The family of major royal jelly proteins and its evolution.

A cDNA encoding a new member of the gene family of major royal jelly proteins (MRJPs) from the honeybee, Apis mellifera, was isolated and sequenced. Royal jelly (RJ) is a secretion of the cephalic glands of nurse bees. The origin and biological function of the protein component (12.5%, w/w) of RJ is unknown. We show that the MRJP gene family encodes a group of closely related proteins that share a common evolutionary origin with the yellow protein of Drosophila melanogaster. Yellow protein functions in cuticle pigmentation in D. melanogaster. The MRJPs appear to have evolved a novel nutritional function in the honeybee.