Characterization of major royal jelly protein-like DNA sequences in Apis dorsata

Major proteins of royal jelly (MRJP) are well characterized in the honey bee, Apis mellifera. They are secreted by hypopharyngeal glands and provide major proteinaceous components of the larval food. To date nothing is known about royal jelly proteins in other bee species. To fill this gap, we screened the genome of the Asian giant honey bee, Apis dorsato, for the two MRJP protein coding sequences MRJP3 and MRJP5. With PCR primers originally designed for A. mellifera we were able to amplify the presumably orthologous sequences in A. dorsata. Sequence analyses revealed high similarity in the two honey bees. As described in A. mellifera we found an orthologous extensive repetitive region in the MRJP3 sequence of A. dorsata. The number of reiterated repetitive motifs is highly variable in different A. dorsata individuals and is therefore well suited as a marker in population studies. The MRJP5 sequence region contains another repetitive region at the orthologous position as described for A. mellifera. These findings confirm the presence and indicate the functional equivalence of MRJP proteins in A. dorsata compared to A. mellifera. The origin of the MRJP protein family can therefore be dated back probably 22 million years ago to a common ancestor of A. mellifera and A. dorsata.