Figure 2

The distributional characterization of intron Alu density in chromosome-1. A: the scatter plot of intron Alu densities versus log10 transformed lengths of gene sequences. B: The distribution of the lengths of the multi-exon genes without any Alu elements in the intron sequence(s). C: The distribution of the lengths of the multi-exon genes with at least one Alu element in the intron sequence(s). D: The distribution of intron Alu densities of the multi-exon genes with at least one Alu in the intron sequence(s). The curve represents a gamma density function with 0.615 and 1.313 as the shape and scale parameters, respectively.