title: A cytological approach to the role of guanine in determining quinacrine fluorescence response in eukaryotic chromosomes.
abstract: Photooxidation is believed to preferentially remove guanine (G) residues from chromosomal DNA. G interspersion, moreover, has been hypothesized as quenching quinacrine (Q) fluorescence in cytological preparations. Hence, we used photooxidation as a tool for inducing possible changes in the Q-banding pattern of Drosophila melanogaster, Drosophila virilis, and Mus musculus metaphase chromosomes. An enhanced Q fluorescence, which was particularly evident in certain chromosomal regions, was found. This finding would support the postulated primary role of G in determining Q bands in eukaryotic chromosomes.
mesh_terms: D000818:Animals; D001482:Base Composition; D002871:Chromosome Banding; D004247:DNA / Q000032:analysis / Q000378:metabolism*; D004330:Drosophila; D004331:Drosophila melanogaster; D005453:Fluorescence; D006147:Guanine / Q000502:physiology*; D051379:Mice; D011796:Quinacrine / Q000378:metabolism*
chemical_list: D006147:Guanine; D004247:DNA; D011796:Quinacrine