Epidermal collagenase activity and its induction by 20- hydroxyecdysone in the fiddler crab Uca pugilator

The epidermal collagenase activity and its induction by 20-hydroxyecdysone in Uca pugilator were investigated. Zymographic electrophoresis showed four bands of collagenase activity, 16, 19, 22 and 29 kDa in molecular weight, with the former two accounting for 60% and 36% , respectively, of the total collagenase activity. The collagenase activity varies during the molting cycle. Among the molt stages tested, Premolt Stage Do exhibited the highest epidermal collagenase activity for both the 16 and 19 kDa isoenzymes and, as the molt stage proceeded, the enzymatic activity of these two isoenzymes decreased, with the lowest activity for both found in Premolt Stage D3 -4 - Injection of 20-hydroxyecdysone significantly induced the activity of the 16 kDa eollagenase in the epidermis of Uca pugilator, suggesting that the activity of this isoenzyme is under molting hormone control. Although 20-hydroxyeedysone injection did not result in a statistically significant increase in the activity of the 19 kDa isoenzyme, a tendency of the induction was nonetheless demonstrated. This is the first report on epidermal collagenase activity and its induction by the molting hormone in a crustacean .