Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG-LPCV 38054, Grenoble Cedex 9, France.
Sci Rep. 2020 Mar 25;10(1):5374. doi: 10.1038/s41598-020-61967-3.
Prostaglandins (PGs) are hormone-like mediators in many physiological and pathological processes that are present in all vertebrates, in some terrestrial and aquatic invertebrates, and have also been identified in some macroalgae. They have recently been reported also in marine microalgae but their role as chemical mediators is largely unknown. Here we studied the expression pattern of the PG biosynthetic pathway during different growth phases of the centric diatom Thalassiosira rotula and assessed the release of PGs in the surrounding environment for the first time. We show that enzymes responsible for PGs formation such as cyclooxygenase, prostaglandin E synthase 2-like and prostaglandin F synthase are mainly expressed at the end of the exponential phase and that PGs are released especially during the stationary and senescent phases, suggesting a possible signaling function for these compounds. Phylogenetic analysis of the limiting enzyme, COX, indicate the presence in diatoms of more than one enzyme related to the oxidative metabolism of fatty acids belonging to the peroxidase-cyclooxygenase superfamily. These findings suggest a more complex evolution and diversity of metabolic pathways leading to the synthesis of lipid mediators in diatoms.
前列腺素（PGs）是许多生理和病理过程中的激素样介质，存在于所有脊椎动物、一些陆地和水生无脊椎动物中，并且在一些大型藻类中也已被鉴定。最近也有报道称，它们存在于海洋微藻中，但作为化学介质的作用在很大程度上尚不清楚。在这里，我们研究了等中心硅藻塔玛斯氏藻在不同生长阶段的 PG 生物合成途径的表达模式，并首次评估了 PGs 在周围环境中的释放情况。我们表明，负责 PG 形成的酶，如环氧化酶、前列腺素 E 合酶 2 样和前列腺素 F 合酶，主要在指数生长期末期表达，并且 PGs 主要在静止期和衰老期释放，这表明这些化合物可能具有信号功能。限速酶 COX 的系统发育分析表明，过氧化物酶-环氧化酶超家族中与脂肪酸的氧化代谢有关的酶在硅藻中存在不止一种。这些发现表明，在硅藻中，导致脂质介质合成的代谢途径的进化和多样性更加复杂。
