長時間的飼養週期是許多生長周期較長魚種的共通缺點。儘管這些魚種通常具有較高的市場價值，但其緩慢的生長速度使其面臨更多外部風險。台灣的石斑魚便是一個典型例子，其產業發展多年間受限。因此，培育生長速度更快的石斑魚苗是當務之急。瘦素在能量恆定中扮演關鍵角色，而抑制瘦素訊號可顯著提升動物的增重能力。在本研究中，我們透過口服免疫抑制技術於體內抑制石斑魚的瘦素功能，並藉由轉錄體分析探討在瘦素抑制下的反應性基因。實驗結果顯示，自第10週起，成功建立起瘦素功能抑制的石斑魚模式。此外，與對照組相比，食物轉換率（FCR）下降了3%至12%，顯示在不同程度瘦素抑制下，石斑魚的生長效率提升。透過轉錄體與即時定量PCR分析，我們發現腦部的促食慾反應並未被活化，反而是胰島素的訊號路徑受到調動，此外，肝臟中的脂肪生成基因表現亦上升。綜合而言，瘦素免疫抑制能有效促進石斑魚的生長表現。然而，這種成效並非源於食慾刺激，而是來自脂肪生成的增強，使得魚體更容易累積體重。本研究證實了瘦素免疫抑制可促進石斑魚生長，突顯其在水產養殖產業中的應用潛力。

Prolonged culturing period is a common drawback among fish species with long growth cycles. Although these species often possess high market value, their slow growth rate exposes them to greater external risks. The grouper in Taiwan is a representative case. Its industrial development has been hindered by many years. Therefore, it is important to develop grouper fish fry with higher growth rate. Leptin play key role in energy homeostasis. Disruption of leptin signaling significantly improve weight-gaining ability of animal.
In this study, we suppress the grouper leptin function in vivo with immune-inhibition technique by oral delivery system. And investigate the responsive genes under leptin-inhibition by transcriptomic analysis. The model of leptin-inhibited grouper had been successfully built since 10th week post immunization. Besides, the food conversion ratio decreased by 3-12% compared to control, indicating improved growth rate with graded leptin inhibition. Through both transcriptome and real-time PCR analysis, the orexigenic response in the brain was not activated; instead, the insulin signaling pathway was engaged. Furthermore, the expression levels of lipogenesis genes in liver were up-regulated. Taken together, leptin immune-inhibition effectively enhanced growth performance in grouper. However, this effect did not result from appetite stimulation, but rather from metabolic modulation involving enhanced lipogenesis, which facilitated greater body weight accumulation. This study demonstrates that leptin immunosuppression promotes growth in grouper, highlighting its potential application in aquaculture.

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