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.

中文翻译：

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褐藻作为沿海生态系统关键组成部分的进化基因组学


棕色海藻是沿海生态系统的关键物种，通常形成广阔的水下森林，并受到气候变化的相当大的威胁。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见解，从最初的出现，到后来褐藻目（brown algal orders）的多样化，再到属水平的微进化事件。褐藻谱系的出现与新的直系同源基因家族的显着增加、蛋白质结构域重排的增强、水平基因转移事件的增加以及新信号分子和关键代谢途径的获得有关，后者与藻酸盐基细胞外基质的生物合成以及卤素和根皮单宁的生物合成有关。我们表明褐藻基因组多样化与表型分化密切相关，包括生命周期策略和 zoid 鞭毛结构的变化。该研究还表明，在整个谱系出现过程中，大型病毒基因组的整合对褐藻基因组内容产生了重大影响。