Deschamps Jacqueline
Hubrecht Institute, Developmental Biology and Stem Cell Research, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
Curr Opin Genet Dev. 2007 Oct;17(5):422-7. doi: 10.1016/j.gde.2007.07.008. Epub 2007 Sep 17.
Genes from the Hox family are involved in the common task of providing nascent embryonic tissues with their positional identity. They are organised in clusters in most species. Mouse Hox genes are regulated in part by gene-proximal regulatory elements, but owe several of their essential properties to the use of global regulatory elements located outside the complexes. The clustered Hox genes in that sense behave as a single large locus. Genomic and sequence data from different animal species suggest that a concerted regulation of the Hox clusters, inherently coupled to their patterning properties, originated early during evolution and pre-figured the temporal colinearity of expression of vertebrate Hox genes. In addition, vertebrates have recruited novel global mechanisms to control the expression of linear subsets of Hox genes in specific embryonic structures. Several of such novel global regulatory circuits have recently been characterised at the molecular genetic level in the mouse.
Hox家族的基因参与为新生胚胎组织赋予位置身份这一共同任务。在大多数物种中，它们成簇排列。小鼠Hox基因部分受基因近端调控元件的调节，但其一些基本特性归因于对位于基因复合体之外的全局调控元件的利用。从这个意义上说，成簇的Hox基因表现为一个单一的大位点。来自不同动物物种的基因组和序列数据表明，Hox基因簇的协同调控与其模式形成特性内在相关，在进化早期就已出现，并预示了脊椎动物Hox基因表达的时间共线性。此外，脊椎动物已经采用了新的全局机制来控制特定胚胎结构中Hox基因线性亚群的表达。最近，其中一些新的全局调控回路已在小鼠中得到分子遗传学层面的表征。
