Plant & Animal Genome VI Conference

P2

PRELIMINARY ANALYSIS OF THE Arabidopsis thaliana GENOME

1. Lita Annenberg Hazen Genome Sequencing Center, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
2. Plant Biology Group, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724

In this report we present the analysis of our efforts thus far in sequencing the Arabidopsis thaliana genome. These efforts are directed toward the short arm of chromosome IV and a central region of chromosome V and a comprehensive report is accessible by WWW. The genome is relatively gene-rich, with a gene occurring every 5.2 kbp. Approximately 90% of the genes identified are newly described for Arabidopsis, and of these, about 55% are newly described for plants. In addition, about 35% of the genes constructed with gene prediction algorithms have EST or cDNA matches. Between 60-65% of the identified genes exhibit matches to known sequences in the public databases, while 35-40% of the genes are labeled as hypothetical: They either have no database match or exhibit similarity to hypothetical proteins from other genome sequencing efforts (notably, S. cerevisiae and C. elegans). Genome sequencing has also revealed a clustering of genes such as disease resistance genes (both of the LRR and MLO types) and protein kinases. Once the genome sequence is complete, it will become necessary to systematically study each of the identified genes. Transposon-directed insertional mutagenesis is a powerful tool for these functional genomic studies. As a prelude to this post-genome research, we are expending effort to identify putative transposable elements and other genetic repeats, such as LINE elements and solo LTRs, and these results indicate that the Arabidopsis genome is more complex than originally thought.