Fig. 5.

The Pitx gene is expressed asymmetrically in larval Ciona robusta. a Detail of a late-dechorionated 25 hpf Ciona larvae showing Pitx expression by in situ hybridization co-labeled with VGAT (anterior is up; midline indicated by dotted line). Pitx shows left-sided expression in the MG (arrows), in contrast to VGAT which is expressed in the MG on both sides of the midline. Pitx expression in the osp is also bilateral. In this view, Pitx is also seen in the photoreceptor cells on the right side. b An early-dechorionated larva shows the same bilaterality for VGAT in the MG, and for Pitx in the osp, but Pitx in the MG is found on both left and right sides of the dorsal midline (arrows). Scale bars are 20 μm. Abbreviations: osp, oral siphon primordium; pBV, posterior brain vesicle; PR, photoreceptor; MG, motor ganglion; AMG, ascending motor ganglion neurons; ACIN, ascending contralateral inhibitory neuron