QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online November 10, 2003

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vézina, F. Articles by Williams, T. D. Search for Related Content PubMed PubMed Citation Articles by Vézina, F. Articles by Williams, T. D. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB ESTRADIOL Social Bookmarking                         What's this?

The Journal of Experimental Biology 206, 4443-4451 (2003)
doi: 10.1242/jeb.00702

The metabolic cost of avian egg formation: possible impact of yolk precursor production?

François Vézina^*, Katrina G. Salvante and Tony D. Williams

Department of Biological Sciences, Simon Fraser University, Burnaby, 8888 University Drive, Burnaby, V5A 1S6, Canada

^* Author for correspondence (e-mail: fvezina{at}sfu.ca)

Accepted 2 September 2003

Little is known about the energy costs of egg production in birds. We showed in previous papers that, during egg production, European starlings (Sturnus vulgaris) undergo a 22% increase in resting metabolic rate (RMR) and that the maintenance and activity costs of the oviduct are responsible for 18% of the variation in elevated laying RMR. Therefore, other energy-consuming physiological mechanisms must be responsible for the remaining unexplained variation in elevated laying RMR. Yolk precursor [vitellogenin (VTG) and very-low-density lipoprotein (VLDL)] production is likely to be costly because it signifies a marked increase in the biosynthetic activity of the liver. We documented the pattern of yolk precursor production in response to daily injections of 17ß-estradiol (E₂) in zebra finches (Taeniopygia guttata). Based on this pattern we carried out an experiment in order to evaluate the metabolic costs of producing VTG and VLDL. Our E₂ treatment resulted in a significant increase in plasma VTG and VLDL levels within the natural breeding range for the species. Although RMR was measured during the period of active hepatic yolk precursor production, it did not differ significantly within individuals in response to the treatment or when comparing E₂-treated birds with sham-injected birds. This could mean that yolk precursor production represents low energy investment. However, we discuss these results in light of possible adjustments between organs that could result in energy compensation.

Key words: egg production, energy cost, resting metabolic rate, RMR, vitellogenin, very-low-density lipoprotein, zebra finch, Taeniopygia guttata, yolk precursor production

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				S. P. Caro and M. E. Visser Temperature-induced elevation of basal metabolic rate does not affect testis growth in great tits J. Exp. Biol., July 1, 2009; 212(13): 1995 - 1999. [Abstract] [Full Text] [PDF]

				E. C. Wagner, J. S. Prevolsek, K. E. Wynne-Edwards, and T. D. Williams Hematological changes associated with egg production: estrogen dependence and repeatability J. Exp. Biol., February 1, 2008; 211(3): 400 - 408. [Abstract] [Full Text] [PDF]

				F. Vezina and T. D. Williams The metabolic cost of egg production is repeatable J. Exp. Biol., July 1, 2005; 208(13): 2533 - 2538. [Abstract] [Full Text] [PDF]

				K. Phillips EFFORTLESS EGG LAYING? J. Exp. Biol., December 15, 2003; 206(24): 4381 - 4381. [Full Text] [PDF]