Molecular Evolution of Floral Homeotic Genes in the Hawaiian Silversword Alliance (Asteraceae)

9708540 Purugganan MADS盒调控基因家族代表了一组控制花发育关键方面的基因。 这些发育控制基因的分子进化动力学仍然知之甚少。 该项目旨在研究夏威夷银剑联盟（Madiinae，Asteraceae），岛屿植物适应性辐射的首要例子，这个调控基因家族成员的分子进化。 三个花控制基因-APETALA 1，APETALA 3和AGAMOUS -将通过分子技术在14个银剑联盟物种和它们的大陆加州亲戚，tarweeds分离。 这些基因序列的分析将被用来推断这些快速进化的类群中基因进化的速率和模式，并将提供有关这些调控位点多样化的进化力量的信息。 这项研究将评估与最近的适应性多样化花同源异型基因的变化动态，并可能导致新的核标记的开发，用于在低分类水平的基于序列的植物系统发育研究。 确定调控基因进化的模式和克里思对于理解物种之间形态差异背后的遗传基础至关重要。 研究这些基因的背景下，一个良好的研究适应性辐射允许更多的知识如何控制发育性状的基因在迅速多样化的物种进化。 通过剖析这些控制基因进化背后的机制，有可能确定基因调控的变化在多大程度上有助于我们在自然界中看到的花结构的多样性。

9708540 Purugganan The MADS-box regulatory gene family represents a group of genes that control crucial aspects of flower development. The molecular evolutionary dynamics of these developmental control genes remain poorly understood. This project seeks to investigate the molecular evolution of members of this regulatory gene family in the Hawaiian silversword alliance (Madiinae, Asteraceae), the premier example of island plant adaptive radiation. Three floral control genes - APETALA1, APETALA3 and AGAMOUS - will be isolated by molecular techniques in 14 silversword alliance species and their mainland California relatives, the tarweeds. Analysis of these gene sequences will be used to infer the rates and patterns of gene evolution in these rapidly-evolving taxa, and will provide information on the evolutionary forces that shape the diversification of these regulatory loci. This study will assess the dynamics of change in floral homeotic genes associated with a recent adaptive diversification, and may lead to the development of new nuclear markers for use in sequence-based, plant phylogenetic studies at low taxonomic levels. Determining mode and tempo of regulatory gene evolution is vital to understanding the genetic basis behind differences in morphologies between species. Studying these genes in the context of a well-studied adaptive radiation permits a greater knowledge of how genes that control developmental traits evolve in rapidly diversifying species. By dissecting the mechanisms behind the evolution of these control genes, it may be possible to determine the extent to which changes in gene regulation contribute to the diversity in floral structures we see in the natural world.