Change in phenoloxidase and its precursor during silkworm (a80 strain) development

The changes in phenoloxidase and its precursor, so-called prophenoloxidase, of the silkworm, Bombyx mori (a80 strain) were examined using detection as say with or without detergent to distinguish PO and pro-PO in hemolymph (Ya mamoto, et al., 1999). Little or no phenoloxidase activity was detected in hemolymph at the silkworm development during the final larval instar and pu pal stage. On the other hand, prophenoloxidase was detected for same time f rame. In males, after prophenoloxidase increased slightly at day 4, it decr eased to a minimum level at spinning and increased to a maximum level on th e day of pupation and decreased gradually to day 5 after pupation. In femal es, prophenoloxidase decreased gradually to a minimum level on day of spinn ing and a slight increase was observed at day 8 and it increased to maximum level between day 2 and 3 after pupation and decreased thereafter. Prophen oloxidase mRNA expression was preceded a day or two before, when comparing the change of phenoloxidase mRNA with its product.