Key message

A protocol for the isolation of egg apparatus cells from the basal angiosperm Amborella trichopoda to generate RNA-seq data for evolutionary studies of fertilization-associated genes.

Abstract

Sexual reproduction is particularly complex in flowering plants (angiosperms). Studies in eudicot and monocot model species have significantly contributed to our knowledge on cell fate specification of gametophytic cells and on the numerous cellular communication events necessary to deliver the two sperm cells into the embryo sac and to accomplish double fertilization. However, for a deeper understanding of the evolution of these processes, morphological, genomic and gene expression studies in extant basal angiosperms are inevitable. The basal angiosperm Amborella trichopoda is of special importance for evolutionary studies, as it is likely sister to all other living angiosperms. Here, we report about a method to isolate Amborella egg apparatus cells and on genome-wide gene expression profiles in these cells. Our transcriptomics data revealed Amborella-specific genes and genes conserved in eudicots and monocots. Gene products include secreted proteins, such as small cysteine-rich proteins previously reported to act as extracellular signaling molecules with important roles during double fertilization. The detection of transcripts encoding EGG CELL 1 (EC1) and related prolamin-like family proteins in Amborella egg cells demonstrates the potential of the generated data set to study conserved molecular mechanisms and the evolution of fertilization-related genes and their encoded proteins.

中文翻译：

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手动分离的沙门氏菌卵子卵器细胞的转录组学。

关键信息

从基础被子植物Amborella trichopoda分离卵器细胞以产生RNA-seq数据的协议，用于受精相关基因的进化研究。

抽象

有性繁殖在开花植物（被子植物）中特别复杂。对双子叶植物和单子叶植物模型物种的研究极大地促进了我们对配子植物细胞命运决定的知识以及将两个精子细胞传递到胚囊中并完成双重受精所必需的众多细胞通讯事件的知识。然而，为了更深入地了解这些过程的演变，在现有基础被子植物中进行形态学，基因组学和基因表达研究是不可避免的。基底被子植物Amborella trichopoda在进化研究中特别重要，因为它可能是所有其他活被子植物的姊妹。在这里，我们报告一种分离Amborella的方法卵器细胞以及这些细胞中全基因组基因表达谱。我们的转录组学数据揭示了Amborella特异性基因以及双子叶植物和单子叶植物中保守的基因。基因产物包括分泌的蛋白质，例如以前报道的在双受精过程中起重要作用的细胞外信号分子，如富含小半胱氨酸的蛋白质。在Amborella卵细胞中检测到编码EGG CELL 1（EC1）和相关谷醇溶蛋白家族蛋白的转录本，证明了所产生数据集的潜力，可用于研究保守分子机制以及受精相关基因及其编码蛋白的进化。