Characterization of cis-regulatory elements of the homeobox gene Xanf-1
Characterization of cis-regulatory elements of the homeobox gene Xanf-1
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DOI：
10.1016/s0378-1119(02)00393-1
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发表时间：
2002-02-20
期刊：
影响因子：
3.5
通讯作者：
Zaraisky, A
中科院分区：
文献类型：
--
作者：
Eroshkin, F;Kazanskaya, O;Zaraisky, A
研究神经系统早期模式形成的分子机制是现代发育生物学的重要任务。在此之前，我们发现了一个新的同源异型盒基因ANF，它在神经外胚层指定的最前部区域表达。ANF的表达模式对应于端脑的原基和间脑的吻侧部分。在本工作中，我们研究了非洲爪哇ANF，XANF-1的顺式表达调控。在Xanf-1启动子区域发现了两个在非洲爪哇中高度保守的元件，鸡和人。第一个元件位于-500位附近，是全面增强XANF-1表达所必需的。第二个元件位于-200位附近，对于维持Xanf-1在中等水平的表达以及对其在前神经外胚层的表达进行特异性定位是至关重要的。因此，该元件的远端部分负责抑制该基因正常表达结构域后面的XANF-1。所得数据与神经诱导的Nieuwkoop双信号模型相吻合。该模型指出，在诱导的第一步，所有的神经外胚层都获得了向前脑结构发展的潜力，但后来这些潜力在后脑区域被抑制。(C)2002 Elsevier Science B.V.保留所有权利。
Investigation of molecular mechanisms underlying early patterning of the nervous system is an important task of modem developmental biology. Previously, we identified a novel homeobox gene, Anf, that is expressed in the most anterior zone at the beginning of neuroectoderm specification. The expression pattern of Anf corresponds to primordia of the telencephalon and the rostral part of the diencephalon. In the present work, we investigated cis-regulation of expression of the Xenopus laevis Anf, Xanf-1. Two elements, highly conserved in Xenopus, chick and human, were identified within the Xanf-1 promoter region. The first element, located near position -500, is necessary for overall enhancement of the Xanf-1 expression. The second element, near position -200, is crucial for maintenance of the Xanf-1 expression at moderate levels and also for specific localization of the expression in the anterior neuroectoderm. Thus, the distal part of this element is responsible for suppression of Xanf-1 posterior to the normal expression domain of this gene. The data obtained corroborate with the Nieuwkoop two-signal model of neural induction. This model states that at the first step of induction, all neuroectoderm acquires potencies to develop toward forebrain structures, but later these potencies are suppressed in posterior regions. (C) 2002 Elsevier Science B.V. All rights reserved.