(
A) Scatterplot comparing the difference in proportion of enhancer peaks containing motif pairs in photoreceptors and bipolar cells. Each point corresponds to a distinct motif pair generated by taking all pairs from a list of 67 non-redundant motifs from the HOMER database (see Materials and methods). Statistically significant differences in the proportion of peaks harboring each pair are indicated in red (greater proportion in photoreceptors) or green (greater proportion in bipolar cells) (Fisher's exact test, FDR < 0.01). Motif pairs with the most significant difference in proportion (by p-value) are indicated and include individual motifs which are highly differentially enriched between the two cell classes, including K50 HD (GSC), Q50 HD (LHX3), and E-box (SCL). (
B) Scatterplot as in A, showing the proportion of motif pairs within photoreceptor or bipolar cell-enriched peak sets (as defined in
Figure 5A). (
C) Scatterplot as in A and B, comparing the difference in proportion of motif pairs between enhancer peaks in ON and OFF bipolar cells. Motif pairs with statistically significant differences in proportion are indicated in purple (greater proportion in ON BC) or gold (greater proportion in OFF BC) (Fisher's exact test, FDR < 0.01).