OBJECTIVE: To investigate the intraspecific difference of the triose phosphate isomerase (tim) gene from Giardia lamblia (G. lamblia). METHODS: Total genomic DNA of G. lamblia was extracted and partial fragments of th...OBJECTIVE: To investigate the intraspecific difference of the triose phosphate isomerase (tim) gene from Giardia lamblia (G. lamblia). METHODS: Total genomic DNA of G. lamblia was extracted and partial fragments of the triose phosphate isomerase (tim) gene were amplified by polymerase chain reaction (PCR). All nucleotide sequences were analyzed by using a phylogenetic analysis, which was constructed with parsimony and Neighbor-joining (N-J) methods. RESULTS: A total of 124 variable sites (23% of all sequences detected) was defined, most of which were found at the silent sites of codons. Two similar phylogenetic trees were constructed, subdividing 16 Giardia isolates into two groups. CONCLUSION: The genetic diversity of G. lamblia appeared to be little affected by factors of both host and geography, while natural-selection played an important role in DNA molecular evolution level of the tim gene. The tim gene may be considered a very useful genetic marker of the population genetic structure of G. lamblia.展开更多
目的从基因水平探讨湖北地区汉族人食管癌 HEN-DQB1等位基因的遗传易感性.方法运用序列特异性引物聚合酶链反应技术,检测无亲缘关系湖北汉族健康人136例、食管癌组42例患者的 HLA-DQB1等位基因.SAS system 统计软件数据处理.结果湖北汉...目的从基因水平探讨湖北地区汉族人食管癌 HEN-DQB1等位基因的遗传易感性.方法运用序列特异性引物聚合酶链反应技术,检测无亲缘关系湖北汉族健康人136例、食管癌组42例患者的 HLA-DQB1等位基因.SAS system 统计软件数据处理.结果湖北汉族人食管癌患者与正常人比较,HEN-DQB1*0301基因频率显著增高(0.2976 vs 0.1875),P=0.046,OR=1.835,病因分数=0.1354);两组间 HLA-DQB1其余各等位基因分布频率的比较,HLA-DQB1*0201(0.0833 vs 0.1016),*0301(0.2976 vs 0.1875),*0302(0.0595 vs 0859),*0303(0.2381 vs 0.1875),*0304(0.0000 vs 0.0039),*0401(0.0714 vs 0.0469),*0402(0.0119 vs 0.0156),*0501(0.0357 vs 0.0703),*0502(0.0595 vs 0.0664),*0503(0.0119 vs 0.0195),*0504(0.0000 vs 0.0039),*0601(0.0595 vs 0.0781),*0602(0.0476 vs 0.0742),*0603(0.0000 vs 0.0078),*0604(0.0238 vs 0.0508),差异均无显著性.结论 HLA-DQB1*0301等位基因与湖北汉族人食管癌正关联,为其易感基因.展开更多
文摘OBJECTIVE: To investigate the intraspecific difference of the triose phosphate isomerase (tim) gene from Giardia lamblia (G. lamblia). METHODS: Total genomic DNA of G. lamblia was extracted and partial fragments of the triose phosphate isomerase (tim) gene were amplified by polymerase chain reaction (PCR). All nucleotide sequences were analyzed by using a phylogenetic analysis, which was constructed with parsimony and Neighbor-joining (N-J) methods. RESULTS: A total of 124 variable sites (23% of all sequences detected) was defined, most of which were found at the silent sites of codons. Two similar phylogenetic trees were constructed, subdividing 16 Giardia isolates into two groups. CONCLUSION: The genetic diversity of G. lamblia appeared to be little affected by factors of both host and geography, while natural-selection played an important role in DNA molecular evolution level of the tim gene. The tim gene may be considered a very useful genetic marker of the population genetic structure of G. lamblia.
文摘目的从基因水平探讨湖北地区汉族人食管癌 HEN-DQB1等位基因的遗传易感性.方法运用序列特异性引物聚合酶链反应技术,检测无亲缘关系湖北汉族健康人136例、食管癌组42例患者的 HLA-DQB1等位基因.SAS system 统计软件数据处理.结果湖北汉族人食管癌患者与正常人比较,HEN-DQB1*0301基因频率显著增高(0.2976 vs 0.1875),P=0.046,OR=1.835,病因分数=0.1354);两组间 HLA-DQB1其余各等位基因分布频率的比较,HLA-DQB1*0201(0.0833 vs 0.1016),*0301(0.2976 vs 0.1875),*0302(0.0595 vs 0859),*0303(0.2381 vs 0.1875),*0304(0.0000 vs 0.0039),*0401(0.0714 vs 0.0469),*0402(0.0119 vs 0.0156),*0501(0.0357 vs 0.0703),*0502(0.0595 vs 0.0664),*0503(0.0119 vs 0.0195),*0504(0.0000 vs 0.0039),*0601(0.0595 vs 0.0781),*0602(0.0476 vs 0.0742),*0603(0.0000 vs 0.0078),*0604(0.0238 vs 0.0508),差异均无显著性.结论 HLA-DQB1*0301等位基因与湖北汉族人食管癌正关联,为其易感基因.
