ToxChip PCR Arrays for Two Arctic-Breeding Seabirds: Applications for Regional Environmental Assessments

Abstract

Increasing pollution in the Arctic poses challenges in terms of geographical and ecological monitoring. The Baffin Bay-Davis Strait (BBDS) region in the Canadian Arctic Archipelago is of particular concern due to the potential for increased shipping traffic and oil exploration. However, data on background contaminants associated with oil exploration/spills/natural seeps (e.g., polycyclic aromatic compounds [PAC]) and measures of potential effects for Arctic birds are limited. We developed a toxicogenomics approach to investigate the background gene expression profiles for two Arctic-breeding seabirds, the thick-billed murre (Uria lomvia) and the black guillemot (Cepphus grylle), which will aid effects-based monitoring efforts. Chemical burdens (53 PACs and 5 trace elements) and transcriptomic profiles (31 genes using a ToxChip PCR array) were examined in liver tissues (n = 30) of each species collected from the Qaqulluit and Akpait National Wildlife Areas in the BBDS region. While chemical and transcriptomic profiles demonstrated low variability across individuals for each species, gene expression signatures were able to distinguish guillemots collected from two distinct colonies. This toxicogenomics approach provides benchmark data for two Arctic seabirds and is promising for future monitoring efforts and strategic environmental assessments in this sensitive ecosystem and areas elsewhere in the circumpolar Arctic that are undergoing change.

44-Year Retrospective Analysis of Ultraviolet Absorbents and Industrial Antioxidants in Seabird Eggs from the Canadian Arctic (1975 to 2019)

“…Therefore, to understand more accurate indicators of the potential effects of contaminants on seabirds, a cumulative or integrative approach should be considered. Recently, metabolomic and toxicogenomic approaches have been applied to murres in the Canadian Arctic to explore the potential effects of groups of contaminants. , Given the higher levels of several industrial antioxidants and UV absorbents in kittiwake and fulmar eggs, future work using genomic and metabolomic measures may be useful to explore how industrial chemicals as a group may affect these Arctic seabirds.…”

Developmental and Hepatic Gene Expression Changes in Chicken Embryos Exposed to p‐Tert‐Butylphenyl Diphenyl Phosphate and Isopropylphenyl Phosphate via Egg Injection

“…Raw cycle threshold (C t ) data for the Chicken ToxChip PCR array were collected using MxPro Ver 4.10 software (Agilent Technologies). Normalized C t values (ΔC t ) were determined by trimmed mean of M values normalization using the edgeR software package for R, as described (Zahaby et al, 2021). Relative fold changes were determined by comparing expression levels between the control and treatment groups using the 2 C t −∆ method (Schmittgen & Livak, 2008).…”

Plastics as a carrier of chemical additives to the Arctic: possibilities for strategic monitoring across the circumpolar North

“…This ToxChip approach was created to identify/monitor avian populations following oil spills -a concern in the BBDS region as shipping traffic increases as a result of climate change. Zahaby et al (2021) determined contaminant burden in the livers of thickbilled murres (Uria lomvia) and black guillemont (Cepphus grylle), but also successfully distinguished between the two distinct colonies of seabirds based on the genomic expression of genes known to be associated with contaminants exposure (Zahaby et al 2021). Such novel approaches to effects monitoring are important in developing robust and consistent monitoring efforts across the pan-Arctic that consider cumulative and interactive effects of contaminants mixtures, like plastic additives When assessing the exposure, uptake, and effects of a pollutant, time is a very important factor (Newman 2009) that needs consideration.…”