Data release policy Preliminary drafts of the X. tropicalis sequence are made freely available before scientific publication by the Department of Energy's Joint Genome Institute and the X. tropicalis Genome Consortium, with the following understanding: 1. The data may be freely downloaded, used in analyses, and repackaged in databases. 2. Users are free to use the data in scientific papers analyzing particular genes and regions if the provider of this data (DoE Joint Genome Institute) is properly acknowledged. 3. Additional shotgun sequencing is ongoing, and future assembly releases will be made in a timely fashion. We expect to publish an initial analysis of a high quality draft X. tropicalis genome sequence in 2005 (with submission targeted for the spring of 2005) which will include descriptions of the large scale organization of the frog genome as well as genome-scale comparisons of the frog sequence and gene set with those of other animals. Others who would like to coordinate other genome-wide analysis with this work should contact us. We welcome a coordinated approach to describing this community resource. 4. Any redistribution of the data should carry this notice. http://genome.jgi-psf.org/Xentr4/Xentr4.download.html