The melanocortin system is a key structure in the regulation of energy balance. Overexpression of inverse agonists, agouti-signaling protein (ASIP), and agouti-related protein (AGRP) results in increased food intake, linear growth, and body weight. ASIP regulates dorsal-ventral pigment polarity through melanocortin 1 receptor (MC1R) and overexpression induces obesity in mice by binding to central MC4R. Asip1 overexpression in transgenic zebrafish (asip1-Tg) enhances growth, yet experiments show fish overexpressing Asip1 do not develop obesity even under severe feeding regimes. Asip1-Tg fish do not need to eat more to grow larger and faster; thus, increased food efficiency can be observed. In addition, asip1-Tg fish reared at high density are able to grow far more than wild-type (WT) fish reared at low density, although asip1-Tg fish seem to be more sensitive to crowding stress than WT fish, thus making the melanocortin system a target for sustainable aquaculture, especially as the U.S. Food and Drug Association has recently approved transgenic fish trading.

中文翻译：

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Agouti信号蛋白1（Asip1）过表达后在转基因斑马鱼中的生长性能。

黑皮质素系统是调节能量平衡的关键结构。反向激动剂，刺骨信号蛋白（ASIP）和刺骨相关蛋白（AGRP）的过度表达会导致食物摄入量，线性增长和体重增加。ASIP通过黑皮质素1受体（MC1R）调节背腹色素的极性，过表达通过与中枢MC4R结合诱导肥胖。Asip1在转基因斑马鱼中的过度表达（asip1- Tg）可以促进生长，但是实验表明，即使在严峻的饲养条件下，鱼的过表达Asip1也不产生肥胖。Asip1- Tg鱼不需要吃更多的东西就可以变得更大更快。因此，可以观察到食物效率的提高。另外，asip1尽管asip1 -Tg鱼似乎比WT鱼对拥挤压力更敏感，但以高密度饲养的-Tg鱼比低密度饲养的野生型（WT）鱼能生长得多。可持续水产养殖，特别是美国食品药品协会最近批准了转基因鱼类贸易。