Effect of diet on levels of amino acids during embryonic and naupliar development of the copepod Calanus helgolandicus

1999 ◽  
Vol 134 (1) ◽  
pp. 89-98 ◽  
Author(s):  
M. Laabir ◽  
S. A. Poulet ◽  
A. Cueff ◽  
A. Ianora
Keyword(s):  
Amino Acids ◽  
Naupliar Development ◽  
Calanus Helgolandicus

On the Nutrition and metabolism of zooplankton IV. The forms of nitrogen excreted By Calanus

1967 ◽  
Vol 47 (1) ◽  
pp. 113-120 ◽  
Author(s):  
E. D. S. Corner ◽  
B. S. Newell
Keyword(s):  
Amino Acids ◽  
Positive Reaction ◽  
Laboratory Experiments ◽  
Long Island Sound ◽  
Acartia Tonsa ◽  
Nitrogenous Compounds ◽  
Nitrogenous Substances ◽  
Experimental Density ◽  
Island Sound ◽  
Calanus Helgolandicus

A study has been made of the nitrogenous compounds excreted by Calanus helgolandicus (Claus) collected at Plymouth.Most of the excreted nitrogen is in the form of ammonia which accounts for 60–100% (average 74.3%) of the total, and some of the remainder may be lost as urea. There is no evidence for the excretion of measurable amounts of amino acids.Whether the animals are starved or fed they are primarily ammonotelic, and the quantity of ammonia produced at 10° C (3.33 μg/g. dry body wt/day) is not significantly changed when the animals are used at an abnormally high experimental density. This latter condition does, however, lead to the production of large quantities of additional nitrogenous substances that give a positive reaction with ninhydrin.IntroductionThe amounts of nitrogen excreted by zooplankton have been measured by several workers. Harris (1959) used the method of Riley (1953) to estimate the copious quantities of ammonia produced by animals (mainly Acartia tonsa and A. clausi) collected from Long Island Sound; Beers (1964), in laboratory experiments with the chaetognath Sagitta hispida, estimated the excreted ammonia by the procedure of Kruse & Mellon (1952); and Corner, Cowey & Marshall (1965) determined the ammonia excreted by Calanus helgolandicus and C. finmarchicus, using a ninhydrin technique described by Moore & Stein (1954). The methods employed by Harris and by Beers are specific for ammonia: that used by Corner et al. estimates nitrogenous substances (e.g. amino acids) in addition to ammonia, but certain tests were made which seemed to exclude the possibility that these substances contributed significantly to the nitrogen excreted by the animals.

scholarly journals On the Nutrition and Metabolism of Zooplankton II. The relationship between the marine copepod Calanus helgolandicus and particulate material in Plymouth sea water, in terms of amino acid composition

1963 ◽  
Vol 43 (2) ◽  
pp. 495-511 ◽  
Author(s):  
C. B. Cowey ◽  
E. D. S. Corner
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Total Nitrogen ◽  
Skeletonema Costatum ◽  
Particulate Material ◽  
Amino Acid Nitrogen ◽  
Calanus Helgolandicus

The amino acid composition of adult female Calanus helgolandicus Claus and particulate material at station L4 has been analysed from March to December. The average concentration of amino acid nitrogen in Calanus was 7·7% of the dry body weight and accounted for 83% of the total nitrogen. The average level of amino acid nitrogen in the particulate material was 11·9 μg/1. and accounted for 54% of the total nitrogen.The relative quantities of amino acids in Calanus remained remarkably constant throughout the year. The relative quantities of amino acids in particulate material were more variable.The rate of respiration of Calanus measured at 8°C varied from 31 μl. O2/mg. dry body weight/day in winter (December–February) to 79 μl. O2/mg dry body weight/day in summer (April–August).Starving winter Calanus lost 1·8% and starving summer Calanus 2·1% of their dry body weight as amino acids each day. In order to replenish its daily losses of amino acids winter Calanus must sustain a filtering rate of about 30 ml./animal/day: the corresponding value in summer is greater than 50 ml./animal/day.The amino acid composition of Skeletonema costatum is so close to that of the particulate material in the sea, that, as far as amino acids are concerned, Calanus would gain no nutritional advantage by selecting the diatom in preference to the amino acid containing fraction of particulate material as a whole.

The seasonal abundance of the copepodite stages of Calanus helgolandicus and Pseudocalanus elongatus off Plymouth

1993 ◽  
Vol 73 (1) ◽  
pp. 109-122 ◽  
Author(s):  
E. P. Green ◽  
R. P. Harris ◽  
A. Duncan
Keyword(s):  
Seasonal Variation ◽  
Relative Abundance ◽  
Spring Bloom ◽  
Food Limitation ◽  
The Body ◽  
Seasonal Abundance ◽  
English Channel ◽  
Major Period ◽  
Naupliar Development ◽  
Calanus Helgolandicus

The relative abundance of the six copepodite stages (CI-CVI) of Calanus helgolandicus Claus (Copepoda: Calanoida) and Pseudocalanus elongatus Boeck (Copepoda: Calanoida) was recorded at a station in the English Channel throughout 1989. There was a pronounced seasonal variation in the abundance of the early stages. Increased recruitment from the nauplii corresponded in both species to rising primary production early in the year, producing small CI abundance peaks in March. The major period of naupliar development occurred after the April/May spring bloom. During seasonal peaks the CI and CII stages typically formed 40% of the copepodites of these species but were scarce at other times. The body carbon weight of Calanus and Pseudocalanus CIs decreased by 38% and 21% respectively from May to August, indicating an increase in food limitation for the nauplii. Summer was passed predominantly in the CIV and CV stage at low abundances.

Homochirality as the Signature of Extra-Terrestrial Life

1997 ◽  
Vol 161 ◽  
pp. 505-510
Author(s):  
Alexandra J. MacDermott ◽  
Laurence D. Barron ◽  
Andrè Brack ◽  
Thomas Buhse ◽  
John R. Cronin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Optical Rotation ◽  
Physical Origin ◽  
Natural Choice ◽  
Rosetta Mission ◽  
Terrestrial Life ◽  
Subsurface Layers ◽  
Solar System Bodies ◽  
Origin Of Homochirality

AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Methionine-Specific Staining of Collagen

1982 ◽  
Vol 40 ◽  
pp. 294-295
Author(s):  
E.M. Kuhn ◽  
K.D. Marenus ◽  
M. Beer
Keyword(s):  
Amino Acids ◽  
Collagen Fibers ◽  
Type Iii Collagen ◽  
Type I ◽  
Electron Microscopic ◽  
Good Correspondence ◽  
Specific Staining ◽  
Type Iii ◽  
Different Types ◽  
Sulfur Containing

Fibers composed of different types of collagen cannot be differentiated by conventional electron microscopic stains. We are developing staining procedures aimed at identifying collagen fibers of different types.Pt(Gly-L-Met)Cl binds specifically to sulfur-containing amino acids. Different collagens have methionine (met) residues at somewhat different positions. A good correspondence has been reported between known met positions and Pt(GLM) bands in rat Type I SLS (collagen aggregates in which molecules lie adjacent to each other in exact register). We have confirmed this relationship in Type III collagen SLS (Fig. 1).

Prevalence of the pit and antipit in the genus Glycine

1987 ◽  
Vol 45 ◽  
pp. 986-987
Author(s):  
R. W. Yaklich ◽  
E. L. Vigil ◽  
W. P. Wergin
Keyword(s):  
Amino Acids ◽  
Endoplasmic Reticulum ◽  
Glycine Max ◽  
Seed Coat ◽  
Cell Types ◽  
Abaxial Surface ◽  
Legume Seed ◽  
Initial Report ◽  
Cone Cells ◽  
Glycine Max L

The legume seed coat is the site of sucrose unloading and the metabolism of imported ureides and synthesis of amino acids for the developing embryo. The cell types directly responsible for these functions in the seed coat are not known. We recently described a convex layer of tissue on the inside surface of the soybean (Glycine max L. Merr.) seed coat that was termed “antipit” because it was in direct opposition to the concave pit on the abaxial surface of the cotyledon. Cone cells of the antipit contained numerous hypertrophied Golgi apparatus and laminated rough endoplasmic reticulum common to actively secreting cells. The initial report by Dzikowski (1936) described the morphology of the pit and antipit in G. max and found these structures in only 68 of the 169 seed accessions examined.

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