Hormonal control of chitinolytic activity in the integument of Balanus amphitrite, in vitro

Abstract

1. 1. Mantle epidermis explants of Balanus amphitrite incorporated 3H- n-acetylglucosamine into the epidermis and exoskeleton, in vitro. Incorporation into the exoskeleton occurred in all molt cycle stages, but was substantially reduced during early pre-molt (stages D 0 and D 1). 2. 2. Ecdysterone (10–20μg/ml, 20–24 hr) stimulated the chitinolytic removal of n-acetylglucosamine from the cuticle, in vitro. Molt-inhibiting hormone (10 es eq/ml, 24 hr) significantly reduced the amount of ecdysterone-stimulated chitinolytic activity. 3. 3. These findings suggest that exoskeletal digestion during early proecdysis is under the influence of both ecdysterone and molt-inhibiting hormone.