Hunter C P, Kenyon C
Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0554, USA.
Nature. 1995 Sep 21;377(6546):229-32. doi: 10.1038/377229a0.
Antennapedia class homeobox (Hox) genes specify cell fates in successive anteroposterior body domains in vertebrates, insects and nematodes. The DNA-binding homeodomain sequences are very similar between vertebrate and Drosophila Hox proteins, and this similarity allows vertebrate Hox proteins to function in Drosophila. In contrast, the Caenorhabditis elegans homeodomains are substantially divergent. Further, C. elegans differs from both insects and vertebrates in having a non-segmented body as well as a distinctive mode of development that involves asymmetric early cleavages and invariant cell lineages. Here we report that, despite these differences, Drosophila Hox proteins expressed in C. elegans can substitute for C. elegans Hox proteins in the control of three different cell-fate decisions: the regulation of cell migration, the specification of serotonergic neurons, and the specification of a sensory structure. We also show that the specificity of one C. elegans Hox protein is partly determined by two amino acids that have been implicated in sequence-specific DNA binding. Together these findings suggest that factors important for target recognition by specific Hox proteins have been conserved throughout much of the animal kingdom.
触角足类同源异型框（Hox）基因在脊椎动物、昆虫和线虫的前后体域中依次指定细胞命运。脊椎动物和果蝇的Hox蛋白之间的DNA结合同源结构域序列非常相似，这种相似性使得脊椎动物的Hox蛋白能够在果蝇中发挥作用。相比之下，秀丽隐杆线虫的同源结构域则有很大差异。此外，秀丽隐杆线虫与昆虫和脊椎动物不同，它没有分节的身体，并且具有独特的发育模式，包括不对称的早期卵裂和不变的细胞谱系。我们在此报告，尽管存在这些差异，但在秀丽隐杆线虫中表达的果蝇Hox蛋白可以替代秀丽隐杆线虫的Hox蛋白来控制三种不同的细胞命运决定：细胞迁移的调控、血清素能神经元的特化以及一种感觉结构的特化。我们还表明，一种秀丽隐杆线虫Hox蛋白的特异性部分由两个与序列特异性DNA结合有关的氨基酸决定。这些发现共同表明，特定Hox蛋白识别靶标的重要因子在动物界的大部分物种中都得以保留。
