Observations concerning the metabolism of iodine by polyps of Aurelia aurita

Silverstone, Mark; Galton, Valerie Anne; Ingbar, Sidney H.

doi:10.1016/0016-6480(78)90203-4

Cited by 14 publications

(11 citation statements)

References 12 publications

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“…Based on radioiodine incorporation, the most common identifiable iodocompounds have been MIT and DIT. Labeled T4 was reported by Spangenberg (149,150) and by Black and Webb (152), but not by Silverstone et al (156).…”

Section: Survey Of Thyroid-related Functions In Organisms Lacking Thymentioning

confidence: 80%

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Iodine Metabolism and Thyroid-Related Functions in Organisms Lacking Thyroid Follicles: Are Thyroid Hormones also Vitamins?

Eales¹

1997

Experimental Biology and Medicine

135

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Thyroid-related functions in organisms devoid of follicular thyroid tissue have been reviewed. In the lamprey, a primitive vertebrate, the larva concentrates iodide and synthesizes thyroid hormones (TH) by iodoperoxidase (IP)-mediated iodination of a thyroglobulin (TG)-like molecule in a subpharyngeal afollicular endostyle. The endostyle is the thyroid homolog, and it reorganizes into a follicular thyroid at metamorphosis to the adult. Ascidians and amphloxus, invertebrate protochordate relatives of vertebrates, also concentrate iodide and synthesize TH in a subpharyngeal afollicular endostyle, but the endostyle never transforms to follicles. Ascidian plasma contains L-thyroxine and its more biologically active derivative 3,5,3'-triiodo-L-thyronine, and TH receptors exist, but TH effects are poorly understood. No other invertebrates possess an endostyle. Several invertebrates concentrate iodide at other sites and form protein-incorporated iodohistidines and iodotyrosines; however, de novo iodothyronine biosynthesis through IP-mediated TG iodination has not been established. Nevertheless, TH occur in invertebrates, and exogenous iodothyrosines or iodothyronines have effects on jellyfish, insects, and sea urchins. Furthermore, gut bacteria metabolize TH, and plants may synthesize TH by nonenzymatic oxidative iodination. Thus, TH occur in many organisms and, after ingestion and enteric absorption, can enter the food chain. Indeed, sea urchin larvae obtain TH required to induce metamorphosis from plant diatoms. Thyroid hormones can therefore have vitamin-like effects and, in conjunction with vitamin D, and possibly with other steroids, may be more aptly termed vitamones. Availability of exogenous TH has implications for models of invertebrate and vertebrate TH metabolism and iodine salvaging, and it may explain the prominent and probable ancestral role of peripheral mechanisms in regulating thyroidal status.

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Section: Survey Of Thyroid-related Functions In Organisms Lacking Thymentioning

confidence: 80%

“…Iodide concentrates in the polyp (155). This is probably due to trapping by organification, since iodide uptake was not blocked by perchlorate (156). Iodide efficacy in inducing strobilation was reduced by MMI, which blocks iodide organification (156).…”

Section: Survey Of Thyroid-related Functions In Organisms Lacking Thymentioning

confidence: 96%

Iodine Metabolism and Thyroid-Related Functions in Organisms Lacking Thyroid Follicles: Are Thyroid Hormones also Vitamins?

Eales¹

1997

Experimental Biology and Medicine

135

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“…For example, bryozoans (Bugula neretina and Shizoporella errata) accumulate radioiodide from seawater by ouabain-and dinitriphenol-sensitive uptake that is unaffected by perchlorate and also thiourea (reviewed in Eales, 1997). In scyphozoan jellyfish (cnidarians), where iodine is required for signaling developmental transitions (Spangenberg, 1974) and for use in a non-enzymatic antioxidant system (Berking et al, 2005), iodine uptake is also unaffected by perchlorate (Silverstone et al, 1978). Considering the vast phylogenetic distance between bryozoans, cnidarians and echinoderms, it appears that perchlorate-inhibited iodide uptake mechanisms, namely NIS/AIT, are more the exception than the rule among animals as a whole, and may even be vertebrate specific.…”

Section: Sea Urchin Iodine Influx Is Not Dependent On Nis or Ait Orthmentioning

confidence: 99%

Iodine accumulation in sea urchin larvae is dependent on peroxide

Miller

Heyland

2012

Journal of Experimental Biology

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SUMMARYIodine has many important biological functions and its concentrations vary with the environment. Recent research has provided novel insights into iodine uptake mechanisms in marine bacteria and kelp through hydrogen peroxide-dependent diffusion (PDD). This mechanism is distinct from sodium-dependent mechanisms known from vertebrates. In vertebrates, iodine accumulates in the thyroid gland by the action of the apical iodide transporter (AIT) and the sodium/iodide symporter (NIS). Neither of these proteins has, thus far, been identified outside of the chordates, and PDD (as an iodine uptake mechanism) has never been studied in animals. Using 125 I as a marker for total iodine influx, we tested iodine uptake via sodium-dependent transport versus PDD in embryos and larvae of the sea urchin Strongylocentrotus purpuratus. We found that iodine uptake in S. purpuratus is largely independent of NIS/AIT. Instead, we found that uptake is dependent on the presence and production of hydrogen peroxide, indicating that sea urchin larvae use PDD as a mechanism for iodine acquisition. Our data, for the first time, provide conclusive evidence for this mechanism in an animal. Furthermore, our data provide preliminary evidence that sodium-dependent iodine uptake via active transporter proteins is a synapomorphy of vertebrates. Supplementary material available online at

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“…within the optimal range for medusae, 10 to 16) (Hood et al unpubl.). The mechanism underlying the negative effect of low salinity on strobilation may be related to the dependence of strobilation on iodide and the synthesis of thyroxin (Black & Webb 1973, Silverstone et al 1978. Iodide concentration is directly proportional to salinity (Luther & Cole 1988), and thus, at very low salinities, iodide may be insufficient for strobilation (Purcell et al 1999).…”

Section: Effects Of Temperature and Salinity On Chrysaora Quinquecirrmentioning

confidence: 99%

Predicting the distribution of the scyphomedusa Chrysaora quinquecirrha in Chesapeake Bay

Decker¹,

Brown²,

Hood³

et al. 2007

Mar. Ecol. Prog. Ser.

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Jellyfish blooms are important events controlling plankton dynamics in coastal waters worldwide, yet factors that influence bloom development are not well understood. We used the scyphomedusa Chrysaora quinquecirrha as a model to examine physical factors that control jellyfish populations and to develop an ecological forecasting system. Over 700 in situ observations collected from Chesapeake Bay and its tributaries during 1987-2000 were used to develop habitat models that predict the probability of occurrence and the likely concentration of medusae as a function of seasurface temperature and salinity. Medusae were found within a relatively narrow range of temperature (26 to 30°C) and salinity (10 to 16). Regression analyses reveal that a combination of temperature and salinity is a significant predictor of medusa occurrence. Assessments of the predictive performance of these models using medusae and environmental data collected at independent survey sites (n = 354) indicated that model-predicted medusa occurrence and concentration correspond well with observations. Our models can be forced with near-real time and retrospective estimates of temperature and salinity to generate probability of occurrence maps of C. quinquecirrha medusa presence and abundance in order to better understand how this top predator varies in space and time, and how this species could potentially affect energy flow through the Chesapeake Bay system.

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Observations concerning the metabolism of iodine by polyps of Aurelia aurita

Cited by 14 publications

References 12 publications

Iodine Metabolism and Thyroid-Related Functions in Organisms Lacking Thyroid Follicles: Are Thyroid Hormones also Vitamins?

Iodine Metabolism and Thyroid-Related Functions in Organisms Lacking Thyroid Follicles: Are Thyroid Hormones also Vitamins?

Iodine accumulation in sea urchin larvae is dependent on peroxide

Predicting the distribution of the scyphomedusa Chrysaora quinquecirrha in Chesapeake Bay

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