Muglia L J, Jenkins N A, Gilbert D J, Copeland N G, Majzoub J A
Division of Endocrinology, Children's Hospital, Boston, Massachusetts 02115.
J Clin Invest. 1994 May;93(5):2066-72. doi: 10.1172/JCI117201.
Corticotropin-releasing hormone (CRH), one of the primary regulators of the hypothalamic-pituitary-adrenal (HPA) axis, exhibits abnormal regulation in pathologic states such as depression and anorexia nervosa. Analysis of the role of CRH in regulation of the HPA axis would be facilitated by the creation of animal models in which CRH gene structure and function could be manipulated. We have determined the DNA sequence of the mouse CRH gene. Using a highly sensitive reverse transcription-polymerase chain reaction method, we have found expression of CRH mRNA in adrenal, ovary, testis, gut, heart, anterior pituitary, lung, and spleen, in addition to cerebral cortex and hypothalamus. Within the spleen, CRH mRNA is localized specifically to T-lymphocytes. We mapped the chromosomal location of mouse CRH via interspecific mouse backcrosses to chromosome 3, which is not the site of any naturally occurring mutations consistent with CRH deficiency. Because of this, we inactivated a CRH allele in mouse embryonic stem (ES) cells by homologous recombination with a mutant mouse CRH gene lacking the entire coding region of preproCRH. Mice chimeric for each of two ES clones with an inactivated CRH allele are being used to generate animals with complete CRH deficiency.
促肾上腺皮质激素释放激素（CRH）是下丘脑 - 垂体 - 肾上腺（HPA）轴的主要调节因子之一，在诸如抑郁症和神经性厌食症等病理状态下表现出异常调节。创建能够操纵CRH基因结构和功能的动物模型将有助于分析CRH在HPA轴调节中的作用。我们已经确定了小鼠CRH基因的DNA序列。使用高度灵敏的逆转录 - 聚合酶链反应方法，我们发现除了大脑皮层和下丘脑外，CRH mRNA在肾上腺、卵巢、睾丸、肠道、心脏、垂体前叶、肺和脾脏中也有表达。在脾脏内，CRH mRNA特异性定位于T淋巴细胞。我们通过种间小鼠回交将小鼠CRH的染色体定位到3号染色体，而3号染色体并非与CRH缺乏一致的任何自然发生突变的位点。因此，我们通过与缺乏前阿黑皮素原（preproCRH）整个编码区的突变小鼠CRH基因进行同源重组，在小鼠胚胎干细胞（ES细胞）中使一个CRH等位基因失活。利用两个带有失活CRH等位基因的ES克隆构建的嵌合小鼠正在用于培育完全缺乏CRH的动物。
