FIGURE 3.

Phylogeny of type III polyketide synthases (PKSs) in the fungal kingdom. (A) Maximum-likelihood phylogenetic tree of type III PKSs on fungal origin. Published and characterized fungal type III PKSs are included. The fungal taxonomic class of each branch is indicated with colors on the outer circle. Red stars indicate fungal type III PKSs that have been functionally characterized. The functional classification of characterized type III PKS according to Shimizu et al. (2017) is indicated next to the star. Black circles indicate the nodes that define fungal phylogenetic clades, which are indicated on the inner circle. The middle ring indicates the core gene content in the predicted gene clusters. The size of the circles is proportional to the number of core gene present at the locus. Yellow triangles indicate potential horizontal gene transfers according to the reconciliation analysis; transfers within clades 7 and 8 are not shown because too many events were inferred. The outer circle indicates the phylum: Ascomycota, Basidiomycota and Chytridiomycota are indicated with dark green, dark red and dark gray colors, respectively. Phylogenetic clades 3 (B) and 4 (C) as defined in (A) show four and 15 duplication events, respectively, according to the reconciliation analysis. Other phylogenetic clades were collapsed. Paralogs are linked by black and red lines, the latter linking paralogs located at the same locus. Duplication events are indicated with red circles. Only sub-tree topology is shown. Bootstrap values over 90 are indicated with black dots at the nodes.