Ael亚型的分子生物学研究

目的　研究汉族ABO血型系统Ael亚型分子基因基础。方法　在标准血清学鉴定的基础上 ,对 2例汉族Ael亚型进行PCR SSP基因分型。并根据第 6、7外显子及两侧内含子的保守序列设计引物进行扩增 ,PCR产物经割胶纯化后直接序列分析。结果　PCR SSP基因分型排除了其中一个等位基因为A2 、B、O1和O2 基因的可能。DNA序列分析表明 ,该Ael亚型基因与A1基因相比 ,有 (798～ 80 4 )G插入和C(I 5 / 5 32 )T两处突变 ,推测的蛋白质除羧基端 86个氨基酸残基与A1糖基转移酶不同外 ,还比A1转移酶多 37个残基。结论 (798～ 80 4 )G插入和C(I 5 / 5 32 )T两处突变揭示了Ael亚型的分子基础

Molecular genetic analysis of Ael subgroup of the ABO blood group system

Objective To understand the molecular genetic basis of Ael subgroup of ABO blood group system in the Han nationality.Method 2 Ael individuals were defined by standard blood group serological techniques,and genomic DNA was prepared for PCR SSP genotyping.Primers were designed and synthesized to amplify complete exon 6 and 7 including flanking intron sequence,and direct sequencing of gel purified PCR amplified fragments was performed using Bigdye Sequencing kit.Result A possibility of regarding the Ael allele as A2,B,O1 and O2 genes had been eliminated by the PCR SSP assay.According to the sequence analysis,Ael gene had 2 mutations of which one was a nucleotide substitution at position 532 in intron 5 (C to T),and the other was a single nucleotide(G) insertion at position 798 to 804 in exon 7 which alter the 86 amino acids sequence of the glycosyltransferase and furthermore extend the translated proteins by 37 amino acids compared with A1 allele.Conclusion The mutations of (789 804)G insertion and C(I 5/532)T substitution is the molecular genetic basis for Ael phenotype.