The effects of hydrostatic pressure change on DNA integrity in the hydrothermal-vent mussel Bathymodiolus azoricus: implications for future deep-sea mutagenicity studies

Comet and agarose gel electrophoresis (AGE) assays were used to show that haemocytes (blood cells) and gill tissues of vent mussels, Bathymodiolus azoricus, are sensitive to hydrostatic pressure change, but can repair DNA damage induced by retrieval from 840 m to the sea surface. In contrast, animals collected from 1700 m survived for only a few days in the laboratory, which was reflected in their poor DNA quality. These findings support the hypothesis of a physiological barrier to survival around 1000–1500 m depth, which these results show affects both vent and non-vent species alike. Based on in vitro experimental exposures to hydrogen peroxide and MMC, vent mussels appear to have sensitivities to the environmental mutagens that are not significantly different from those of coastal mussels.