Nup98-HoxA9 is recruited to Hox gene cluster regions together with the chromosomally pre-bound nuclear export factor Crm1, which induces aberrant expression of several Hox genes and affecting the differentiation of embryonic stem cells.
The collinear activation of a subset of posterior Hox genes is responsible for establishing a Wnt/T activity gradient that is required to generate the complete body axis, and hence the full set of segments within a vertebrate embryo.
Despite their extreme morphologies, snakes display a global regulatory strategy of their Hox genes similar to that implemented by mammals with, however, important modifications in enhancer specificity.
In vertebrates, large regulatory landscapes sometimes behave as coherent regulatory units, which may explain the lack of effect sometimes observed when single enhancer sequences are deleted in isolation.
Tucked within a well-known story of diverging gene function is a single enhancer encoding two inseparable specificities that regulates two adjacent genes, each with different spatiotemporal expression patterns.