Western blot analysis of major royal jelly protein1 (MRJP1) (A), MRJP2 (B) and MRJP3 (C). Whole cell lysates from hypopharyngeal gland on day 1, 3, 6, 12, 15 and 20 of honeybee worker (Apis mellifera L.) were subjected to SDS-PAGE followed by western blot analysis. MRJP1, 2 and 3 were detected using polyclonal antibody anti-MRJP1, 2 and 3, respectively. Equal loading of lanes was maintained by performing a total protein assay and is confirmed by western blot analysis using an anti-actin antibody. Upper panel, western blot analysis; lower panel, relative densitometry analysis (normalized by actin). A is significantly higher than b, c and d, b is significantly higher than c and d, c is significantly higher than d.