Aberrant Transpositions of Maize Double Ds-Like Elements Usually Involve Ds Ends on Sister Chromatids.
McClintock's analysis of chromosome-breaking Dissociation (Ds) elements in maize demonstrated that sister chromatids fuse at the position of Ds, forming a dicentric chromosome and an acentric fragment. In tobacco, Ds left and right ends in direct orientation (that is, half a double Ds) are sufficient to promote Activator-dependent marker gene loss. We present here a detailed analysis of germinally inherited rearrangements promoted by "half double Ds" elements and a characterization of rearrangements that involve inversion of the segment between the Ds ends and/or deletion of a segment adjacent to the Ds construct. The results support a model in which chromosome breakage promoted by these elements, and presumably by double Ds elements, involves Ds ends on sister chromatids.
English
J. J.
JJ
The Sainsbury Laboratory, John Innes Centre, Colney Lane, Norwich, NR4 7UH, United Kingdom.
Harrison
K.
K
Jones
JDG.
J