A1 Journal article (refereed)
Is maternal thyroid hormone deposition subject to a trade-off between self and egg because of iodine? : An experimental study in rock pigeon (2021)

Sarraude, T., Hsu, B.-Y., Ruuskanen, S., & Groothuis, T. (2021). Is maternal thyroid hormone deposition subject to a trade-off between self and egg because of iodine? : An experimental study in rock pigeon. Journal of Experimental Biology, 224(20), Article jeb242203. https://doi.org/10.1242/jeb.242203

JYU authors or editors

Publication details

All authors or editors: Sarraude, Tom; Hsu, Bin-Yan; Ruuskanen, Suvi; Groothuis, Ton

Journal or series: Journal of Experimental Biology

ISSN: 0022-0949

eISSN: 1477-9145

Publication year: 2021

Publication date: 15/10/2021

Volume: 224

Issue number: 20

Article number: jeb242203

Publisher: The Company of Biologists

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1242/jeb.242203

Research data link: https://doi.org/10.5281/zenodo.5024376

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/78766

Publication is parallel published: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8545739/


Maternal hormones constitute a key signalling pathway for mothers to shape offspring phenotype and fitness. Thyroid hormones (THs; triiodothyronine, T3; and thyroxine, T4) are metabolic hormones known to play crucial roles in embryonic development and survival in all vertebrates. During early developmental stages, embryos exclusively rely on exposure to maternal THs, and maternal hypothyroidism can cause severe embryonic maldevelopment. The TH molecule includes iodine, an element that cannot be synthesised by the organism. Therefore, TH production may become costly when environmental iodine availability is low. This may yield a trade-off for breeding females between allocating the hormones to self or to their eggs, potentially to the extent that it even influences the number of laid eggs. In this study, we investigated whether low dietary iodine may limit TH production and transfer to the eggs in a captive population of rock pigeons (Columba livia). We provided breeding females with an iodine-restricted (I−) diet or iodine-supplemented (I+) diet and measured the resulting circulating and yolk iodine and TH concentrations and the number of eggs laid. Our iodine-restricted diet successfully decreased both circulating and yolk iodine concentrations compared with the supplemented diet, but not circulating or yolk THs. This indicates that mothers may not be able to independently regulate hormone exposure for self and their embryos. However, egg production was clearly reduced in the I− group, with fewer females laying eggs. This result shows that restricted availability of iodine does induce a cost in terms of egg production. Whether females reduced egg production to preserve THs for themselves or to prevent embryos from exposure to low iodine and/or THs is as yet unclear.

Keywords: reproduction (biology); reproductive behaviour; nutrition; nutrients (animals and humans); iodine; hormonal effects; hormones; female parents (animals); laying eggs; birds; Columbidae

Free keywords: maternal effects; maternal hormones; maternal investment; trade-offs; birds

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2021

JUFO rating: 2

Last updated on 2022-20-09 at 13:36