Does contaminant exposure disrupt maternal hormones deposition? A study on per- and polyfluoroalkyl substances in an Arctic seabird
Résumé
Maternal effects are thought to be essential tools for females to modulate offspring development. The selective deposition
of avianmaternal hormones could therefore allowfemales to strategically adjust the phenotype of their offspring
to the environmental situation encountered. However, at the time of egg formation, several contaminants are also
transferred to the egg, including per- and polyfluoroalkyl substances (PFAS) which are ubiquitous organic contaminants
with endocrine disrupting properties. It is, however, unknown if they can disruptmaternal hormone deposition.
In this study we explored relationships between female PFAS burden and maternal deposition in the eggs of steroids
(dihydrotestosterone, androstenedione and testosterone), glucocorticoids (corticosterone) and thyroid hormones
(triiodothyronine and thyroxine) in a population of the Arctic-breeding black-legged kittiwake (Rissa tridactyla). Egg
yolk hormone levels were unrelated to female hormone plasma levels. Second-laid eggs had significantly lower
concentrations of androstenedione than first-laid eggs. Triiodothyronine yolk levels were decreasing with increasing
egg mass but increasing with increasing females' body condition. Testosterone was the only transferred yolk hormone
correlated to maternal PFAS burden: specifically, we found a positive correlation between testosterone in yolks and
circulating maternal perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDcA) and perfluoroundecanoic acid
(PFUnA) in first-laid eggs. This correlative study provides a first insight into the potential of some long-chain
perfluoroalkyl acids to disrupt maternal hormones deposition in eggs and raises the question about the consequences
of increased testosterone deposition on the developing embryo.
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