Egg Cell-Secreted EC1 Triggers Sperm Cell Activation During Double Fertilization
Egg Cell-Secreted EC1 Triggers Sperm Cell Activation During Double Fertilization
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DOI：
10.1126/science.1223944
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发表时间：
2012-11-23
期刊：
影响因子：
56.9
通讯作者：
Dresselhaus, Thomas
中科院分区：
文献类型：
--
作者：
Sprunck, Stefanie;Rademacher, Svenja;Dresselhaus, Thomas
双受精是显花植物的显著特征。然而，调节一个精子与卵子融合以及第二个精子与中央细胞融合的分子机制在很大程度上是未知的。我们表明，在拟南芥配子的相互作用依赖于小的富含半胱氨酸的EC 1（EGG细胞1）蛋白积累在存储囊泡的卵细胞。精子到达后，含有EC 1的囊泡被胞吐。精子内膜系统通过将潜在的配子融合原HAP 2/GCS 1（无HAP 2/生殖细胞特异性1）重新分布到细胞表面来响应外源性EC 1肽。此外，对ec 1五重突变体的受精研究表明，成功的雄性-雌性配子相互作用是防止多精子细胞传递所必需的。我们的研究结果提供的证据表明，相互配子激活，调节胞吐作用，精子质膜的修饰控制开花植物配子的相互作用。
Double fertilization is the defining characteristic of flowering plants. However, the molecular mechanisms regulating the fusion of one sperm with the egg and the second sperm with the central cell are largely unknown. We show that gamete interactions in Arabidopsis depend on small cysteine-rich EC1 (EGG CELL 1) proteins accumulating in storage vesicles of the egg cell. Upon sperm arrival, EC1-containing vesicles are exocytosed. The sperm endomembrane system responds to exogenously applied EC1 peptides by redistributing the potential gamete fusogen HAP2/GCS1 (HAPLESS 2/GENERATIVE CELL SPECIFIC 1) to the cell surface. Furthermore, fertilization studies with ec1 quintuple mutants show that successful male-female gamete interactions are necessary to prevent multiple-sperm cell delivery. Our findings provide evidence that mutual gamete activation, regulated exocytosis, and sperm plasma membrane modifications govern flowering plant gamete interactions.