Figure 1

Flow diagram for mapping orthologous bidirectional promoters. The initial stage identifies orthologous regions between humans and other species. This stage is further refined by defining whether these regions align to non-gapped regions (as nearly perfect matches) or as chained alignments with gaps. After narrowing the region of orthology, genes with orthology can be identified and bidirectional promoters examined. Genes are placed into three categories: Type I genes have orthologous bidirectional promoters surrounded by orthologous pairs of genes. Type II genes have one of two of the orthologous genes in the gene pair and therefore no bidirectional promoter based on the ENSEMBL gene annotations. Type III genes have no orthologs in the ENSEMBL annotations.