Mahaffey James W
Department of Genetics, Campus Box 7614, North Carolina State University, Raleigh, NC 27695-7614, USA.
Curr Opin Genet Dev. 2005 Aug;15(4):422-9. doi: 10.1016/j.gde.2005.06.009.
Hox proteins regulate specific sets of target genes to give rise to morphological distinctions along the anterior-posterior body axis of metazoans. Though they have high developmental specificity, Hox proteins have low DNA binding specificity, so how they select the appropriate target genes has remained enigmatic. There is general agreement that cofactors provide additional specificity, but a comprehensive model of Hox control of gene expression has not emerged. There is now evidence that a global network of zinc finger transcription factors contributes to patterning of the Drosophila embryo. These zinc finger proteins appear to establish fields in which certain Hox proteins can function. Though the nature of these fields is uncertain at this time, it is possible that these zinc finger proteins are Hox cofactors, providing additional specificity during Hox target-gene selection. Furthermore, these zinc finger proteins are conserved, as are aspects of their anterior-posterior expression, suggesting that their roles might be conserved, as well. Perhaps this layer in the genetic control of body patterning will help bridge some of the chasms that remain in our understanding of the genetic control of pattern formation.
Hox蛋白调控特定的靶基因组合，从而在后生动物的前后体轴上产生形态差异。尽管Hox蛋白具有高度的发育特异性，但其DNA结合特异性较低，因此它们如何选择合适的靶基因仍然是个谜。人们普遍认为辅因子提供了额外的特异性，但尚未形成一个全面的Hox基因表达调控模型。现在有证据表明，锌指转录因子的全局网络有助于果蝇胚胎的模式形成。这些锌指蛋白似乎建立了某些Hox蛋白能够发挥作用的区域。尽管目前这些区域的性质尚不确定，但这些锌指蛋白有可能是Hox辅因子，在Hox靶基因选择过程中提供额外的特异性。此外，这些锌指蛋白及其前后表达模式是保守的，这表明它们的作用可能也是保守的。也许这一层次的身体模式遗传控制将有助于弥合我们在模式形成遗传控制理解上仍然存在的一些差距。
