Benthic diatoms dominate primary production in marine subtidal and intertidal environments. Their extraordinary species diversity and ecological success is thought to be linked with their predominantly heterothallic sexual reproduction. Little is known about pheromone involvement during mating of pennate diatoms. Here we describe pheromone guided mating in the coastal raphid diatom Cylindrotheca closterium. We show that the two mating types (mt⁺ and mt⁻) have distinct functions. Similar to other benthic diatoms, mt⁺ cells are searching for the mt⁻ cells to pair. To enhance mating efficiency mt⁻ exudes an attraction pheromone which we proved by establishing a novel capillary assay. Further, two more pheromones produced by mt⁻ promote the sexual events. One arrests the cell cycle progression of mt⁺ while the other induces gametogenesis of mt⁺. We suggest that C. closterium shares a functionally similar pheromone system with other pennate diatoms like Seminavis robusta and Pseudostaurosira trainorii which synchronize sexual events and mate attraction. Remarkably, we found no evidence of mt⁺ producing pheromones, which differentiates C. closterium from other pennates and suggests a less complex pheromone system in C. closterium.

底栖硅藻在海洋潮下带和潮间带环境中主导初级生产。它们非凡的物种多样性和生态成功被认为与它们主要的异种有性繁殖有关。对羽状硅藻交配过程中信息素的参与知之甚少。在这里，我们描述了沿海硅藻Cylindrotheca closterium中信息素引导的交配。我们表明两种交配类型（mt ⁺和 mt ^-）具有不同的功能。与其他底栖硅藻类似，mt ⁺细胞正在寻找 要配对的 mt ^-细胞。提高交配效率 mt ^- 散发出一种吸引信息素，我们通过建立一种新的毛细管试验证明了这一点。此外，mt 产生的另外两种信息素^- 促进性活动。一种阻止 mt ⁺的细胞周期进程，而另一种诱导 mt ^{+ 的}配子发生。我们建议C. closterium与其他羽状硅藻如 S eminavisrobusta和Pseudostaurosira trainorii共享功能相似的信息素系统，它们同步性事件和配偶吸引力。值得注意的是，我们没有发现 mt ⁺产生信息素的证据，这将C. closterium与其他羽状体区分开来，并表明在C. 梭菌。