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|Title: ||點帶石斑( Epinephelus coioides )攝食調控因子-神經胜肽(Neuropeptide Y)基因之分子選殖及特性分析與其對攝食行為之影響|
Molecular cloning and characterization of feeding regulator-Neuropeptide Y and its impact on feeding behavior of orange-spotted grouper ( Epinephelus coioides )
|Authors: ||Chia-Hsuan Sung|
|Contributors: ||NTOU:Department of Aquaculture|
neuropeptide Y;feeding behavior
|Issue Date: ||2011-06-30T08:39:49Z
|Abstract: ||神經胜肽Y（neuropeptide Y，NPY）廣泛的分佈於生物體中樞神經系統及周邊神經系統，經由NPY受體的作用對於攝食、攝食行為、生長、生殖、性轉變和血壓等生理現象進行調控。本實驗之目的為研究點帶石斑（Epinephelus coioides）攝食調控因子-NPY基因之分子特性及其對攝食行為之影響。根據已知魚類分離出的NPY基因之胺基酸及核酸序列設計退化性引子以點帶石斑腦部組織之cDNA使用RT-PCR、及RACE方法進行NPY基因選殖。本研究所選殖出NPY基因全長之cDAN序列為672個核苷酸，可轉譯出99個演譯胺基酸序列。NPY基因結構由四個編碼子及三個插入子所組成。NPY蛋白質3-D結構N端包含一個隨意螺線（random coil）及C端包含一個α螺旋（α helix）。 經由RT-PCR分析結果顯示點帶石斑NPY基因會表現在腦、鰓、肝、胃。在攝食前NPY基因的表現量會隨著饑餓感的增加而上升，在開始攝食時基因表現量達到最高，攝食後NPY基因表現量快速下降。連續饑餓時NPY基因的表現量會隨著饑餓時間增加而增加（time-related）。限制攝食量的石斑其NPY基因的表現量會隨著不飽足感的持續而維持高量。胚胎發育時期，NPY基因在仔魚開口與開始自行攝食時表現量為最高。有厭食（anorexia）現象的點帶石斑腦組織中NPY基因的表現量明顯較低。以甜菜鹼及大蒜精作為誘引劑可以明顯刺激點帶石斑腦組織NPY基因的表現。腦室內注射合成grNPY可以促進石斑的攝食量，且是以劑量相關的模式影響點帶石斑平均進食量。本研究證實NPY扮演一重要的攝食調控因子，刺激點帶石斑的攝食行為的產生以及促進攝食。|
Neuropeptide Y (NPY) is widely distributed in the central and peripheral nervous system. It has been shown that NPY would involve in regulation of feeding behavior, food intake, growth, reproduction, sex reversal and regulation of blood pressure. NPY mediates it effects on its regulation via Y receptors which belong to the G-protein-coupled receptor superfamily. In this study, we have cloned and characterization of the full-length cDNA of NPY gene from orange-spotted grouper (Epinephelus coioides). Grouper full-length NPY cDNA was 672bp in length and deduced 280 amino acids. The genomic DNA structure of NPY was composed of four exons and three introns. Semi-quantitative RT-PCR analysis showed NPY gene dominant expressed in brain. Grouper maintained on a scheduled feeding regimen display rapid and sequential changes in NPY mRNA level in brain 1-2 hr before the scheduled feeding time, and then level decrease by 40-50% at 1 and 2 hr after scheduled feeding regimen. Food deprivation result in a significant, time-related, and brain specific increased in NPY mRNA level. Restriction of daily feed ration also resulted in increasing NPY gene expression in brain as well. Ontology study of NPY gene expression in post-hatching larvae indicated that NPY gene expression was significantly increased at mouth opening stage and start to feeding. Lower NPY mRNA was found in anorexia grouper. Two potent attractants, betaine and garlic extract, could stimulate NPY gene expression in brain at very low concentration. Brain intracerebroventricular (i.c.v) injection of synthetic grouper NPY showed the stimulation of food intake with dose-dependent manner in orange-spotted grouper. In the present study, we have demonstrated that NPY play a key role and serve as a potent feeding regulator in regulation of food intake in grouper.
|Appears in Collections:||[水產養殖學系] 博碩士論文|
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