Schematic representation of remobilized SB transposons in the X. tropicalis genome. (a) Local hopping on X. tropicalis chromosome 6 depicts the integration sites for eight local (< 200 kb) remobilization events (hops). (Not to scale.) This region of X. tropicalis chromosome 6 is syntenic with human chromosome 7. The Vista http://genome.lbl.gov/vista alignment shows regions of homology between the frog and human genomic sequences; pink represents non-coding regions and blue represents conserved exons. The position of the 8F donor concatemer is indicated by the grey box. The remobilized transposition events are depicted by the grey triangles. The position and orientation of predicted genes near the 8F locus are depicted in the lower section of the panel. (b) Schematic representation of the X. tropicalis chromosomes indicating the distribution of remobilized SB transposons. The parental 8F donor site is on chromosome 6 (thick line). The predicted loci of the remobilized transposons are depicted by the thin black lines. Approximately 80% of the remobilization events occur near the donor locus (local hopping), and the remaining 20% are distributed randomly throughout the genome. SB: Sleeping Beauty.