More than royal food - major royal jelly protein genes in sexuals and workers of the honeybee Apis mellifera

摘要

BACKGROUND: In the honeybee Apis mellifera, female larvae destined to become a queen are fed with royal jelly, asecretion of the hypopharyngeal glands of young nurse bees that rear the brood. The protein moiety of royal jellycomprises mostly major royal jelly proteins (MRJPs) of which the coding genes (mrjp1-9) have been identified onchromosome 11 in the honeybee’s genome.RESULTS: We determined the expression of mrjp1-9 among the honeybee worker caste (nurses, foragers) and thesexuals (queens (unmated, mated) and drones) in various body parts (head, thorax, abdomen). Specific mrjpexpression was not only found in brood rearing nurse bees, but also in foragers and the sexuals.CONCLUSIONS: The expression of mrjp1 to 7 is characteristic for the heads of worker bees, with an elevatedexpression of mrjp1-4 and 7 in nurse bees compared to foragers. Mrjp5 and 6 were higher in foragers compared tonurses suggesting functions in addition to those of brood food proteins. Furthermore, the expression of mrjp9 washigh in the heads, thoraces and abdomen of almost all female bees, suggesting a function irrespective of bodysection. This completely different expression profile suggests mrjp9 to code for the most ancestral major royaljelly protein of the honeybee.