title: Metallothionein genes from hydrothermal crabs (Bythograeidae, Decapoda): characterization, sequence analysis, gene expression and comparison with coastal crabs.
abstract: Hydrothermal vent conditions can alter DNA and hydrothermal organisms may develop detoxification mechanisms and/or genetic adaptations. Hydrothermal vent animals notably synthesize a high quantity of metallothioneins (MT). Recent studies have revealed that the levels of MT within hydrothermal crustacean tissues are higher than those found in other vent animals. To improve our understanding of the environmental impacts exerted on the vent organisms, we characterized the metallothioneins (cDNA and Mt genes) of several members of the Bythograeidae (Bythograea thermydron, Cyanagraea praedator and Segonzacia mesatlantica) which is the only endemic hydrothermal crab family. In comparison, the isolation of metallothionein cDNA was also carried out in several coastal crab families. The results showed that the hydrothermal crabs possess Mt composed of three exons and two introns presenting conserved splicing signals. The cDNA sequences isolated from distinct crabs showed multiple substitutions. In spite of the unique environmental conditions, the protein sequence analysis revealed no specific amino acid residue for the MT of the three hydrothermal crabs. However, gene expression analysis performed by real-time PCR based on S. mesatlantica (hydrothermal crab) compared to Pachygrapsus marmoratus (coastal crab) confirmed the higher metallothionein induction in hydrothermal crabs suggested by others authors.
authors.affiliation: Université du Maine, EA3265, Laboratoire de Biologie et Génétique Evolutive, Le Mans, F-72085, France. vincent.leignel@univ-lemans.fr
authors.forename: Vincent
authors.initials: V
authors.lastname: Leignel
authors.forename: Justine
authors.initials: J
authors.lastname: Marchand
authors.forename: Brigitte
authors.initials: B
authors.lastname: Moreau
authors.forename: Benoît
authors.initials: B
authors.lastname: Chénais
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001267:Atlantic Ocean; D001483:Base Sequence; D003386:Brachyura / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary; D005091:Exons; D005786:Gene Expression Regulation; D006358:Hot Temperature; D007438:Introns; D008668:Metallothionein / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010140:Pacific Ocean; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D015854:Up-Regulation
chemical_list: D018076:DNA, Complementary; D008668:Metallothionein