Terrestrial snails (Gastropoda) possess Cd-selective metallothioneins (CdMTs) that inactivate Cd
2+ with high affinity. Most of these MTs are small Cysteine-rich proteins that bind 6 Cd
2+ equivalents within two distinct metal-binding domains, with a binding stoichiometry of 3 Cd
2+ ions per
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Terrestrial snails (Gastropoda) possess Cd-selective metallothioneins (CdMTs) that inactivate Cd
2+ with high affinity. Most of these MTs are small Cysteine-rich proteins that bind 6 Cd
2+ equivalents within two distinct metal-binding domains, with a binding stoichiometry of 3 Cd
2+ ions per domain. Recently, unusually large, so-called multi-domain MTs (md-MTs) were discovered in the terrestrial door snail
Alinda biplicata (A.b.). The aim of this study is to evaluate the ability of
A.b. to cope with Cd stress and the potential involvement of md-MTs in its detoxification. Snails were exposed to increasing Cd concentrations, and Cd-tissue concentrations were quantified. The gene structure of two
md-MTs (
9md-MT and
10md-MT) was characterized, and the impact of Cd exposure on
MT gene transcription was quantified via qRT PCR.
A.b. efficiently accumulates Cd at moderately elevated concentrations in the feed, but avoids food uptake at excessively high Cd levels. The structure and expression of the long
md-MT genes of
A.b. were characterized. Although both genes are intronless, they are still transcribed, being significantly upregulated upon Cd exposure. Overall, our results contribute new knowledge regarding the metal handling of
Alinda biplicata in particular, and the potential role of md-MTs in Cd detoxification of terrestrial snails, in general.
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