【摘要】 目的在对念珠菌发生变异后其形态、结构等生物学性状研究的基础上,进一步探讨念珠菌类细菌样变异株基因特征。方法在低温、营养缺乏条件下诱导白色念珠菌标准菌株使其变异;用不同浓度梯度的氟康唑等临床常用抗真菌药物诱导白色念珠菌标准菌株变异。采用煮沸法制备真菌基因模板,采用细菌保守基因16SRNA序列引物和真菌保守基因18SRNA序列引物分别扩增16SRNA和18SRNA序列,琼脂糖凝胶电泳,观察并记录结果。同时将细菌保守基因16S RNA扩增片段进行测序,所得序列进行BLAST比对分析。结果念珠菌类细菌样变异株16SRNA序列均扩增阳性,而白色念珠菌标准株未出现相应的扩增条带。念珠菌类细菌样变异株18SRNA序列扩增除2号菌株有微弱的条带外,其余变异株均未扩增出目的条带,而白色念珠菌标准株则出现相应的扩增条带,表明念珠菌类细菌样变异株基因组中18S RNA序列所占比例不多或是因多次传代遗失。念珠菌类细菌样变异株16SRNA扩增片段经纯化后进行DNA序列测定,BLAST进行比对分析,发现念珠菌类细菌样变异株序列与数据库中细菌序列有较高的相似性。结论念珠菌类细菌样变异株基因组含有细菌保守基因及少量真菌保守基因,具有原核生物学性状的念珠菌类细菌样变异株是源于真核生物的念珠菌。此研究在生物进化特别是在原核细胞与真核细胞的进化联系上有非常重要的意义。更多还原

【Abstract】 Objective To further explore the genetic characteristics of oidiomycetes mutant strains like bacterial morphology on the basis of the study on morphology and structure of mutated candida.Methods The standard strains of candida albicans were induced by low temperature and under the condition of low temperature and nutrient deficiency.Variation of standard strains of Candida albicans were induced by clinical antifungal drugs such as fluconazole with different concentration gradient.Fungal gene template was prepared by boiling method,sequences of 16 SRNA and 18 SRNA were amplified using bacteria conservative gene sequence of 16 SRNA and fungal conserved gene sequence of 18 SRNA,and observed and recorded the results agarose gel electrophoresis.At the same time,the amplified fragment of bacterial conservative gene 16 SRNA was sequenced,and the sequence was analyzed by BLAST comparison.Results the 16 SRNA sequences of candida variant were amplified positive,while the standard strain of candida albicans did not show the corresponding amplification band.Except 2 strains which showed a faint band,the other variants of the 18 SRNA sequences did not amplified the target band,while the standard strains of candida albicans showed a corresponding amplification bands.Suggested that proportion of 18 SRNA sequences in the genome of oidiomycetes mutant strains like bacterial morphology was not much even lack.The 16 SRNA fragments amplified of oidiomycetes mutant strains like bacterial morphology did determination of DNA sequence after purification.BLAST comparison analysis,it was found that sequence of oidiomycetes mutant strains like bacterial morphology had higher similarity with bacterial sequences in the database.Conclusion Oidiomycetes mutant strains like bacterial morphology contained bacterial and a small amount of fungus conservative gene.Oidiomycetes mutant strains like bacterial morphology with original nuclear biological character are ones from eukaryotes.This study is great significance in biological evolution,especially in the evolution of prokaryotic cells and eukaryotic cells.更多还原