Serotonin Receptors and Their Involvement in Melanization of Sensory Cells in Ciona intestinalis

Abstract

Serotonin (5-hydroxytryptamine (5-HT)) is a biogenic monoamine with pleiotropic functions. It exerts its roles by binding to specific 5-HT receptors (5HTRs) classified into different families and subtypes. Homologs of 5HTRs are widely present in invertebrates, but their expression and pharmacological characterization have been scarcely investigated. In particular, 5-HT has been localized in many tunicate species but only a few studies have investigated its physiological functions. Tunicates, including ascidians, are the sister group of vertebrates, and data about the role of 5-HTRs in these organisms are thus important for understanding 5-HT evolution among animals. In the present study, we identified and described 5HTRs in the ascidian Ciona intestinalis. During development, they showed broad expression patterns that appeared consistent with those reported in other species. Then, we investigated 5-HT roles in ascidian embryogenesis exposing C. intestinalis embryos to WAY-100635, an antagonist of the 5HT1A receptor, and explored the affected pathways in neural development and melanogenesis. Our results contribute to unraveling the multifaceted functions of 5-HT, revealing its involvement in sensory cell differentiation in ascidians.

Stress Granule-Related Genes during Embryogenesis of an Invertebrate Chordate

“…Kanamycin-resistant colonies were selected and cultured o/n purified with Plasmid Miniprep system (Promega) and verified by sequencing (Microsynth, Switzerland). PCR products with flanking T7 promoters were used as template for the synthesis of anti-sense riboprobes using a T7 RNA polymerase (Roche) (Mercurio et al 2023). Riboprobes were purified by precipitation with 0.1 M LiCl and 75% EtOH.…”

Serotonin system in tunicates: insight from morphological and molecular approaches

“…In the genome of Ciona, five genes corresponding to serotonin receptors have been identified (Mercurio et al, 2023). The phylogenetic analysis showed that two sequences, 5HT1.1 and 5HT1.2, are basal to all 5HT1 paralogs of vertebrates.…”

Extraction, Isolation, Characterization, and Biological Activity of Sulfated Polysaccharides Present in Ascidian Viscera Microcosmus exasperatus

“…Next, to overcome 1D 1 H NMR overlapping signals, we performed a 2D 1 H- 13 C HSQC experiment, shown in Figure 3B. We highlighted three important regions in the spectrum.…”

“…Nuclear magnetic resonance (NMR, 1D, and 2D spectra) was performed for the SP1 fraction (2 mg) using a triple resonance probe (900 MHz Bruker, Karlsruhe, Germany). 1 H NMR 1D spectra were recorded using 32 scans with a 1.5-s inter-scan delay at 35 • C. 1 H/ 13 C HSQC (heteronuclear single quantum coherence) spectrum using time proportion phase incrementation (TPPI) for quadrature detection in the indirect dimension. A total of 64 scans and 1048 × 512 points were recorded.…”

“…Ascidians are marine invertebrates that comprise more than 2000 species [1][2][3][4][5][6][7]. They are classified into three orders: Aplousobranchia, Stolidobranchia, and Phlebobranchia [3,[8][9][10][11][12][13]. Ascidians are filter feeders and can be found solitary or in colonies [14,15].…”