Haerry T E, Gehring W J
Biozentrum, University of Basel, Switzerland.
Proc Natl Acad Sci U S A. 1996 Nov 26;93(24):13884-9. doi: 10.1073/pnas.93.24.13884.
The 5' flanking sequences and the intron of the mouse Hoxa-7 gene were searched for regulatory elements that can function in Drosophila. Only the intron is able to activate a lacZ fusion gene in various tissues of Drosophila embryos. This enhancer function requires a cluster of three homeodomain binding sites (HB1-element) that are also found in the introns of other Hox genes as well as in a putative autoregulatory element of Ultrabithorax (Ubx), the Drosophila homolog of Hoxa-7. If a single binding site in the autoregulatory element of fushi tarazu (ftz) is replaced by the HB1-element of Hoxa-7, the expression pattern is altered and newly controlled by the homeotic gene caudal (cad). These data suggest that HB1 is a potential target for different homeodomain proteins of both vertebrates and invertebrates.
对小鼠Hoxa - 7基因的5'侧翼序列和内含子进行了搜索，以寻找能在果蝇中发挥作用的调控元件。只有内含子能够在果蝇胚胎的各种组织中激活lacZ融合基因。这种增强子功能需要一组三个同源结构域结合位点（HB1元件），这些位点也存在于其他Hox基因的内含子以及Hoxa - 7的果蝇同源物超双胸（Ubx）的一个假定的自调控元件中。如果将腹节基因（ftz）自调控元件中的一个单一结合位点替换为Hoxa - 7的HB1元件，其表达模式就会改变，并由同源异型基因尾节（cad）进行新的调控。这些数据表明，HB1是脊椎动物和无脊椎动物不同同源结构域蛋白的潜在靶点。
