Figure 3.

Ciliated GnRH neurons express functional CNGA. a–c, Larvae stained with phalloidin (grey). a, Dorsal view of a larva stained with an acetylated α-tubulin antibody; dotted line indicates the oral opening. b, Lateral view of a larva electroporated with GnRH. mCherry and stained with an acetylated α-tubulin antibody. c, Lateral view of a larva electroporated with CNGA. mCherry. Arrowheads indicate PPE-derived GnRH neurons in all panels. d, Ratiometric calcium imaging of HEK 293 cells transfected with Ciona CNGA, assayed by the intracellular Ca²⁺ indicator Fura-2. The graph shows the efficiency of response of CNGA to the cyclic nucleotide analogues 8-Br-cGMP and 8-Br-cAMP in seven individual cells (coloured lines) over a 120-min period. Indicated are the time points (red arrows) and durations (pink bars) of each analogue perfusion. e, Schematic that compares the PPE-derived GnRH neurons in tunicates such as Ciona (left) and olfactory-derived neurons in vertebrates (right). CNS, central nervous system; HEK, human embryonic kidney.