Pathways that limit leaflet formation in Cardamine hirsuta.

生物学的一个关键挑战是理解不同的生物体是如何形成不同的形态的。在植物中，这种形式的变化很明显，在公园散步或吃沙拉时，你会看到许多不同的叶子形状。研究叶片也很有趣，因为它们在食物链中扮演着关键角色，是陆地植物的主要光合器官，因此在陆地生态系统中负责二氧化碳的固定。由于这些原因，了解叶片形态的多样性是如何产生的对科学家来说是相当感兴趣的。为了研究这个问题，我们研究了多毛苦菜（Cardamine hirsuta），这是一种叶子完全细分为更小的小叶的植物。小叶的存在使这种植物与它的近亲拟南芥（拟南芥）非常不同，拟南芥有完整的、不分裂的叶子。我们已经知道了很多关于整个叶片形状是如何在芥蓝中产生的，因为它很容易种植和做实验。毛苦菜在实验室里也很容易处理，所以我们用它来了解小叶是如何产生的，是什么控制了它们的形成。在这里，我们想了解在苦菜发育过程中限制小叶生长的过程，以导致正确的小叶数量和位置，这是该植物的特征。我们的研究结果也将有助于理解指导重复过程的发育机制，例如小叶形成，发生有限次数，从而获得任何给定物种的典型精确形式。

A key challenge in biology is to understand how different organisms come to have different forms. In plants this variation in form is obvious in the many different leaf shapes one sees during a walk in the park or when eating a salad. Leaves are also interesting to study because they play a key role in the food chain being the main photosynthetic organs of land plants and thus responsible for CO2 fixation in terrestrial ecosystems. For these reasons, understanding how diversity in leaf form is generated is of considerable interest to scientists. To study this problem we work with hairy bittercress (Cardamine hirsuta), which is a plant that has leaves fully subdivided into smaller leaflets. The presence of leaflets makes this plant very different from its close relative thale cress (Arabidopsis thaliana), which has entire, undivided leaves. We already know a lot about how an entire leaf shape is produced in thale cress because it is easy to grow and do experiments with. Hairy bittercress is also very easy to work with in the lab, so we use it to understand how leaflets are produced and what controls their formation. Here we want to understand processes that restrict leaflet growth during bitter cress development to result in the correct leaflet number and position that characterizes this plant. Our results will also help understand the developmental mechanisms that direct repeated processes, such as leaflet formation, to take place a limited number of times such that the precise form typical of any given species is attained.