Figure 1.

Phylogenetic relationships of the Gr 1-3 proteins in the twelve drosophilid flies, three mosquitoes, the silk moth, and the flour beetle. This is a corrected distance tree so cummulative distances along the longest branches total as much as 185%, while the actual distances are never larger than 78%. Species names are abbreviated to the first letter of the genus in capitals and the first three letters of the species name in lower case. The extreme N-termini of the BmorGr1 and BmorGr2 proteins could not be identified in the genome sequence, indicated by the suffix N after the protein name, but this does not affect the alignment used here. Similarly, a few amino acids are missing from the DmojGr21a C-terminus. Bootstrap support from 1000 replications of full heuristic uncorrected distance analysis was over 75% for all nodes except within the drosophilid flies. Inferred intron gains and losses are indicated by upper and lower case letters, respectively, on the relevant branches. Note that intron t, although only present in the Gr2 lineage, is inferred to be a much older intron because it is shared by other Grs (see Figure 2 legend).