Hemolymph clotting in Bombyx mori

Abstract

Clotting mechanism of heat-pretreated hemolymph from the silkworm (B. mori) was studied. The hemolymph from 5th instar larvae was incubated under various conditions to analyze the effect of hemocytes, EDTA and other factors on clotting. The gel forming substances in clotted hemolymph were also examined. Heat-pretreatment of hemolymph (e. g. for 20min at 60°C) induced clotting and the clotting activity increased in the 5th instar. Hemolymph was divided into two fractions after centrifugation and the bottom fraction (hemocyte rich fraction) clotted faster than the top one (hemocyte poor fraction). The clotting was promoted by shaking but inhibited by addition of EDTA. Blackening slightly affected the clotting. A few proteins were found in the precipitate of centrifuged gel, and the precipitate highly promoted the hemolymph clotting.