The cloning cdna fragment was extracted from positive clones and sequenced . the results showed that the cdna fragment was 816bp in size , encoding a protein which included 272 amino acids . the sequence homology analysis was carried out via the software blast 2 . 0 network service in the four large databases - genbank , embl , ddbj , pdb , which had recorded 1 337 978 nucleotide and protein sequences . the results of the analysis indicated that the nucleotide homologous rates between the rubber tree etr and 15 recorded etrl of other plants ( mango , passion fruit , persia plum , strawberry , grape . . . etc ) were 75 % - 80 % ; the protein homologous rates between the rubber tree etrl and these recorded etrl genes were 90 % - 95 % . from the results mentioned above , we could confirm that the cdna of rubber tree etrl had been cloned 从阳性克隆子中提取克隆片段，经序列测定分析，结果表明，克隆片段的cdna大小为816bp ，编码的蛋白质包含272个氨基酸。基因序列通过blast2 . 0networkservice软件对genbank ， embl ， ddbj ， pdb四个大型数据库中记录的1337978条核酸和蛋白质序列进行序列相似性检索，结果表明与芒果、一西番莲、波斯梅、草毒、葡萄、西洋梨等15种已报道的植物的etrl基因cdnag的同源率为75 88 ；蛋白质氨基酸序列的同源率为90 95 ，表明本研究确实克隆到了橡胶树etri基因的cdna序列。 4
