Molecular and Cellular Neuroscience. Pattern formation genes are genes that commit cells into developmental pathways. A number of these genes are expressed in both the epidermis and developing central nervous system of Drosophila but how they contribute to differentiation is unclear. In grasshoppers, neuroblast-7 is the progenitor of seritonin neurons. To determine if the same is true in Drosophila they examined the expression of engrailed and huckebein genes as molecular markers.
Results show that both engrailed and heckebein are required for serotonin neurons to differentiate.
Both genes are needed because loss of function experiments for either gene show losses of several markers for these cells. The DNA Binding Specificity of Engrailed Homeodomain. Journal of Molecular Biology. The crystal structure of this domain is very similar to other homeodomain complexes. Although they are similar they do show specificity towards certain DNA sequences.