Tomotsune D, Shoji H, Wakamatsu Y, Kondoh H, Takahashi N
Department of Molecular Biology, School of Science, Nagoya University, Japan.
Nature. 1993 Sep 2;365(6441):69-72. doi: 10.1038/365069a0.
The homeobox is a 183-base-pair DNA sequence originally found in Drosophila segmentation and homeotic genes. In Drosophila, homeotic genes are clustered in the Antennapedia and Bithorax complexes, collectively called the homeotic gene complex (HOM-C). In the mouse genome, about 40 homeobox genes (Hox) are clustered in four chromosomal regions (Hox A to D). The Hox genes are arranged in the same order and have the same anteroposterior pattern of expression as their structural homologue in the HOM-C, suggesting that they control mouse pattern formation in the same way that HOM-C members do in Drosophila. Homeobox gene products are believed to be transcription factors that regulate expression of target genes. A few candidate target genes have been identified in Drosophila by various approaches but the Hox gene targets are poorly understood, mostly because of limitations in the available approaches. Here we identify several candidate Hox gene targets, including a mouse homologue of the Drosophila tumour-suppressor gene l(2)gl, by immunopurification of DNA sequences bound to a Hox protein in native chromatin.
同源异型框是一段183个碱基对的DNA序列，最初在果蝇的体节和同源异型基因中被发现。在果蝇中，同源异型基因聚集在触角足复合体和双胸复合体中，统称为同源异型基因复合体（HOM-C）。在小鼠基因组中，约40个同源异型框基因（Hox）聚集在四个染色体区域（Hox A至D）。Hox基因按相同顺序排列，并且具有与HOM-C中的结构同源物相同的前后表达模式，这表明它们以与HOM-C成员在果蝇中控制模式形成相同的方式来控制小鼠的模式形成。同源异型框基因产物被认为是调节靶基因表达的转录因子。通过各种方法在果蝇中已经鉴定出一些候选靶基因，但对Hox基因靶标的了解甚少，主要是因为现有方法存在局限性。在这里，我们通过免疫纯化与天然染色质中Hox蛋白结合的DNA序列，鉴定出了几个候选Hox基因靶标，包括果蝇肿瘤抑制基因l(2)gl的小鼠同源物。
