The characterization of intron Alu densities of multi-exon genes in chromosomes-1, -19, -X and -Y with a mixture model. A: the curves represent the probability density functions given the intron Alu density larger than zero. B: the probability densities are adjusted according to the proportion of the genes without Alus. For each chromosome, the sum of its proportion of genes without intron Alus and the area under the Gamma curve equals to one.
Zhang et al. BMC Genomics 2011 12:157 doi:10.1186/1471-2164-12-157