Storage proteins in ants during development and colony founding

Abstract

Three classes of storage proteins from larvae of four species of ants ( Crematogaster opuntiae, Pheidole spadonia, Solenopsis xyloni and Conomyrma sp.) were identified and characterized for native and subunit sizes, density and amino acid composition. First, hexamerins contained moderately high proportions of aromatic amino acids ( x ̄ = 12.9 mol% ). A second type of storage protein contained extremely high proportions of glutamine/glutamic acid ( x ̄ = 21.1 mol% ). Third, dimeric proteins had densities suggesting they were very high density lipoproteins (VHDL). These VHDLs may be homologous with similar proteins that carry chromophores in Lepidoptera. The same types of storage proteins found in larvae were also present in the fat bodies of adult queens at the time of their mating flights. The class of the dominant protein varied with species. In Cr. opuntiae queens, storage proteins were almost completely depleted during colony founding. In ants, the ability of adult females to express storage protein genes may have been an important step in the evolution of the claustral mode of colony initiation, in which females can produce the first set of workers without leaving the nest to search of food.