title: Elucidating causes of Diporeia decline in the Great Lakes via metabolomics: physiological responses after exposure to different stressors.
abstract: The benthic macroinvertebrate Diporeia spp. have been extirpated from many areas of the Laurentian Great Lakes, but the mechanisms underlying such declines are not fully understood. Diporeia declines coinciding with the invasion of exotic dreissenid mussels (zebra and quagga) have led to the hypothesis that Diporeia declines are a result of decreased food availability from increasing competition with dreissenids for diatoms. There is additional evidence that Diporeia are negatively affected when in close proximity to dreissenids, probably because of exposure to toxins present in the mussels' pseudofeces. Diporeia are also known to be sensitive to anthropogenic contaminants (such as polychlorinated biphenyls [PCBs]) present in Great Lakes sediments. To better understand the physiological responses of Diporeia to diverse stressors, we conducted three 28-d experiments evaluating changes in the metabolomes of Diporeia (1) fed diatoms (Cyclotella meneghiniana) versus starved, (2) exposed (from Lake Michigan and Cayuga Lake) to quagga mussels (Dreissena bugensis), and (3) exposed to sediments contaminated with PCBs. The metabolomes of samples were examined using both two-dimensional gas and liquid chromatography coupled with mass spectrometry. Each stressor elicited a unique metabolome response characterized by enhanced citric acid cycle, fatty acid biosynthesis, and protein metabolism in diatom-fed Diporeia; impaired glycolysis, protein catabolism, and folate metabolism in Diporeia from Lake Michigan irrespective of quagga mussel exposure, suggesting lake-specific adaptation mechanisms; and altered cysteine and phospholipid metabolism during PCB exposure. Subsequent comparisons of these stressor-specific metabolic responses with metabolomes of a feral Diporeia population would help identify stressors affecting Diporeia populations throughout the Great Lakes.
authors: Department of Forestry and Natural Resources, Purdue University, 195 Marsteller Street, West Lafayette, IN 47907, USA. maity@bcm.edu.
authors: Suman
authors: S
authors: Maity
authors: Amber
authors: A
authors: Jannasch
authors: Jiri
authors: J
authors: Adamec
authors: James M
authors: JM
authors: Watkins
authors: Thomas
authors: T
authors: Nalepa
authors: Tomas O
authors: TO
authors: Höök
authors: Maria S
authors: MS
authors: Sepúlveda
mesh_terms: D033304:Amphipoda / Q000502:physiology*; D000818:Animals; D049872:Bivalvia / Q000502:physiology*; D002853:Chromatography, Liquid; D005243:Feces / Q000737:chemistry; D005247:Feeding Behavior; D008401:Gas Chromatography-Mass Spectrometry; D058865:Introduced Species; D060106:Lakes; D055442:Metabolome; D008824:Michigan; D009518:New York; D011078:Polychlorinated Biphenyls / Q000378:metabolism; D011157:Population Dynamics; D011897:Random Allocation; D014874:Water Pollutants, Chemical / Q000378:metabolism
chemical_list: D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls