我国长春地区正常人c－abl等位基因分型及其物理图谱的鉴定

TYPES AND RESTRICTON PHYSICAL MAPS OF C-ABLALLELE IN CHINESE

我们以完整的ｖ－ａｂｌ癌基因为探针，用Ｓｏｕｔｈｅｒｎ印迹杂交方法在长春地区随机正常人群中检测到ｃ－ａｂｌ癌基因位点存在限制性片段长度多态性（ＰＦＬＰ）。ＲＦＬＰ的产生是由于ｃ－ａｂｌ位点存在ａ、ｂ、ｃ三个等位基因所致，ｂ等位基因是在ｃ－ａｂｌ基因酪氨酸残基受体位点下游一个内含子内发生大约５００ｂｐ缺失所致，ｃ等位基因是在同一位置缺失大约４ｋｂ。ａ等位基因频率为９４．７％；ｂ为１．９％；ｃ为３．４％。与白种人群ｃ－ａｂｌＲＦＬＰ比较，ａ、ｂ等位基因相同，频率相似，但我们首先发现一新的等位基因：ｃ等位基因。

he restriction fragment length polynlorphism(RFLP) at human c-ablocus was detected in a normalChinese population by Southern blotting with a￣(32) P-la-beled intact v-abl probe. This polymorphism resultsfrom the existence of three alleles, a,b and c. The alleleb is due to a deletion of about 500 bp in an intron locateddownstream to the phosphate tyrosine residue site of thec-abl gene, and the allele c, a deletion of about 4kb atthe same regicn. The frequencies of alleles a,b and c are94. 7% , 1. 9% and 3. 4% respectively. Compared withcabl RFLP in Caucasian population, alleles a and bmake no difference from Caucasian people in both DNAsequences and frequencies. However, the novel allele cwas discovered for the first time in Chinese people.