新生隐球菌白化株酚氧化酶结构基因的突变研究

CNLAC1Gene Mutation of Cryptococcus neoformans

目的探讨新生隐球菌白化突变的分子机制,进一步研究白化突变株与野生产黑株之间漆酶基因(CNLAC1)的差异。方法用聚合酶链反应(PCR)扩增白化突变株与野生产黑株在比较研究中发现的差异基因片段;克隆异常片段的PCR产物,用PGEM-T载体构建重组表达质粒载体,转化大肠杆菌,进行目的基因测序。结果克隆了产黑株及白化株存在差异的片段,构建了差异基因片段的重组质粒载体,转化后测序发现在1715bp～2617bp之间白化突变株不仅存在基因片段大小的改变,而且存在碱基序列的改变。结论新生隐球菌白化突变的分子机制,可能在于其CNLAC1基因在1715bp～2617bp之间碱基序列的改变,而不是基因片段的单纯缺失。白化突变株差异基因片段可能为新生隐球菌病的预后和治疗提供一个靶基因。

Objective To explore the mechanism of Cryptococcus neoformans mutant in CNLAC1and investigate the difference of CNLAC1between wild type(Mel+ )and the mutant (Mel- ).Methods The ab-normal PCR DNA product of Cryptococcus neoformans was cloned into sequencing vector PG EM-T for se-quencing.An expression vector was c onstructed for efficient expressio n in E.coli DH 5α .The gene was sequenced.Results The cloned DNA sequence was found to b e different between wild type(Mel+)and the mutant (Mel-)(between 1715bp and 2617bp).The differences were not only in len gth,but also in base sequence.Con-clusion The mechanism of the mutant in CNLAC1might be a change of sequence(between 1715bp and 2617bp),and not a DNA deletion.This finding might provide us a target gene for the prognosis and treatment of cryptococcosis.