Interactions between growth and pattern formation during development

基因表达和形态之间的相互作用是复杂的，而且鲜为人知。随着植物和动物独立地进化出多细胞，找出不同王国的形态发生机制在多大程度上相似或不同将特别令人着迷。目前的数据表明，驱动生长中的鱼鳍的骨射线图案形成的机制与正在生长的植物叶片中的血管图案相似。我们将结合实验和计算方法来揭示协调网络结构(叶脉、鳍骨射线)的发展与发育中的多细胞附属物(拟南芥的叶子、丹尼欧的鳍)生长的基本机制。 生长素是一种参与叶片生长和叶脉模式形成的植物激素，因此是协调这两个过程的机制的关键组成部分。我们首先将使用实验室最近开发的新显微镜和计算方法来测试叶片中局部生长素生产对生长模式和脉序模式的影响。我们还将通过对多个叶脉图案和叶形突变体的生长和叶脉图案的比较分析，来研究叶脉图案和叶形变异的遗传基础。所得到的数据将用于建立和测试正在生长的叶子中的叶脉图案形成的模拟模型。同时，我们将使用类似的方法来表征鱼鳍的生长模式和骨骼模式的形成。通过比较植物叶片和鱼鳍的形态发生机制，我们可以提出一个关于生长和模式耦合的统一理论。 从长远来看，潜在的应用包括1)园艺和作物改良，因为叶片大小和植物维管束与植物的形态和生物量密切相关；2)再生医学，因为Danio rerio(斑马鱼)正在成为研究骨骼生长和再生基本机制的模型系统。

Interactions between gene expression and morphology are complex and little understood. As plants and animals evolved multicellularity independently, it would be particularly fascinating to find out to what extent mechanisms of morphogenesis are similar or differ across kingdoms. Current data suggests similarities in the mechanisms driving bony ray pattern formation in growing fish fins and vascular patterns in growing plant leaves. We will combine experimental and computational approaches to uncover fundamental mechanisms that coordinate the development of network structures (leaf veins, fin bony rays) with growth in developing multicellular appendages (leaves of Arabidopsis thaliana, fins of Danio rerio). Auxin is a plant hormone involved in leaf growth and leaf vein pattern formation, and is therefore a key component of the mechanism coordinating both processes. We will first test the effect of local auxin production in leaves on growth patterns and venation patterns, using novel microscopy and computational methods recently developed in the lab. We will also investigate the genetic basis for leaf vein pattern and leaf shape variation, by doing a comparative analysis of growth and vein patterning in multiple vein patterning and leaf shape mutants. The resulting data will be used to build and test simulation models of vein pattern formation in growing leaves. In parallel, we will use similar methodologies to characterize growth patterns and bone pattern formation in fish fins. Comparing morphogenetic mechanisms between plant leaves and fish fins may allow us to propose a unifying theory on the coupling of growth and patterning. Long term, potential applications include 1) horticulture and crop amelioration, as leaf size and plant vasculature are closely correlated to plant morphology and biomass, 2) regenerative medicine, as Danio rerio (the zebrafish) is emerging as a model system to study fundamental mechanisms of bone growth and regeneration.