Fig 1. Contingence tables showing overrepresentation of Alu elements, but not of other retrotransposons, inside 3’UTRs of human PP parent genes.

Plus and minus signs above the tables indicate presence or absence, respectively, of Alus (A), other SINEs (B), LINEs (C), or LTRs (D) inside the 3’UTR(s) of a gene. Plus and minus signs on the left mean presence or absence, respectively, of PPs generated from a gene. Numbers in bold are gene counts; total number of genes are also displayed in the right column and the bottom row for each table. Percentages with respect to each total are also shown. P-values of the χ² test are indicated below each corresponding table.