Molecular analysis of homologous recombination catalysed by human nuclear extract: fidelity and DNase protection.

We present a molecular analysis of DNA's resulting from homologous recombination, between two duplex molecules, and catalysed by human nuclear extracts. Sequence analysis of 20 recombined clones (400 nucleotides per clone), in a genetically silent sequence surrounding the recombination initiation or termination site, shows no modification compared to the parental sequence. Transient protection of the DNA's against DNase treatment was brought about by the nuclear extract. This protection was found to be strickly confined to the homologous sequences potentially implicated in recombination.