Fig. 1

Classification of unspliced EST cluster w.r.t. their location relative to RefSeq genes. With the exception of totally intronic RNAs (TINs) and cluster in the upstream (UT) and downstream (DT) region within 5 kb, all other classes partially overlap RefSeq exons: 5’ and 3’ partially intronic RNAs (5’PIN, 3’PIN), EST cluster overlapping 3’UTR and downstream region (3’R) or 5’UTR and upstream region (5’R), resp., and cluster covering complete introns indicating retained introns (rI) are distinguished in the statistical analysis. Furthermore, we record totally exonic cluster (TEX) and the intergenic clusters (IGR) that are unrelated to RefSeq loci. The bar plots above and below the scheme summarize the numbers of unspliced EST for each cluster type in human (above) and mouse (below). The Venn diagram below lists the exact numbers. About one fifth of the unspliced EST clusters (21,022 in human and 11,179 in mouse) cannot be classified unambiguously because they are overlapped by more than one RefSeq gene and would fall into different classes with respect to these, see subsection Classification in the Methods part for details. These ambiguous clusters are not included here