TEMPORAL SYNTHESIS OF CUTICLE PROTEINS DURING LARVAL DEVELOPMENT IN GLOSSINA-MORSITANS

1. Larval development in Glossina species occurs in utero with the mat ure third instar larva being deposited after a developmental period of 7 days. 2. In this study, the patterns of cuticular protein synthesis during larval development were analysed by two-dimensional gel electr ophoresis. 3. From the results, four types of cuticle proteins were id entified: those specific to larval, pupal and adult cuticles, and othe rs common to all the stages. 4. Few cuticular proteins were synthesize d between the first and second larval instars. By the third larval ins tar (two days before larviposition), a large number of proteins (M(r) less-than-or-equal-to 30 kDa) were induced. These proteins persisted u p to the brown pupal stage and showed a rapid decline thereafter. Most of the proteins with molecular weights M(r) less-than-or-equal-to 30 kDa were undetectable at apolysis (5 days after larviposition). 5. By day 15 of the pupal stage, the number of cuticle proteins was very sma ll. The protein profile during the pupal stages remained relatively co nstant. This was probably due to the fact that the pupal cuticle does not provide any protection since it is itself enclosed at all times wi thin the protective puparium.