Fig. 9.

A model for transitions in gene expression in Diervilleae and Lonicera placed on a phylogeny and in the order that we hypothesize that they occurred (boxed). Striped orange lines indicate expression of both DipsCYC2a and DipsCYC2b in V. plicatum. Red shading shows expression of DipsCYC2A and black striped lines show the expression of DipsCYC2B in Caprifoliaceae. The first step occurred around the divergence of Caprifoliaceae and the duplication event leading to two copies. This transition is correlated with the loss of expression in the ventral corolla lobe (Diervilleae). The second transition involved the decoupling of DipsCYC2A and DipsCYC2B expression, with DipsCYC2A only in dorsal corolla lobes, and DipsCYC2B in dorsal and lateral lobes (Lonicera). This transition could have happened anywhere along the grayed nodes. A third shift occurred in the nearly radial L. sempervirens, in which both copies shifted ventrally.