Figure 4From: Natural selection drives rapid evolution of mouse embryonic heart enhancersProperties of heart enhancers. Heart enhancers include more specific enhancers (A) and enhancers adjacent to highly expressed genes (B). (A) The numbers in boxes represent the number of enhancers in a group. (B) The values of upper quartile, median, and lower quartile are indicated in each box, whereas the bars outside the box indicate semi-quartile ranges. Pairwise comparisons with significantly different expression levels of the adjacent gene are connected with gray lines (*0.01<P≦0.05 and ***P≦0.001 by (A) × 2 test or (B) Mann-Whitney U test). FB, forebrain; MB, midbrain; LB, limb; HT, heart.Back to article page