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dc.contributor.advisorXiao, Weien_US
dc.contributor.advisorWang, Hongen_US
dc.creatorWANG, SHENGen_US
dc.date.accessioned2013-02-26T12:00:20Z
dc.date.available2013-02-26T12:00:20Z
dc.date.created2011-12en_US
dc.date.issued2013-02-25en_US
dc.date.submittedDecember 2011en_US
dc.identifier.urihttp://hdl.handle.net/10388/ETD-2011-12-222en_US
dc.description.abstractDNA-damage tolerance (DDT) in yeast is composed of two parallel pathways and mediated by sequential ubiquitination of proliferating cell nuclear antigen (PCNA). While monoubiquitination of PCNA promotes translesion synthesis (TLS), which is dependent on low fidelity polymerase ζ (Pol ζ) composed of a catalytic subunit Rev3 and a regulatory subunit Rev7, polyubiquitination of PCNA by Mms2-Ubc13-Rad5 promotes error-free lesion bypass. Inactivation of these two pathways results in a synergistic effect on DNA-damage responses; however, this two-branch DDT model has not been reported in any multicellular organisms. In order to examine whether Arabidopsis thaliana possesses a two-branch DDT system, rad5a rev3 double mutant plants were created and compared with the corresponding single mutants. Arabidopsis rad5a and rev3 mutations are indeed synergistic with respect to growth inhibition induced by replication-blocking lesions, suggesting that AtRAD5a and AtREV3 are required for error-free and TLS branches of DDT, respectively. Unexpectedly this study reveals three modes of genetic interactions in response to different types of DNA damage, indicating that plant RAD5 and REV3are also involved in DNA damage responses independent of DDT. By comparing with yeast cells, it is apparent that plant TLS is a more frequently utilized means of lesion bypass than error-free DDT. In addition, it was also observed that treatments with the DNA damaging agent methylmethanesulfonate increased the nuclear ploidy level in the double mutant plants.en_US
dc.language.isoengen_US
dc.subjectDNA-damage tolerance (DDT), Yeast, Arabidopsis, translesion synthesis (TLS), error-free lesion bypassen_US
dc.titleRAD5a and REV3 Function in Two Alternative Pathways of DNA Damage Tolerance in Arabidopsisen_US
thesis.degree.departmentMicrobiology and Immunologyen_US
thesis.degree.disciplineMicrobiology and Immunologyen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Science (M.Sc.)en_US
dc.type.materialtexten_US
dc.type.genreThesisen_US
dc.contributor.committeeMemberCulter, Adrianen_US
dc.contributor.committeeMemberGoldie, Hughesen_US


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