Orthologs. Comparative analysis of orthologous protein groups between six sequenced insect genomes. Predicted proteins from the genome sequences of mountain pine beetle (MPB), Tribolium castaneum, Apis mellifera (honey bee), Bombyx mori (silk moth), Drosophila melanogaster, and Acyrthosiphon pisum (pea aphid) were clustered into orthologous groups with OrthoMCL . (A) Venn diagram indicates the number of protein groups found in either one or both beetle species among the 12,156 orthologous groups found. Numbers in parentheses indicate the percentage of these groups that were not found in any of the four non-beetle species. (B) Of the 6,663 groups found in both beetle species, 83% had an n to n correspondence between the two beetle species, whereas other groups had more or fewer members in mountain pine beetle (MPB) versus T. castaneum. The histogram indicates the distribution of the ratios of the number of MPB to T. castaneum proteins in each group.