Fig. 4

Gene families related to symbiotic currency exchange in Conchocele bisecta. A Schematic representation of currency exchange in C. bisecta. Expansion events of gene families responsible for substrate transports and phagocytosis are illustrated, and the boxes that followed each gene indicate if the gene family is expanded (red) or not (white) in C. bisecta (right), Archivesica marissinica (middle), and Gigantidas platifrons (left). B Phylogenetic tree based on amino acids of mucolipins (Conbis: C. bisecta; Gigpla: G. platifrons; Lutrhy: Lutraria rhynchaena; Mizyes: Mizuhopecten yessoensis; Modphi: Modiolus philippinarum; Pinfuc: Pinctada fucata; Cragig: Crassostrea gigas; Outgroup: Danio rerio). C Phylogenetic relationships of cathepsin L genes (ctsL) in C. bisecta. Expression levels of different tissues (Gi, gill; Ma, mantle; Fo, foot; Ad, adductor) and Row-wise Z-score of TPM (transcript per million) counts in gill tissue and gene divergence times (My, million years) are shown if ctsL copy lengths range from 600 to 1200 bp, and yellow dots indicate the tandem duplicate gene pairs. Three duplicated genes (in red) with short divergent time constitute most of the ctsL transcripts in gill tissue