Theses and Dissertations
Date of Award
12-2023
Document Type
Thesis
Degree Name
M.S.
Department
Biological Sciences
Committee Chair
Dr. Jonathan H. Perez
Advisor(s)
Dr. Jason L. Strickland and Dr. Heidi Lyn
Abstract
The regulation of reproductive physiology in animals is mediated by the Hypothalamus-Pituitary-Gonad (HPG) axis. In seasonal breeders, a conserved reciprocal switching of deiodinase enzymes alters thyroid hormone signaling, which controls HPG activity. This study tested the hypothesis that neural regulation of the HPG axis as described in seasonal systems is conserved and repurposed to respond to other cues in aseasonal species. Using water deprivation and nest restriction in the opportunistic Zebra Finch, we were able to create a breeding group and non-breeding group, confirmed by egg laying and changes in ovarian anatomy. Breeding females had clear follicular hierarchy, increased ovary mass, and follicle size, as well as elevated follicle-stimulating hormone expression. Upstream neural mechanisms showed elevated deiodinase 2 expression in non-breeding birds, while the repressive deiodinase 3 did not change between breeding groups. Ultimately, high inter-individual variation complicated interpretation and points to the need for further investigation and direct experimental manipulations of the proposed pathways. Overall, our study suggests that females are more responsive to environmental cues than males.
Recommended Citation
Moodie, Jessica A., "Unlocking the Mysteries of Opportunism: Neuroendocrine Insights from an Aseasonal Breeder (Taeniopygia guttata)" (2023). Theses and Dissertations . 176.
https://jagworks.southalabama.edu/theses_diss/176
Included in
Animal Experimentation and Research Commons, Behavior and Ethology Commons, Biology Commons, Physiology Commons, Population Biology Commons, Poultry or Avian Science Commons, Terrestrial and Aquatic Ecology Commons