Fig. 1.

Phylogenomic analyses and cell cycle of the aphelid Paraphelidium tribonemae. a Bayesian phylogenetic tree based on single-copy protein domains for 49 species (SCPD49) inferred using a CAT-Poisson model. Statistical supports indicated at some crucial nodes correspond, from left to right, to PhyloBayes Bayesian posterior probabilities and IQ-TREE ML ultrafast-bootstrap support using the C60 model. Branches with maximum support values (pp = 1 and ubs = 100%) are indicated by black circles. The support for the monophyly of Paraphelidium and fungi (blue star) using the three datasets (SCPD, BMC and GBE) with the 49 species and after removing the fastest-evolving microsporidian sequences (36 species) is shown in Table 1. b Schematic cell cycle of P. tribonemae. Briefly, infecting cysts (red wall), deliver an ameboid trophont to an algal filament cell via an infection tube; the trophont engulfs the algal cytoplasm by phagocytosis, leaving a growing residual body (dark red particle); after nuclear and cell division, a mature sporangium releases amoeboflagellated zoospores (occasionally ameboid only) that get out the algal cell wall and close the life cycle¹¹. c Evolution of IQ-TREE ML ubs support for the monophyly of aphelids and fungi (A + F) and the monophyly of Opisthosporidia (O) as a function of the proportion of fast-evolving sites removed from the dataset. All the phylogenomic trees can be seen in Supplementary Fig. 1