Fig. 5

Inferred feedback inputs in Lv and Sp ectoderm during the first 9 and 18 h of specification. Based on time of first expression recorded in Additional file 5: Table S1, the feedback inputs emerged for every gene that had an experimentally based input into the regulation of a gene first expressed earlier. In comparing the two species most feedback inputs are conserved (13/18) though several feedbacks differ because of heterochronic shifts in gene expression (red arrows). Heterochronic shifts in expression of foxQ2, six3, and msx account for a difference of 5 feedback inputs between the two ectoderm dGRNs