A role for storage proteins in autogenous reproduction in Aedes atropalpus

Abstract

In the autogenous mosquito, Aedes atropalpus, storage proteins accumulated during the larval stage may serve as an amino acid reserve for oogenesis, in addition to metamorphosis. Hexameric storage proteins accumulate during larval development and include subunits of three different masses: 62.5, 66, 72.5 kDa. All three types of subunits are found in the female but only the larger two are in males. In females, storage proteins are only partially depleted by the time of eclosion. The remaining protein amounts to about 40% of the original store. Males, in contrast, exhaust their supply of stored protein during metamorphosis. In the female, the storage proteins disappear over the first days after eclosion, and are depleted before vitellogenin/vitellin levels reach their maximum. This suggests that the amino acids held in storage proteins are transferred to vitellogenesis, enabling autogenous egg development. The fact that these amino acids are not available for egg development until after eclosion, later than in many other insects, probably reflects a relatively recent evolution from blood-feeding ancestors.