title: Aberrant Transpositions of Maize Double Ds-Like Elements Usually Involve Ds Ends on Sister Chromatids.
abstract: 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.
authors.affiliation: The Sainsbury Laboratory, John Innes Centre, Colney Lane, Norwich, NR4 7UH, United Kingdom.
authors.forename: J. J.
authors.initials: JJ
authors.lastname: English
authors.forename: K.
authors.initials: K
authors.lastname: Harrison
authors.forename: JDG.
authors.initials: J
authors.lastname: Jones