Only effect is suppression of er. Semidominant. Exposure to 1000r of X rays from shortly after fertilization to middle of second larval instar inhibits Su(er) and er is then manifested in about 98% of flies. Tryptophan fed to larvae has similar effect. Some related compounds have a lesser effect; kynurenine and indole acetic acid have little or no effect. RK3.
Arose in: Many stocks.