Colony queen number, a major feature of social organization, is associated with worker genotype for Gp-9. Colonies are headed by either a single reproductive queen (monogyne form) or multiple queens (polygyne form). Differences in worker Gp-9 genotypes between social forms may cause differences in workers' abilities to recognize queens and regulate their numbers. Homodimer. Allele shown represents B1, B2 and B3, a monogyne population from USA and B1, a monogyne population from Argentina. Workers bearing only the B allele invariably have a single queen, whereas colonies with workers bearing the alternate, b allele have multiple queens. The two social forms differ in many key reproductive and life history characteristics. Belongs to the PBP/GOBP family. The queen's perfume - Issue 97 of September 2008