Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
Science. 2014 Feb 14;343(6172):780-3. doi: 10.1126/science.1248384.
In this work, we investigate morphological differences between Arabidopsis thaliana, which has simple leaves, and its relative Cardamine hirsuta, which has dissected leaves comprising distinct leaflets. With the use of genetics, interspecific gene transfers, and time-lapse imaging, we show that leaflet development requires the REDUCED COMPLEXITY (RCO) homeodomain protein. RCO functions specifically in leaves, where it sculpts developing leaflets by repressing growth at their flanks. RCO evolved in the Brassicaceae family through gene duplication and was lost in A. thaliana, contributing to leaf simplification in this species. Species-specific RCO action with respect to its paralog results from its distinct gene expression pattern in the leaf base. Thus, regulatory evolution coupled with gene duplication and loss generated leaf shape diversity by modifying local growth patterns during organogenesis.
在这项工作中，我们研究了具有简单叶片的拟南芥和具有分裂叶片的其近缘种芝麻菜之间的形态差异。通过遗传学、种间基因转移和延时成像，我们表明小叶的发育需要简化复合体（RCO）同源域蛋白。RCO 特异性地在叶片中发挥作用，通过抑制侧翼生长来塑造发育中的小叶。RCO 在十字花科植物中通过基因复制进化而来，并在拟南芥中丢失，导致该物种叶片简化。由于其在叶片基部的独特基因表达模式，物种特异性的 RCO 与其同源物的作用是不同的。因此，通过在器官发生过程中改变局部生长模式，调控进化与基因复制和丢失相结合，产生了叶片形状的多样性。
