Hexameric storage proteins during metamorphosis and egg production in the diamondback moth, Plutella xylostella (Lepidoptera)

Abstract

As in many Lepidoptera, Plutella xylostella adults do not feed on protein and females must use accumulated reserves to supply vitellogenin synthesis. Storage proteins were quantified in females and males from the late larval stage through day 4 of adult life. The level of storage protein peaked in the early pupal stage, with females having about twice as much as males. In males, the level fell through pupal development and dropped to a trace by one day after eclosion. In females, level of storage proteins fell until eclosion, and then rose dramatically within four hours after the molt to about 2/3 of the original peak level. This post-eclosion increase, which has not been reported previously in insects, suggests that adult females synthesize hexamerins to resequester amino acids. Subsequently, the level of storage proteins fell as vitellogenin appeared and eggs were laid. The ability to synthesize and sequester amino acids as storage proteins during the adult stage has wide-ranging implication for protein management in insects, particularly those that are long-lived and have flexible schedules of reproduction.