Fig. 2
Gene length and compactness biases in gene expression changes during preimplantation development. Exon (left panel) and intron (middle panel) length and exonic content (right panel) distributions of genes that are up-regulated (orange curves) or down-regulated (cyan curves) in blastocyst as compared to early embryo in human (a, b) and mouse (c, d) in comparison to the background genes (black curves). As shown in the panels, the primary Y axis describes the difference of each cumulative distribution from the background cumulative distribution (curves are smoothened with a 3-point moving average); the background cumulative distribution is plotted in gray line projecting on the secondary Y axis. Positive values reflect an increase in each parameter, e.g., a shift of the distribution towards longer exons. Vertical lines are drawn at the median value of each gene set. Asterisks indicate a statistically significant difference from the background distribution (P value < 10−4; Kolmogorov-Smirnov test)