Lethal mutations induced in Drosophila melanogaster by direct or indirect action of pteridines.

The experiments described in this paper show that synthetic pteridines, especially biopterin and pterin, injected directly into Drosophila melanogaster induce recessive lethals. On the contrary, D-neopterin seems to have little effect. A mutagenic effect has previously been shown for an extract of Pieris brassicae in diapause, treated with these pteridines and tetrahydrofolic acid (FH4). It appears that chromosome II is more sensitive to these mutagenic treatments than chromosome X.