Synthetic and Systems Biology Unit, Institute of Biochemistry, BRC-HAS, 62 Temesvári krt, 6726, Szeged, Hungary.
Department of Plant Anatomy, Institute of Biology, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117, Budapest, Hungary.
Biol Rev Camb Philos Soc. 2018 Nov;93(4):1778-1794. doi: 10.1111/brv.12418. Epub 2018 Apr 19.
Complex multicellularity represents the most advanced level of biological organization and it has evolved only a few times: in metazoans, green plants, brown and red algae and fungi. Compared to other lineages, the evolution of multicellularity in fungi follows different principles; both simple and complex multicellularity evolved via unique mechanisms not found in other lineages. Herein we review ecological, palaeontological, developmental and genomic aspects of complex multicellularity in fungi and discuss general principles of the evolution of complex multicellularity in light of its fungal manifestations. Fungi represent the only lineage in which complex multicellularity shows signatures of convergent evolution: it appears 8-11 times in distinct fungal lineages, which show a patchy phylogenetic distribution yet share some of the genetic mechanisms underlying complex multicellular development. To explain the patchy distribution of complex multicellularity across the fungal phylogeny we identify four key observations: the large number of apparently independent complex multicellular clades; the lack of documented phenotypic homology between these clades; the conservation of gene circuits regulating the onset of complex multicellular development; and the existence of clades in which the evolution of complex multicellularity is coupled with limited gene family diversification. We discuss how these patterns and known genetic aspects of fungal development can be reconciled with the genetic theory of convergent evolution to explain the pervasive occurrence of complex multicellularity across the fungal tree of life.
复杂的多细胞性代表了生物组织的最高级形式，它只进化了几次：在后生动物、绿色植物、褐藻和红藻以及真菌中。与其他谱系相比，真菌中多细胞性的进化遵循不同的原则；简单和复杂的多细胞性都是通过在其他谱系中没有发现的独特机制进化而来的。在此，我们综述了真菌中复杂多细胞性的生态、古生物学、发育和基因组方面，并根据真菌的表现讨论了复杂多细胞性进化的一般原则。真菌是唯一表现出趋同进化特征的谱系：它在不同的真菌谱系中出现了 8-11 次，这些谱系的系统发育分布参差不齐，但却共享一些复杂多细胞发育的遗传机制。为了解释真菌系统发育中复杂多细胞性的斑驳分布，我们确定了四个关键观察结果：大量明显独立的复杂多细胞分支；这些分支之间缺乏记录在案的表型同源性；调控复杂多细胞发育开始的基因回路的保守性；以及复杂多细胞性进化与有限的基因家族多样化相关的分支的存在。我们讨论了如何将这些模式和已知的真菌发育的遗传方面与趋同进化的遗传理论相协调，以解释复杂多细胞性在真菌生命之树上的普遍存在。
