HORMONAL-CONTROL OF EXPRESSION OF A PUPAL CUTICULAR PROTEIN GENE DURING METAMORPHOSIS IN GALLERIA

To trace the developmentally regulated expression of a gene coding for a pupal cuticle protein (GmPCP52), total RNA of carcasses was extract ed at different times during metamorphosis and subjected to Northern b lot analysis. Blots were probed with a dig-labelled antisense in vitro transcript of GmPCP52 cDNA. In untreated animals, GmPCP52 mRNA is abs ent during the wandering stage in last instar larvae. The amount of mR NA rises after pupal ecdysis to a maximum at a pupal age of 18 h. At 4 2 h it again becomes undetectable. Injection of the JH analogue epofen onane immediately after pupal ecdysis delays the decline of GmPCP52 mR NA, without the transcript have completely disappeared at 60 h. Therea fter it comes up again from day 3 to day 7 in the course of synthesis of a secondary pupal cuticle. Injection of 20E causes precocious disap pearance of GMPCP52 mRNA. It becomes undetectable at day 2. Comparison of the Northern blot data with results of in vitro translation experi ments reveals participation of translational control. (C) 1996 Wiley-L iss, Inc.