Sequence organization and the mechanism of interstitial deletion clustering in a plant genome (Vicia faba).

Intercalary deletions and duplication-deletions are types of chromatid aberrations typical of the aberration spectrum observed in the first mitosis of plant cells after mutagen treatment. They are the results of error-prone recombination repair and arise when reunion is not prevented by inhibition of DNA synthesis. Both types of aberrations are nearly exclusively located in chromosome regions composed of tandemly arranged highly repetitive DNA sequences (e.g. FokI elements). The data discussed in the present paper make it possible to arrive at a simple mechanistic interpretation of the origin of these aberration types.