Each UniGene entry is a set of transcript sequences that appear to come from the same transcription locus (gene or expressed pseudogene), together with information on protein similarities, gene expression, cDNA clone reagents, and genomic location.

In addition to sequences of well-characterized genes, hundreds of thousands novel expressed sequence tag (EST) sequences have been included. Consequently, the collection may be of use to the community as a resource for gene discovery. UniGene has also been used by experimentalists to select reagents for gene mapping projects and large-scale expression analysis.

However, it should be noted that the procedures for automated sequence clustering are still under development and the results may change from time to time as improvements are made. Feedback from users has been especially useful in identifying problems and we encourage you to report any problems you encounter.

It should also be noted that no attempt has been made to produce contigs or consensus sequences. There are several reasons why the sequences of a set may not actually form a single contig. For example, all of the splicing variants for a gene are put into the same set. Moreover, EST-containing sets often contain 5' and 3' reads from the same cDNA clone, but these sequences do not always overlap.

Currently, sequences from the animals human, rat, mouse, cow, zebrafish, clawed frog, fruitfly and mosquito have been processed. Plant organisms are wheat, rice, barley, maize and cress. These species were chosen because they have the greatest amounts of EST data available and represent a variety of species. Additional organisms may be added in the future.

A representation of the UniGene datasets is available by ftp

Descriptions of the UniGene transcript based and genome based build procedures are available.