Homologous recombination: ends as the means.

Broken chromosomal ends in somatic cells of higher plants frequently heal by the ligation of DNA ends to unrelated sequences or to sequences with micro-homologies. This pathway of DNA-strand-break repair is the bane of gene-targeting attempts in plants. However, there is a second somatic pathway of chromosome repair, which is driven by DNA-sequence homology. Observations from yeast, fly and plants of homologous-recombination mechanisms point towards new strategies of gene targeting in plants.