Fig. 4

Comparison of the regulatory activity of tunicate-specific and chordate-specific Hox5 and Otx T-CNE/CNE. (A-C) Comparable expression of M. occulta Hox5 T-CNE, C. robusta chordate-specific Hox5 CNE and D. rerio Hoxa5a CNE in the most anterior part of the tail neural tube (black arrowheads). MoccHox5 T-CNE shows a more restricted expression in a subdomain of CrHox5 and DrHox5CNEs at larva stage. (D-F) The tunicate-specific M. occulta Otx T-CNE (D), and the chordate-specific C. robusta Otx CNE-A (E) and CNE-B (F) show a similar expression profile in the ventral part of the sensory vesicle (black arrows). (G,H) The tunicate-specific OdOtx T-CNE reproduces almost the same expression profile of the chordate-specific DrOtx CNE-B in the posterior sensory vesicle and in the neural axons along the visceral ganglion. Black/white arrowheads and arrows indicate the corresponding conserved territories of expression. Asterisks indicate ectopic expression in the mesenchyme. A-F,H: lateral view; G, dorsal view. Anterior is on the left.