Chromosome changes in methotrexate-resistant cell lines ofDrosophila melanogaster

✍ Scribed by G. Mosna; M. Pulcini; A. Ghidoni

• Publisher: Springer Netherlands
• Year: 1984
• Tongue: English
• Weight: 861 KB
• Volume: 65
• Category: Article
• ISSN: 0016-6707
• DOI: 10.1007/bf00122906

✦ Synopsis

Cells resistant to methotrexate (MTX) were obtained from two established cell lines of D. melanogaster and a karyological analysis was performed. No conspicuous changes in the frequencies of cell types were observed in MTX-resistant (MTXR) subline 0.57, as compared with the original line, whose cells were mostly near-tetraploid. On the contrary, altered karyotypes were frequently noticed in the Cl 82 MTXR subline, as compared with the original line, whose cells were mostly diploid. The Cl 82 MTXR subline was characterized by mostly tetraploid cells and by the presence of chromosome fragments (in 4870 of them). The mitotic segregation suggests the presence of a centromere in these fragments and the fluorescence pattern, after quinacrine staining, suggests that they may be derivatives of the X chromosome.