Fig. 3

Evolution of FARs among nematodes from Clade IV. A Maximum-Likelihood tree of 310 FAR proteins from nematodes in Clade IV. The scale bar represents the number of amino acid substitutions per site. The circles with different colors on the branches represent FAR protein from Clades IVa, IVb, and IVc. The color of the inner ring is corresponding to the color of solid circle on the branch. The green, yellow, and blue blocks on the outer ring represent clusters 1, 2, and 3, respectively. The dark gray box and the blue purple hexagon represent the monophyletic groups of Steinernema and Strongyloides, respectively. * and @ indicate tandem replication on scaffolds or contigs, respectively. B, D Numbers of 1:1 far orthologs that are syntenic in Ste. carpocapsae and other Steinernema species. Syntenic blocks in scaffolds or contigs containing far genes in species from Clades IVa and IVb. The blue line represents far orthologs with collinearity on the genome of these species, and the gray line represents far orthologs without collinearity on the genome of these species. C, E Expression pattern of far genes across developmental stages in two Steinernema species and four Strongyloides species with available RNA-seq data. Detailed expression values are shown in Additional file 4: Table S3. * means Str. ratti FAR-12 was grouped into cluster 2 but not cluster 1. iL3: infective third-stage larvae, Y_A:young adult, AF:adult female, Y_AF:young adult female, P_AF:parasitized adult female, F_AF:free-living adult female