Abstract
1. Prophenoloxidase was isolated and purified from the blood of BT (black pupa strain) and normal strains of Datenishiki and Daizo in the silkworm. At the same time, activators were extracted from the integument, activating the prophenoloxidase. As a result, the activity of prophenoloxidase was strong in descending order of BT, Datenishiki and Daizo, but the activity of the activators was just reverse in order, namely in the order of Daizo, Datenishiki and BT.
2. As a result of a comparative experimentation of the purified prophenoloxidase by means of agar-gel electrophoresis, it was observed that there is a difference between the black pupa strain and the normal strain in electrophoretic mobility (Fig. 2). However, no remarkable difference was detected between those strains by meas of the cane sugar density gradient and the ultra centrifugation.
3. According to the investigation on the activators in various aspects by gel filtration with Sephadex G-200, it was disclosed that there are at least two kinds of ingredients in the activators, namely A and B. Compared with the normal strain, the black pupa strain generally contained less activator, especially ingredient B. Moreover, these results were confirmed by agar-gel electrophoresis.
4. Throughout various stages from the late stages of fifth instar to the third day after pupation, the quantitative variation of prophenoloxidase in blood was studied by agar-gel electrophoresis. A remarkable difference was observed between an individual which became black and the other which became normal color in the period from the end of the spinning to the time just after pupation.
