Macroalgae are multicellular, aquatic autotrophs that play vital roles in global climate maintenance and have diverse applications in biotechnology and eco-engineering, which are directly linked to their multicellularity phenotypes. However, their genomic diversity and the evolutionary mechanisms underlying multicellularity in these organisms remain uncharacterized. In this study, we sequenced 110 macroalgal genomes from diverse climates and phyla, and identified key genomic features that distinguish them from their microalgal relatives. Genes for cell adhesion, extracellular matrix formation, cell polarity, transport, and cell differentiation distinguish macroalgae from microalgae across all three major phyla, constituting conserved and unique gene sets supporting multicellular processes. Adhesome genes show phylum- and climate-specific expansions that may facilitate niche adaptation. Collectively, our study reveals genetic determinants of convergent and divergent evolutionary trajectories that have shaped morphological diversity in macroalgae and provides genome-wide frameworks to understand photosynthetic multicellular evolution in aquatic environments.

中文翻译：

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巨藻深层基因组学阐明了水生光合多细胞生物的多种途径


大型藻类是多细胞水生自养生物，在全球气候维持中发挥着至关重要的作用，并在生物技术和生态工程中具有多种应用，这与其多细胞表型直接相关。然而，它们的基因组多样性和这些生物体中多细胞性的进化机制仍然未知。在这项研究中，我们对来自不同气候和门的 110 种大型藻类基因组进行了测序，并确定了将它们与其微藻亲属区分开来的关键基因组特征。细胞粘附、细胞外基质形成、细胞极性、运输和细胞分化的基因将所有三个主要门中的大型藻类与微藻类区分开来，构成了支持多细胞过程的保守且独特的基因集。粘附体基因显示出特定于门和气候的扩展，这可能有助于利基适应。总的来说，我们的研究揭示了趋同和趋异进化轨迹的遗传决定因素，这些进化轨迹塑造了大型藻类的形态多样性，并提供了全基因组框架来理解水生环境中的光合作用多细胞进化。