Induction of sister-chromatid exchange in human blood lymphocytes by aqueous extract of palmyrah (Borassus flabellifer) flour

The influence of a (GT)29 microsatellite sequence on homologous recombination in the hamster adenine phosphoribosyltransferase gene

Several DNA sequence elements are thought to stimulate homologous recombination, illegitimate recombination, or both in mammalian cells. Some are implicated by their recurrence around rearrangement breakpoints, others by their effects on recombination of extrachromosomal plasmids. None of these sequences, however, has been tested on the chromosome in a defined context. In this paper we show how the adenine phosphoribosyltransferase locus in CHO cells can be used to study the recombinogenic potential of defined DNA sequences. As an example we have measured the effect on homologous recombination of a dinucleotide repeat, (GT)29, which has been shown to stimulate homologous recombination in extrachromosomal vectors 3-20 fold. On the chromosome at the adenine phosphoribosyltransferase locus, however, this sequence shows no capacity to stimulate recombination or to influence the distribution of recombination events.

Sister-chromatid exchange induction produced by in vivo and in vitro exposure to alpha-asarone

The effect of alpha-asarone, a chemical with hypocholesterolemic properties extracted from Guatteria gaumeri, on SCE induction was studied both in human lymphocytes in vitro and in murine bone marrow cells in vivo. A slight but consistent increase in SCE was observed in both biological systems.