M.S. (Master of Science)
Department of Biological Sciences
DNA; Genetics; Enzymes
Recent work has suggested that the Pyr(6-A)Pyo lesion, a minor component of the DNA lesions generated after exposure to ultraviolet light, may be more mutagenic than the dominant (5-6) cyclobutane dimer. Testing this hypothesis in cells from placental mammals has not been possible because the presence of a photolyase, an enzyme capable of monomerizing the (5-6) dimer but not the (6-A) lesion, has not been clearly demonstrated. Previous experiments have demonstrated photolyase activity in a variety of embryonic chick tissues. The work described herein details the use of direct transfection and the screening of a genomic cosmid library to isolate the gene(s) encoding this photolyase. The results show the difficulties in using transfection and failure of the library to generate a phr+ transfectant. Isolated phr would be used to generate phr+ mammalian cells. Generation of photolyase-containing excision- deficient mammalian cells would allow the mutagenic and lethal effects of minor photoproducts induced by ultraviolet light to be compared to the dominant (5-6) cyclobutane dimer. Isolation of the chick photolyase gene would also enable evolutionary comparisons to be made with the E. coli and yeast phr genes.
Murley, Jeffrey S., "The infeasibiblity of isolating chick DNA photolyase gene by direct transfection of cosmid library" (1989). Graduate Research Theses & Dissertations. 5903.
vii, 114 pages
Northern Illinois University
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