【摘要】 目的:在中国人群肾上腺素α_2A受体(α_2A-AR)基因中搜寻单核苷酸多态性（SNP）并研究其对基因表达的影响。方法:对α_2A-AR基因进行序列分析,搜寻SNP。从全血中提取基因组DNA,扩增包含G/C多态性位点的239 bp DNA片段。利用PCR-RFLP方法对中国北方人群α_2A-AR基因-1296 bp位点SNP进行基因分型。利用凝胶阻滞方法研究含G/C的390 bp DNA片段与细胞核提取物的结合。结果:在中国北方人群α_2A-AR基因中共发现2处SNP。-1296位SNP等位基因G、C频率分别为0.61和0.39,基因型GG,GC,CC频率分别为0.34,0.54,0.13。EMSA结果表明,细胞核提取物与-1296 bp为C的DNA片段可特异性结合。结论:中国北方人群α_2A-AR基因中存在2处SNP,调控区（-1296位）SNP等位基因为C的DNA片段可与特异性蛋白质结合,可能通过这一机制影响基因表达。更多还原

【Abstract】 Objective : To scan single nucleotide polymorphism ( SNP ) in Chinese alpha-2A adrcnergic receptor(α2A-AR] gene and study the cffects of the SNP on the gene expres-sion. Methods: The complete sequence of α2A-AR gene was analyzed with automated DNA se-quencer to scan SNPs . Genomic DNA was extracted from whole blood and a 239 bp fragment containing the G/C polymorphism was amplified with PCR using a pair of specific primers. PCR-RFLP was used to perform the genotyping of the SNP at the site-1 296 bp of the people in the North of China . Electrophoresis mobility shift assay( EMSA ) was used to study the binding of the 390 bp fragments ( -1414-1025 bp) with G or C at the site-1296 bp and nuclear ex-tracts . Results : In our study, two SNPs were found in α2A-AR gene . Allele frequencies of the SNP at the site-1296 bp were 0.61 and 0.39 for G and C, and the genotype frequencies were 0.34,0.54 and 0.13 for GG, GC and CC respectively from the people in the North of China . In the EMSA, a specific binding appeared in the complex of nuclear extracts and DNA with C at-1296 bp . Conclusion : Two SNPs exist in α2A-AR gene from the people in the North of China , and DNA fragment with allele C of the SNP at the site-1296 bp could bind with a specific protein , which could influence the gene expression .更多还原