The background model statistics for Arabidopsis thaliana are derived from the frequencies of all possible 3-8mer words in the upstream sequences (i.e. "promoters") of 22,400 Arabidopsis genes (TAIR version 6, released November 11, 2005) represented on the Affymetrix ATH1 Arabidopsis microarrays.

The background model statistics for Oryza sativa ssp. japonica are derived from the frequencies of all possible 3-8mer words in the upstream sequences of 34,967 non-transposable-element-related Japonica rice genes (TIGR version 4, released January 12, 2006) represented on the Affymetrix rice microarrays.

The background model statistics for Populus trichocarpa are derived from the frequencies of all possible 3-8mer words in the upstream sequences of 35,950 poplar genes (JGI version 1.1, released December 2004) represented on the Affymetrix poplar microarrays.

The background model statistics for Brachypodium distachyon are derived from the frequencies of all possible 3-8mer words in the upstream sequences of 44,411 FGENESH predicted genes in the JGI 4X draft genome assembly.

Reference:
J. L. Nemhauser, T. C. Mockler, J. Chory, PLoS Biol 2, 1460 (2004).

Project Support - ELEMENT and the Diurnal Plant Gene Expression Project are supported generously by a Plant Genome Research Program (PGRP) grant from the National Science Foundation (DBI-0605240). The project uses facilities and resources provided by the Department of Botany and Plant Pathology, the Center for Genome Research and Biocomputing, Oregon State University.