Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université Evry, Université Paris-Saclay, Evry 91057, France.
Sorbonne Université, CNRS, Integrative Biology of Marine Models Laboratory, Station Biologique de Roscoff, Roscoff, France.
Cell. 2024 Nov 27;187(24):6943-6965.e39. doi: 10.1016/j.cell.2024.10.049. Epub 2024 Nov 20.
Brown seaweeds are keystone species of coastal ecosystems, often forming extensive underwater forests, and are under considerable threat from climate change. In this study, analysis of multiple genomes has provided insights across the entire evolutionary history of this lineage, from initial emergence, through later diversification of the brown algal orders, down to microevolutionary events at the genus level. Emergence of the brown algal lineage was associated with a marked gain of new orthologous gene families, enhanced protein domain rearrangement, increased horizontal gene transfer events, and the acquisition of novel signaling molecules and key metabolic pathways, the latter notably related to biosynthesis of the alginate-based extracellular matrix, and halogen and phlorotannin biosynthesis. We show that brown algal genome diversification is tightly linked to phenotypic divergence, including changes in life cycle strategy and zoid flagellar structure. The study also showed that integration of large viral genomes has had a significant impact on brown algal genome content throughout the emergence of the lineage.
褐藻是沿海生态系统的关键物种，常形成广阔的水下森林，它们受到气候变化的严重威胁。在这项研究中，对多个基因组的分析提供了对该谱系整个进化历史的深入了解，从最初的出现，到后来的褐藻目多样性，再到属水平的微进化事件。褐藻谱系的出现与新的同源基因家族的显著增加、增强的蛋白质结构域重排、更多的水平基因转移事件以及新的信号分子和关键代谢途径的获得有关，后者与藻酸盐为基础的细胞外基质以及卤化物和岩藻黄质生物合成的合成密切相关。我们表明，褐藻基因组的多样化与表型分化密切相关，包括生命周期策略和游动孢子鞭毛结构的变化。该研究还表明，大型病毒基因组的整合对该谱系出现过程中褐藻基因组的内容产生了重大影响。
