The nature of high frequency sister chromatid exchange cells (HFCs)

Isabella Ponzanelli, Stefano Landi, Francesca Bernacchi, Roberto Barale
1997 Mutagenesis  
We employed the three-way differential staining technique (TWD), which allows SCEs to be distinguished on a per generation basis by scoring third metaphases (M3), in order to study the spontaneous levels of SCEs in normal and high frequency cells (HFCs) that occurred in the first (SI), second (S2) and third (S3) S phases. Fifty one of 900 lymphocytes from 37 healthy donors were defined as HFCs by calculating the 95th percentile of the distribution of SCEs in SI + S2. 'Normal' cells presented
more » ... cells presented almost the same number of SCEs after the first, second and third cell cycles (SCE averages of 2.43, 2.04 and 3.53 respectively). In contrast, HFCs showed a higher SCE count in SI, which decreased rapidly through the cycles and reached baseline level at S3 (SCE averages of 7.18,4.29 and 3.45 respectively) . This would suggest that the lesions responsible for the higher SCE frequency in HFCs were effectively removed after two cell cycles and strongly support the hypothesis that HFCs are lymphocytes which accumulate higher levels of DNA lesions through time.
doi:10.1093/mutage/12.5.329 pmid:9379910 fatcat:dwy6lm5czvcqtmq7kgzdlu32li