家蚕血液胰凝乳蛋白酶抑制剂的多态性分布

Polymorphsim distribution of hemolymph chymotrypsin inhibitor (CI) in Bombyx mori

家蚕Bombyxmori的胰凝乳蛋白酶抑制剂(chymotrypsininhibitor,CI)在家蚕发育过程中发挥着重要作用,具有丰富的多态性。为了进一步研究家蚕胰凝乳蛋白酶抑制剂在群体水平上的多态性分布,通过非变性聚丙烯酰胺凝胶电泳,调查了425个家蚕品系的血液胰凝乳蛋白酶抑制剂的分布情况。结果表明,基因IctA、IctD和IctE在所有家蚕品系中存在,暗示它们是家蚕正常生长发育必需的基因;相反,至少在9个家蚕品系中发现基因IctB和IctH都没有表达,而这些品系没有明显的生理缺陷。在中国品系和日本品系家蚕之间,胰凝乳蛋白酶抑制剂分布规律基本一致。对52个纯品系家蚕的胰凝乳蛋白酶抑制剂分布进行的聚类分析结果表明,胰凝乳蛋白酶抑制剂分布与其系统、眠性和化性都没有明显的相关性。所以家蚕胰凝乳蛋白酶抑制剂广泛存在于不同家蚕品系中,同时多态性的分布特征也表明其生理功能在进化过程中发生了明显的分化。

Chymotrypsin inhibitor （CI） in Bombyx mori may play important roles in its normal development and growth with rich polymorphsim. In the experiment the distribution of CI polymorphsim in hemolymph among 425 silkworm strains was investigated by native-polyaerylamide gel eleetrophoresis （Native-PAGE）. The results indicated that three genes Ict-E, Ict-D and Ict-A expressed in every strain, suggesting that these genes should be necessary for the development of silkworm, and the products of genes Ict-H and Ict-B were not found in 9 strains, which had no distinct deficiency in development. The polymorphsim distribution of CI exhibited the similar pattern in both the Japanese and Chinese strains. Finally, the cluster analysis of the CI polymorphsim distribution in 52 pure strains showed that the clustered groups were not correlative to the strain system, mohinism or vohinism. It was so concluded that CI existed commonly in different strains of silkworm, and the characteristics of CI polymorphsim distribution suggest that differentiation of their function may have occurred in evolution.