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(35-01) Genetic differentiation of the metallothionein gene in different Orchesella cincta populations. Sterenborg, I.*,1, Gols, R.1, Van Gestel, C.1, Van Straalen, N.1, 1 Vrije Universiteit Amsterdam, Amsterdam, The Netherlands ABSTRACT- The adaptation of organisms to contaminants offers an interesting opportunity to study evolutionary processes. One of the best examples of natural selection is adaptation to heavy metals. Populations of the springtail Orchesella cincta living in metal polluted environments have developed tolerance for cadmium that is accomplished by increased metal retention in the midgut epithelium and excretion at every moult. It has been demonstrated that in Orchesella cincta the metal-binding protein metallothionein, that might play an important role in tolerance mechanisms, is induced upon exposure to cadmium. Tolerant individuals are expected to have duplications or other mutations of the metallothioneins in metal tolerance, Orchesella cincta collected from two metal polluted forests (Plombières and Stolberg) and one reference forest site (Savelsbos) were exposed to cadmiium in the diet at the chronic LC50 level (186 Key words: metallothionein, tolerance, Orchesella cincta, heavy metals |
g Cd/g food). Dead animals were collected daily and PCR was performed with primers specific for the Orchesella cincta metallothionein gene, followed by sequencing of the products. Animals from the reference forest Savelsbos were less tolerant to cadmium than other populations. The metallothionein gene was expressed in all populations. Preliminary results show a frameshift mutation in one individual from the metal polluted forest Stolberg, which would result in a shorter protein and possible loss of metal binding capacity.