CADMIUM-INDUCED MESSENGER-RNA ENCODING A NONMETALLOTHIONEIN 33-KDA PROTEIN IN ENCHYTRAEUS-BUCHHOLZI (OLIGOCHAETA)

Enchytraeus buchholzi (Oligochaeta) were exposed to various concentrat ions of CdCl2 in agar and aqueous solution. The Cd uptake was determin ed by atomic absorption spectroscopy as well as Cd effects on survival , reproduction, and mRNA synthesis by in vitro translation of total RN A in a rabbit reticulocyte lysate system. Although Cd was rapidly accu mulated by the worms, any acute toxic Cd effects at concentrations bel ow 4 mg Cd/liter were not detectable. However, such subtoxic Cd concen trations caused the induction of an mRNA species coding for a nonmetal lothionein 33-kDa protein as revealed by 2D electrophoresis of in vitr o translated proteins using [S-35]methionine. The Cd-induced synthesis of this transcriptionally regulated protein might be a preindicator f or a Cd intoxication in enchytraeids. (C) 1994 Academic Press, Inc.