Initial analysis of immunochemical cell surface properties, location and formation of the serotonergic apical ganglion in sea urchin embryos

Yaguchi, Shunsuke; Kanoh, K.; Amemiya, Shonan; Katow, Hideki

doi:10.1046/j.1440-169x.2000.00535.x

Cited by 38 publications

(51 citation statements)

References 30 publications

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“…They extended their axons in the space between the basal lamina and the ectoderm initially toward the middle-ridge (Yaguchi et al, 2000), and suggesting the presence of axon guidance cues probably provided by the middle-ridge region. This region is comprised of characteristically tall cells that form a thickened ectoderm area in the middle of the animal plate.…”

Section: Discussionmentioning

confidence: 92%

“…However, serotonergic cells appear from the prism stage toward the pluteus stage, extending axons to form a neural plexus beneath the serotonergic apical ganglion and then constructing the remainder of the serotonergic nervous system (e.g. Yaguchi et al, 2000). This histological observation based on WMIHC is supported by Northern blotting analysis of the transcription period of the tryptophan 5-hydroxylase gene of H. pulcherrimus (HpTPH), a serotonin synthetase.…”

Section: Spatio-temporal Protein Expression Pattern During Serotonergmentioning

confidence: 91%

“…Although the onset of transcription was well before the apical ganglion formation at 24-hpf prism stage (e.g. Yaguchi et al, 2000;Yaguchi and Katow, 2003), it distinctively decreased in 48-hpf plutei when formation of the serotonergic nervous system was still in progress.…”

Section: Structure Of the Netrin Homolog In H Pulcherrimus And Its Tmentioning

confidence: 97%

“…52: 1077-1088 (2008) Yaguchi and Katow, 2003), and the serotonin receptor cell network in the blastocoel (Katow et al, 2004;Katow et al, 2007). Like most neural wiring mechanisms, the neural plexus formation at the apical ganglion of the echinolarvae is associated with intricate weaving of the axons on the basal surface of the oral lobe ectoderm (Yaguchi et al, 2000). Initially the axons are extended from serotonergic cells that appear both on the left and right sides of the animal plate ectoderm toward the middle-ridge, where tall ectoderm cells comprise a ridge at the middle of the area, suggesting the presence of a chemoattractant that guides serotonergic axons to the middle-ridge.…”

Section: Introductionmentioning

confidence: 99%

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Spatio-temporal expression of a Netrin homolog in the sea urchin Hemicentrotus pulcherrimus (HpNetrin) during serotonergic axon extension

Katow

2008

Int. J. Dev. Biol.

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Section: Discussionmentioning

confidence: 92%

Section: Spatio-temporal Protein Expression Pattern During Serotonergmentioning

confidence: 91%

Section: Structure Of the Netrin Homolog In H Pulcherrimus And Its Tmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Spatio-temporal expression of a Netrin homolog in the sea urchin Hemicentrotus pulcherrimus (HpNetrin) during serotonergic axon extension

Katow

2008

Int. J. Dev. Biol.

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“…The anterior opening is actually a large indentation in the stomodeal region located just posterior to the anterior neuroectoderm, which is identified by serotonergic neurons (Fig. 1C, green) (Yaguchi et al, 2000). The posterior opening corresponds to the blastopore, as it is adjacent to cells labeled by the posterior gut marker Endo1 (Fig.…”

Section: Wnt1 Morphants Have Dramatic Posterior-ventral Defectsmentioning

confidence: 99%

Axial patterning interactions in the sea urchin embryo: suppression of nodal by Wnt1 signaling

et al. 2012

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SUMMARYWnt and Nodal signaling pathways are required for initial patterning of cell fates along anterior-posterior (AP) and dorsal-ventral (DV) axes, respectively, of sea urchin embryos during cleavage and early blastula stages. These mechanisms are connected because expression of nodal depends on early Wnt/-catenin signaling. Here, we show that an important subsequent function of Wnt signaling is to control the shape of the nodal expression domain and maintain correct specification of different cell types along the axes of the embryo. In the absence of Wnt1, the posterior-ventral region of the embryo is severely altered during early gastrulation. Strikingly, at this time, nodal and its downstream target genes gsc and bra are expressed ectopically, extending posteriorly to the blastopore. They override the initial specification of posterior-ventral ectoderm and endoderm fates, eliminating the ventral contribution to the gut and displacing the ciliary band dorsally towards, and occasionally beyond, the blastopore. Consequently, in Wnt1 morphants, the blastopore is located at the border of the re-specified posterior-ventral oral ectoderm and by larval stages it is in the same plane near the stomodeum on the ventral side. In normal embryos, a Nodaldependent process downregulates wnt1 expression in dorsal posterior cells during early gastrulation, focusing Wnt1 signaling to the posterior-ventral region where it suppresses nodal expression. These subsequent interactions between Wnt and Nodal signaling are thus mutually antagonistic, each limiting the range of the other's activity, in order to maintain and stabilize the body plan initially established by those same signaling pathways in the early embryo.

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Expression of tryptophan 5‐hydroxylase gene during sea urchin neurogenesis and role of serotonergic nervous system in larval behavior

Yaguchi¹,

Katow²

2003

J of Comparative Neurology

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Tryptophan 5-hydroxylase (TPH) is the rate-limiting enzyme in the biosynthesis of serotonin. cDNA cloning of TPH was carried out, and the occurrence of spatiotemporal transcription of TPH message was examined in larvae of the sea urchin, Hemicentrotus pulcherrimus (HpTPH), with in situ hybridization by using the tyramide signal amplification (TSA) technique and Northern hybridization. Based on deduced amino acids sequence of HpTPH, phylogenetically sea urchin locates at the closest position to vertebrates among invertebrates, and HpTPH had common conserved sequences in a catalytic domain. Initiation of HpTPH transcription occurred at the late gastrula stage exclusively in serotonin cells of apical ganglion (SAG) that was composed of a cluster of HpTPH-positive cells and the negative cells in between. In situ hybridization showed that the mRNA expression pattern was similar to the immunohistochemical localization of serotonin cells reported before (Bisgrove and Burke [1986] Dev. Growth Differ. 28:557-569; Yaguchi et al. [2000] Dev. Growth Differ. 42:479-488). p-Chlorophenylalanine (CPA), an irreversible inhibitor of TPH activity, considerably decreased serotonin content in the serotonin cells, whereas the HpTPH expression pattern and timing, and the extension of neurofibers from SAG cells were apparently unaffected, suggesting CPA exclusively perturbed synthesis of serotonin but not nervous system organization. CPA-treated larvae did not swim, despite the occurrence of ciliary beating in culture chamber, suggesting that proper serotonin synthesis is necessary for normal swimming of the larvae.

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Initial analysis of immunochemical cell surface properties, location and formation of the serotonergic apical ganglion in sea urchin embryos

Abstract: In the present study it was found that serotonergic apical ganglion (SAG)-forming cells in plutei of

Cited by 38 publications

References 30 publications

Spatio-temporal expression of a Netrin homolog in the sea urchin Hemicentrotus pulcherrimus (HpNetrin) during serotonergic axon extension

Spatio-temporal expression of a Netrin homolog in the sea urchin Hemicentrotus pulcherrimus (HpNetrin) during serotonergic axon extension

Axial patterning interactions in the sea urchin embryo: suppression of nodal by Wnt1 signaling

Expression of tryptophan 5‐hydroxylase gene during sea urchin neurogenesis and role of serotonergic nervous system in larval behavior

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