Sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals
Many polygynous, capital breeders exhibit sexual dimorphism with respect to body size and composition. Sexual dimorphism is often facilitated by sex differences in foraging behavior, growth rates and patterns of nutrient deposition during development. In species that undergo extended fasts during de...
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fthighwire:oai:open-archive.highwire.org:jexbio:215/15/2637 2023-05-15T16:05:39+02:00 Sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals Kelso, Elizabeth J. Champagne, Cory D. Tift, Michael S. Houser, Dorian S. Crocker, Daniel E. 2012-08-01 00:00:00.0 text/html http://jeb.biologists.org/cgi/content/short/215/15/2637 https://doi.org/10.1242/jeb.068833 en eng Company of Biologists http://jeb.biologists.org/cgi/content/short/215/15/2637 http://dx.doi.org/10.1242/jeb.068833 Copyright (C) 2012, Company of Biologists Research Articles TEXT 2012 fthighwire https://doi.org/10.1242/jeb.068833 2013-05-26T19:10:28Z Many polygynous, capital breeders exhibit sexual dimorphism with respect to body size and composition. Sexual dimorphism is often facilitated by sex differences in foraging behavior, growth rates and patterns of nutrient deposition during development. In species that undergo extended fasts during development, metabolic strategies for fuel use have the potential to influence future reproductive success by directly impacting somatic growth and acquisition of traits required for successful breeding. We investigated sexual dimorphism associated with metabolic strategies for fasting in developing northern elephant seals. Thirty-one juvenile seals of both sexes were sampled over extended fasts during annual autumn haul-outs. Field metabolic rate (FMR) and the contribution of protein catabolism to energy expenditure were estimated from changes in mass and body composition over 23±5 days of fasting (mean ± s.d.). Protein catabolism was assessed directly in a subset of animals based on urea flux at the beginning and end of the fast. Regulatory hormones and blood metabolites measured included growth hormone, cortisol, thyroxine, triiodothyronine, insulin, glucagon, testosterone, estradiol, glucose, urea and β-hydroxybutyrate. Males exhibited higher rates of energy expenditure during the fast but spared body protein stores more effectively than females. Rates of protein catabolism and energy expenditure were significantly impacted by hormone levels, which varied between the sexes. These data suggest that sex differences in fuel metabolism and energy expenditure during fasting arise early in juvenile development and may play an important role in the development of adult traits associated with reproductive success. Text Elephant Seals HighWire Press (Stanford University) Journal of Experimental Biology 215 15 2637 2645 |
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Research Articles |
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Research Articles Kelso, Elizabeth J. Champagne, Cory D. Tift, Michael S. Houser, Dorian S. Crocker, Daniel E. Sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals |
topic_facet |
Research Articles |
description |
Many polygynous, capital breeders exhibit sexual dimorphism with respect to body size and composition. Sexual dimorphism is often facilitated by sex differences in foraging behavior, growth rates and patterns of nutrient deposition during development. In species that undergo extended fasts during development, metabolic strategies for fuel use have the potential to influence future reproductive success by directly impacting somatic growth and acquisition of traits required for successful breeding. We investigated sexual dimorphism associated with metabolic strategies for fasting in developing northern elephant seals. Thirty-one juvenile seals of both sexes were sampled over extended fasts during annual autumn haul-outs. Field metabolic rate (FMR) and the contribution of protein catabolism to energy expenditure were estimated from changes in mass and body composition over 23±5 days of fasting (mean ± s.d.). Protein catabolism was assessed directly in a subset of animals based on urea flux at the beginning and end of the fast. Regulatory hormones and blood metabolites measured included growth hormone, cortisol, thyroxine, triiodothyronine, insulin, glucagon, testosterone, estradiol, glucose, urea and β-hydroxybutyrate. Males exhibited higher rates of energy expenditure during the fast but spared body protein stores more effectively than females. Rates of protein catabolism and energy expenditure were significantly impacted by hormone levels, which varied between the sexes. These data suggest that sex differences in fuel metabolism and energy expenditure during fasting arise early in juvenile development and may play an important role in the development of adult traits associated with reproductive success. |
format |
Text |
author |
Kelso, Elizabeth J. Champagne, Cory D. Tift, Michael S. Houser, Dorian S. Crocker, Daniel E. |
author_facet |
Kelso, Elizabeth J. Champagne, Cory D. Tift, Michael S. Houser, Dorian S. Crocker, Daniel E. |
author_sort |
Kelso, Elizabeth J. |
title |
Sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals |
title_short |
Sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals |
title_full |
Sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals |
title_fullStr |
Sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals |
title_full_unstemmed |
Sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals |
title_sort |
sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals |
publisher |
Company of Biologists |
publishDate |
2012 |
url |
http://jeb.biologists.org/cgi/content/short/215/15/2637 https://doi.org/10.1242/jeb.068833 |
genre |
Elephant Seals |
genre_facet |
Elephant Seals |
op_relation |
http://jeb.biologists.org/cgi/content/short/215/15/2637 http://dx.doi.org/10.1242/jeb.068833 |
op_rights |
Copyright (C) 2012, Company of Biologists |
op_doi |
https://doi.org/10.1242/jeb.068833 |
container_title |
Journal of Experimental Biology |
container_volume |
215 |
container_issue |
15 |
container_start_page |
2637 |
op_container_end_page |
2645 |
_version_ |
1766401552451371008 |