Characteristics of Y. lipolytica introns. (a) Size distribution of the 1,083 introns from strain E150 located within the coding regions of genes. Introns are separated into three size classes: multiples of 3 nucleotides (blue line), multiples of 3 plus 1 nucleotides (orange line), and multiples of 3 plus 2 nucleotides (green line). For each class, the number of introns is reported as a function of size, with a window of 20 nucleotides from 41 nucleotides to more than 1,000 nucleotides. (b) Position of introns within the CDS. Introns are separated according to their order in the gene model, from start to stop: first introns of genes (red boxes), second introns of genes (orange boxes) and other introns (green boxes). Data for all introns considered together are shown in black. The proportion of introns in each group is plotted as a function of their relative position within the CDS, with a window of 10% of the CDS length.