contributor.committeeMemberMaeder, Corina
thesis.degree.departmentChemistry and Biochemistry
thesis.degree.disciplineBiochemistry
thesis.degree.grantorTexas State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science
txstate.departmentChemistry and Biochemistry


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