Yao R, Patterson D, Onodera K
Department of Agricultural Chemistry, University of Tokyo, Bunkyo-ku, Tokyo 113, Japan.
Jpn J Hum Genet. 1993 Sep;38(3):243-55. doi: 10.1007/BF01874135.
In order to investigate the repetitive sequences located on human chromosome 21, we have isolated DNA fragments containing Alu sequences. One of the clones, p1, was chosen for further study, because it contained repetitive sequences different from the Alu sequence. Nucleotide sequence analysis of p1 indicates that p1 contains L1 and O-family sequences. Interestingly, when the L1 sequence was used as a probe, a discrete band of 5 kb was seen in HindIII-digested DNA from somatic cell hybrids containing human chromosome 21 as the sole human chromosome. The L1 sequence was rearranged and was interrupted by O-family sequence, which was flanked by 6 bp target site duplications. Since all three repetitive sequences are known to act as retroposons, these results imply that there is an integration hot spot on human chromosome 21. The sequence was mapped within 21q11-21.
为了研究位于人类21号染色体上的重复序列，我们分离出了包含Alu序列的DNA片段。其中一个克隆p1被选作进一步研究对象，因为它含有不同于Alu序列的重复序列。对p1的核苷酸序列分析表明，p1含有L1和O家族序列。有趣的是，当用L1序列作为探针时，在仅含人类21号染色体的体细胞杂种的HindIII消化DNA中可见一条5 kb的离散条带。L1序列发生了重排，并被O家族序列打断，O家族序列两侧有6 bp的靶位点重复。由于已知所有这三种重复序列都作为逆转座子起作用，这些结果表明人类21号染色体上存在一个整合热点。该序列定位于21q11 - 21区域内。
