【目的】蓖麻蚕Samia cynthia ricini属于鳞翅目昆虫,其体内存在的胰凝乳蛋白酶抑制剂(chymotrypsin inhibitor,CI)对蓖麻蚕的正常生长发育和自身防御能力有重要的作用。获得蓖麻蚕的CI种类分布信息,以及研究各种CI的功能,可以为鳞翅目害虫的生物防治提供理论依据。【方法】本实验通过非变性聚丙烯酰胺凝胶电泳(native-PAGE)和CI活性染色技术,对18个蓖麻蚕品系的主要组织器官中胰凝乳蛋白酶抑制剂的多态性分布进行了调查,并对各品系血液中的蛋白含量和CI活性进行了测定。【结果】在p H 8.6电泳下,各品系血液中共检测到7条CI活性带,在p H4.0电泳下,各品系血液中可检测到3条CI活性带;血液中的CI含量从5龄第3天幼虫期到化蛹当天一直维持着很高的含量;头、体壁和脂肪体中的CI都不如血液中的CI含量高,而丝腺中未检测到任何CI。【结论】与家蚕Bombyx mori血液中的含量相比,蓖麻蚕血液中的CI含量更高,CI种类多态性分布不仅体现在不同品系的同一组织,还体现在同一品系的不同组织。
【Aim 】 The Eri-silkworm,Samia cynthia ricini,is a lepidopteran insect. Chymotrypsin inhibitors( CI) play important roles in the development and defense of the Eri-silkworm. The analysis of the polymorphism of CIs between different strains and the functional study of CIs in the Eri-silkworm could provide theoretical evidence for controlling Lepidoptera insects. 【Methods】We investigated CIs in major tissues of 18 strains of S. cynthia ricini by using p H 8. 3 and p H 4. 0 native polyacrylamide gel electrophoresis. At the same time,the total protein content and CI activity in the hemolymph were determined. 【Results】Seven CIs were found in the hemolymph of different strains of S. cynthia ricini in the p H 8. 3 PAGE,and three CIs were found in the p H 4. 0 PAGE. The CIs in the hemolymph maintained very high level from the 3rd day of the 5th instar larvae to the 1st day of the pupae. CIs had relative lower contents in the head,integument and fat body than in the hemolymph,and could not be detected in the silkgland. 【Conclusion】The expression level of CIs in S. cynthia ricini is higher than that in the silkworm,Bombyx mori. The polymorphism of CIs in S. cynthia ricini means that CIs vary in the same tissue of different stains and different tissues of the same strain.