人基因组中的短串联重复(Short tandem repeat,STR)顺序由数目不等的重复单位组成,可作为一类高度多态的遗传标记(Genetic marker)。STR顺序不仅可用于基因组遗传连锁图的构建以及基因的定位和克隆,也可用于遗传性疾病的连锁分析和基因...人基因组中的短串联重复(Short tandem repeat,STR)顺序由数目不等的重复单位组成,可作为一类高度多态的遗传标记(Genetic marker)。STR顺序不仅可用于基因组遗传连锁图的构建以及基因的定位和克隆,也可用于遗传性疾病的连锁分析和基因诊断。目前分离并定位的STR虽然已有6000余个,但其在基因组中的分布很不均匀,许多区段中STR间的图距很大,例如在人染色体14q24.3区带长达12 800kb范围内仅确定了少数几个(CA)_n多态STR,这对于该区带的遗传学制图和基因定位研究来说是远远不够的,故仍需分离和定位更多的STR位标,迄今国内尚未见到这类工作的报道。展开更多
One of the major complications of pregnancy, preeclampsia makes pregnancy term ination inevitable in most cases. Similarities exist between the mechanisms that maintain normal pregnancy, allograft transplants, and, it...One of the major complications of pregnancy, preeclampsia makes pregnancy term ination inevitable in most cases. Similarities exist between the mechanisms that maintain normal pregnancy, allograft transplants, and, it is postulated, periph eral self-tolerance. In addition, the critical role of the cytotoxic T-lymphoc yte antigen-4 (CTLA-4) molecule in maintaining self-tolerance has been establ ished. Therefore, the frequency of CTLA-4 A49G polymorphism was investigated in severe preeclampsia. Genomic DNA extracted from mononuclear cells of the periph eral blood of 36 pregnant women with severe preeclampsia and 151 healthy women w as analyzed. A49G polymorphism in position 49 of exon-1 of the CTLA-4 gene was studied by the polymerase chain reaction-single-strand conformation polymorph ism (PCR-SSCP) method. The frequency of the GG genotype was 2 (5.6%) in patien ts and 19 (12.6%) in controls, while the frequency of the AA genotype was 4 (11 .1%) and 60 (39.7%). Interestingly, the frequency of the AG genotype was signi ficantly higher in preeclamptic than in healthy women from the general populatio n (83.3%vs. 47.7%; P=0.0005). These data suggest that heterozygosity in the CT LA-4 A49G allele might be a predisposing factor for severe preeclampsia. Whethe r the observed association results from linkage imbalance with other loci on chr omosome 2 or other polymorphisms of the CTLA-4 gene or even from a preferential transfer and/or expression of one allele from a heterozygous mother to the fetu s will be the subject of future investigations.展开更多
文摘人基因组中的短串联重复(Short tandem repeat,STR)顺序由数目不等的重复单位组成,可作为一类高度多态的遗传标记(Genetic marker)。STR顺序不仅可用于基因组遗传连锁图的构建以及基因的定位和克隆,也可用于遗传性疾病的连锁分析和基因诊断。目前分离并定位的STR虽然已有6000余个,但其在基因组中的分布很不均匀,许多区段中STR间的图距很大,例如在人染色体14q24.3区带长达12 800kb范围内仅确定了少数几个(CA)_n多态STR,这对于该区带的遗传学制图和基因定位研究来说是远远不够的,故仍需分离和定位更多的STR位标,迄今国内尚未见到这类工作的报道。
文摘One of the major complications of pregnancy, preeclampsia makes pregnancy term ination inevitable in most cases. Similarities exist between the mechanisms that maintain normal pregnancy, allograft transplants, and, it is postulated, periph eral self-tolerance. In addition, the critical role of the cytotoxic T-lymphoc yte antigen-4 (CTLA-4) molecule in maintaining self-tolerance has been establ ished. Therefore, the frequency of CTLA-4 A49G polymorphism was investigated in severe preeclampsia. Genomic DNA extracted from mononuclear cells of the periph eral blood of 36 pregnant women with severe preeclampsia and 151 healthy women w as analyzed. A49G polymorphism in position 49 of exon-1 of the CTLA-4 gene was studied by the polymerase chain reaction-single-strand conformation polymorph ism (PCR-SSCP) method. The frequency of the GG genotype was 2 (5.6%) in patien ts and 19 (12.6%) in controls, while the frequency of the AA genotype was 4 (11 .1%) and 60 (39.7%). Interestingly, the frequency of the AG genotype was signi ficantly higher in preeclamptic than in healthy women from the general populatio n (83.3%vs. 47.7%; P=0.0005). These data suggest that heterozygosity in the CT LA-4 A49G allele might be a predisposing factor for severe preeclampsia. Whethe r the observed association results from linkage imbalance with other loci on chr omosome 2 or other polymorphisms of the CTLA-4 gene or even from a preferential transfer and/or expression of one allele from a heterozygous mother to the fetu s will be the subject of future investigations.
