|Document Type:||Journal Article|
|Title:||Phylogenomics reveals convergent evolution of lifestyles in close relatives of animals and fungi|
|Author:||Alex Torruella, Alex de Mendoza, Xavier Grau-Bove, Meritxell Anto, Mark A. Chaplin, Javier del Campo, Laura Eme, Gregorio Perez-Cordon, Christopher M. Whipps, Krista M. Nichols, Richard Paley, Andrew J. Roger, Ariadna Sitja-Bobadilla, Stuart Donachie, Inaki Ruiz-Trillo|
The Opisthokonta is a eukaryotic supergroup divided in two main lineages. One lineage comprises animals and related protistan taxa, and the other comprises fungi and their allies. Among those protistan lineages there is a great diversity of lifestyles and morphologies, from free-living phagotrophic flagellated bacteriovores and filopodiated amoebas to cell-walled osmotrophic parasites and saprotrophs. However, these characteristics do not group into monophyletic assemblages, suggesting rampant convergent evolution within Opisthokonta. To test this hypothesis, we assembled a new phylogenomic dataset through sequencing 12 new strains of protists. Phylogenetic relationships among opisthokonts revealed independent origins of filopodiated amoebas in two lineages, one related to fungi and the other related to animals. Moreover, we observed that specialized osmotrophic lifestyles evolved independently in Fungi and protistan relatives of animals, indicating convergent evolution. We therefore analyzed two key characters in fungal evolution: the flagellum and chitin synthases. Comparative analyses of the flagellar toolkit showed a previously unnoticed flagellar apparatus in two close relatives of animals, the filasterean Ministeria vibrans and Corallochytrium limacisporum. This implies that at least four different opisthokont lineages secondarily underwent flagellar simplification. Analysis of the evolutionary history of chitin synthases revealed significant expansions in both animals and fungi, and also in the Ichthyosporea and C. limacisporum, a group of cell-walled animal relatives. This indicates that the last opisthokont common ancestor (LOCA) had a complex toolkit of chitin synthases that was differentially retained in extant lineages. Thus our data provide evidence for convergent evolution of specialized lifestyles in close relatives of animals and fungi from a generalist ancestor.
|Theme:||Sustainable, safe and secure seafood for healthy populations and vibrant communities|
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