A Note on the Copper Content of Sea-Urchin Semen and Sea Water

1950 ◽  
Vol 27 (2) ◽  
pp. 123-125
Author(s):  
H. BARNES ◽  
LORD ROTHSCHILD
Keyword(s):  
Sea Urchin ◽  
Seminal Plasma ◽  
Copper Content ◽  
Water Surface ◽  
Sea Water ◽  
Sea Urchins ◽  
Coelomic Fluid ◽  
Original Sample

1. The copper content of semen, seminal plasma and coelomic fluid of Echinus esculentus has been determined. The average figures for sea-urchins examined immediately after collection were: semen, 1.33µg/ml.; seminal plasma, 0.50µg/ml.; coelomic fluid, 0.07µg./ml. The accuracy of the method of estimation was ± 0.08µg. Cu/ml. original sample, which means that the amount of Cu in coelomic fluid is not significant. This figure for coelomic fluid is considerably lower than that obtained by Webb (1937) in the only previous examination. 2. The copper content of sea water (surface, off Keppel Pier, Millport) was 0.0064µg./ml.

The Physiology of Sea-Urchin Spermatozoa

1948 ◽  
Vol 25 (4) ◽  
pp. 344-352
Author(s):  
LORD ROTHSCHILD
Keyword(s):  
Sea Urchin ◽  
Seminal Plasma ◽  
Sea Water ◽  
O2 Activation ◽  
Residual Tension ◽  
K Concentration

1. Echinus esculentus spermatozoa are normally motionless in undiluted semen. They become active when the semen is diluted with sea water or seminal plasma obtained by gentle centrifugation (1500 r.p.m., 12 cm. radius, for 15 min.). 2. A sperm-immobilizing substance can, however, be obtained in seminal plasma by more prolonged centrifugation of semen. 3. Spermatozoa can be made motile in undiluted semen by increasing the O2 tension in the atmosphere surrounding the semen. 4. This O2 activation is completely inhibited by N2; the N2 effect is reversible. 5. Measurements of seminal O2 tension were made with an O2 electrode. The O2 tension of semen is low, being at most 15 mm. Hg. It was not possible to decide whether this residual tension was due to O2 or some other substance reacting at the electrode. 6. The K content of seminal plasma is about 1·55 mg./ml., which is four times higher than that of perivisceral fluid or sea water. 7. The pH of semen is lower than that of sea water, being approx. 7·5. 8. Neither K concentration nor pH is responsible for the inactivity of sperm in semen. 9. A hormone, Androgamone I, is often considered to be responsible for the inactivity of spermatozoa in non-mammalian semen. No support has been found for this view and it is concluded that in E. esculentus semen the spermatozoa are motionless through lack of O2.

Differences in ion regulation in the sea urchins Lytechinus variegatus and Arbacia lixula (Echinodermata: Echinoidea)

2007 ◽  
Vol 87 (3) ◽  
pp. 769-775 ◽  
Author(s):  
Denilton Vidolin ◽  
Ivonete A. Santos-Gouvea ◽  
Carolina A. Freire
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Tap Water ◽  
Distinct Species ◽  
Coelomic Fluid ◽  
Lytechinus Variegatus ◽  
Ion Regulation ◽  
Magnesium Supplementation ◽  
Ionic Concentrations ◽  
Arbacia Lixula

The regular sea urchin Lytechinus variegatus, a species previously reported from areas of reduced salinities, and Arbacia lixula, a species unreported from diluted waters, were submitted to seawater dilution or seawater dilution in magnesium-supplemented waters. Seawater (35 psu) was either proportionally diluted with filtered dechlorinated tap water (30 psu, 25 psu), or diluted and supplemented with magnesium as MgCl2 (30+Mg, 25+Mg), up to full-strength seawater Mg2+ levels (35 psu, ~54 mM Mg2+). Magnesium supplementation was intended to verify the interfering effect of magnesium on osmo-ionic concentrations of the coelomic fluid (CF) of two ecologically distinct species of sea urchins. After 6 h in control (35 psu) or experimental seawater, CF samples were withdrawn by puncturing through the peristomial membrane. Coelomic fluid osmolality ([Osm]), and concentrations of ([Na+]), ([Cl-]), ([Mg2+]) and ([K+]) were measured for both species. Under all conditions, L. variegatus displayed higher CF osmolality, [Na+], and [K+] values than the water (and A. lixula). Comparatively, L. variegatus is designated as a‘hyper-conformer’, while A. lixula is an ‘iso-conformer’. The CF [Mg2+] showed no evidence of being controlled by either species. Mg2+ supplementation in diluted seawater affected Mg2+ and Cl- levels only. Na+ appears to be taken up actively by L. variegatus, rendering its CF mostly hyper-ionic for Na+ (and hyperosmotic) relative to external seawater. The different gradients observed with the different ions suggest selective permeabilities or ion regulation by L. variegatus.

scholarly journals Microdissection Experiments on Sea-Urchin Eggs at Cleavage

1953 ◽  
Vol 30 (4) ◽  
pp. 515-524
Author(s):  
J. M. MITCHISON
Keyword(s):  
Internal Pressure ◽  
Sea Urchin ◽  
Sea Water ◽  
Sea Urchins ◽  
The Other ◽  
Membrane Tension ◽  
Membrane Theory ◽  
Sea Urchin Egg ◽  
Pass Through ◽  
Irreparable Damage

1. Chambers (1938) described an experiment in which he cut open one blasto-mere of a cleaving sea-urchin egg at the dumb-bell stage in isotonic KCl. The other blastomere contracted like a ‘deflating balloon’, and this has been taken by other workers as evidence of a positive membrane tension in the cleaving egg. This experiment has been repeated with other sea urchins in various media. It is concluded that this effect only takes place in one species of sea urchin, in an abnormal medium, and after it has suffered irreparable damage. It is not, therefore, legitimate to suppose that there is normally a positive membrane tension in a cleaving egg. It is found that eggs will continue to cleave with one blastomere in an irregular shape which indicates that, on the contrary, there is no membrane tension and no internal pressure. These are the conditions demanded by the ‘expanding membrane’ theory of cleavage. 2. It is found that the furrow of a cleaving egg will pass through a needle placed in its path. This result argues against a simple contracting ring in the furrow region being responsible for cleavage. 3. Chambers (1938) found that an egg will continue to cleave when its asters have been destroyed by stirring. This result has been confirmed by a similar experiment on a different species of sea urchin. This is crucial evidence against an astral mechanism of cleavage. 4. The effects of compressing cleaving eggs have been studied. It is found that compressed eggs continue to cleave unless the degree of flattening is considerable; that cleavage is delayed before it is finally stopped; and that eggs in Ca-free sea water are more susceptible to compression than eggs in ordinary sea water. These results are consistent with the ‘expanding membrane’ theory.

The Physiology of Sea-Urchin Spermatozoa Action of Versene

1954 ◽  
Vol 31 (2) ◽  
pp. 252-259
Author(s):  
LORD ROTHSCHILD ◽  
A. TYLER
Keyword(s):  
Trace Metals ◽  
Sea Urchin ◽  
Seminal Plasma ◽  
Sea Water ◽  
Dilution Effect ◽  
Dense Suspension

1. The effect of adding sea water containing different concentrations of versene to suspensions of sea-urchin spermatozoa (Echinus esculentus) has been investigated, as regards their respiration, motility and fertilizing capacity. 2. The respiratory Dilution Effect is progressively reduced and finally abolished when, instead of sea water, sea water containing 10-6, 10-5, 10-4 or 10-3 M versene is added to sperm suspensions. 3. At the same time versene greatly delays the senescence of the spermatozoa, both as regards their motility and fertilizing capacity. For example, after seventeen hours, a 105 sperm/ml. suspension in sea water containing 10-3 M versene has 125 times the fertilizing capacity of a suspension containing 107 sperm/ml. without versene. 4. The change in the ratio of seminal plasma to sea water which occurs when a dense suspension is diluted does not explain the Dilution Effect. 5. These results are discussed in relation to the hypothesis which accounts for the Dilution Effect in terms of trace metals, particularly copper, normally occurring in sea water, and the amounts available per spermatozoon under various conditions of dilution.

scholarly journals The Diverse Transformer (Trf) Protein Family in the Sea Urchin Paracentrotus lividus Acts through a Collaboration between Cellular and Humoral Immune Effector Arms

2021 ◽  
Vol 22 (13) ◽  
pp. 6639
Author(s):  
Iryna Yakovenko ◽  
Asaf Donnyo ◽  
Or Ioscovich ◽  
Benyamin Rosental ◽  
Matan Oren
Keyword(s):  
Sea Urchin ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Paracentrotus Lividus ◽  
Protein Family ◽  
Coelomic Fluid ◽  
Immune Gene ◽  
Immune Effector ◽  
E Coli ◽  
Humoral Immune

Sea urchins are long-living marine invertebrates with a complex innate immune system, which includes expanded families of immune receptors. A central immune gene family in sea urchins encodes the Transformer (Trf) proteins. The Trf family has been studied mainly in the purple sea urchin Strongylocentrotus purpuratus. Here, we explore this protein family in the Mediterranean Sea urchin Paracentrotus lividus. The PlTrf genes and predicted proteins are highly diverse and show a typical Trf size range and structure. Coelomocytes and cell-free coelomic fluid from P. lividus contain different PlTrf protein repertoires with a shared subset, that bind specifically to E. coli. Using FACS, we identified five different P. lividus coelomocyte sub-populations with cell surface PlTrf protein expression. The relative abundance of the PlTrf-positive cells increases sharply following immune challenge with E. coli, but not following challenge with LPS or the sea urchin pathogen, Vibrio penaeicida. Phagocytosis of E. coli by P. lividus phagocytes is mediated through the cell-free coelomic fluid and is inhibited by blocking PlTrf activity with anti-SpTrf antibodies. Together, our results suggest a collaboration between cellular and humoral PlTrf-mediated effector arms in the P. lividus specific immune response to pathogens.

scholarly journals Sea Urchin (Echinoidea) Distribution and Abundance in the Intertidal Zone of Bengkayang Regency

2018 ◽  
Vol 10 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Andi Ristanto ◽  
Ari Hepi Yanti ◽  
Tri Rima Setyawati
Keyword(s):  
Sea Urchin ◽  
Water Waves ◽  
Intertidal Zone ◽  
Sea Water ◽  
Sea Urchins ◽  
Marine Water

Sea urchins is the member of Echinoidea. This species can be found in tropical marine water to the poles. The study aimed to know the types, the abundance and spread of sea urchins in Bengkayang Regency. The research, used the transect method. Each station consisted of 3 transects with a length of 50 meters from the shore into the sea with the distance of 10 meters among the transects. This research obtained five species consisting of three species of the Diadema (genus) and two species of the Echinotrix (genus) i.e. Diadema antillarium, D. savignyi, D. setosum, Echinotrix calamaris and E. deadema. The density of sea urchins in Lemukutan Island ranges from 273 – 453 ind/Ha. The Density of sea urchins on Penata Kecil island ranges from 167 - 347 ind / Ha and on Penata Besar Island has a range from 307 - 387 ind/Ha. The highest diversity of sea urchins was found in Penata Kecil Island of (1.2355). The distribution of sea urchins in Lemukutan and Penata Besar Island was categorized into clumped and evenly distributed, while the distribution of sea urchin on Penata Kecil Island is included in the clustered and random categories. Distribution of sea urchins on the island is influenced by several factors such as sea water waves and food contained in the environment.

Fine Structure of Sea Urchin Sperm Membranes

1970 ◽  
Vol 28 ◽  
pp. 312-313
Author(s):  
S. Inoue ◽  
A. Buday ◽  
G.H. Cousineau
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Sea Urchin ◽  
Sea Water ◽  
Sea Urchins ◽  
Water Mixture ◽  
Thin Sections ◽  
Surface Replica ◽  
Sperm Membrane ◽  
Surface Replica Method

From electron microscope studies of thin sections it is known that the entire surface of a spermatozoon of sea urchin is covered by a plasma membrane, or sperm membrane, of an approximate thickness of 100Å (1). In these experiments the surface replica method was applied for the study of the fine structure of the sperm membrane.Spermatozoa from Strongylocentrotus purpuratus (sea urchins supplied by the Pacific Biomarine Supply Company, Venice, Calif.) were washed several times by centrifugation in Millipore-filtered sea water. After fixation in a 2.5% glutaraldehyde-paraformaldehyde (sea water mixture at 4°C) for an hour, spermatozoa were washed with sea water and then with distilled water for several times. A few drops of specimen were dried on a glass slide and the surface replica was prepared according to the method previously described (2) with the exception that the spermatozoa were decomposed in 18 N H2SO4 for about 20 hours at room temperature. The replica films were examined with a JEM-7A electron microscope.

scholarly journals Composition and geographic variation of the bacterial microbiota associated with the coelomic fluid of the sea urchin Paracentrotus lividus

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Teresa Faddetta ◽  
Francesco Ardizzone ◽  
Francesca Faillaci ◽  
Chiara Reina ◽  
Emilia Palazzotto ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Nature Reserve ◽  
Sea Urchins ◽  
Geographical Location ◽  
Paracentrotus Lividus ◽  
Coelomic Fluid ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
Bacterial Strains ◽  
Microbiota Structure

AbstractIn the present work, culture-based and culture-independent investigations were performed to determine the microbiota structure of the coelomic fluid of Mediterranean sea urchin Paracentrotus lividus individuals collected from two distinct geographical sites neighboring a high-density population bay and a nature reserve, respectively. Next Generation Sequencing analysis of 16S rRNA gene (rDNA) showed that members of the Proteobacteria, Bacteroidetes and Fusobacteria phyla, which have been previously reported to be commonly retrieved from marine invertebrates, dominate the overall population of microorganisms colonizing this liquid tissue, with minority bacterial genera exhibiting remarkable differences among individuals. Our results showed that there is a correlation between microbiota structure and geographical location of the echinoderm collection site, highlighting over-representation of metagenomic functions related to amino acid and bioactive peptides metabolism in specimens inhabiting the nature reserve. Finally, we also described the developmental delay and aberrations exhibited by sea urchin embryos exposed to distinct bacterial isolates, and showed that these defects rely upon hydrophilic compound(s) synthesized by the bacterial strains assayed. Altogether, our findings lay the groundwork to decipher the relationships of bacteria with sea urchins in their aquatic environment, also providing an additional layer of information to understand the biological roles of the coelomic fluid.

Further studies of the effects of deprivation of sulfate on the early development of the sea urchin Paracentrotus lividus

Development ◽  
1965 ◽  
Vol 14 (3) ◽  
pp. 289-305
Author(s):  
J. Immers ◽  
J. Runnström
Keyword(s):  
Sea Urchin ◽  
Developmental Stages ◽  
Sea Water ◽  
Sea Urchins ◽  
Paracentrotus Lividus ◽  
The Other ◽  
Free Medium ◽  
Dominant Group ◽  
And Function ◽  
Early Developmental

The morphological effects of sulfate-free medium on sea urchin embryos were described in detail by Herbst (1904). Further studies were carried out by Lindahl (1936, 1942). He was the first to consider metabolic aspects of the rôle of sulfate in the development of the sea urchin. Immers (1956, 1959, 1961a and b, 1962) studied the distribution and function of acid mucopolysaccharides in early developmental stages of sea urchins, mainly Paracentrotus lividus. A dominant group of these acid polysaccharides are sulfated. Their location in the blastocoel, in the hyaline layer and in the lumen of the intestine could be demonstrated by staining of sectioned specimens with the ferri-acetic reagent of Hale (1946). In blastulae or gastrulae raised in sulfate-free sea water these regions are negative with respect to Hale staining (Immers, 1961b). On the other hand, the ectodermal nuclei of the animal region of the embryos are stained with the Hale reagent although the nuclei of the vegetal region remained unstained (1.c.).

scholarly journals MORPHOLOGY OF GAMETE MEMBRANE FUSION AND OF SPERM ENTRY INTO OOCYTES OF THE SEA URCHIN

1965 ◽  
Vol 25 (2) ◽  
pp. 81-100 ◽  
Author(s):  
Luther E. Franklin
Keyword(s):  
Electron Microscope ◽  
Sea Urchin ◽  
Acrosome Reaction ◽  
Sea Water ◽  
Sea Urchins ◽  
Detailed Examination ◽  
Lytechinus Variegatus ◽  
Arbacia Punctulata ◽  
Sperm Entry ◽  
Ultrathin Sections

Sea urchin gametes predominate in molecular studies of fertilization, yet relatively little is known of the subcellular aspects of sperm entry in this group. Accordingly, it seemed desirable to make a detailed examination of sperm entry phenomena in sea urchins with the electron microscope. Gametes of the sea urchins Arbacia punctulata and Lytechinus variegatus were used in this study. Samples of eggs containing 2 to 8 per cent oocytes were selected and fixed with osmium tetroxide in sea water at various intervals after insemination. Fixed specimens were embedded in Epon 812, sectioned, and examined with an electron microscope. An apical vesicle was observed at the anterior end of the acrosome. The presence of this structure, together with other observations, suggested that initiation of the acrosome reaction in sea urchin sperm involves dehiscence of the acrosomal region with the subsequent release of the acrosomal granule. Contact and initial fusion of gamete membranes was observed in mature eggs and oocytes and invariably involved the extended acrosomal tubule of the spermatozoon. Only one spermatozoon normally enters the mature egg. The probability of locating such a sperm in ultrathin sections is exceedingly low. Several sperm do normally enter oocytes. Consequently, observations of sperm entry were primarily restricted to the latter. The manner of sperm entry into oocytes did not resemble phagocytosis. Organelles of the spermatozoon were progressively divested of their plasma membrane as they entered the ground cytoplasm of the oocyte fertilization cone. Initiation of the acrosome reaction, contact and initial fusion of gamete membranes, and sperm entry into oocytes of sea urchins conform to the Hydroides-Saccoglossus pattern of early fertilization events as described by Colwin and Colwin (13).

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