Induction of metallothionein mRNA in the blue crab (Callinectes sapidus) after treatment with cadmium.

1. Dietary treatment of blue crabs with cadmium led to an increase of cadmium metallothionein in the hepatopancreas. 2. Utilizing a unique purification procedure, poly A+ RNA was isolated from the hepatopancreas of control and cadmium-treated blue crabs with 260/280 nm ratios of 2.0 or better. 3. Poly A+ RNA was hybridized with a series of oligonucleotide probes derived from a portion of the amino acid sequence of lobster metallothionein. A single band of approx. 300 base pairs was present in control and cadmium-treated RNA from the hepatopancreas of blue crab. 4. A four-fold induction of the band occurred following cadmium exposure.