How are sticky chromosomes formed?
Al Achkar, W.; Sabatier, L.; Dutrillaux, B.
Annales de Genetique 32(1): 10-15
1989
ISSN/ISBN: 0003-3995 PMID: 2751243 Document Number: 342246
Blood lymphocytes in culture were irradiated by .gamma.-rays 3 h to 30 mn before harvesting. The various induced lesions were analysed, with a particular attention on sticky chromosomes, i.e. radial figures in which chromosomes are not obviously broken, but are linked by a tiny filament. Such anomalies are preferentially induced in mild to late G2-phase. They result from recombinations occurring at nonrandom chromosome regions: junction between hetero- and euchromatin, and telomeric regions. It is proposed that they are formed when double strand breaks are induced while intrachromatidic links have started to be formed in the course of chromosome condensation. If this interpretation is correct, the apparent lack of induced breakage of premitotic chromosomes is artifactual.