The molecular basis of morphological evolution

我们的长期目标是了解自然遗传变异是如何产生形态变异的。我们通过结合发育遗传学和进化生物学的方法来实现这一目标。我们的实验室和其他人最近的工作表明，基因调控的改变可能是形态进化基础上分子变化的主要模式。然而，我们目前对调控基因表达的基因组区域的结构和功能了解有限。此外，一些研究表明，调控区域可以在保留保守功能的同时进化出截然不同的DNA序列。与对基因表达保守模式的研究相比，在分子水平上对导致形态进化的基因功能改变几乎一无所知。我们的工作重点是鉴定和描述DNA变化，这些变化负责密切相关物种之间的形态进化。我们已经确定了一些基因，这些基因在密切相关的果蝇物种之间进化，改变了幼虫和成年果蝇的细毛（毛状体）的图案。我们将通过结合功能研究和DNA序列变异的系统发育比较，对这些基因的调控区域的进化进行详细的研究。尽管基因调控区域编码了许多发育逻辑，但目前还不可能直接从基因组数据中读取这种逻辑。理解这些基因区域功能的进化方法可能为基因调控区域的逻辑提供重要见解，并有助于解释比较基因组学数据。

Our long term goal is to understand how natural genetic variation generates morphological variation. We pursue this goal by combining approaches from developmental genetics and evolutionary biology. Recent work from our lab and others has demonstrated that alterations in gene regulation are likely to be the predominant mode of molecular change underlying morphological evolution. However, we currently have a limited understanding of the structure and function of the genomic regions that regulate gene expression. In addition, several studies have demonstrated that regulatory regions can evolve dramatically different DNA sequences while retaining conserved function. In contrast to studies of genes with conserved patterns of gene expression, almost nothing is known at the molecular level about the alterations in gene function that lead to morphological evolution. Our work is focused on identifying and characterising the DNA changes that are responsible for morphological evolution between closely related species. We have already identified some of the genes that have evolved between closely related Drosophila species to alter the patterning of fine hairs (trichomes) on the larvae and adult. We will perform a detailed investigation of the evolution of the regulatory regions of these genes by combining functional studies and phylogenetic comparisons of DNA sequence variation. Although gene regulatory regions encode much of the logic of development, it is not yet possible to read this logic directly from genomic data. An evolutionary approach to understanding the function of these gene regions is likely to provide important insights into the logic of gene regulatory regions and assist in the interpretation of comparative genomics data.