Gilardi P, Schneider-Maunoury S, Charnay P
Laboratoire de Génétique Moléculaire, CNRS D 1302, Ecole Normale Supérieure, Paris, France.
Biochimie. 1991 Jan;73(1):85-91. doi: 10.1016/0300-9084(91)90079-g.
The mouse gene Krox-20 was isolated on the basis of cross-hybridization with Krüppel, a Drosophila segmentation gene. During recent years, an accumulation of structural, biochemical and expression data has indicated that Krox-20 encodes a transcription factor which may play a key role within a regulatory network involved in pattern formation in the developing hindbrain. The DNA-binding domain of Krox-20 consists of 3 zinc fingers and the protein recognizes a specific GC-rich nucleotide sequence. It can activate the transcription of genes located in the vicinity of this sequence. Krox-20 transcription itself is modulated by growth factors. During formation of the vertebrate central nervous system (CNS), the hindbrain is organized into segmental units, called rhombomeres. Prior to the appearance of morphological segmentation, Krox-20 is expressed in 2 stripes within the hindbrain. Later on, the Krox-20 expression domains match with 2 alternate rhombomeres. These data suggest that Krox-20 may regulate aspects of the segmentation process. The observation of segment-specific expression boundaries for homeobox containing genes in the hindbrain suggests that these genes may also be part of the regulatory network governing pattern formation in this region of the CNS. The possible interactions between Krox-20 and homeobox containing genes as well as the search for other members of the network will be discussed.
小鼠基因Krox-20是基于与果蝇分节基因Krüppel的交叉杂交而分离出来的。近年来，结构、生化和表达数据的积累表明，Krox-20编码一种转录因子，它可能在发育中的后脑模式形成所涉及的调控网络中起关键作用。Krox-20的DNA结合结构域由3个锌指组成，该蛋白识别特定的富含GC的核苷酸序列。它可以激活位于该序列附近的基因的转录。Krox-20的转录本身受生长因子的调节。在脊椎动物中枢神经系统（CNS）形成过程中，后脑被组织成称为菱脑节的节段单位。在形态学上的分节出现之前，Krox-20在后脑的2条条纹中表达。后来，Krox-20的表达域与2个交替的菱脑节相匹配。这些数据表明，Krox-20可能调节分节过程的某些方面。在后脑中对含同源框基因的节段特异性表达边界的观察表明，这些基因也可能是控制CNS该区域模式形成的调控网络的一部分。将讨论Krox-20与含同源框基因之间可能的相互作用以及对该网络其他成员的寻找。
