ABSTRACT Introduction. Aphanorrhegma (Physcomitrella) patens (Hedw.) Lindb. is an attractive model system for comparative analyses of leaf development because it evolved leaves (phyllids) independently to flowering plants, yet its genome contains homologues of many gene families that regulate angiosperm leaf development. In addition, A. patens phyllids are primarily a single cell layer thick, making it simple to identify the cellular basis of defects that perturb shape. Identification of gene functions in shape determination depends on like-for-like comparison of mutant versus wild-type plants. Key results. Here we show that, if heteroblasty is not perturbed, such comparisons should use phyllid L13 or above in the heteroblastic series, and fully expanded phyllids above P7 in the developmental series. Using a quantitative approach, we show that heteroblastic size variation reflects differences in cell proliferation rather than cell size and shape. A comparison of control to pinA pinB mutant phyllid development verifies that PIN proteins promote cell proliferation and suppress expansion to determine phyllid shape. Conclusion. The results and approach that we have generated will be applicable to any study of A. patens phyllid development to reveal the cellular basis of phyllid size and shape variations.

中文翻译：

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Aphanorrrhegma (Physcomitrella) patens phyllid发育的同类比较分析中的定量方法。

摘要介绍。Aphanorrrhegma (Physcomitrella) patens (Hedw.) Lindb。是用于比较分析叶子发育的有吸引力的模型系统，因为它独立于开花植物进化叶子（叶状体），但其基因组包含调节被子植物叶子发育的许多基因家族的同源物。此外，A. patens phyllids 主要是单细胞层厚，这使得识别扰乱形状缺陷的细胞基础变得简单。形状确定中基因功能的鉴定取决于突变体与野生型植物的同类比较。关键结果。在这里我们表明，如果异母细胞不受干扰，则此类比较应在异母细胞系列中使用 L13 或以上的叶状体，并在发育系列中使用 P7 以上的叶状体。使用定量方法，我们表明异母细胞大小变化反映了细胞增殖的差异，而不是细胞大小和形状的差异。对照与 pinA pinB 突变体叶状体发育的比较证实 PIN 蛋白促进细胞增殖并抑制扩张以确定叶状体形状。结论。我们产生的结果和方法将适用于 A. patens 叶状发育的任何研究，以揭示叶状体大小和形状变化的细胞基础。