Fig. 3

Gene family dynamics in the genomes of Conchocele bisecta, Archivesica marissinica, and Gigantidas platifrons. A Venn diagram showing the number of shared and unique expanded and contracted gene families in the three symbiotic species compared to five asymbiotic bivalves. Annotated to KEGG orthologs (KOs). B Total counts of KOs that expanded or contracted in each of the three bivalves, and the rates (%) of shared KOs. There are more exclusively expanded KOs than contracted ones in each bivalve. C Bubble plot of key expanded or contracted KOs in the three bivalves. Bubble size indicates the gene number of each KO in the eight species: C. bisecta (Conbis), G. platifrons (Gigpla), A. marissinica (Arcmar), Lutraria rhynchaena (Lutrhy), Mizuhopecten yessoensis (Mizyes), Modiolus philippinarum (Modphi), Pinctada fucata (Pinfuc), Crassostrea gigas (Cragig). Significant expansion (red), contraction (blue), or no significance (dark gray) were determined by Fisher’s exact test (P < 0.05)