Analysis of flanking sequences from Dissociation insertion lines: A database for reverse genetics in Arabidopsis

We have generated Dissociation (Ds) element insertions throughout the Arabi dopsis genome as a means of random mutagenesis. Here, we present the molecu lar analysis of genomic sequences that flank the Ds insertions of 931 indep endent transposant lines. Flanking sequences from 511 lines proved to be id entical or homologous to DNA or protein sequences in public databases, and disruptions within known or putative genes were indicated for 354 lines. Be cause a significant portion (45%) of the insertions occurred within sequenc es defined by GenBank BAC and P1 clones, we were able to assess the distrib ution of Ds insertions throughout the genome. We discovered a significant p reference for Ds transposition to the regions adjacent to nucleolus organiz er regions on chromosomes 2 and 4. Otherwise, the mapped insertions appeare d to be evenly dispersed throughout the genome. For any given gene, inserti ons preferentially occurred at the 5' end, although disruption was clearly possible at any intragenic position. The insertion sites of >500 lines that could be characterized by reference to public databases are presented in a tabular format at http:// www.plantcell.org/cgi/content/full/11/12/2263/DC 1. This database should be of Value to researchers using reverse genetics a pproaches to determine gene function.