Sister-cluster evolution: Comparison between clusters 9@106 and 17@3. (a) GESTALT map of cluster 9@106, including graph of G + C content, GenScan predictions, interspersed repeats, and kilobase scale. Vertical gray lines indicate sequencing gaps. The order and orientation of the OR-containing contigs is final. Closed boxes represent intact ORs, and the open box indicates an OR pseudogene. The blue bar on top of the G + C content graph indicates an ∼10-kb segment surrounding OR5C1 , with G + C content corresponding to an H1 isochore. (b) Subfamily reconstruction of the 9@106 cluster at the postulated time of divergence from cluster 17@3. The dotted triangle indicates the single subfamily (1B) for which a counterpart was not observed. This subfamily is most similar to subfamily 1L, present in the same cluster, and may represent a gene duplication or deletion event that happened immediately after the cluster duplication. (c) Protein identity (PID) levels for each pair of subfamilies. (d,e) Subfamily reconstruction and GESTALT map of the 17@3 cluster, adapted from Glusman et al. (2000b), shown here in the opposite orientation. The recombinatorial events leading to the generation of OR1D4 and OR3A3 were omitted for clarity.
