摘要
Objective: To scan single nucleotide polymorphism ( SNP ) in Chinese alpha-2Aadrenergic receptor (α_(2A)-AR) gene and study the effects of the SNP on the gene expression.Methods: The complete sequence of α_(2A)-AR gene was analyzed with automated DNA sequencer to scanSNPs. Genomic DNA was extracted from whole blood and a 239 bp fragment containing the G/Cpolymorphism was amplified with PCR using a pair of. specific primers. PCR-RFLP was used to performthe genotyping of the SNP at the site-1 296 bp of the people in the North of China. Electrophoresismobility shift assay ( EMSA ) was used to study the binding of the 390 bp fragments (- 1 414-1 025bp) with G or C at the site-1 296 bp and nuclear extracts . Results: In our study, two SNPs werefound in α_(2A)-AR gene. Allele frequencies of the SNP at the site-1 296 bp were 0.61 and 0.39 forG and C , and the genotype frequencies were 0.34 , 0.54 and 0.13 for GG, GC and CC respectively fromthe people in the North of China. In the EMSA, a specific binding appeared in the complex ofnuclear extracts and DNA with C at-1 296 bp . Conclusion: Two SNPs exist in α_(2A)-AR gene from thepeople in the North of China , and DNA fragment with allele C of the SNP at the site-1 296 bp couldbind with a specific protein, which could influence the gene expression.
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。
