ABSTRACT
Lethality induced in larval populations of Drosophila melanogaster was recorded after treatment with (1) caffeine, (2) MMS or (3) caffeine plus MMS. The mixture of caffeine plus MMS was less toxic than expected from the effects observed after treatment with either substance individually. It is postulated that in the combined treatment the caffeine, by inhibiting semiconservative DNA replication, allows for some additional time for repair of alkylated DNA by a repair pathway which is not sensitive to caffeine, possibly excision repair.
Subject(s)
Caffeine/pharmacology , Drosophila melanogaster/genetics , Genes, Lethal , Mesylates/antagonists & inhibitors , Methyl Methanesulfonate/antagonists & inhibitors , Animals , DNA Repair/drug effects , DNA Replication/drug effects , Drosophila melanogaster/drug effects , Larva/genetics , Methyl Methanesulfonate/pharmacology , Mutagens , MutationABSTRACT
Larvae of Drosophila melanogaster were fed with caffeine, and the induced lethality was recorded using two different methods. With a wild-type strain a whole dose-response curve was obtained. The two sexes were equally sensitive. Four genetically different strains, showing different MMS sensitivities, were tested with two caffeine doses. The strains differed significantly in their caffeine sensitivity, but there existed no correlation between MMS and caffeine sensitivity.
