title: Linking sub-cellular biomarkers to embryo aberrations in the benthic amphipod Monoporeia affinis.
abstract: To adequately assess and monitor environmental status in the aquatic environment a broad approach is needed that integrates physical variables, chemical analyses and biological effects at different levels of the biological organization. Embryo aberrations in the Baltic Sea key species Monoporeia affinis can be induced by both metals and organic substances as well as by hypoxia, increasing temperatures and malnutrition. This amphipod has therefore been used for more than three decades as a biological effect indicator in monitoring and assessment of chemical pollution and environmental stress. However, little is known about the sub-cellular mechanisms underlying embryo aberrations. An improved mechanistic understanding may open up the possibility of including sub-cellular alterations as sensitive warning signals of stress-induced embryo aberrations. In the present study, M. affinis was exposed in microcosms to 4 different sediments from the Baltic Sea. After 88-95 days of exposure, survival and fecundity were determined as well as the frequency and type of embryo aberrations. Moreover, oxygen radical absorption capacity (ORAC) was assayed as a proxy for antioxidant defense, thiobarbituric acid reactive substances (TBARS) level as a measure of lipid peroxidation and acetylcholinesterase (AChE) activity as an indicator of neurotoxicity. The results show that AChE and ORAC can be linked to the frequency of malformed embryos and arrested embryo development. The occurrence of dead broods was significantly associated with elevated TBARS levels. It can be concluded that these sub-cellular biomarkers are indicative of effects that could affect Darwinian fitness and that oxidative stress is a likely mechanism in the development of aberrant embryos in M. affinis.
authors.affiliation: Department of Environmental Science and Analytical Chemistry, Stockholm University, Svante Arrhenius väg 8, SE-106 91 Stockholm, Sweden. Electronic address: martin.reutgard@gmail.com.
authors.forename: Martin
authors.initials: M
authors.lastname: Reutgard
authors.affiliation: Department of Environmental Science and Analytical Chemistry, Stockholm University, Svante Arrhenius väg 8, SE-106 91 Stockholm, Sweden. Electronic address: sara.furuhagen@aces.su.se.
authors.forename: Sara
authors.initials: S
authors.lastname: Furuhagen
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis; D033304:Amphipoda / Q000187:drug effects* / Q000196:embryology; D000818:Animals; D015415:Biomarkers / Q000032:analysis*; D004625:Embryo, Nonmammalian / Q000187:drug effects; D004781:Environmental Exposure; D005298:Fertility / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D016019:Survival Analysis; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D017392:Thiobarbituric Acid Reactive Substances; D014874:Water Pollutants, Chemical; D000110:Acetylcholinesterase
keywords: Acetylcholinesterase; Darwinian fitness; Embryo aberrations; Monoporeia affinis; Oxidative stress