Comparative analysis of thyroxine distribution in ascidian larvae

D'Agati, Paolo; Cammarata, Matteo

doi:10.1007/s00441-005-0015-1

Cited by 14 publications

(14 citation statements)

References 34 publications

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“…It is interesting to notice that the role of thyroid hormones in metamorphosis had been reported previously in ascidians (Patricolo et al, 1981;Patricolo et al, 2001), and also in amphibians (Dodd and Dodd, 1976;Nakajima et al, 2005) and lamprey (Youson and Sower, 2001). Moreover, in four ascidian species, thyroxin is present in larval mesenchyme and seems to be involved in the control of metamorphosis (D'Agati and Cammarata, 2005). The expression of Ci-oatp via JNK activation in the CNS may enhance thyroid signalling in larvae.…”

Section: Hormone Signallingmentioning

confidence: 73%

ERK- and JNK-signalling regulate gene networks that stimulate metamorphosis and apoptosis in tail tissues of ascidian tadpoles

et al. 2007

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In ascidian tadpoles, metamorphosis is triggered by a polarized wave of apoptosis, via mechanisms that are largely unknown. We demonstrate that the MAP kinases ERK and JNK are both required for the wave of apoptosis and metamorphosis. By employing a gene-profiling-based approach, we identified the network of genes controlled by either ERK or JNK activity that stimulate the onset of apoptosis. This approach identified a gene network involved in hormonal signalling, in innate immunity, in cell-cell communication and in the extracellular matrix. Through gene silencing, we show that Ci-sushi, a cell-cell communication protein controlled by JNK activity, is required for the wave of apoptosis that precedes tail regression. These observations lead us to propose a model of metamorphosis whereby JNK activity in the CNS induces apoptosis in several adjacent tissues that compose the tail by inducing the expression of genes such as Ci-sushi.

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Section: Hormone Signallingmentioning

confidence: 73%

ERK- and JNK-signalling regulate gene networks that stimulate metamorphosis and apoptosis in tail tissues of ascidian tadpoles

et al. 2007

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“…Some experiments suggest that TH treatments on larvae accelerate the (already very rapid) metamorphosis and settlement of the larvae, although this is less spectacular than in the case of amphibians or amphioxus (Patricolo et al, 1981(Patricolo et al, , 2001. The presence of T4 in Ciona intestinalis has been suggested by immunodetection methods (D'Agati and Cammarata, 2006). This is however not entirely convincing since the specificity of the antibody used is unclear, as it has been assessed only in the context of compounds known in human.…”

Section: But Not In All Known Cases Since the Tunicate Tr Appearsmentioning

confidence: 99%

“…Therefore, these data indicate that there probably exists a TH-like compound, but do not formally prove that it is T4. An ortholog of vertebrate deiodinase has been identified in the tunicate Halocynthia roretzi with both T4 and rT3 as substrates (D'Agati and Cammarata, 2006;Sheperdley et al, 2004). A clear TR ortholog has been cloned, but this receptor is very divergent, in particular in the ligand binding domain (25% sequence identity with human TRs, whereas the amphioxus LBD display 38% (Carosa et al, 1998).…”

Section: But Not In All Known Cases Since the Tunicate Tr Appearsmentioning

confidence: 99%

Evolution of ligands, receptors and metabolizing enzymes of thyroid signaling

Holzer

Roux

Laudet

2017

Molecular and Cellular Endocrinology

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Thyroid hormones (THs) play important roles in vertebrates such as the control of the metabolism, development and seasonality. Given the pleiotropic effects of thyroid disorders (developmental delay, mood disorder, tachycardia, etc), THs signaling is highly investigated, specially using mammalian models. In addition, the critical role of TH in controlling frog metamorphosis has led to the use of Xenopus as another prominent model to study THs action. Nevertheless, animals regarded as non-model species can also improve our understanding of THs signaling. For instance, studies in amphioxus highlighted the role of Triac as a bona fide thyroid hormone receptor (TR) ligand. In this review, we discuss our current understanding of the THs signaling in the different taxa forming the metazoans (multicellular animals) group. We mainly focus on three actors of the THs signaling: the ligand, the receptor and the deiodinases, enzymes playing a critical role in THs metabolism. By doing so, we also pinpoint many key questions that remain unanswered. How can THs accelerate metamorphosis in tunicates and echinoderms while their TRs have not been yet demonstrated as functional THs receptors in these species? Do THs have a biological effect in insects and cnidarians even though they do not have any TR? What is the basic function of THs in invertebrate protostomia? These questions can appear disconnected from pharmacological issues and human applications, but the investigation of THs signaling at the metazoans scale can greatly improve our understanding of this major endocrinological pathway.

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“…Likewise, the morphological transformation from larva to frog/salamander in amphibians is orchestrated by prolactin and the thyroid hormones (THs) (reviewed by Denver and others 2002). Interestingly, recent evidence suggests that THs function similarly during metamorphosis in solitary sea squirts (Chordata: Tunicata: Patricolo and others 2001; Davidson and others 2004;D'Agati and Cammarata 2006) and sea stars and sea urchins (Echinodermata; reviewed by Heyland and others 2005), as well as possibly abalone (Mollusca: Fukazawa and others 2001). In scyphozoans (Cnidaria), too, TH's or their precursors are involved in the metamorphic-like strobilation process: the transition from benthic polyp to pelagic jellyfish (Spangenberg 1974;Berking and others 2005).…”

Section: Feature #1: Morphological Remodeling/change and The Role Of mentioning

confidence: 99%

Expanding networks: Signaling components in and a hypothesis for the evolution of metamorphosis

Hodin

2006

Integrative and Comparative Biology

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Metamorphosis is a substantial morphological transition between 2 multicellular phases in an organism's life cycle, often marking the passage from a prereproductive to a reproductive life stage. It generally involves major physiological changes and a shift in habitat and feeding mode, and can be subdivided into an extended phase of substantial morphological change and/or remodeling, and a shorter-term phase (for example, marine invertebrate "settlement," insect "adult eclosion," mushroom fruiting body emergence) where the actual habitat shift occurs. Disparate metamorphic taxa differ substantially with respect to when the habitat shift occurs relative to the timing of the major events of morphogenetic change. I will present comparative evidence across a broad taxonomic scope suggesting that longer-term processes (morphogenetic changes) are generally hormonally regulated, whereas nitric oxide (NO) repressive signaling often controls the habitat shift itself. Furthermore, new evidence from echinoids (sea urchins, sand dollars) indicates a direct connection between hormonal and NO signaling during metamorphosis. I incorporate 2 hypotheses for the evolution of metamorphosis-one involving heterochrony, the other involving phenotypic integration and evolutionarily stable configurations (ESCs)-into a network model for metamorphosis in echinoderms (sea urchins, starfish, and their kin). Early indications are that this core regulatory network can be acted upon by natural selection to suit the diverse ecological needs of disparate metamorphic organisms, resulting in evolutionary expansions and contractions in the core network. I briefly speculate on the ways that exposure to xenobiotic pollutants and other compounds might influence successful settlement of juveniles in the wild. Indeed, environmentally regulated life history transitions-such as settlement, metamorphosis, and reproductive maturation-may be developmental periods that are especially sensitive to such pollutants.

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Comparative analysis of thyroxine distribution in ascidian larvae

Cited by 14 publications

References 34 publications

ERK- and JNK-signalling regulate gene networks that stimulate metamorphosis and apoptosis in tail tissues of ascidian tadpoles

ERK- and JNK-signalling regulate gene networks that stimulate metamorphosis and apoptosis in tail tissues of ascidian tadpoles

Evolution of ligands, receptors and metabolizing enzymes of thyroid signaling

Expanding networks: Signaling components in and a hypothesis for the evolution of metamorphosis

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