Figure 2. Western blot analysis to determine the onset of vitellogenin synthesis in honeybee queen and worker pupae. SDS-PAGE (7.5%) was performed with 1mg of hemolymph proteins. After blotting to a PVDF membrane vitellogenin was detected by a rabbit antiserum raised against honeybee egg proteins and revealed by a PAP-DAB system. Pb: brown-eyed pupae with unpigmented cuticle; Pbl, Pbm and Pbd: brown-eyed pupae showing, light, intermediary, or dark pigmented cuticle, respectively; Pha: pharate adult; Ne: Newly emerged bee; 205, 116: molecular weight references (kDa); Arrow shows the 180 kDa vitellogenin band.