Shen Q, Townes P L, Padden C, Newburger P E
Department of Pediatrics, University of Massachusetts Medical School, Worcester 01655.
Genomics. 1994 Sep 1;23(1):292-4. doi: 10.1006/geno.1994.1499.
We report the variation in vivo and instability in vitro of an in-frame GCG trinucleotide repeat in the human cellular glutathione peroxidase (GPX1) gene. In a population study of 110 alleles from 55 unrelated individuals, the allele frequencies for 4, 5, and 6 GCG repeats were 0.40, 0.35, and 0.25, respectively. No allele was associated with diminished enzyme activity. Current stocks of HL-60 cells, a human myeloid leukemia cell line, are homozygous for the 6-repeat allele. Early passage HL-60 cells frozen in 1976 show a 4/6 genotype and "intermediate" passage cells frozen in 1985 contain both 4/6 and 5/6 genotypes. Thus, the expansion of the repeat appears to have developed in the course of multiple passages of the rapidly proliferating cell line.
我们报告了人类细胞谷胱甘肽过氧化物酶（GPX1）基因中一个符合读框的GCG三核苷酸重复序列在体内的变异情况以及在体外的不稳定性。在一项对55名无关个体的110个等位基因的群体研究中，4个、5个和6个GCG重复序列的等位基因频率分别为0.40、0.35和0.25。没有等位基因与酶活性降低相关。人髓系白血病细胞系HL-60的现有细胞株对于6重复等位基因是纯合的。1976年冻存的早期传代HL-60细胞显示为4/6基因型，而1985年冻存的“中期”传代细胞同时含有4/6和5/6基因型。因此，重复序列的扩增似乎是在这个快速增殖的细胞系多次传代过程中发生的。
