Functional annotation of proteomic analysis from the hypothalamus of Leghorn layers by thyroxine induction
| Autor: | Yu-Ting Hsiung, 熊郁婷 |
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| Rok vydání: | 2015 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 103 Animals can adjust their physical, physiological, and behavioral responses such as reproduction, migration, hibernation, and molting, in response to changing lengths of sun light. Behavioral adjustment in adaption to seasonal changes is called photoperiodism. Photoreceptors detect stimulation of light. A central clock or timer translates the signals. Then the outputs of neuroendocrine information activate behaviors and ally physiological responses such as reproductive functions. In addition to the effect on energy homeostasis, thyroid hormone can also regulate reproduction. Mediobasal hypothalamus is an important center controlling photoperiodic rhythm in avian species. The level of type 2 iodothyronine deiodinase (Dio2) in the mediobasal hypothalamus increases under the long-day photoperiod to catalyze thyroxine (T4) to its active form, 3,5,3‘–triiodothyronine (T3), which in turn stimulates gonadotropin-releasing hormone (GnRH) nerve terminals located in close contact with the basal lamina for GnRH release, which then go through the hypophysial portal system to activate the pituitary-gonad axis. The c-Fos is highly expressed after neuron depolarization, and its protein product, c-Fos, tends to be used as a biomarker of neuron activation. Therefore, the aim of this study was to delineate the possible mechanisms how circulating T3 exerts effects on the hypothalamic neurons in relation to the secretion of GnRH by proteomic approaches. Leghorn hens at 50 weeks of age were given T3 (5μg/kg) or saline (1 mL/kg body weight) by intravenous injection before dark (at 6 o’clock, PM). The hypothalamuses were collected for proteomic analysis 4 hours after treatment. Results showed that 14 out of 420 quantified protein spots differed significantly by T3 induction (P < 0.05). Among the differentially expressed proteins, 6 and 8 spots were upregulated and downregulated, respectively. Most of the differentially expressed proteins are involved in metabolic pathways of energy homeostasis and formation and mobilization of cytoskeletons. Western blotting analysis confirmed the downregulation of pyruvate kinase expression by T3 induction as observed in proteomic analysis (P |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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