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Abstract：
How tissue-level information encoded by fields of regulatory gene activity is translated into the patterns of cell polarity and growth that generate the diverse shapes of different species remains poorly understood. Here, we investigate this problem in the case of leaf shape differences between Arabidopsis thaliana, which has simple leaves, and its relative Cardamine hirsuta that has complex leaves divided into leaflets. We show that patterned expression of the transcription factor CUP-SHAPED COTYLEDON1 in C. hirsuta (ChCUC1) is a key determinant of leaf shape differences between the two species. Through inducible genetic perturbations, time-lapse imaging of growth, and computational modeling, we find that ChCUC1 provides instructive input into auxin-based leaf margin patterning. This input arises via transcriptional regulation of multiple auxin homeostasis components, including direct activation of WAG kinases that are known to regulate the polarity of PIN-FORMED auxin transporters. Thus, we have uncovered a mechanism that bridges biological scales by linking spatially distributed and species-specific transcription factor expression to cell-level polarity and growth, to shape diverse leaf forms.
摘要：
由调节基因活性领域编码的组织水平信息如何被转化为产生不同物种的不同形状的细胞极性和生长模式仍然知之甚少。这里,我们在拟南芥之间的叶片形状差异的情况下研究了这个问题，有简单的叶子，和其相对的Cardaminehirsuta，具有复杂的叶子，分为小叶。我们表明，转录因子CUP形状的COTYLEDON1在C.hirsuta（ChCUC1）中的模式化表达是两个物种之间叶片形状差异的关键决定因素。通过可诱导的遗传扰动，生长的延时成像，和计算建模，我们发现ChCUC1为基于生长素的叶缘图案提供了指导性输入。这种输入是通过多种生长素稳态成分的转录调节而产生的，包括已知可调节PIN形成的生长素转运蛋白极性的WAG激酶的直接激活。因此，我们发现了一种通过将空间分布和物种特异性转录因子表达与细胞水平的极性和生长联系起来的机制，塑造不同的叶子形式。
