Formation of dicentrics with variable lengths in transformed cells.

Several dicentric chromosomes in transformed cells exhibit drastic variations in the length of the region between the two centromeres. In these dicentric chromosomes, the position of the centromeres from the proximal end remains unaltered. The increase or decrease in the length of the intercentromeric segment is attributed to interchromatid reorganization so that one chromatid gains a piece of the sister chromatid. This is achieved simply through two chromatid breaks in the interchromosomal loop, followed by nonreciprocal rejoining. These observations provide new credence to Revell's hypothesis.