Changes in mRNA lengths for genes affected by APA.

A. Analysis of poly(A) site shifts for S. neurona gene that possess poly(A) sites whose usage changes significantly during development. For each gene, a weighted and normalized mRNA length was calculated as described in Methods, and the differences in this value between the merozoite and schizont stages calculated. The values were binned into discreet groups and the numbers of genes with changes falling into each bin plotted as shown. Positive values denote genes whose mRNA lengths are longer in merozoites than in schizonts. B. Browser tracks showing typical APA patterns for mRNAs encoding a membrane transporter (SN3_00700860) and a ribosomal protein (SN3_00900035). In both cases, the 5’-3’ orientations of these genes are right to left.