Fig. 1.
A landscape of mononucleotide strand asymmetry in exons and introns. (A) Diagram of five types of region analyzed in this study. (B) Strand asymmetry of human (Upper) and mouse (Lower) genes. TA and GC asymmetries are shown in blue and red, respectively. For intronic regions (5′I, midLI, and 3′I), strand asymmetry was calculated for each nucleotide position. For exonic regions (5′E and 3′E), strand asymmetry was calculated in sliding 3-nt windows, to smooth out the differences among the three positions of codons. Note that the coordinates in the abscissa are not relative to the splice sites, because nucleotides that are part of the consensus motifs were removed. (C) Strand asymmetry of coding and 5′ UTR exons and coding and 5′ UTR portions of intronless genes for human (Upper) and mouse (Lower). Average strand asymmetry was calculated for each whole exon or region. Error bars represent the 95% confidence interval. The color-coding scheme is the same as in B.