Initiation of vitellogenesis in pharate adult females of the Indianmeal moth, Plodia interpunctella

Abstract

AbstractEgg maturation in the Indianmeal moth, Plodia interpunctella (Hübner), is initiated during adult metamorphosis. The temporal sequence for the initiation of vitellogenin (Vg) synthesis in fat body, the accumulation of Vg in hemolymph, and the accumulation of yolk proteins in terminal follicles during adult development are described. On the basis of quantitation by rocket immunoelectrophoresis, the amount of Vg in hemolymph prior to 80 h after pupation was below 50 ng/μl hemolymph. At 83 h after pupation, Vg was detectable at 0.4 μg/μl hemolymph and increased to over 20 μg/μl within 24 h after adult eclosion. Using immunofluorescent histochemical staining for Vg subunit yolk polypeptide 1 (YP1), the production of Vg was observed to increase rapidly in fat body between 96 and 100 h after pupation. Western blot analysis showed that YP2 was the first YP to accumulate in terminal follicles appearing at 96 h after pupation while the other three major YPs were first observed at 116 h. These findings demonstrate that initiation of vitellogenesis in terminal follicles begins around 96 h after pupation and involves the temporal coordination of fat body and follicle activities that provide Vgs before terminal follicles achieve competency to accumulate yolk proteins. © 1992 Wiley‐Liss, Inc.