Kaelin Christopher B, Xu Allison Wanting, Lu Xin-Yun, Barsh Gregory S
Department of Genetics, Stanford University School of Medicine, Stanford, California 94305-5323, USA.
Endocrinology. 2004 Dec;145(12):5798-806. doi: 10.1210/en.2004-0956. Epub 2004 Sep 2.
Agouti-related protein (Agrp) encodes a hypothalamic neuropeptide that promotes positive energy balance by stimulating food intake and reducing energy expenditure. Agrp expression in the brain is restricted to neurons within the arcuate nucleus of the hypothalamus, and expression levels are elevated as a consequence of food deprivation. We tested a series of bacterial artificial chromosome reporter constructs with varying amounts of sequence flanking the Agrp transcription unit in transgenic mice to identify and refine a region of DNA capable of recapitulating characteristics of Agrp expression. We report that a 42.5-kb region upstream of Agrp, containing three distinct regions that are evolutionarily conserved between mouse and human, is necessary and sufficient to consistently drive reporter expression specifically within AgRP neurons in a fasting-responsive manner. In addition, we demonstrate that this region allows for the stable expression of Cre recombinase in transgenic mice, providing a genetic tool for studying anabolic neural circuits that control energy balance.
刺鼠相关蛋白（Agrp）编码一种下丘脑神经肽，它通过刺激食物摄入和减少能量消耗来促进正能量平衡。Agrp在大脑中的表达局限于下丘脑弓状核内的神经元，并且由于食物剥夺，其表达水平会升高。我们在转基因小鼠中测试了一系列细菌人工染色体报告基因构建体，这些构建体在Agrp转录单元两侧具有不同数量的序列，以鉴定和优化能够重现Agrp表达特征的DNA区域。我们报告称，Agrp上游42.5 kb的区域，包含在小鼠和人类之间进化保守的三个不同区域，对于以禁食反应方式在AgRP神经元内持续驱动报告基因表达是必要且充分的。此外，我们证明该区域允许Cre重组酶在转基因小鼠中稳定表达，为研究控制能量平衡的合成代谢神经回路提供了一种遗传工具。
