Abstract：
Diplonemids are a group of flagellate protists, that belong to the phylum Euglenozoa alongside euglenids, symbiontids and kinetoplastids. They primarily inhabit marine environments, though are also found in freshwater lakes. Diplonemids have been considered as rare and unimportant eukaryotes for over a century, with only a handful of species described until recently. However, thanks to their unprecedented diversity and abundance in the world oceans, diplonemids now attract increased attention. Recent improvements in isolation and cultivation have enabled characterization of several new genera, warranting a re-examination of all available knowledge gathered so far. Here we summarize available data on diplonemids, focusing on the recent advances in the fields of diversity, ecology, genomics, metabolism, and endosymbionts. We illustrate the life stages of cultivated genera, and summarise all reported interspecies associations, which in turn suggest lifestyles of predation and parasitism. This review also includes the latest classification of diplonemids, with a taxonomic revision of the genus Diplonema. Ongoing efforts to sequence various diplonemids suggest the presence of large and complex genomes, which correlate with the metabolic versatility observed in the model species Paradiplonema papillatum. Finally, we highlight its successful transformation into one of few genetically tractable marine protists.
摘要：
外交官是一群鞭毛的原生生物，属于Euglenozoa门和euglenids，共生体和动体。它们主要生活在海洋环境中，虽然也在淡水湖中发现。一个多世纪以来，外交官一直被认为是稀有和不重要的真核生物，直到最近才描述了少数物种。然而,由于它们在世界海洋中前所未有的多样性和丰富，双粒现在引起了越来越多的关注。最近在分离和培养方面的改进使几个新属得以表征，保证重新检查到目前为止收集的所有可用知识。在这里，我们总结了关于双粒的可用数据，关注多样性领域的最新进展，生态学,基因组学，新陈代谢，和内共生体。我们说明了栽培属的生命阶段，并总结所有报告的种间关联，这反过来又暗示了捕食和寄生的生活方式。这篇综述还包括双粒的最新分类，对Diplonema属进行了分类学修订。正在进行的对各种双粒进行测序的努力表明存在大而复杂的基因组，这与在模型物种乳头副plonema中观察到的代谢多功能性相关。最后,我们强调它成功地转变为少数可遗传处理的海洋原生生物之一。
