Dlx gene contributions to craniofacial patterning during development and evolution

了解动物基因组的变化如何使地球上惊人的生命多样性得以进化，是现代生物学的一个重大挑战。进化发育生物学领域的一个主要预测是，动物群体之间的差异可以追溯到胚胎发育的差异。了解调节发育的基因的功能变化如何改变身体结构是我们研究的一个重要目标。在进化的时间尺度上，新的基因功能可能是通过现有基因的复制出现的。这被认为在进化成脊椎动物（像我们这样有脊骨的动物）的动物谱系中大规模发生过。看看今天活着的动物，我们发现像昆虫这样的无脊椎动物通常只有一个特定基因的单一版本，而人类和其他脊椎动物通常有多个相关基因，这些基因根据它们在体内的活跃部位来执行衍生功能。利用现有的和新的分子遗传学技术相结合，我们提出研究Dlx家族的调控基因如何共同作用，为鸟类上颚和下颚的正常发育提供细胞的位置信息。为了了解鸟类Dlx蛋白是否进化出了新的功能，或者是否更多古老的Dlx功能被吸收到新的胚胎组织中，我们还将研究鸟类胚胎是否能够识别来自果蝇或非脊椎动物脊索动物的Dlx基因的单一版本编码的信息。这项工作将提高我们在分子水平上控制动物发育机制的知识，以及基因表达或功能的变化如何在进化时间尺度上影响动物形态。

Understanding how changes in animal genomes permitted the evolution of the staggering diversity of life on earth is a major challenge in modern biology. A major prediction from the field of evolutionary developmental biology is that the differences between groups of animals can be traced to variations in embryonic development. Understanding how functional changes in genes that regulate development might change body structures is an important goal of our research. One means by which new gene functions might have emerged over evolutionary timescales is via the duplication of existing genes. This is thought to have happened on a large scale in a lineage of animals that evolved into the vertebrates (animals, like us, with backbones). Looking at animals alive today, we find that invertebrates like insects often have a single version of a particular gene, whereas humans and other vertebrates usually have multiple related genes that carry out derived functions depending upon where in the body they are active. Using a combination of established and novel techniques of molecular genetics, we propose to study how the Dlx family of regulatory genes function together to provide positional information to cells in the developing jaws of birds, such that the upper and lower jaws develop normally. To ask whether avian Dlx proteins have evolved new functions or whether more ancient Dlx functions were co-opted into new embryonic tissues, we will also ask whether bird embryos can recognize the information coded in the single version of the Dlx gene from a fruit fly or a non-vertebrate chordate. This work will improve our knowledge of the mechanisms that control animal development at the molecular level and how changes to gene expression or function may have impacted animal form over evolutionary timescales.