A Study of genetic instability and DNA repair in selected mutants of streptomyces cattleya

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dc.contributor.advisorKirby, Ralphen_ZA
dc.contributor.authorHromic, Almaen_ZA
dc.date.accessioned2016-09-25T16:46:56Z
dc.date.available2016-09-25T16:46:56Z
dc.date.issued1987en_ZA
dc.descriptionBibliography : pages 164-179.en_ZA
dc.description.abstractThree mutants of Streptomyces cattleya NRRL 8057 with lesions in the DNA repair pathway were obtained by NTG mutagenesis. The mutants were selected on the basis of their resistance or sensitivity to Mitomycin c. Of the three mutants, two, R6 and Rl2, were selected as MMC resistant and one, S26, as MMC sensitive. They were also UVr and UVˢ, respectively. The mutants were subjected to UV irradiation in order to obtain UV kill curves. The curves generated for the two MMCʳ mutants showed induction or derepression of a second repair system. In instability studies performed on them, the two MMCʳ mutants showed increased instability compared to the wild type at low UV dosage. However, the instability dropped to below that of the wild type at high UV dosages. Both these mutants appeared to roughly mimic the plateau shown by the wild type as higher levels of UV irradiation were achieved. S26 in contrast showed a much higher initial incidence of instability, and no plateau was observed at high UV dosages. Single strand breaks were induced in the wild type and mutant strains by incorporation of P³² into their DNA. R6 showed a five-fold increase in instability after this treatment. Rl2 showed no significant change, and S26 showed a slight decrease, which may be due to the increased lethality of DNA damage sustained by this strain due to its relatively labile nature. The strains were further analysed using polyacrylamide gel electrophoresis of total cellular proteins. S26 showed a startlingly different protein profile. R6 was almost identical to the wild type, while Rl2 was extremely similar, showing only the loss of one major band and a significant lowering of the amount of detectable protein in the region below this band.en_ZA
dc.identifier.apacitationHromic, A. (1987). <i>A Study of genetic instability and DNA repair in selected mutants of streptomyces cattleya</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Molecular and Cell Biology. Retrieved from http://hdl.handle.net/11427/21897en_ZA
dc.identifier.chicagocitationHromic, Alma. <i>"A Study of genetic instability and DNA repair in selected mutants of streptomyces cattleya."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Molecular and Cell Biology, 1987. http://hdl.handle.net/11427/21897en_ZA
dc.identifier.citationHromic, A. 1987. A Study of genetic instability and DNA repair in selected mutants of streptomyces cattleya. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Hromic, Alma AB - Three mutants of Streptomyces cattleya NRRL 8057 with lesions in the DNA repair pathway were obtained by NTG mutagenesis. The mutants were selected on the basis of their resistance or sensitivity to Mitomycin c. Of the three mutants, two, R6 and Rl2, were selected as MMC resistant and one, S26, as MMC sensitive. They were also UVr and UVˢ, respectively. The mutants were subjected to UV irradiation in order to obtain UV kill curves. The curves generated for the two MMCʳ mutants showed induction or derepression of a second repair system. In instability studies performed on them, the two MMCʳ mutants showed increased instability compared to the wild type at low UV dosage. However, the instability dropped to below that of the wild type at high UV dosages. Both these mutants appeared to roughly mimic the plateau shown by the wild type as higher levels of UV irradiation were achieved. S26 in contrast showed a much higher initial incidence of instability, and no plateau was observed at high UV dosages. Single strand breaks were induced in the wild type and mutant strains by incorporation of P³² into their DNA. R6 showed a five-fold increase in instability after this treatment. Rl2 showed no significant change, and S26 showed a slight decrease, which may be due to the increased lethality of DNA damage sustained by this strain due to its relatively labile nature. The strains were further analysed using polyacrylamide gel electrophoresis of total cellular proteins. S26 showed a startlingly different protein profile. R6 was almost identical to the wild type, while Rl2 was extremely similar, showing only the loss of one major band and a significant lowering of the amount of detectable protein in the region below this band. DA - 1987 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1987 T1 - A Study of genetic instability and DNA repair in selected mutants of streptomyces cattleya TI - A Study of genetic instability and DNA repair in selected mutants of streptomyces cattleya UR - http://hdl.handle.net/11427/21897 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/21897
dc.identifier.vancouvercitationHromic A. A Study of genetic instability and DNA repair in selected mutants of streptomyces cattleya. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Molecular and Cell Biology, 1987 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/21897en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Molecular and Cell Biologyen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherMicrobiologyen_ZA
dc.titleA Study of genetic instability and DNA repair in selected mutants of streptomyces cattleyaen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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