Negative energy balance in a male songbird, the Abert's towhee, constrains the testicular endocrine response to luteinizing hormone stimulation

Scott Davies, Sisi Gao, Shelley Valle, Stephanie Bittner, Pierce Hutton, Simone L. Meddle, Pierre Deviche

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Energy deficiency can suppress reproductive function in vertebrates. As the orchestrator of reproductive function, endocrine activity of the hypothalamo-pituitary-gonadal (HPG) axis is potentially an important mechanism mediating such effects. Previous experiments in wildcaught birds found inconsistent relationships between energy deficiency and seasonal reproductive function, but these experiments focused on baseline HPG axis activity and none have investigated the responsiveness of this axis to endocrine stimulation. Here, we present data from an experiment in Abert's towhees, Melozone aberti, using gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) challenges to investigate whether energy deficiency modulates the plasma testosterone responsiveness of the HPG axis.Wild-caught birdswere either ad libitum fed or energetically constrained via chronic food restriction during photoinduced reproductive development. Energy deficiency did not significantly affect the development of reproductive morphology, the baseline endocrine activity of the HPG axis, or the plasma testosterone response to GnRH challenge. Energy deficiency did, however, decrease the plasma testosterone responsiveness to LH challenge. Collectively, these observations suggest that energy deficiency has direct gonadal effects consisting of a decreased responsiveness to LH stimulation. Our study, therefore, reveals a mechanism by which energy deficiency modulates reproductive function in wild birds in the absence of detectable effects on baseline HPG axis activity.

Original languageEnglish (US)
Pages (from-to)2685-2693
Number of pages9
JournalJournal of Experimental Biology
Volume218
Issue number17
DOIs
StatePublished - Sep 1 2015

Fingerprint

energy deficiencies
Songbirds
songbird
songbirds
luteinizing hormone
Luteinizing Hormone
energy balance
hormone
Testosterone
Gonadotropin-Releasing Hormone
Birds
testosterone
energy
gonadotropin-releasing hormone
Vertebrates
plasma
Food
bird
experiment
wild birds

Keywords

  • Food restriction
  • Luteinizing hormone
  • Passerine
  • Photoperiod
  • Reproductive development
  • Testosterone

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Ecology, Evolution, Behavior and Systematics
  • Molecular Biology
  • Physiology
  • Insect Science
  • Aquatic Science

Cite this

Negative energy balance in a male songbird, the Abert's towhee, constrains the testicular endocrine response to luteinizing hormone stimulation. / Davies, Scott; Gao, Sisi; Valle, Shelley; Bittner, Stephanie; Hutton, Pierce; Meddle, Simone L.; Deviche, Pierre.

In: Journal of Experimental Biology, Vol. 218, No. 17, 01.09.2015, p. 2685-2693.

Research output: Contribution to journalArticle

Davies, Scott ; Gao, Sisi ; Valle, Shelley ; Bittner, Stephanie ; Hutton, Pierce ; Meddle, Simone L. ; Deviche, Pierre. / Negative energy balance in a male songbird, the Abert's towhee, constrains the testicular endocrine response to luteinizing hormone stimulation. In: Journal of Experimental Biology. 2015 ; Vol. 218, No. 17. pp. 2685-2693.
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