Measuring corticosterone in seabird egg yolk and the presence of high yolk gestagen concentrations.

• Published in: General and Comparative Endocrinology
• Main Authors: Quillfeldt, Petra, Poisbleau, Maud, Parenteau, Charline, Trouvé, Colette, Demongin, Laurent, van Noordwijk, Hendrika J, Möstl, Erich
• Other Authors: Max Planck Institute for Ornithology, Max-Planck-Gesellschaft, Centre d'Études Biologiques de Chizé (CEBC), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Department of Biomedical Sciences, Institute of Biochemistry, University of Veterinary Medicine
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: [SDE]Environmental Sciences; Phalacrocorax atriceps
• Online Access: https://hal.science/hal-00622994; https://doi.org/10.1016/j.ygcen.2011.05.005

International audience Large inter-species differences have been found in yolk corticosterone amounts in avian eggs. While some studies have failed to detect significant amounts of corticosterone, in other species high amounts have been recorded, such as in a recent study of southern rockhopper penguins Eudyptes chrysocome chrysocome. However, attention has been drawn recently to the fact that many antibodies for corticosterone measurement cross-react with other steroids present in the yolk. In particular, progesterone and related substances can occur in yolk in high concentrations, such that also low cross-reactions of corticosterone assays may lead to measurement errors. We thus performed high-performance liquid chromatographic (HPLC) analyses of yolk extracts and determined the concentration of immunoreactive corticosterone, as well as cross-reacting progesterone and cortisol in egg yolks of southern rockhopper penguins and imperial shags Phalacrocorax atriceps albiventer. We found that high gestagen concentrations in the yolk result in large measurement errors for yolk corticosterone, even when the cross-reactivity seems small. This was observed for both species. We further found species-specific differences in the actual corticosterone amounts present in the egg yolks.