水稻几丁质酶基因(Oschi)cDNA的克隆及序列分析

 以成功克隆大蕉几丁质酶基因（MpChi-1）时设计的一对引物,采用RT-PCR技术从广亲和水稻品种（Oryza．satival L．Cpslo17）中扩增到一水稻几丁质酶的全长cDNA，长1 115 bp，命名为Oschi；此序列已在GenBank中注册,登录号为EU045451；将Oschi基因核苷酸测序结果在NCBI服务器上用BLAST搜索软件进行同源性基因检索；并将Oschi的cDNA序列及氨基酸序列与大蕉及其它单子叶植物的相应序列进行多重序列排列比较并构建系统树；结果显示此基因具有编码Ⅰ类几丁质酶的基本结构；与大蕉核苷酸序列相比同源性为99%，氨基酸序列同源性为99%，与预测登记的最相近的水稻［Oryza sativa(japonica cultivar-group)］核苷酸序列相比同源性为98%, 氨基酸序列同源性为98%；广亲和水稻Oschi基因与大蕉MpChi-1基因的序列及蛋白结构有较高的一致性。

The Analysis of the Cloning and Sequence of the cDNA Gene Encoding Chitinase from Rice(Oschi)

Using a degenerate primer designed for cloning chitinase cDNA from plantain banana (MpChi-1), we obtained a full length cDNA clone named Oschi from rice by RT-PCR. The rice chitinase cDNA was 1 115 bp long and registered in GenBank with the accession number, EU045451. Using Clustal W online, we compared the cDNA sequence and amino acid sequence of Oschi with that from the plantain banana and the other monocotyledon, and constructed a phylogeny tree. The result shows that Oschi has some basic structures which are common among chitinase I gene. It shares a 99% homology with the gene sequence as well as amino sequence with those from plantain banana, and a 98% homology with that from Oryza sativa(japonica cultivar group) which has been reported. These evidences supported that Oschi and Mpchi-1 were highly identical to the gene sequences and protein structures.