Polycyclic aromatic hydrocarbon exposure impairs pre-migratory fuelling in captively-dosed Sanderling (Calidris alba)

Polycyclic Aromatic Hydrocarbons Alter the Hepatic Expression of Genes Involved in Sanderling (Calidris alba) Pre‐migratory Fueling

“…However, we are confident that the dosing solution was the only source of contaminant exposure in this controlled, captive dosing study. We also remain confident—given the dose‐dependent responses previously observed at higher levels of biological organization (Bianchini and Morrissey 2018)—that our results are indicative of PAH‐induced changes in Sanderling.…”

“…Activation of the PAH‐responsive AhR pathway and a phase I response have been previously documented in other species of oil‐exposed birds (e.g., Seaside Sparrow [ Ammospiza maritima ], Perez‐Umphrey et al 2018; Bonisoli‐Alquati et al 2020; double‐crested cormorant, Alexander et al 2017). In addition, CYP1A activity is frequently measured as EROD induction, a common biomarker for PAH exposure in birds (Head et al 2015), and Bianchini and Morrissey (2018) reported elevated EROD activity in the high‐dose group relative to controls in these same birds. Collectively, this combined evidence suggests that AhR signaling was upregulated in the high‐dose group relative to controls but with high levels of interindividual variability.…”

“…Selected genes were associated with: 1) lipid homeostasis, or 2) oxidative stress or 3) AhR activation. Genes associated with lipid homeostasis were selected because changes in lipid homeostasis could directly affect pre‐migratory fueling, and these genes had associated serum components that were altered in orally dosed Sanderling (Bianchini and Morrissey 2018). Genes associated with oxidative stress and AhR activation were selected because both effects are typical biomarkers of PAH exposure (Bursian et al 2017; Willie et al 2017).…”

“…Bianchini and Morrissey (2018) previously showed that PAH ingestion impaired shorebird pre‐migratory fueling. Captive wild‐caught Sanderling ( Calidris alba ), a long‐distance migrant shorebird species, were orally dosed with environmentally relevant PAH concentrations over a 21‐d, pre‐migratory fueling period to simulate dietary PAH exposures during staging.…”

“…Our objective was to explore the molecular mechanisms underlying observed serum and whole‐body effects to link molecular‐ and organism‐level outcomes. Using liver subsamples from the same individual Sanderling (Bianchini and Morrissey 2018), we optimized 9 quantitative polymerase chain reaction (PCR) primer pairs (8 target genes and one housekeeping gene) for this species. The 8 target genes were hypothesized to be related to fat deposition and PAH exposure.…”