Figure 7
From: V1R promoters are well conserved and exhibit common putative regulatory motifs
Frequency of occurrence of motifs near transcription start sites (TSS's). For each of the five motifs, we compared the frequency of the motif in randomly-selected 9 gene samples (1 gene from each promoter subfamily) occurring within 250 bp of putative TSS's (black) versus random 500-bp windows in gene blocks (grey). A total of one thousand 9-gene samples were taken to produce the distribution (see Methods). The frequency of random occurrence in gene blocks for Motif 1 is higher (and less resolved from the test set) because Motif1 is especially AT-rich, and thus is expected to occur more frequently by chance in gene blocks, which are also AT-rich. The five motifs are present near TSS's in an average of 7.1 genes per 9-gene cross-subfamily sample; background frequency of the five motifs within gene blocks average 2.8 genes per 9-gene cross-subfamily sample.