Present address: SNRG, CNRS, Université Pierre et Marie Curie, UMR7102, 9 Quai Saint Bernard, 75005 Paris.
Morphological and gene expression similarities suggest that the ascidian neural gland may be osmoregulatory and homologous to vertebrate peri-ventricular organs
Article first published online: 24 OCT 2006
European Journal of Neuroscience
Volume 24, Issue 8, pages 2299–2308, October 2006
How to Cite
Deyts, C., Casane, D., Vernier, P., Bourrat, F. and Joly, J.-S. (2006), Morphological and gene expression similarities suggest that the ascidian neural gland may be osmoregulatory and homologous to vertebrate peri-ventricular organs. European Journal of Neuroscience, 24: 2299–2308. doi: 10.1111/j.1460-9568.2006.05073.x
- Issue published online: 24 OCT 2006
- Article first published online: 24 OCT 2006
- Received 24 March 2006, revised 11 July 2006, accepted 26 July 2006
- choroid plexus;
- ciliated funnel;
- saccus vasculosus;
The central nervous system (cerebral ganglion) of adult ascidians is linked to the neural gland complex (NGC), which consists of a dorsal tubercle, a ciliated duct and a neural gland. The function of the NGC has been the subject of much debate. The recent publication of the complete genomic sequence of Ciona intestinalis provides new opportunities to examine the presence and distribution of protein families in this basal chordate. We focus here on the ascidian neuropeptide G-protein-coupled receptors (GPCRs), the vertebrate homologues of which are involved in homeostasis. In situ hybridization revealed that five Ciona GPCRs [vasopressin receptor, somatostatin receptor, CRH (corticotropin-releasing hormone) receptor, angiotensin receptor and tachykinin receptor] are expressed in the NGC of adult ascidians. These findings, together with histological and ultrastructural data, provide evidence to support a role for the ascidian NGC in maintaining ionic homeostasis. We further speculate about the potential similarities between the ascidian NGC and the vertebrate choroid plexus, a neural peri-ventricular organ.