Abstract: To study the change of proteins in hemolymph after hemopoietic organs of silkworm (Bombyx mori) being damaged, heavy ion beams (¹²C⁵⁺, 18.3 MeV/μ, range = 1.1 mm, 100 Gy) were used to locally irradiate the hemopoietic organs-wing disc complex at the premolting stage of the 4th instar. The total hemolymph proteins and bacterial challenge-related proteins induced by E. coli were investigated during the 5th instar. The results indicated that there was no significant difference in hemolymph proteins between irradiated individuals and the controls. Only the concentration of 70 kD proteins in irradiated silkworms were observed higher at day 0 of the 5th instar and lower at the later stage of the 5th instar than those of the respective controls. The content of storage protein in fat body showed the similar change tendency with that in hemolymph. The storage proteins were analyzed by Western blotting, and the results showed the 1st protein band near 70 kD was storage protein SP-1, the below two were storage proteins SP-2. Additionally 24 kD proteins in irradiated individuals also changed: it was lower than that of the controls at early days, hardly detected at the 3rd day of 5^th instar. Similar effects were also observed in the larvae generally irradiated with heavy ion beams. For irradiated individuals the quantity of bacterial challenge-related proteins in hemolymph induced by E. coli significantly decreased. It was so concluded that silkworm hemopoietic organs were related to the formation of hemolymph proteins, and due to the decrease of hemocytes caused by functional disruption of hemopoietic organs, synthesis of protein in fat body was affected and protein components in hemolymph changed.

Key words: Bombyx mori, heavy ion beam, local irradiation, hemopoietic organ, hemolymph, protein