Figure 1

Characterization of fundamental properties of 5'UTR introns. (a) Histogram of the total 5'UTR intron length. A well annotated set of RefSeq transcript IDs are used in this analysis and this histogram shows the distribution of the log₁₀ of the total number of intronic nucleotides in the 5'UTR. (b) Distribution of the number of introns in the 5'UTR. The log₁₀ of number of transcripts that have a given number of introns in their 5'UTR is shown. The number of transcripts with a given number of 5'UTR introns decreases exponentially. (c) Heat map depicting the relationship between total lengths of 5'UTR introns and 5'UTR exons. (d) Heat map depicting the relationship between total lengths of 5'UTR introns and non-5'UTR introns. In both heatmaps, darker shades of gray indicate more transcripts.