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生命的惊人多样性得以进化，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变化。了解调控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，新的基因功能可能出现的一种方式是通过现有基因的复制。这被认为是在进化成脊椎动物（像我们一样有脊椎的动物）的动物谱系中大规模发生的。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的基因，这些基因根据它们在体内的活跃位置来执行衍生功能。使用分子遗传学的既定和新的技术相结合，我们建议研究Dlx家族的调控基因如何共同发挥作用，以提供位置信息的细胞在发展中的颌骨的鸟类，使上下颌正常发展。为了询问鸟类Dlx蛋白是否已经进化出新的功能，或者更古老的Dlx功能是否被增选到新的胚胎组织中，我们还将询问鸟类胚胎是否可以识别来自果蝇或非脊椎动物脊索动物的Dlx基因的单一版本中编码的信息。这项工作将提高我们对在分子水平上控制动物发育的机制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的认识。

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.