Sexual reproduction is a fundamental phase in the life cycle of most diatoms. Despite its role as a source of genetic variation, it is rarely reported in natural circumstances and its molecular foundations remain largely unknown. Here, we integrate independent transcriptomic datasets to prioritize genes responding to sex inducing pheromones (SIPs) in the pennate diatom Seminavis robusta. We observe marked gene expression changes associated with SIP treatment in both mating types, including an inhibition of S phase progression, chloroplast division, mitosis, and cell wall formation. Meanwhile, meiotic genes are upregulated in response to SIP, including a sexually induced diatom specific cyclin. Our data further suggest an important role for reactive oxygen species, energy metabolism, and cGMP signaling during the early stages of sexual reproduction. In addition, we identify several genes with a mating type specific response to SIP, and link their expression pattern with physiological specialization, such as the production of the attraction pheromone diproline in mating type − (MT−) and mate-searching behavior in mating type + (MT+). Combined, our results provide a model for early sexual reproduction in pennate diatoms and significantly expand the suite of target genes to detect sexual reproduction events in natural diatom populations.

有性生殖是大多数硅藻生命周期中的一个基本阶段。尽管它是遗传变异的来源，但在自然环境中鲜有报道，其分子基础仍然未知。在这里，我们整合了独立的转录组数据集，以优先考虑在剑形硅藻Seminavisrobusta中响应性诱导信息素（SIP）的基因。。我们在两种交配类型中均观察到与SIP处理相关的显着基因表达变化，包括抑制S期进程，叶绿体分裂，有丝分裂和细胞壁形成。同时，减数分裂基因响应于SIP而被上调，包括性诱导的硅藻特异性细胞周期蛋白。我们的数据进一步表明，在有性生殖的早期阶段，活性氧，能量代谢和cGMP信号传导具有重要作用。此外，我们鉴定了几个对SIP具有交配型特异性反应的基因，并将它们的表达模式与生理专一性联系起来，例如交配型-（MT-）的吸引力信息素双脯氨酸的产生和交配型的伴侣搜索行为。 +（MT +）。结合起来