Cytological changes during bioluminescence production in dissociated photocytes from the ophiuroid Amphipholis squamata (Echinodermata)

Deheyn, Dimitri D.; Mallefet, Jérôme; Jangoux, M.

doi:10.1007/s004410050011

Cited by 16 publications

(10 citation statements)

References 16 publications

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“…The photocyte bioassay uses isolated light-producing cells from an osmoconforming invertebrate. Seawater is therefore the best medium in which photocytes can be maintained (Deheyn et al, 2000a). The artificial seawater medium used in this study approaches the salt composition and physicochemical properties of natural seawater, which has an average ionic strength of 0.611 (0.511-0.650 range; 0.61 in the bioassay; Turner et al, 1981;Atkinson and Bingman, 1997).…”

Section: Discussionmentioning

confidence: 99%

“…Photocyte isolation was based on the method of (Deheyn et al, 2000a). In summary, 3-5 brittlestars (ca.…”

Section: Photocyte Bioassaymentioning

confidence: 99%

“…Light emission was chemically stimulated using 200 mM potassium chloride (KCl) to exhaust total luminescence capacity (Mallefet et al, 1992), and the light emission was recorded for 40 s using a Lumat 9507 luminometer (EG&G, Perkin Elmer, Gaithersburg, MD, USA). KClinduced light production is monophasic, consisting of a single flash of bioluminescence characterized by the maximum intensity (Imax) of light production (Deheyn et al, 2000a). Imax values were normalized by the number of photocytes in the 25-L volume, knowing the initial mass of arm tissue used in the isolation process, the number of cells extracted per gram of tissue, and the final volume of ASW-enriched photocyte solution.…”

Section: Photocyte Bioassaymentioning

confidence: 99%

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Chemical speciation and toxicity of metals assessed by three bioluminescence‐based assays using marine organisms

Deheyn

Bencheikh-Latmani

Latz

2004

Environmental Toxicology

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ABSTRACT:Metal toxicity is a function of the biology of the target organism and the chemical speciation of the metal. The toxicity of 11 metals was assessed with three cell-based bioassays based on marine organisms: the bacterium Photobacterium phosphoreum of the Microtoxா bioassay, an environmental strain of P. phosphoreum, and photocytes isolated from the brittlestar Ophiopsila californica. Metal speciation was calculated for three commonly used media: NaCl-based Microtoxா bioassay medium, artificial seawater glycerol, and artificial seawater. Decreased bioluminescence was considered a proxy for cell toxicity. In all three assays the elements Cd and Hg exhibited similar speciation as well as similar toxicity profiles. The element Cu was toxic in all three assays despite different metal speciation for the P. phosphoreum bioassay. The element Ag was toxic to both bacterial strains but not to photocytes despite a similar chemical speciation for all three assays. In general, the Microtoxா bioassay was sensitive to all metals (except Pb), whereas the photocytes were the least sensitive to the metals. The heightened response of the Microtoxா bioassay probably resulted from a combination of the limited complexing power of the medium and the greater sensitivity of the bacterial strain.

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Section: Discussionmentioning

confidence: 99%

“…Photocyte isolation was based on the method of (Deheyn et al, 2000a). In summary, 3-5 brittlestars (ca.…”

Section: Photocyte Bioassaymentioning

confidence: 99%

Section: Photocyte Bioassaymentioning

confidence: 99%

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Chemical speciation and toxicity of metals assessed by three bioluminescence‐based assays using marine organisms

Deheyn

Bencheikh-Latmani

Latz

2004

Environmental Toxicology

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“…The species is also bioluminescent. Bioluminescence is produced only in the arms and is attributed to specific photocytes under ganglial control (Deheyn et al 2000a). It has been shown that each colour variety produces light of characteristic intensity, irrespective of the geographic origin of specimens (Deheyn et al 1997, Deheyn 1998.…”

Section: Introductionmentioning

confidence: 99%

Large genetic distances within a population of Amphipholis squamata (Echinodermata; Ophiuroidea) do not support colour varieties as sibling species

Sponer¹,

Deheyn²,

Roy³

2001

Mar. Ecol. Prog. Ser.

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The brittle star Amphipholis squamata is paradoxical in that it lacks an obvious dispersive phase yet has a world-wide distribution. Although individuals from distant populations are morphologically similar, a recent phylogenetic analysis found multiple clades separated by large genetic divergences. These clades were not phylogeographically structured and genetic divergences within populations were typically as high as those amongst populations. The recent suggestion that the sympatric colour varieties 'orange', 'dark brown', 'beige', 'black' and 'grey' represent sibling species, led us to test whether colour variety and phylogeny were congruent. Genetic distances among sequences of the mitochondrial gene 16S rRNA from the colour varieties were surprisingly high (up to 13% uncorrected distance) and phylogenetic analyses using maximum parsimony, maximum likelihood and neighbour joining gave well supported, congruent phylogenies. However, the clades were not consistent with colour variety. When clades were constrained to make colour varieties monophyletic, tree scores were always significantly worse. We conclude from the results of this study that colour varieties do not represent distinct phylogenetic lineages. We discuss the implications of our results in the light of the possibility of clonality or self-fertilization in this species.KEY WORDS: Cryptic species · Phylogeny · 16S mtDNA · Bioluminescence · Speciation · Colour morphs Resale or republication not permitted without written consent of the publisher

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“…In their description of the spine ligament node of Amphipholis squamata (Delle Chiaje, 1828), Deheyn et al [93] referred to the capsular cells as “type D” cells, which, like those of O . nigra , are ciliated, contain heterogeneous vacuoles and compartmentalise DCV-containing cells [93,96]. In addition they were shown to be the source of bioluminescence in A .…”

Section: Discussionmentioning

confidence: 99%

Functional Morphology of the Arm Spine Joint and Adjacent Structures of the Brittlestar Ophiocomina nigra (Echinodermata: Ophiuroidea)

Wilkie

2016

PLoS ONE

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The skeletal morphology of the arm spine joint of the brittlestar Ophiocomina nigra was examined by scanning electron microscopy and the associated epidermis, connective tissue structures, juxtaligamental system and muscle by optical and transmission electron microscopy. The behaviour of spines in living animals was observed and two experiments were conducted to establish if the spine ligament is mutable collagenous tissue: these determined (1) if animals could detach spines to which plastic tags had been attached and (2) if the extension under constant load of isolated joint preparations was affected by high potassium stimulation. The articulation normally operates as a flexible joint in which the articular surfaces are separated by compliant connective tissue. The articular surfaces comprise a reniform apposition and peg-in-socket mechanical stop, and function primarily to stabilise spines in the erect position. Erect spines can be completely immobilised, which depends on the ligament having mutable tensile properties, as was inferred from the ability of animals to detach tagged spines and the responsiveness of isolated joint preparations to high potassium. The epidermis surrounding the joint has circumferential constrictions that facilitate compression folding and unfolding when the spine is inclined. The interarticular connective tissue is an acellular meshwork of collagen fibril bundles and may serve to reduce frictional forces between the articular surfaces. The ligament consists of parallel bundles of collagen fibrils and 7–14 nm microfibrils. Its passive elastic recoil contributes to the re-erection of inclined spines. The ligament is permeated by cell processes containing large dense-core vesicles, which belong to two types of juxtaligamental cells, one of which is probably peptidergic. The spine muscle consists of obliquely striated myocytes that are linked to the skeleton by extensions of their basement membranes. Muscle contraction may serve mainly to complete the process of spine erection by ensuring close contact between the articular surfaces.

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Cytological changes during bioluminescence production in dissociated photocytes from the ophiuroid Amphipholis squamata (Echinodermata)

Cited by 16 publications

References 16 publications

Chemical speciation and toxicity of metals assessed by three bioluminescence‐based assays using marine organisms

Chemical speciation and toxicity of metals assessed by three bioluminescence‐based assays using marine organisms

Large genetic distances within a population of Amphipholis squamata (Echinodermata; Ophiuroidea) do not support colour varieties as sibling species

Functional Morphology of the Arm Spine Joint and Adjacent Structures of the Brittlestar Ophiocomina nigra (Echinodermata: Ophiuroidea)

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