人巨细胞病毒UL142基因在临床低传代分离株中的多态性  

Polymorphism of Human Cytomegalovirus UL142 Gene in Low Passage Clinical Isolates

作　　者：卢颖[1] 阮强[1] 何蓉[1] 齐莹[1] 马艳萍[1] 吉耀华[1] 刘庆[1] 陈淑荣[1] 

机构地区：[1]中国医科大学附属第二医院病毒研究室,沈阳110004

出　　处：《国际儿科学杂志》2006年第3期147-149,共3页International Journal of Pediatrics

基　　金：国家自然科学基金资助项目(30170986)

摘　　要：目的 研究人巨细胞病毒（HCMV）UL142基因在低传代分离株中的多态性。探讨其多态性与HCMV先天性感染不同致病性之间的关系。方法 27株经荧光定量PCR方法检测HCMV DNA阳性的低传代分离株进行UL142全序列PCR扩增，阳性13株PCR产物进行UL142基因测序及结果分析。结果27株分离株UL142PCR扩增，13株阳性，阳性率48．2％，以Toledo株为参考株序列比较表明，13株UL142可读框长度均与Toledo株相同，为921bp，编码307个氨基酸的蛋白。DNA序列变异均为核苷酸替换，不同临床分离株UL142基因与Toledo株进行同源性比较，结果在核苷酸水平为94．4％-95．9％，氨基酸水平为89．9％-99．6％。二级结构预测分为三种构象。大多数HCMV UL142蛋白重要功能基团位点在所有分离株中均高度保守，仅四个位点在一些分离株中存在缺失或新增。系统进化树分析：除Toledo株外，13株核苷酸及氨基酸序列可分为3个基因组。结论13株临床低传代分离株HCMV UL142基因DNA及其编码产物的氨基酸序列比较保守，但仍存在一定多态性。未发现不同临床分离株UL142基因多态性与HCMV先天性感染不同疾病表现的关系。Objective To investigate the polymorphism of human cytomegalovirus UL142 gene in low passage isolates and try to find the relationship between the polymorphism and different pathogenesis of congenital HCMV infection. Methods PCR was performed to amplify the entire HCMV UL142 gene region of 27 clinical isolates, which had been proven containing detectable HCMV-DNA by FQ-PCR PCR amplification products of 13 isolates were sequenced directly and the sequence data was analysed. Results 13 among 27 isolates were amplified successfully and the positive rate was 48.2%. By comparison with Toledo sequence, the length of UL142 ORF in all 13 clinical isolates was similar to that of Toledo,921 bp in size,encoding 307amino acids＇ protein. All of the DNA sequence variations were nucleofide substitutions, neither insertions nor deletions were detected. Alignment comparison of the UL142 sequences with that of Toledo revealed that nucleotide and amino acid sequence homologies were 94.4%-95.9% and 89.9%-92.5% respectively. Three kinds of secondary structure had been found. Most functional motifs of UL142 protein were highly conserved although several strains had deleted or additional sites.The phylogenetie trees based on UL142 DNA and amino acid sequence of HCMV demonstrated that 13 clinical isolates could be divided into 3 gene groups. Conclusion All DNA and deduced amino acid sequences of UL142 gene shared great similarity among HCMV clinical strains regardless of their polymorphism. No linkage was found between diversities of UL142 gene and the outcomes d congenital HCMV infection.

关 键 词：巨细胞病毒 多态现象 遗传学 UL142基因 

分 类 号：R373[医药卫生—病原生物学]