鞭毛藻是Mesodinium纤毛虫的捕食者,它们只保留隐藻起源的质体。Dinphysis中不存在核光合隐藻基因,这引起了有关这些临时kleptoplastids在外源细胞环境中的功能动力学的有趣的生理和进化问题。在包括两种光照条件的实验装置中,与Mesodiniumrubrum和cryptophyteTeleaulax两栖植物的比较分析表明,Dinphysisacuminata具有较小和较少动态的功能光合天线,由藻红蛋白执行的功能。我们表明,隐藻核的缺乏阻止了藻红蛋白α亚基的合成,从而阻碍了Dinphysis中完整的藻红蛋白的形成。特别是,生化分析表明,Dinphysisacuminata合成的稳定性差,由发色化β亚基组成的不完全藻红蛋白,表现受损。我们证明,因此,新质体的持续供应对于该生物体的生长和有效的光适应至关重要。转录组分析显示,所有检查过的Dinphysisspp菌株。通过水平基因转移获得了隐藻pebA和pebB基因,表明具有合成与隐藻藻红蛋白结合的藻胆素色素的潜在能力。通过强调潜在的长期获得隐藻质体依赖于建立基本功能的遗传独立性,例如光捕获,这项研究强调了细胞器被奴役所固有的复杂的分子挑战,以及光合生物通过内共生多样化的过程。
Dinophysis dinoflagellates are predators of Mesodinium ciliates, from which they retain only the plastids of cryptophyte origin. The absence of nuclear photosynthetic cryptophyte genes in Dinophysis raises intriguing physiological and evolutionary questions regarding the functional dynamics of these temporary kleptoplastids within a foreign cellular environment. In an experimental setup including two light conditions, the comparative analysis with Mesodinium rubrum and the cryptophyte Teleaulax amphioxeia revealed that Dinophysis acuminata possessed a smaller and less dynamic functional photosynthetic antenna for green light, a function performed by phycoerythrin. We showed that the lack of the cryptophyte nucleus prevented the synthesis of the phycoerythrin α subunit, thereby hindering the formation of a complete phycoerythrin in Dinophysis. In particular, biochemical analyses showed that Dinophysis acuminata synthesized a poorly stable, incomplete phycoerythrin composed of chromophorylated β subunits, with impaired performance. We show that, consequently, a continuous supply of new plastids is crucial for growth and effective photoacclimation in this organism. Transcriptome analyses revealed that all examined strains of Dinophysis spp. have acquired the cryptophyte pebA and pebB genes through horizontal gene transfer, suggesting a potential ability to synthesize the phycobilin pigments bound to the cryptophyte phycoerythrin. By emphasizing that a potential long-term acquisition of the cryptophyte plastid relies on establishing genetic independence for essential functions such as light harvesting, this study highlights the intricate molecular challenges inherent in the enslavement of organelles and the processes involved in the diversification of photosynthetic organisms through endosymbiosis.