Popescu N C, Bowden P E, DiPaolo J A
Division of Cancer Etiology, National Cancer Institute, Bethesda, MD 20892.
Hum Genet. 1989 May;82(2):109-12. doi: 10.1007/BF00284039.
Human genomic DNA containing two type II keratin genes, one coding for keratin 1 (K1, a 68-kD basic protein) and another closely linked type II gene 10-15 kb upstream (K?, gene product unknown), was isolated on a single cosmid clone. EcoRI restriction fragments of the cosmid were subcloned into pGEM-3Z, and specific probes comprising the C-terminal coding and 3' noncoding regions of the two genes were constructed. The type II keratin genes were localized by in situ hybridization of the subcloned probes to normal human lymphocyte chromosomes. In a total of 70 chromosome spreads hybridized with the K? probe (gHK?-3', PstI, 800 bp), 36 of the 105 grains observed were on chromosome 12, and 32 of these were clustered on the long arm near the centromere (12q11-13). In 100 labeled metaphases hybridized with the K1 probe (gHK1-3', BamHI-PstI, 2100 bp), 53 grains localized to chromosome 12 and 46 of these were found in the same region (q11-13). Therefore, both the gene for human keratin 1, a specific marker for terminal differentiation in mammalian epidermis, and another closely linked unknown type II keratin gene (K?, 10-15 kb upstream of K1) are on the long arm (q11-13) of human chromosome 12.
含有两个II型角蛋白基因的人类基因组DNA被分离到一个单一的黏粒克隆上，其中一个基因编码角蛋白1（K1，一种68-kD的碱性蛋白），另一个与之紧密连锁的II型基因位于其上游10 - 15 kb处（K?，基因产物未知）。将该黏粒的EcoRI限制性片段亚克隆到pGEM - 3Z中，并构建了包含这两个基因C端编码区和3'非编码区的特异性探针。通过将亚克隆的探针与正常人淋巴细胞染色体进行原位杂交，对II型角蛋白基因进行定位。在用K?探针（gHK? - 3'，PstI，800 bp）杂交检测的总共70个染色体铺片中，观察到的105个银粒中有36个位于12号染色体上，其中32个聚集在靠近着丝粒的长臂上（12q11 - 13）。在用K1探针（gHK1 - 3'，BamHI - PstI，2100 bp）杂交检测的100个标记中期相中，53个银粒定位于12号染色体上，其中46个位于同一区域（q11 - 13）。因此，人类角蛋白1基因（哺乳动物表皮终末分化的特异性标志物）以及另一个与之紧密连锁的未知II型角蛋白基因（K?，位于K1上游10 - 15 kb处）均位于人类12号染色体的长臂（q11 - 13）上。
