The genetic basis for leaf shape diversity: exploiting the Arabidopsis relative Cardamine hirsuta

生物学中的一个关键挑战是理解生物形式是如何产生的，以及它们多样性的基础。模型系统中的遗传分析已经确定了塑造后生动物和种子植物的身体计划的关键调控因素。然而，关于这种调控途径中的保守性和发散性的平衡是如何产生多细胞真核生物巨大的形态多样性的，人们还知之甚少。回答这些问题的一个障碍是缺乏合适的实验平台，可以利用遗传工具以全基因组、无偏见的方式明确地研究基因功能的进化。我们已经在克服这一问题上迈出了重要的一步，将拟南芥的近缘豆蔻碱毛形成一个强大的系统来研究形态进化。我们正致力于了解这些物种的叶形态进化到产生简单的、不分裂的叶的分子机制，以及毛冠果的裂叶和明显的小叶。我们最近发现了一个新的叶复杂性基因，该基因在拟南芥基因组中缺失，这是一个关键发现。在这里，我们建议进一步开发这一系统，首先通过阐明叶几何多样性的基础上的遗传网络，其次，了解这种多样性是否产生于自然选择。

A key challenge in biology is to understand how organismal forms are generated and the basis for their diversity. Genetic analyses in model systems have identified key regulators sculpting the body plans of metazoa and seed plants. However, less is known about how the balance of conservation versus divergence in such regulatory pathways generated the tremendous morphological diversity of multicellular eukaryotes. One impediment to answering these questions is the paucity of suitable experimental platforms where genetic tools can be utilized to unambiguously study the evolution of gene function in a genome-wide, unbiased fashion. We have made an important step in overcoming this problem by developing the Arabidopsis thaliana relative Cardamine hirsuta into a powerful system for studying morphological evolution. We are working to understand the molecular mechanisms through which leaf morphology evolved in these species to produce simple, undivided leaves in A. thaliana and dissected leaves with distinct leaflets in C. hirsuta. Our recent identification of a novel leaf complexity gene that is absent from the A. thaliana genome is a key finding. Here, we propose to exploit this system further, first by elucidating the genetic networks underlying the basis for diversity in leaf geometry and second, to understand whether such diversity arose in response to natural selection.