Phylogenetic tree of the odorant receptor (Or) family. (A) Phylogenetic tree constructed using A. cerana (red), A. mellifera (blue), and D. melanogaster odorant receptor proteins. (B) Relative Or gene expression profiling using RPKM values in A. cerana (left) and A. mellfera (right). Red color indicates high expression compared to blue. (C) Microsynteny between A. cerana and A. mellfera Or genes. Orthologous and paralogous of A. cerana (red) and A. mellifera (blue) Ors were analyzed with BLASTZ. A. cerana scaffold number and A. mellifera chromosome number are on the left and right side, respectively.