Isolation and characterization of mRNAs coding for the third instar larvae cuticle proteins of Dacus oleae

In vitro translation of diapause mRNA from the fat body of active and diapause larvae of the pink bollworm, Pectinophora gossypiella (Saunders)

A diapause associated protein (DAP) (M(r) 103,000) was isolated from the hemolymph and fat body of diapausing fourth instar larvae of the pink bollworm Pectinophora gossypiella. The protein has been named Pectinophora diapause protein (PDP). The in vitro translation peptide patterns of total RNA from the fat body of actively feeding fourth instar, wandering, prediapause, early diapause, mid-diapause, and late diapause larvae in rabbit reticulocyte lysates showed the presence of poly (A)+ RNA sequence of PDP. The antigen was immunoprecipitated by polyclonal antiserum. It was concluded that the transcription of the PDP gene in the fat body cells started in the late fourth instar larva and that the expression of this gene was regulated at the level of transcription in the fat body of diapausing larvae. Northern hybridization analysis revealed that wandering fourth instar larvae (diapause individuals) maintain a relatively low level of diapause message (mRNA/2.4 kb) in their fat body cells which may be necessary for the induction of diapause.

The urea-soluble low molecular weight cuticle proteins from the different developmental stages of Dacus oleae

The cuticle proteins of the insect Dacus oleae have been isolated by extraction with a solution of 7 M urea. The affinity properties of cuticle proteins, isolated from the third instar larvae (L3DCPs 1-7), to chitin have been studied. Purified cuticle antigens were polymerized by glutaraldehyde and used for raising antibodies. The developmental appearance of the cuticle proteins has been studied by two-dimensional electrophoresis.