| Sclerodermus sichuanensis Xiao belongs to Hymenoptera, Bethylidae; it is an idiobiont ectoparasitiod to many wood-boring insects such as Monochamus alternatus Hope, Callidium villosulum Fairmaire and so on. The female ectoparasitiod has a simple reproductive system, its venom sac takes a large proportion in abdomen, and it does not have an obvious calyx region. All above, it declares that venom played an important role in the relationship between wasp(Sclerodermus sichuanensis Xiao) and host (Tenebrio molitor L. pupa). To explore the regulatory mechanism and parasitic regulatory mechanism of parasitism, Sclerodermus sichuanensis Xiao parasitizing on Tenebrio molitor L. pupa, many methods, for example the natural parasitism, venom injection, Sephadex G75 chromatography and PCR method and so on, were conducted to investigate the effects of venom on pupa in the parasitic process. Besides, one of the paralytic venom proteins was isolated, and two of the venom proteins’clones were preliminary explored. The main results were summarized as follows:1. Sclerodermus sichuanensis Xiao spent 0.5-3 h on lulling host of Tenebrio molitor L. pupa. In a certain range, when the proportion that wasp was parasitic on host pupa was larger, the natural injected number of times was larger, the natural injected venom content was larger, and the parasitic degree of host pupa was more obvious (positive correlation). Besides, the host pupa was also parasitic when injected with venom artificially. In a certain range, when the artificial injected content of venom was larger, the parasitic degree of host pupa was more obvious (positive correlation), and the reactivated host pupa was less obvious (negative correlation).2. Venom of Sclerodermus sichuanensis Xiao had the effects of paralysis, bacteriostasis, and delay melanization, and the active materials were proteins in effect of paralysis. Venom inhibited grows of Escherichia coli and Staphyloccocus aureus Rosenbach. Moreover, the bacteriostasis of venom on Staphylococcus aureus Rosenbach was significantly stronger than bacteriostasis on Escherichia coli.3. Temperature played an important role on paralytic activity and bacteriostatic activity of venom. After 40℃, as the temperature rose, the paralytic activity dropped significantly until disappeared at 60℃. The bacteriostasis on Escherichia coli was increased at 40℃, and it did not changed after 50℃. The bacteriostasis on Staphylococcus aureus Rosenbach was dropped at 60℃, and as the temperature rose after 60℃, the bacteriostasis disappeared at last.4. Venom of Sclerodermus sichuanensis Xiao had vpr 1-6 (venom protein 1-6) 6 venom macromolecular proteins. Those venom proteins would be decomposed in vpr Ⅰ～Ⅸ (venom protein Ⅰ～Ⅹ) 9 macromolecular peptide chains, when dealt byβ-mercaptoethanol. Furthermore, the molecular weight of 9 peptide chains were between 6.5 and 200 KDa, they were vpr I 187.83 KDa, vpr II 88.73 KDa, vpr Ⅲ 68.33 KDa, vpr Ⅳ 59.40 KDa, vpr V 38.23 KDa, vpr VI 27.30 KDa, vpr VII 16.89 KDa, vpr Ⅷ 14.13 KDa, vpr IX 12.94 KDa.5. The venom macromolecular protein vpr 4, which was contained in venom of Sclerodermus sichuanensis Xiao, had paralytic activity. Besides, vpr 4 would be decomposed in two macromolecular peptide chains (vpr V, vprIX), when dealt by β-mercaptoethanol. It declared that the molecular weight of vpr 4 was sum of molecular weight of vpr V and vprIX, it was 51.17 KDa approximately.6. The paralytic activity of venom macromolecular protein vpr 4 was not equilibrium. For slight paralytic activity, the vpr 4 was significantly higher than venom of 0.03 VRE, and there were no significantly difference between vpr 4 and venom of 0.05 VRE. For complete paralytic activity, the vpr 4 was significantly higher than venom of 0.03 VRE, and it was significantly lower than venom of 0.05 VRE. For reactivated activity, the vpr 4 was significantly lower than venom of 0.03 VRE, and it was significantly higher than venom of 0.05 VRE.7. The total DNA distill was much easier in alive Sclerodermus sichuanensis Xiao, and it was difficult decomposed in alive sample. The optimal annealing temperature of parasitic protein was 54℃ in central segment clone. And the optimal annealing temperature of serine proteinase was 52℃ in central segment clone. |
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