PURPOSE: The detection of incomplete exchanges and interstitial fragments by fluorescence in situ hybridization using a telomeric peptide nucleic acid (PNA) probe. MATERIALS AND METHODS: Isolated human lymphocytes were exposed in vitro to X-rays at a dose of 3 Gy. Aberrations were analysed in the first mitosis after irradiation using a telomeric PNA probe. RESULTS: After an acute dose of 3 Gy, only about 16% of the cells contained a pair of incomplete chromosome elements with telomeric signals at only one terminal end. Acentric interstitial fragments, lacking telomeric signals, were observed with a frequency of 0.56 per cell, which was very similar to the dicentric frequency (0.61 per cell). CONCLUSIONS: The low frequency of incompleteness suggests that most of the non-reciprocal interchanges observed using chromosome painting must originate from terminal exchanges rather than from incomplete exchanges. Furthermore, it was estimated that about 78% of excess acentric fragments originate from interstitial fragments and only 22% from terminal fragments.
PURPOSE: The detection of incomplete exchanges and interstitial fragments by fluorescence in situ hybridization using a telomeric peptide nucleic acid (PNA) probe. MATERIALS AND METHODS: Isolated human lymphocytes were exposed in vitro to X-rays at a dose of 3 Gy. Aberrations were analysed in the first mitosis after irradiation using a telomeric PNA probe. RESULTS: After an acute dose of 3 Gy, only about 16% of the cells contained a pair of incomplete chromosome elements with telomeric signals at only one terminal end. Acentric interstitial fragments, lacking telomeric signals, were observed with a frequency of 0.56 per cell, which was very similar to the dicentric frequency (0.61 per cell). CONCLUSIONS: The low frequency of incompleteness suggests that most of the non-reciprocal interchanges observed using chromosome painting must originate from terminal exchanges rather than from incomplete exchanges. Furthermore, it was estimated that about 78% of excess acentric fragments originate from interstitial fragments and only 22% from terminal fragments.
Authors: Elke Beyreuther; Wolfgang Dörr; Anna Lehnert; Elisabeth Lessmann; Jörg Pawelke Journal: Radiat Environ Biophys Date: 2009-03-17 Impact factor: 1.925