Figure 5. Western blot analysis to determine the onset of vitellogenin synthesis in honeybee queen and worker pupae, showing the effect of ecdysone on vitellogenin expression. A) workers, and B) queens treated in Pbl stage with 5 mg of ecdysone (in ethanol/Ringer's solution 1:4), or with ethanol/Ringer's solution (controls). Pbm and Pbd: brown-eyed pupae showing, intermediary or dark pigmented cuticle, respectively. Pbm I and Pbm II: progressive ages within Pbm phase. Pha: pharate adult * Advanced brown-eyed dark, pigmented cuticle pupae. Arrows indicate the 180kDa vitellogenin band.