Effects of amino acid supplementations on metabolic and physiological parameters in Atlantic cod (Gadus morhua) under stress

The purpose of this study was to analyse the amino acid composition of otolith matrix protein, estimate the proportion of the water-soluble protein fraction, and analyse the effect of matrix composition on otolith visual appearance. Juvenile Atlantic cod (Gadus morhua) were reared under constant temperature and feeding conditions and sampled at the beginning and the end of the experiment. The amino acid composition was dominated by asparagine, glutamic acid, leucine, serine, and proline. A change in amino acid composition was observed with increasing temperature and time, caused by changing proportions of the water-soluble and -insoluble protein fractions. Feeding level had no effect. The relative content of water-soluble protein was linearly related to fish dry weight and temperature. Otolith opacity, defined as the percentage of incident light absorbed by an otolith section, did not differ significantly between experimental treatments. The soluble protein fraction had a positive, albeit insignificant, correlation with opacity. Using opacity and otolith volume, deposited total otolith protein content was estimated with an R2 of 0.91, where otolith volume alone explained 83% of the observed variation.

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Nucleotide Polymorphism and Natural Selection at the Pantophysin (Pan I) Locus in the Atlantic Cod, Gadus morhua (L.)

Genetics ◽

10.1093/genetics/157.1.317 ◽

2001 ◽

Vol 157 (1) ◽

pp. 317-330 ◽

Cited By ~ 1

Author(s):

Grant H Pogson

Keyword(s):

Natural Selection ◽

Amino Acid ◽

Gadus Morhua ◽

Atlantic Cod ◽

Amino Acid Level ◽

Amino Acid Substitutions ◽

Significant Heterogeneity ◽

Nucleotide Sequence Variation ◽

Spatially Varying ◽

Spatially Varying Selection

Abstract Molecular studies of nucleotide sequence variation have rarely attempted to test hypotheses related to geographically varying patterns of natural selection. The present study tested the role of spatially varying selection in producing significant linkage disequilibrium and large differences in the frequencies of two common alleles at the pantophysin (Pan I) locus among five populations of the Atlantic cod, Gadus morhua. Nucleotide sequences of 124 Pan I alleles showed strong evidence for an unusual mix of balancing and directional selection but no evidence of stable geographically varying selection. The alleles were highly divergent at both the nucleotide level (differing on average by 19 mutations) and at amino acid level (each having experienced three amino acid substitutions since diverging from a common ancestral allele). All six amino acid substitutions occurred in a 56-residue intravesicular loop (IV1 domain) of the vesicle protein and each involved a radical change. An analysis of molecular variation revealed significant heterogeneity in the frequencies of recently derived mutations segregating within both allelic classes, suggesting that two selective sweeps may be presently occurring among populations. The dynamic nature of the Pan I polymorphism in G. morhua and clear departure from equilibrium conditions invalidate a simple model of spatially varying selection.

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Antifreeze glycoproteins in the plasma of Newfoundland Atlantic cod (Gadus morhua)

Canadian Journal of Zoology ◽

10.1139/z81-296 ◽

1981 ◽

Vol 59 (11) ◽

pp. 2186-2192 ◽

Cited By ~ 34

Author(s):

Choy L. Hew ◽

Don Slaughter ◽

Garth L. Fletcher ◽

Shashikant B. Joshi

Keyword(s):

Amino Acid ◽

High Performance ◽

Gadus Morhua ◽

Atlantic Cod ◽

Antifreeze Proteins ◽

Gel Filtration ◽

Exchange Chromatography ◽

Polar Cod ◽

Antifreeze Glycoproteins ◽

Molecular Weights

The plasma of the Atlantic cod, Gadus morhua, contained antifreeze glycoproteins which were present only during the winter months. The antifreeze proteins were isolated, using gel filtration and ion exchange chromatography, and characterized by high performance liquid chromatography. The antifreeze proteins appeared to consist of at least seven components with molecular weights ranging from 2 500 to 33 000. Chemical analysis of the larger components showed a predominance of alanine, threonine, and galactosamine in a ratio of 2:1:1. The smaller peptides contained proline, in addition to alanine and threonine. The amino acid sequence of the smallest glycopeptide (molecular weight 2500) was found to be Ala Ala Thr Pro Ala Thr Ala Ala Thr Pro Ala Thr Ala Ala.These glycoproteins are very similar, if not identical, in amino acid and carbohydrate composition to those isolated from Antaractic nototheniids and several northern gadoids. The sequence of the smallest glycopeptide from the Atlantic cod is identical to that reported for the polar cod, Boreogadus saida.

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Amino acid sequence of the cold-active alkaline phosphatase from Atlantic cod (Gadus morhua)

Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology ◽

10.1016/s1096-4959(03)00167-2 ◽

2003 ◽

Vol 136 (1) ◽

pp. 45-60 ◽

Cited By ~ 14

Author(s):

Bjarni Ásgeirsson ◽

Berit Noesgaard Nielsen ◽

Peter Højrup

Keyword(s):

Alkaline Phosphatase ◽

Amino Acid ◽

Amino Acid Sequence ◽

Gadus Morhua ◽

Atlantic Cod ◽

Cold Active

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Amino Acid Decarboxylase Activity and Other Chemical Characteristics as Related to Freshness Loss in Iced Cod (Gadus morhua)†

Journal of Food Protection ◽

10.4315/0362-028x-65.7.1152 ◽

2002 ◽

Vol 65 (7) ◽

pp. 1152-1157 ◽

Cited By ~ 9

Author(s):

M. MANUELA HERNÁNDEZ-HERRERO ◽

GUILLAUME DUFLOS ◽

PIERRE MALLE ◽

STÉPHANE BOUQUELET

Keyword(s):

Amino Acid ◽

Biogenic Amine ◽

Gadus Morhua ◽

Atlantic Cod ◽

Storage Period ◽

Acid Decarboxylase ◽

Decarboxylase Activity ◽

Exponential Relationship ◽

Sensory Score ◽

Iced Storage

Biogenic amine levels and other biochemical indicators were measured to study the safety of and the loss of freshness in iced Atlantic cod. Biogenic amine content exhibited high variability during iced storage of Atlantic cod. Ornithine and lysine decarboxylase activity apparently increased at the end of the storage period. Amino acid activity was probably generated by endogenous amino acid decarboxylases of raw fish. No statistical differences were observed in the total volatile base fraction or in the ammonia or monomethylamine contents during iced storage. However, trimethylamine contents showed a significant exponential relationship with time and sensory score. Cod formed inosine as the major metabolite of IMP. The H and G indices showed a linear relationship with time and sensory score and served as good indicators of cod freshness quality. However, the K, Ki, and P indices showed a logarithmic relationship with time and sensory score. IMP, K, Ki, and P served as indicators of freshness lost during the early stages of chilled storage of cod.

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Structure and Proposed Amino-Acid Sequence of a Pepsin from Atlantic Cod (Gadus morhua)

Acta Crystallographica Section D Biological Crystallography ◽

10.1107/s090744499700810x ◽

1998 ◽

Vol 54 (1) ◽

pp. 32-46 ◽

Cited By ~ 23

Author(s):

Solveig Karlsen ◽

Edward Hough ◽

Ragnar L. Olsen

Keyword(s):

Crystal Structure ◽

Amino Acid ◽

Gadus Morhua ◽

Model Building ◽

Atlantic Cod ◽

Tuna Fish ◽

Area Detector ◽

Replacement Method ◽

Molecular Replacement Method ◽

Starting Model

The crystal structure of a pepsin from the gastric mucosa of Atlantic cod has been determined to 2.16 Å resolution. Data were collected on orthorhombic crystals with cell dimensions a = 35.98, b = 75.40 and c = 108.10 Å, on a FAST area-detector system. The phase problem was solved by the molecular-replacement method using porcine pepsin (PDB entry 5PEP) as a search model. The structure has been refined to a crystallographic R factor of 20.8% using all reflections between 8.0 and 2.16 Å, without prior knowedge of the primary sequence. The resulting crystal structure is very similar to the porcine enzyme, consisting of two domains with predominantly β-sheet structure in the same sequential positions as the enzyme from pig. In the course of the model building, 122 residues were substituted and two residues deleted from the starting model to give a polypeptide chain of 324 amino acids and a sequence identity of 57.7% with the pig pepsin. No carbohydrate residues were located. Sequence alignment with available aspartic proteinases, indicates that the fish enzyme seems to be more related to mammalian gastric pepsins than to the mammalian gastricsins and chymosins, lysosomal cathepsin D's and a pepsin from tuna fish. The amino-acid composition of the cod enzyme, however, is more in accordance with the cathepsin D's.

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