Abstract

In Drosophila melanogaster the frequency of adults with melanotic tumors increases both when .larvae from genetically normal and genetically melanotic tum0r strains are exposed to nutrient containing silver nitrate. Larval nutrient containing sodium fluoride also has this effect on genetically normal individuals. The present work was performed to test simultaneously the melanotic tumorigenic
capacity of sodium fluoride in two different genetic lines in which such tumors normally occur or do not occur with appreciable frJ1quency.

. . . .

In D. Melanogaster, when larvae are grown in nutrient containing different concentrations of NaF, the tu-soj strain, which normally has a relatively strong genetic predisposition for the formation of melanotic tumors, demonstrates a significantly higher rate of induced melanotic tumors in the adult stage than does the wild·type Oregon R strain, which normally has a relatively weak genetic predisposition in this respect.

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