Using the plasmid pBR322 as a vector,EcoRI-BamHI and BamHI restrictionfragments of the ribosomal RNA gene (rDNA)from the silk worm Attacus ricini(Philosamia cynthia ricini) have been cloned in E.

• 利用质粒pBR322作运载体；获得了蓖麻蚕(Attacus ricini)核糖体rRNA 基因(rDNA)的部分片段在E.