Lutz B, Kuratani S, Rugarli E I, Wawersik S, Wong C, Bieber F R, Ballabio A, Eichele G
Department of Biochemistry, Baylor College of Medicine, Houston, TX 77030.
Hum Mol Genet. 1994 Oct;3(10):1717-23. doi: 10.1093/hmg/3.10.1717.
Kallmann syndrome is an inherited disorder characterized by an abnormality in olfactory system development. The gene for the X-linked form of this disorder (KAL) maps to Xp22.3 and encodes a protein sharing homologies with molecules involved in neuronal migration and axonal pathfinding. Here we report the expression pattern of the KAL gene in various parts of the human fetal brain. We found KAL transcripts in granule cells of the olfactory bulb and the cerebellum, in the dorsomedial thalamus and in the developing cerebral cortex. To determine whether or not signals from the olfactory nerve are required for KAL expression in the olfactory bulb, we analyzed chick embryos in which the olfactory placode was surgically removed. Those embryos lacking an olfactory nerve had a histologically abnormal bulb which nevertheless expressed the KAL gene at high levels. These findings indicate that, while the development of the proper cytoarchitecture of the olfactory bulb requires the innervation by olfactory axons, the expression of KAL is independent of such developmental processes.
卡尔曼综合征是一种遗传性疾病，其特征是嗅觉系统发育异常。这种疾病的X连锁形式（KAL）的基因定位于Xp22.3，编码一种与参与神经元迁移和轴突寻路的分子具有同源性的蛋白质。在此，我们报告KAL基因在人类胎儿大脑各部位的表达模式。我们在嗅球和小脑的颗粒细胞、背内侧丘脑以及发育中的大脑皮层中发现了KAL转录本。为了确定嗅球中KAL表达是否需要来自嗅神经的信号，我们分析了手术切除嗅基板的鸡胚。那些缺乏嗅神经的胚胎嗅球在组织学上异常，但仍高水平表达KAL基因。这些发现表明，虽然嗅球正常细胞结构的发育需要嗅轴突的支配，但KAL的表达独立于这种发育过程。
