Evolution of regulatory mechanisms controlling distal-less-related homeobox gene expression

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My laboratory studies a family of genes, the Dlx genes, which play important regulatory roles during development of the embryos of a large number of animal species.  They are parts of genetic cascades taking place during development to determine the different cell types and the patterning of the embryo, notably in the branchial arches, embryonic structures that give rise to skeleton of the face, in specific parts of the brain, in the ears, in the olfactory organs and in the limbs. We have identified the parts of the Dlx genes that enable them to function in specific parts of the embryo during development.  We showed that these gene fragments, called enhancers, can function properly not only in the species where they have been identified (e.g. mouse) but also in distantly related animals (e.g. fish).  We now want to determine when the enhancers were acquired during evolution of vertebrates to confer novel functions to the Dlx genes. For this, we are studying the lamprey, a jawless vertebrate. Lampreys have Dlx genes and they are expressed in the mouth area. Our hypothesis is that changes in the patterns of expression of Dlx genes were instrumental in the evolution of the jaw apparatus during vertebrate evolution. This research will enable us to understand how genes acquire new functions during evolution, thus participating in the emergence of morphological and functional innovations. Our research will also help us better understand how genes control the morphology of the developing embryo.