IDEAL GENE-THERAPY - APPROACHES AND HORIZONS

Ideal gene therapy implies correction of a genetic defect at its site on the chromosome, which can be done only by homologous recombination. In prokaryotes, two pathways of homologous recombination are provided by two types of recombinases: ATP-dependent RecA protein and ATP-inde pendent renaturase. In eukaryotes, both ATP-dependent and ATP-independ ent DNA transferases have been found, including enzymes functionally s imilar to the RecA protein. The specific properties of RecA-like prote ins suggest their involvement in both pro- and eukaryotic recombinatio n. Recent studies of eukaryotic mitotic cells indicate their potential for homologous recombination. However, its realization requires a rea sonable length of donor DNA and a high level of its homology to the re cipient DNA. Other possible ways of optimizing gene therapy are discus sed as well.