野桑蚕、蓖麻蚕及家蚕基因组的RFLP分析

以家蚕Bombyx mori丝素重链基因、丝胶基因1和胰凝乳蛋白酶抑制因子13基因为探针,对野桑蚕B.mandarina、蓖麻蚕Philosamia cynthia ricini和家蚕B.mori基因组DNA进行限制性片段长度多态性分析。结果发现,在野桑蚕、蓖麻蚕基因组中存在着家蚕丝素重链基因、丝胶基因1的同源序列,而在中日野桑蚕以及蓖麻蚕品种间存在着限制性酶切位点差异;丝胶基因1在中国野桑蚕基因组的EcoRⅠ酶切图谱较日本野桑蚕与家蚕更为一致,表明家蚕与中国野桑蚕亲缘关系更近。此外,在野桑蚕基因组中发现了家蚕胰凝乳蛋白酶抑制因子13基因的同源序列,并且在家蚕品种间以及中日野桑蚕之间也存在着多态性。这些结果表明不同绢丝昆虫在适应生存环境的进化过程中,基因组发生了结构改变。

RFLP analyses for genomes of Bombyx mandarina, Philosamica cynthia ricini and B. mori

The gene sequences of fibroin heavy chain(Fib-H),sericin 1(Ser1),and chymotrypsin inhibitor 13(CI-13) were used as probes and restriction fragment length polymorphism(RFLP) markers in the genome of Bombyx mori were found to be in genomes of B.mandarina,P.cynthia ricini,and B.mori. The results revealed that not only there existed the homologous sequence of Fib-H and Ser1 in the genome of B.mandarina and P.cynthia ricini,but also the structure in genomes of B.mandarina was different between in China and in Japan,as well as that of P.cynthia ricini between the two kinds of races.However,the EcoRI site of Ser1 in genomes of B.mandarina in China was more consistent with that of B.mori than that of B.mandarina in Japan,which suggested that the evolutionary relation between B.mori and B.mandarina in China was more close than that in Japan.In addition,the homologous sequence of CI-13 was detected in genomes of B.mandarina,furthermore,polymorphism of CI-13 was found to be exist in genomes of different B.mori races and B.mandarina in China and Japan.These results indicated that differences of genomic sequences among different silkworms happened during the evolutionary process to adapt to different environments.