Kaur G P, Athwal R S
Department of Microbiology and Molecular Genetics, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark 07103-2757.
Proc Natl Acad Sci U S A. 1989 Nov;86(22):8872-6. doi: 10.1073/pnas.86.22.8872.
Complementation of the repair defect in xeroderma pigmentosum cells of complementation group A was achieved by the transfer of human chromosome 9. A set of mouse-human hybrid cell lines, each containing a single Ecogpt-marked human chromosome, was used as a source of donor chromosomes. Chromosome transfer to XPTG-1 cells, a hypoxanthine/guanine phosphoribosyltransferase-deficient mutant of simian virus 40-transformed complementation group A cells, was achieved by microcell fusion and selection for Ecogpt. Chromosome-transfer clones of XPTG-1 cells, each containing a different human donor chromosome, were analyzed for complementation of sensitivity to UV irradiation. Among all the clones, increased levels of resistance to UV was observed only in clones containing chromosome 9. Since our recipient cell line XPTG-1 is hypoxanthine/guanine phosphoribosyltransferase deficient, cultivation of Ecogpt+ clones in medium containing 6-thioguanine permits selection of cells for loss of the marker and, by inference, transferred chromosome 9. Clones isolated for growth in 6-thioguanine, which have lost the Ecogpt-marked chromosome, exhibited a UV-sensitive phenotype, confirming the presence of the repair gene(s) for complementation group A on chromosome 9.
通过导入人类9号染色体，实现了对A型互补组着色性干皮病细胞修复缺陷的互补作用。一组小鼠 - 人杂交细胞系，每个细胞系都含有一条经Ecogpt标记的人类染色体，用作供体染色体的来源。通过微细胞融合并筛选Ecogpt，将染色体导入XPTG - 1细胞，XPTG - 1细胞是猿猴病毒40转化的A型互补组细胞的次黄嘌呤/鸟嘌呤磷酸核糖转移酶缺陷型突变体。对XPTG - 1细胞的染色体转移克隆进行分析，每个克隆都含有一条不同的人类供体染色体，检测其对紫外线照射敏感性的互补情况。在所有克隆中，仅在含有9号染色体的克隆中观察到对紫外线的抗性水平增加。由于我们的受体细胞系XPTG - 1缺乏次黄嘌呤/鸟嘌呤磷酸核糖转移酶，在含有6 - 硫鸟嘌呤的培养基中培养Ecogpt +克隆，可以选择丢失该标记的细胞，由此推断，转移的9号染色体也丢失了。在6 - 硫鸟嘌呤中生长而分离得到的克隆，已丢失经Ecogpt标记的染色体，表现出对紫外线敏感的表型，证实9号染色体上存在A型互补组的修复基因。
