Studies on the Respiration of Sea-Urchin Spermatozoa

1963 ◽  
Vol 40 (4) ◽  
pp. 573-586
Author(s):  
H. MOHRI ◽  
I. YASUMASU
Keyword(s):  
Sea Urchin ◽  
Sea Water ◽  
Platinum Electrode ◽  
Paracentrotus Lividus ◽  
Inhibitory Effect ◽  
O2 Uptake ◽  
Partial Pressures ◽  
Ph Variations ◽  
Hemicentrotus Pulcherrimus

1. The effect of PCOCO2 on the respiration and motility of sea-urchin spermatozoa was studied on Anthocidaris crassispina. Some points were also corroborated on Hemicentrotus pulcherrimus, Pseudocentrotus depressus, Paracentrotus lividus and Sphaerechinus granularis. 2. It was found that any level of CO2 above 1%, both in oxygen and in air, inhibited the O2 uptake of spermatozoa suspended in sea water, measured polarographically with a vibrating platinum electrode. The inhibitory effect paralleled the PCOCO2 and was completely reversed by introducing oxygen or air. 3. pH variations between 8.50 and 6.75 had no influence on O2 uptake, when the pH was stabilized with 0.05 Mhistidine-HCl-NaOH. O2 uptake was, however, reduced to some extent outside this range, especially on the acid side. Although the increase in PCOCO2 is inevitably followed by a decrease in pH, the inhibitory effect of CO2 far exceeds that caused by the reduction in pH. 4. The O2 uptake rate was little affected by the addition of both bicarbonate and carbonate ions to the suspending medium, although the former had a slightly stimulating effect at certain concentrations. 5. In buffered sea water, CO2 had little influence on O2 uptake even at partial pressures as high as 10% which inhibited the bulk of O2 uptake in sea water. 6. Sperm motility was also inhibited by CO2. In this case, too, the inhibition paralleled the PCOMCOM2 and was completely reversible. The effect was more pronounced in air than in oxygen, and in dense sperm suspensions than in dilute ones. 7. These results suggest that gaseous CO2 is the factor responsible for the inhibitory effect. The possible role of CO2 in the dilution phenomena of sea-urchin spermatozoa is discussed.

scholarly journals CHANGES IN THE POTASSIUM CONTENT OF SEA URCHIN EGGS ON FERTILIZATION

1951 ◽  
Vol 34 (3) ◽  
pp. 285-293 ◽  
Author(s):  
Anna Monroy Oddo ◽  
Maria Esposito
Keyword(s):  
Sea Urchin ◽  
Sea Water ◽  
Paracentrotus Lividus ◽  
Potassium Content ◽  
Minimum Point ◽  
Sea Urchin Eggs ◽  
Maximum Loss ◽  
Arbacia Lixula

In the eggs of Arbacia lixula and Paracentrotus lividus an uptake of K occurs during the first 10 minutes following fertilization. Between 10 and 40 minutes K is then released. Both in Arbacia and in Paracentrotus the minimum point of the curve coincides with the nuclear streak stage. A maximum loss of 25 per cent in Arbacia and 20 per cent in Paracentrotus with respect to the amount present in the unfertilized eggs has been found. From 40 minutes up to 1 hour K undergoes a further increase and when the first cleavage sets in the same amount of K is present as in the unfertilized eggs. By treating the eggs with K-free artificial sea water it has been established that about 60 per cent of the K content of the eggs is in a non-diffusible condition. Also under such conditions the eggs when fertilized are able to take up even the very small amount of K present in the medium that was released by them prior to fertilization.

scholarly journals The Role of Models in Science: A Multicomprehensive Experience with the Sea Urchin Paracentrotus Lividus

2013 ◽  
Vol 93 ◽  
pp. 1404-1408
Author(s):  
Michela Sugni ◽  
Alice Barbaglio ◽  
Francesco Bonasoro ◽  
Mariarosa Gioria ◽  
Paola Fasano ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Paracentrotus Lividus ◽  
Models In Science

Studies on the Respiration of Sea-Urchin Spermatozoa: III. Respiratory Quotient

1961 ◽  
Vol 38 (2) ◽  
pp. 249-257
Author(s):  
H. MOHRI ◽  
K. HORIUCHI
Keyword(s):  
Sea Urchin ◽  
Respiratory Quotient ◽  
Sea Water ◽  
Direct Method ◽  
O2 Uptake ◽  
Present Material ◽  
A Value ◽  
Sperm Suspension ◽  
Co2 Output ◽  
The Difference

1. The respiratory quotient of sea-urchin spermatozoa has been determined with Pseudocentrotus depressus, Anthocidaris crassispina and Hemicentrotus pulcherrimus. 2. The R.Q. of sea-urchin spermatozoa, measured by the Warburg direct method, has been reported to be near unity. This was also the case with the present material when the suspending medium was sea water, the R.Q. being 0.8-1.0. It was found, however, that the pH of sperm suspensions was markedly different in the presence and absence of alkali to absorb C02. 3. When the pH of the suspension was fixed by such buffers as 0.025 M-glycyl glycine, the R.Q. measured by the above method was about 0.7. This is in accord with the results of earlier metabolic studies, which indicated that endogenous phospholipids are the main substrates for the respiration of sea-urchin spermatozoa. 4. The O2 uptake of the present material, however, was found to be little affected by variation in pH. The difference in the R.Q. values obtained with ordinary sea water and buffered sea water, therefore, cannot be explained in terms of pH. 5. When the spermatozoa were suspended in ordinary sea water, the utilization of endogenous phospholipids was much reduced in the absence of alkali, while in buffered sea water the change in phospholipids was almost the same, with and without the absorption of CO2. 6. Determination of the R.Q. by the first method of Dickens & Šimer, in which the O2 uptake and the CO2 output were measured with one and the same sperm suspension, gave a value of about 0.7 with both ordinary and buffered sea water.

The Physiology of Sea-Urchin Spermatozoa

1950 ◽  
Vol 27 (1) ◽  
pp. 59-72
Author(s):  
LORD ROTHSCHILD ◽  
P. H. TUFT
Keyword(s):  
Sea Urchin ◽  
Sea Water ◽  
Dilution Effect ◽  
O2 Uptake ◽  
Time Curve ◽  
Sperm Density ◽  
Negative Results ◽  
Catalytic Function ◽  
Sperm Suspension ◽  
Dense Suspensions

1. When a suspension of sea-urchin semen in sea water is diluted, the total O2 consumed and the rate of O2 uptake per spermatozoon are greater than before dilution. This is the Dilution Effect, first described by Gray (1928 a). A further investigation of this phenomenon has been made, using the semen of Echinus esculentus. 2. The form of the O2 uptake-time curve of such suspensions varies according to the ratio semen: sea water. 3. In very dense suspensions (d ≥ 5 x 109 sperm/ml.), the apparent low O2 uptake per unit quantity of spermatozoa is mainly due to inadequate O2 saturation of the lower layers of the suspension, in which the spermatozoa are virtually unable to respire. Such suspensions are not suitable for experiments in Warburg or Barcroft manometers. 4. In dense suspensions (4 x 108 < d ≤ 109 sperm/ml.) the Dilution Effect was observed when sea water was added to the suspension, in such proportions that the sperm density was only reduced by a factor of 1.14. No Dilution Effect occurred when isotonic ‘Analar’ NaCl was added in the same proportions. On the basis of the small dilution involved, and the negative results with ‘Analar’ NaCl, it is concluded that the Dilution Effect is not exclusively due to the sperm having more space to move after dilution and therefore being able to expend more energy. 5. The Dilution Effect occurs when isotonic ‘Analar’ NaCl containing 1 p.p.m. CuCl2 is added to a dense sperm suspension, in the above proportions. Stimulation of O2 uptake is proportional, over certain limits, to the amount of CuCl2 added. Both CuCl, ZnCl2, and to a lesser extent CuSO2, have similar effects. 6. In a particular experiment, egg-water and Cu salts were about equally efficacious in increasing the O2 uptake of a sperm suspension. 7. The characteristic decline in the O2 uptake of dense suspensions can be partly reversed by the addition of Cu salts. 8. In dilute suspensions (d < 4 x 108 sperm/ml.), there is no Dilution Effect when sea water or CuCl2 are added in the above proportions. On the other hand, the decline in O2 uptake can be partly arrested by the addition of Cu salts. 9. Diethyldithiocarbamate markedly inhibits the O2 uptake of unwashed sea-urchin spermatozoa diluted with sea water. The inhibition does not take place in the presence of added CuCl2. Cu may therefore have a catalytic function in the metabolism of sea-urchin semen. 10. The possibility that Cu lack is responsible for the reduced O2 uptake of spermatozoa in dense suspensions is considered.

The Metabolism of Fertilized and Unfertilized Sea-Urchin Eggs

1949 ◽  
Vol 26 (1) ◽  
pp. 100-111
Author(s):  
LORD ROTHSCHILD
Keyword(s):  
Partial Pressure ◽  
Sea Urchin ◽  
Inhibitory Action ◽  
Gas Mixtures ◽  
O2 Uptake ◽  
Sea Urchin Eggs ◽  
Psammechinus Miliaris ◽  
Partial Pressures ◽  
Before And After ◽  
Light Inhibition

1. An investigation has been made into the effect of light and carbon monoxide on the respiration of sea-urchin eggs (Psammechinus miliaris), with special reference to unfertilized eggs. 2. The O2 uptake of unfertilized eggs in air is 38% higher in the dark than in light. This inhibitory action of light persists when gas mixtures containing CO and O2 are substituted for air. 3. Fertilized and unfertilized eggs differ in that the former's respiration is only about 10% inhibited by light. 4. In 80% CO in O2 in the dark, the O2 uptake of unfertilized eggs is 55% higher than in 80% N2 in O2 in the dark. In 95% CO in O2 in the dark, the O2 uptake of unfertilized eggs is only 7% higher than in 95% N2 in O2 in the dark, showing that at this partial pressure, CO exerts an inhibitory action on respiration. 5. There is no difference between O2 uptake in 80% CO in O2 in light and dark. O2 uptake in 95% CO in O2 in light is 45% higher than in this gas mixture in the dark, showing that at this partial pressure of CO, photo-reversal of respiratory inhibition occurs. 6. Results similar to those in 80% CO in O2 were obtained with gas mixtures containing lower partial pressures of CO. 7. Cytochromes a and b1 were identified spectroscopically in unfertilized eggs. 8. It is concluded that respiration is mediated through the cytochrome system before and after fertilization. In theories which postulate that cytochrome is ‘thrown into circulation’ at fertilization, the simultaneous light-inhibition of respiration, stimulation of O2 uptake by CO, and photo-reversible inhibition of O2 uptake by CO have not been taken into consideration.

Estrogen administration to the edible sea urchin Paracentrotus lividus (Lamarck, 1816)*

Zoosymposia ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. 247-254 ◽  
Author(s):  
SILVIA MERCURIO ◽  
MICHELA SUGNI ◽  
DENISE FERNANDES ◽  
CINTA PORTE ◽  
MARIA DANIELA CANDIA CARNEVALI
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Gonad Index ◽  
Hormonal Treatment ◽  
Paracentrotus Lividus ◽  
Maturation Stage ◽  
Physiological Values ◽  
Estrogen Administration

Despite the extensive use of sea urchins in embryology, the hormonal mechanisms regulating echinoid reproductive pro­cesses are scarcely known. This research is focused on the role of estradiol (E2), whose presence and seasonal variations in different echinoderm tissues have been previously reported. Three different concentrations of E2 were administered (via peristomial injection, 2/week) to adult specimens of the sea urchin Paracentrotus lividus for 2 and 12 weeks. The lowest concentration was close to physiological values, previously measured in field specimens. Despite the increase of circulating E2 in the coelomic fluids, neither short- nor long-term hormonal treatment induced marked variations in the considered reproductive parameters. The Gonad Index appeared to be more influenced by the feed intake than by E2. Similarly, the maturation stage of the gonads was not markedly affected by E2 injection, although some sex-specific dif­ferences could be observed: treated females never reached the maximum maturation stage compared to controls, although this was observed in males injected with the lowest E2 concentration. Although further research is needed to confirm our observations, according to the present study E2 does not markedly influence echinoid reproduction and, particularly, it does not promote female maturation, as reported for vertebrates and suggested for asteroid echinoderms.

scholarly journals A Cytochemical Study of the Sulfhydryl Groups of Sea Urchin Eggs during the First Cleavage

1958 ◽  
Vol 4 (5) ◽  
pp. 615-620 ◽  
Author(s):  
Naoko Kawamura ◽  
Katsuma Dan
Keyword(s):  
Sea Urchin ◽  
Azo Dye ◽  
Sea Water ◽  
Color Intensity ◽  
Cell Stage ◽  
Cytochemical Study ◽  
Sea Urchin Eggs ◽  
Sh Groups ◽  
Precursor Material ◽  
Hemicentrotus Pulcherrimus

In the eggs of four species of echinoderms, Mespilia globulus, Pseudocentrotus depressus, Hemicentrotus pulcherrimus and Clypeaster japonicus, changes in the distribution of protein-bound SH groups from fertilization to the 2 cell stage have been studied cytochemically by use of a mercaptide-forming azo dye. In the eggs of these species, the color intensity in the cytoplasm increased upon fertilization. The astral centers and spindle during mitosis were stained deeply. When the aster formation was suppressed by ether, hyaline spots appeared in the egg cytoplasm instead of well formed astral centers and these spots were stained by the SH-specific dye. Upon recovery of such eggs in pure sea water, and when cleavage ensued, such spots disappeared and two new astral centers were reorganized. The SH-protein occurring in the centrosphere is considered to be the precursor material for the asters and spindle, and this material is apparently derived from the cytoplasm.

Phosphate-Transport Appearance in the Sea-Urchin Egg. I. Effects of Protein-Synthesis Inhibitors on Fertilized Eggs and Embryos

1974 ◽  
Vol 52 (6) ◽  
pp. 1178-1185 ◽  
Author(s):  
Joël de la Noüe
Keyword(s):  
Protein Synthesis ◽  
Active Transport ◽  
Sea Urchin ◽  
Developmental Stages ◽  
Sea Water ◽  
Mitochondrial Protein ◽  
Phosphate Transport ◽  
Inhibitory Effect ◽  
Protein Synthesis Inhibitors ◽  
Transport Carrier

When fertilized eggs of Strongylocentrotus purpuratus, the purple sea urchin, are incubated in sea water containing 32PO43− and L-14C-valine, valine incorporation is inhibited in the presence of puromycin, cycloheximide, or chloramphenicol, but only the last inhibits the active transport of phosphate. Since chloramphenicol does not depress the egg respiration, it is likely that this drug acts specifically. This is in line with a lack of inhibitory effect of chloramphenicol on phosphate uptake at later developmental stages, except at the time of gastrulation, when the appearance of new phosphate carriers might well occur. It is suggested that the active transport carrier for phosphate, or some element required for its operation, is synthesized after fertilization, with the likely participation of the mitochondrial protein-synthesis machinery. A similar proposal holds for valine uptake.

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