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dc.contributor.advisorDieckmann, Carol L.en_US
dc.contributor.authorRoberts, Douglas Gordon Williams
dc.creatorRoberts, Douglas Gordon Williamsen_US
dc.date.accessioned2013-04-25T10:35:28Z
dc.date.available2013-04-25T10:35:28Z
dc.date.issued1999en_US
dc.identifier.urihttp://hdl.handle.net/10150/284958
dc.description.abstractChlamydomonas reinhardtii is a unicellular biflagellate green alga which has the ability to perceive external light and alter its swimming behavior in response. A specialized light sensing structure, the eyespot, is responsible for this sensory ability. The eyespot is composed of photoreceptors and signal transduction components thought to be localized to the plasma membrane of the cell, and an organized arrangement of carotenoid-filled lipid granules in the chloroplast underlying the plasma membrane. To identify the components involved in eyespot assembly, a screen for eyespot assembly mutants (Lamb, et al., 1999) identified four new loci deficient in eyespot assembly. Herein, we demonstrate the eyespot assembly mutants are generally capable photobehaviors, though the phenotype of the mutant strain affects the nature and manner in which the photobehaviors are affected. Additionally, we report on the isolation of a tagged allele of EYE2. Using DNA adjacent to the tag site, the EYE2 gene was isolated. Attempts to localize the protein in vivo were unsuccessful. The EYE2 gene encodes a protein which contains a putative thioredoxin active site motif. Transformants harboring a mutant EYE2 gene with the more C-terminal cysteine changed to serine possess eyespots and are phototactic. This substitution has only been observed to be tolerated in protein disulfide isomerases; we hypothesize that the function of EYE2 in eyespot assembly may be through the rearrangement of disulfide bonds in substrate proteins that function more directly in eyespot assembly.
dc.language.isoen_USen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.subjectBiology, Molecular.en_US
dc.subjectBiology, Cell.en_US
dc.subjectChemistry, Biochemistry.en_US
dc.titleCharacterization of the EYE2 gene required for eyespot assembly in Chlamydomonas reinhardtiien_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.identifier.proquest9946816en_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineBiochemistryen_US
thesis.degree.namePh.D.en_US
dc.description.noteThis item was digitized from a paper original and/or a microfilm copy. If you need higher-resolution images for any content in this item, please contact us at repository@u.library.arizona.edu.
dc.identifier.bibrecord.b39915219en_US
dc.description.admin-noteOriginal file replaced with corrected file September 2023.
refterms.dateFOA2018-05-26T12:55:28Z
html.description.abstractChlamydomonas reinhardtii is a unicellular biflagellate green alga which has the ability to perceive external light and alter its swimming behavior in response. A specialized light sensing structure, the eyespot, is responsible for this sensory ability. The eyespot is composed of photoreceptors and signal transduction components thought to be localized to the plasma membrane of the cell, and an organized arrangement of carotenoid-filled lipid granules in the chloroplast underlying the plasma membrane. To identify the components involved in eyespot assembly, a screen for eyespot assembly mutants (Lamb, et al., 1999) identified four new loci deficient in eyespot assembly. Herein, we demonstrate the eyespot assembly mutants are generally capable photobehaviors, though the phenotype of the mutant strain affects the nature and manner in which the photobehaviors are affected. Additionally, we report on the isolation of a tagged allele of EYE2. Using DNA adjacent to the tag site, the EYE2 gene was isolated. Attempts to localize the protein in vivo were unsuccessful. The EYE2 gene encodes a protein which contains a putative thioredoxin active site motif. Transformants harboring a mutant EYE2 gene with the more C-terminal cysteine changed to serine possess eyespots and are phototactic. This substitution has only been observed to be tolerated in protein disulfide isomerases; we hypothesize that the function of EYE2 in eyespot assembly may be through the rearrangement of disulfide bonds in substrate proteins that function more directly in eyespot assembly.


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