Gene expression and trace elements in greenlandic ringed seals (Pusa hispida)

Marine top predators such as ringed seals biomagnify environmental contaminants; and with the increasing human activities in the Arctic, ringed seals are exposed to biologically significant concentrations of trace elements resulting in reproductive impairment, immunosuppression, and neurological dam...

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Bibliographic Details
Published in:Environmental Research
Main Authors: Boyi, Joy Ometere, Sonne, Christian, Dietz, Rune, Rigét, Frank, Siebert, Ursula, Lehnert, Kristina
Format: Article in Journal/Newspaper
Language:English
Published: 2023
Subjects:
Online Access:https://doi.org/10.1016/j.envres.2023.117839
https://elib.tiho-hannover.de/receive/tiho_mods_00010344
https://elib.tiho-hannover.de/servlets/MCRFileNodeServlet/tiho_derivate_00002616/1-s2.0-S0013935123026439-main.pdf
https://www.sciencedirect.com/science/article/pii/S0013935123026439?via%3Dihub
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Summary:Marine top predators such as ringed seals biomagnify environmental contaminants; and with the increasing human activities in the Arctic, ringed seals are exposed to biologically significant concentrations of trace elements resulting in reproductive impairment, immunosuppression, and neurological damages. Little is known about the molecular effects of heavy metals on these vulnerable apex predators suffering from a rapidly changing Arctic with significant loss of sea-ice. In the present study, concentrations of cadmium (Cd), mercury (Hg) and selenium (Se) were measured in liver of sixteen Greenlandic ringed seals (nine adults and seven subadults) together with molecular biomarkers involved in bio-transformation, oxidative stress, endocrine disruption and immune activity in blood and blubber. The concentrations of trace elements increased in the following order: Hg > Se > Cd with levels of mercury and selenium being highest in adults. Aryl hydrocarbon receptor nuclear translocator (ARNT), peroxisome proliferator activated receptor alpha (PPARα, estrogen receptor alpha (ESR1), thyroid hormone receptor alpha (TRα) and interleukin - 2 (IL-2) mRNA transcript levels were highest in blubber, while heat shock protein 70 (HSP70) and interleukin - 10 (IL-10) were significantly higher in blood. There were no significant correlations between the concentrations of trace elements and mRNA transcript levels suggesting that stressors other than the trace elements investigated are responsible for the changes in gene expression levels. Since Hg seems to increase in Greenlandic ringed seals, there is a need to re-enforce health monitoring of this ringed seal population.