| First Author | Rettenberger G | Year | 1991 |
| Journal | Cytogenet Cell Genet | Volume | 58 |
| Pages | 2032 (Abstr.) | Mgi Jnum | J:14878 |
| Mgi Id | MGI:63036 | Citation | Rettenberger G, et al. (1991) Localization of the type I DNA topoisomerase gene in man and mouse. Cytogenet Cell Genet 58:2032 (Abstr.) |
| abstractText | Full text of Abstract: Localization of the type I DNA topoisomerase gene in man and mouse. Rettenberger G1, Richter A2, Kunze N2, Baumgartner B2, Hameister H1, Wiedorn K-H3, Knippers R2 1 University of Ulm, Dept. of Clinical Genetics, Albert-Einstein-Allee 11, D-7900 Ulm, Germany; 2 University of Konstanz, Dept. of Biology, D-7750 Konstanz, Germany; 3 University of Marburg, Inst. of Human Genetics, D-3550 Marburg, Germany. Type I DNA topoisomerase, TOP1, is involved in fundamental nuclear processes as gene expression and DNA replication. The enzyme cuts and ligates intertwined DNA strands and resolves by this the torsional strain within the DNA helix. The enzyme is present in the nucleus at relative high concentration. We have used different cDNA probes of this gene and a somatic cell hybrid panel to localize the human TOP1 gene. The active TOP1 gene was assigned to chromosome 20 and two TOP1 pseudogenes to chromosome 1 and 22. In situ hybridization was used to map TOP1 regionally to 20q11.2-13.1 and the TOP1 pseudogene 1 to lq23-24 and TOP1 pseudogene 2 to 22q11.2-13.1, distal from the t(8;22)(q24;q11) breakpoint in variant Burkitt lymphoma (1). Screening of a genomic mouse library with 5' and 3' terminal parts of the human DNA topoisomerase I cDNA identified clones of the active mouse Top-1 gene and a pseudogene similar to the human TOP1 pseudogene 2. By in situ hybridization again two loci were identified on mouse chromosome 16B1-2 and 19B. Work is in progress to identify at which site of both these loci the active mouse Top-1 gene locus does reside. Both localizations - in human and in mouse - are insofar interesting in that chromosomal breakage syndromes have been assigned just into both of these regions. One type of Fanconi anemia has been mapped to human chromosome 20q (2). In the mouse the mutation scid has been mapped just on proximal chromosome 16. The defect scid was shown to be a repair defect (3). 1. Kunze N, Yang GC, Jiang ZY, Hameister H, Adolph S, Wiedoon K-H, Richter A, Knippers R. Localization of the active type I DNA ? topoisomerase on human chromosome 20q11.2-13.1, and two ? pseudogenes on chromosome 1q23-24 and 22q11.2-13.1. Hum. Genet. 84:6-10 (1989). 2. Mann WR, Venkatraj VS, Allen RG, Liu Q, Olsen DA, Adler-Beecher B, Mao J, Weiffenbach B, Sherman SL, Auerbach AD: Fanconi anemia. Evidence for linkage heterogeneity on chromosome 20q. Genomics 9:329-337 (1991). 3. Fulop GM, Philipps RA: the scid mutation in mice causes a general defect in DNA repair. Nature 347:479-482. |
