Reply to Body?, Stiller and Mackiewicz: ''Chromalveolate plastids: direct descent or multiple endosymbioses?''

摘要

Body?, Stiller and Mackiewicz [1] have written in response to our recent Opinion piece [2] in which we discussed progress and problems in resolving the deepest branches of the eukaryotic tree using phylogenomics. The focus of our paper was the challenge of inferring accurate phylogenies from multigene data sets that include sequences from organisms that have acquired plastids by secondary (i.e. eukaryote-eukaryote) endosymbiosis and whose nuclear genomes are a composite of genes from two (or more) distinct nucleocytoplasmic lineages. We highlighted the controversial eukaryotic supergroup 'chromalveolates' as a case in point and discussed changing views on the evolution of photosynthesis in this diverse lineage in light of recent large-scale phylogenomic studies. Body?, Stiller and Mackiewicz [1] take issue with the chromalveolate hypothesis [3] and our views on the tempo and mode of plastid gain and loss among chromalveolates which aim to minimize secondary endosymbiotic events. They favor a model of 'serial plastid transfer,' whereby red algal-derived secondary plastids have been passed between 'chromalveolate' taxa on multiple occasions by tertiary endosymbiosis.