Phaeodactylum tricornutum is a model pennate diatom for molecular studies due to its sequenced genome, genetic tractability, and capacity to produce a myriad of compounds of biotechnological interest. While tools for genetic engineering and heterologous gene expression have been developed for this species, the available set of characterised promoters remains limited. A diverse and well-understood set of genetic regulatory elements is necessary to enable fine tuning of gene expression for metabolic engineering and synthetic biology approaches. In this study, we investigated the expression profile of four endogenous constitutive promoter and terminator pairs Nub (Phatr3_J14260), SVP (Phatr3_J16798), 45582 (Phatr3_J45582), and Pbt (Phatr3_J54958) selected from a multi-experiment, integrated transcriptomics database under a variety of growth conditions, including various light regimes and nitrogen (N) limitation. Expression of the fluorescent reporter mVenus was driven from non-integrative episomes and monitored via flow cytometry. Gene expression was validated on a transcript and protein level using RT-qPCR and western blot, respectively. We found that all four promoter and terminator pairs exhibited stable expression throughout exponential growth, with distinct expression patterns and reduced light dependency compared to the widely-used FcpB promoter. Furthermore, the activity of these promoters was less impacted by N depletion than for FcpB. Our results indicate these novel promoters and terminators are promising tools for fine tuning single or multiple gene expression in P. tricornutum.

三角角锥菌（Phaeodyylum tricornutum）是一种用于分子研究的模型戊二烯硅藻，因为它具有测序的基因组，遗传易处理性以及产生多种具有生物技术意义的化合物的能力。尽管已经为该物种开发了用于基因工程和异源基因表达的工具，但可用的特征化启动子集仍然有限。为了使代谢工程和合成生物学方法的基因表达能够微调，必须使用多种多样且易于理解的遗传调控元件。在这项研究中，我们调查了四个内源性组成型启动子和终止子对Nub（Phatr3_J14260），SVP（Phatr3_J16798），45582（Phatr3_J45582）和Pbt（Phatr3_J54958）是在多种生长条件下（包括各种光照方案和氮（N）限制）从多实验，综合转录组学数据库中选择的。荧光报告基因mVenus的表达由非整合型附加体驱动，并通过流式细胞仪监测。分别使用RT-qPCR和Western blot在转录本和蛋白质水平上验证基因表达。我们发现，与广泛使用的FcpB启动子相比，所有四个启动子和终止子对在整个指数生长过程中均表现出稳定的表达，具有独特的表达模式和降低的光依赖性。此外，与FcpB相比，这些启动子的活性受N消耗的影响较小。我们的结果表明，这些新颖的启动子和终止子是微调单个或多个基因表达的有前途的工具。P。藻。