荔枝铜锌超氧物歧化酶基因的克隆与序列分析

Cloning and sequencing of Cu/Zn superoxide dismutase gene of litchi

以“三月红”荔枝基因组 DNA为模板 ,用 Cu· Zn SOD基因特异寡聚核苷酸为引物 ,进行 PCR扩增 ,得到特异基因片段 ,将其克隆到 p GEM T载体上 ,转化感受态大肠杆菌 TG1中 ,对转化子中重组p GEM T上的 Cu·Zn SOD基因片段的 PCR扩增检测和序列分析 ,表明克隆成功 ;该基因片段有 4 78个核苷酸 ,由 4个外显子和 3个内含子组成 ;外显子由 2 3 4个核苷酸组成 ,编码 78个氨基酸 ;该基因片段编码的氨基酸序列与水稻、玉米、番茄、大白菜和松树的 Cu· Zn SOD基因编码的氨基酸序列的同源性分别为79.5%、 73 .1 %、 73 .1 %、 71 .8%和 75.7%。

Special oligonucleotides to highly conserved regions of Cu/Zn superoxide dismutases(SOD) gene were used to prime the synthesis and amplification of fragment of about 500 bp by polymerase chain reaction(PCR) in samples of genomic DNA from “March Red” litchi leaves. The fragment was cloned into pGEM vector,which was transformed into the competence cells of the strain TG1 of E.coli. After screening of recombinants,PCR detection and sequence analysis,the transformants containing Cu/Zn SOD gene were obtained.Sequencing indicated that the Cu/Zn SOD gene fragment of litchi included 478 nucleotides containing four exons encoding 78 amino acids,interrupted by three introns.The amino acid sequence was respectively 79 5%,73 1%,73 1%,71 8% and 75 7% homologus to those of rice,maize,tomato,cabbage and pine.