Expression of a serine proteinase homolog prophenoloxidase-activating factor from the blue crab, Callinectes sapidus.

摘要: Tanning, or sclerotization, of crustacean cuticle provides initial reinforcement by cross linking cuticular proteins attached to the chitin-fiber matrix. This process is catalyzed in part phenoloxidase, which under control a serine protease activation cascade. The cDNA prophenoloxidase-activating factor (PPAF) was cloned and sequenced from hypodermal tissue blue crab, Callinectes sapidus. It codes for proteinase homolog containing single clip domain. If it involved its transcription might be expected molt-cycle related. Expression patterns were determined quantitative PCR Northern blotting hypodermis underlying both arthrodial dorsal (calcifying) cuticles. Transcript levels pre-molt RNA types high, suggesting that PPAF produced may incorporated into pre-ecdysial layers then activated at ecdysis regulate tanning. After decrease ecdysis, second increase mRNA occurred three four hours post-molt membrane but not hypodermis. suggests deposited after tan non-calcifying regions where calcification occurs. gene also transcribed low hemocytes intermolt crabs, hepatopancreas.