Kato H, Okamura K, Kurosawa Y, Kishikawa T, Hashimoto K
Institute for Comprehensive Medical Science, Fujita-Gakuen Health University, Aichi, Japan.
FEBS Lett. 1989 Jul 3;250(2):529-35. doi: 10.1016/0014-5793(89)80790-2.
We characterized N-myc gene amplification in three human neuroblastoma cell lines (IMR-32, TGW, GOTO). Rearrangements in long-range regions surrounding amplified N-myc genes were examined by pulsed-field gel electrophoresis. Since rare-cutting enzymes completely digested DNA at the middle of the N-myc gene, we were able to construct a physical map upstream and downstream of the germline N-myc gene, and to obtain information on restriction sites surrounding amplified N-myc genes. This method enables us to envisage the organization of amplified units over a long range. Digestion patterns differed considerably among the germline and the three cell lines, but were simple in each case. We estimated that the minimal distance between neighboring N-myc genes is at least several hundred kilobases. Our data suggest that amplification units contain several DNA fragments derived from different loci, but that they are homogeneous.
