Short- and long-term effects of nutritional state on IGF-1 levels in nestlings of a wild passerine

Lodjak, J., Boonekamp, J. , Lendvai, Á. Z. and Verhulst, S. (2023) Short- and long-term effects of nutritional state on IGF-1 levels in nestlings of a wild passerine. Oecologia, 203, pp. 27-35. (doi: 10.1007/s00442-023-05445-3) (PMID:37676486) (PMCID:PMC10615909)

Abstract

Growth trajectories of young animals are intimately connected to their fitness prospects, but we have little knowledge of growth regulation mechanisms, particularly in the wild. Insulin-like growth factor 1 (IGF-1) is a central hormone in regulating resource allocation, with higher IGF-1 levels resulting in more growth. IGF-1 levels generally increase in conjunction with nutritional state, but whether IGF-1 levels are adjusted in response to current nutrient availability or to the nutrient availability integrated over a longer term is not well known. We tested for such effects by supplementary feeding the jackdaw (Corvus monedula) nestlings in experimentally reduced or enlarged broods with either water (control) or a food solution; these manipulations have long- and short-term effects on the nutritional state, respectively. Baseline plasma IGF-1 levels were higher in reduced broods. Food supplementation induced an increase in plasma IGF-1 levels measured one hour later, and this effect was significantly more substantial in nestlings in reduced broods. Changes in plasma IGF-1 levels increased with increased retention of the supplementary food, which was higher in reduced broods, explaining the stronger IGF-1 response. Thus, IGF-1 levels respond to short-term variations in the nutritional state, but this effect is amplified by longer-term variations in the nutritional state. We discuss our findings using a graphical model that integrates the results of the two treatments.

• Item Type: Articles
• Additional Information: Funding: Eesti Teadusagentuur, PUTJD700; Jaanis Lodjak, MOBTP169; Jaanis Lodjak, National Research, Development and Innovation Ofce (HU), K139021, Ádám Z. Lendvai.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Boonekamp, Dr Jelle
• Authors: Lodjak, J., Boonekamp, J., Lendvai, Á. Z., and Verhulst, S.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Oecologia
• Publisher: Springer
• ISSN: 0029-8549
• ISSN (Online): 1432-1939
• Published Online: 07 September 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Oecologia 203:27–35
• Publisher Policy: Reproduced under a Creative Commons licence