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hemoglobin from the antarctic fish notothenia coriiceps neglecta. amino acid sequence of the beta chain.1. notothenia coriiceps neglecta is a cold-adapted notothenioid teleost, widely distributed in the antarctic waters. 2. in comparison with fishes from temperate waters, the blood of this teleost contains a reduced number of erythrocytes and concentration of hemoglobin; the erythrocytes contain two hemoglobins, hb1 and hb2, respectively accounting for approximately 90, and 5% of the total. 3. the two components differ by the alpha chain; the amino acid sequence of the beta chain in common to the ...19902361365
the amino acid sequence of the alpha- and beta-chains of the two hemoglobins of the antarctic fish notothenia coriiceps neglecta.the blood of the antarctic fish notothenia coriiceps neglecta contains two hemoglobins, hb 1 and hb 2, which have a beta-chain in common. we have elucidated the primary structure of the beta-chain (146 residues) and of the alpha-chains (142 residues) of the two hemoglobins. the two alpha-chains differ from each other by 51 residues; in comparison with globin sequences of temperate fishes, the alpha-chain of hb 1 is more similar to that of bluefin tuna than to the alpha-chain of hb 2 of the same ...19892737301
antarctic fish tubulins: heterogeneity, structure, amino acid compositions and charge.1. tubulins purified from the brain tissues of three antarctic fishes (notothenia gibberifrons, notothenia coriiceps neglecta, and chaenocephalus aceratus) contain equimolar quantities of the alpha and beta chains and are free of microtubule-associated proteins (maps) and other non-tubulin proteins. 2. when examined by isoelectric focusing and by two-dimensional electrophoresis, brain tubulins from the antarctic fishes were found to be highly heterogeneous; each was resolved into 15-20 distinct ...19883180738
cold-stable microtubules from antarctic fishes contain unique alpha tubulins.the cytoplasmic microtubules of antarctic fishes assemble from their tubulin subunits at physiological body temperatures in the range -2 to +2 degrees c. our objective is to determine the structural features that enhance the assembly of antarctic fish tubulins at low temperatures. here we compare the structures of tubulin subunits from three antarctic fishes (notothenia gibberifrons, notothenia coriiceps neglecta, and chaenocephalus aceratus), from three temperate fishes (the dogfish shark muste ...19873597376
heterogeneity and structure of brain tubulins from cold-adapted antarctic fishes. comparison to brain tubulins from a temperate fish and a mammal.tubulins purified from brain tissue of antarctic fishes assemble in vitro to form microtubules at the low temperatures experienced by these extreme psychrophiles (williams, r. c., jr., correia, j. j., and devries, a. l. (1985) biochemistry 24, 2790-2798). we have initiated studies to determine the structural requirements for assembly of antarctic fish tubulins at low temperatures. as a first step we have compared the heterogeneity, structures, amino acid compositions, and net charge of brain tub ...19863733739
cold adaptation of microtubule assembly and dynamics. structural interpretation of primary sequence changes present in the alpha- and beta-tubulins of antarctic fishes.the microtubules of antarctic fishes, unlike those of homeotherms, assemble at very low temperatures (-1.8 degrees c). the adaptations that enhance assembly of these microtubules are intrinsic to the tubulin dimer and reduce its critical concentration for polymerization at 0 degrees c to approximately 0.9 mg/ml (williams, r. c., jr., correia, j. j., and devries, a. l. (1985) biochemistry 24, 2790-2798). here we demonstrate that microtubules formed by pure brain tubulins of antarctic fishes exhib ...200010956651
structural characterization and thermal stability of notothenia coriiceps metallothionein.fish and mammalian metallothioneins (mts) differ in the amino acid residues placed between their conserved cysteines. we have expressed the mt of an antarctic fish, notothenia coriiceps, and characterized it by means of multinuclear nmr spectroscopy. overall, the architecture of the fish mt is very similar to that of mammalian mts. however, nmr spectroscopy shows that the dynamic behaviour of the two domains is markedly different. with the aid of absorption and cd spectroscopies, we studied the ...200111171106
muscle fine structure may maintain the function of oxidative fibres in haemoglobinless antarctic fishes.muscle fine structure and metabolism were examined in four species of antarctic fishes that vary in their expression of haemoglobin (hb). to determine how locomotory pectoral muscles maintain function, metabolic capacity, capillary supply and fibre ultrastructure were examined in two nototheniid species that express hb (notothenia coriiceps and gobionotothen gibberifrons) and two species of channichthyid icefish that lack hb (chaenocephalus aceratus and chionodraco rastrospinosus). surprisingly, ...200312477911
mapping of alpha- and beta-globin genes on antarctic fish chromosomes by fluorescence in-situ hybridization.the pathways and mechanisms of genomic change that have led to the peculiar haemoglobinless phenotype of the white-blooded antarctic icefishes (16 species in the family channichthyidae) constitute an important model for understanding the rapid diversification of the antarctic notothenioid fish flock. to provide complementary structural information on genomic change at globin-gene loci in antarctic fish species, cytogenetic studies and in-situ chromosomal mapping have been undertaken. using a dna ...200314516071
structural and functional studies of vertebrate metallothioneins: cross-talk between domains in the absence of physical contact.in previous studies, we showed that the chemical and dynamic properties of fish and mouse mts (metallothioneins) present a number of distinctive differences linked to their primary structures, and that phylogenetic relationships of mammal and fish mts correlate with their three-dimensional structures. the different behaviours of mts may also be linked to the interaction between their two domains. in the present study, we have compared the physicochemical properties of the isolated recombinant do ...200515926886
fatty acyl coa synthetase from antarctic notothenioid fishes may influence substrate specificity of fat oxidation.antarctic notothenioid fishes possess large lipid stores that are important fuels for aerobic metabolism. oxidative muscle tissues of these animals oxidize long-chain mono-unsaturated fatty acids more readily than saturated fatty acids. the mechanistic basis(es) for the substrate specificity of their fatty acid-oxidizing pathway is unknown. we examined the substrate specificity of fatty acyl coenzyme a synthetase (facs) to determine whether the enzyme contributes to targeting unsaturated fatty a ...200415364288
subcellular distribution and characterization of gill carbonic anhydrase and evidence for a plasma carbonic anhydrase inhibitor in antarctic fish.this main purpose of this study was to examine the subcellular distribution and isozyme characteristics of branchial carbonic anhydrase (ca) in chaenocephalus aceratus, an antarctic icefish that lacks erythrocytes. the antarctic fish, notothenia coriiceps, which possesses erythrocytes, was also studied for comparative purposes. the gills of both species were found to have measurable activity of ca. n. coriiceps also had normal levels of blood ca activity. in contrast, the icefish, c. aceratus, l ...200212037591
stability and conformational dynamics of metallothioneins from the antarctic fish notothenia coriiceps and mouse.the structural properties and the conformational dynamics of antarctic fish notothenia coriiceps and mouse metallothioneins were studied by fourier-transform infrared and fluorescence spectroscopy. infrared data revealed that the secondary structure of the two metallothioneins is similar to that of other metallothioneins, most of which lack periodical secondary structure elements such as alpha-helices and beta-sheets. however, the infrared spectra of the n. coriiceps metallothionein indicated th ...200211835501
two new antarctic gyrodactylus species (monogenoidea): description and phylogenetic characterization.two new species of gyrodactylus nordmann, 1832 (gyrodactylidae, monogenoidea) are described, i.e., gyrodactylus coriicepsi n. sp. from gills of black rockcod, notothenia coriiceps richardson, 1844, and gyrodactylus nudifronsi n. sp. from gills of gaudy notothen, lepidonotothen nudifrons lönnberg, 1905, collected in waters surrounding the south shetland islands, antarctica. gyrodactylus coriicepsi n. sp. is characterized by a long, narrowing membrane of the ventral bar and a marginal hook sickle ...200919413367
characterization of the intestinal microbiota of two antarctic notothenioid fish species.the fish fauna of the southern ocean is dominated by species of the perciform suborder notothenioidei, which constitute 46% of fish species and 90% of biomass. notothenioids have undergone rapid morphological and ecological diversification and developed physiological adaptations to a cold, highly oxygenated environment. microbes inhabiting animal intestines include those that perform essential nutritional functions, but notothenioid gut microbial communities have not been investigated using cult ...200919472032
ecology of pseudoterranova decipiens (krabbe, 1878) (nematoda : anisakidae) from antarctic waters.the present study provides further data on the occurrence of pseudoterranova decipiens in fish from two different sampling sites in the antarctic. a total of 690 fish belonging to 33 species from the eastern weddell sea and 322 fish belonging to 12 species from the south shetland islands were examined. altogether, 23 fish species were found to be infested and 11 new host records could be established. p. decipiens occurred at a water depth of between 80 and 820 m. chaenocephalus aceratus and noto ...199910431726
metallothioneins in antarctic fish: evidence for independent duplication and gene conversion.in the present paper, we examine eight species of antarctic fish belonging to the suborder notothenioidei, using reverse-transcriptase polymerase chain reaction, to investigate the presence of mrnas encoding metallothionein (mt) isoforms. a total of 168 bp from the coding region and the complete (133-165 bp) 3' untranslated region (utr) was obtained for all species (for three of them, we also sequenced the full-length cdna, including the 5' utr). phylogenetic analyses carried out on the mt-codin ...199910406107
molecular pedomorphism underlies craniofacial skeletal evolution in antarctic notothenioid fishes.pedomorphism is the retention of ancestrally juvenile traits by adults in a descendant taxon. despite its importance for evolutionary change, there are few examples of a molecular basis for this phenomenon. notothenioids represent one of the best described species flocks among marine fishes, but their diversity is currently threatened by the rapidly changing antarctic climate. notothenioid evolutionary history is characterized by parallel radiations from a benthic ancestor to pelagic predators, ...201020053275
evolution, organization, and expression of alpha-tubulin genes in the antarctic fish notothenia coriiceps. adaptive expansion of a gene family by recent gene duplication, inversion, and divergence.to assess the organization and expression of tubulin genes in ectothermic vertebrates, we have chosen the antarctic yellowbelly rockcod, notothenia coriiceps, as a model system. the genome of n. coriiceps contains approximately 15 distinct dna fragments complementary to alpha-tubulin cdna probes, which suggests that the alpha-tubulins of this cold-adapted fish are encoded by a substantial multigene family. from an n. coriiceps testicular dna library, we isolated a 13.8-kilobase pair genomic clon ...19989852102
studies of evolutionary temperature adaptation: muscle function and locomotor performance in antarctic fish.1. studies of evolutionary temperature adaptation of muscle and locomotor performance in fish are reviewed with a focus on the antarctic fauna living at subzero temperatures. 2. only limited data are available to compare the sustained and burst swimming kinematics and performance of antarctic, temperate and tropical species. available data indicate that low temperatures limit maximum swimming performance and this is especially evident in fish larvae. 3. in a recent study, muscle performance in t ...19989750970
the major adult alpha-globin gene of antarctic teleosts and its remnants in the hemoglobinless icefishes. calibration of the mutational clock for nuclear genes.the icefishes of the southern ocean (family channichthyidae, suborder notothenioidei) are unique among vertebrates in their inability to synthesize hemoglobin. we have shown previously (cocca, e., ratnayake-lecamwasam, m., parker, s. k., camardella, l., ciaramella, m., di prisco, g., and detrich, h. w., iii (1995) proc. natl. acad. sci. u. s. a. 92, 1817-1821) that icefishes retain inactive genomic remnants of adult notothenioid alpha-globin genes but have lost the gene that encodes adult beta-g ...19989614073
molecular and comparative analyses of type iv antifreeze proteins (afpivs) from two antarctic fishes, pleuragramma antarcticum and notothenia coriiceps.antifreeze protein type iv (afpiv) cdnas and genomic dnas from the antarctic fishes pleuragramma antarcticum (pa) and notothenia coriiceps (nc) were cloned and sequenced, respectively. each cdna encoded 128 amino acids, with 94% similarity between the two and 83% similarity with afpiv of the longhorn sculpin, myoxocephalus octodecemspinosus. the genome structures of both genes consisted of four exons and three introns, and were highly conserved in terms of sequences and positions. in contrast, t ...201121571089
two distinct types of fatty acid-binding protein are expressed in heart ventricle of antarctic teleost fishes.this report provides the first evidence for the existence of two distinct types of fatty acid-binding protein (fabp) in cardiac tissue of vertebrates. four species of antarctic teleost fish (chaenocephalus aceratus, cryodraco antarcticus, gobionotothen gibberifrons and notothenia coriiceps) exhibited two fabp mrnas of 1. 0 kb and 0.8 kb, which we have termed hh-fabp and had-fabp (isolated from heart tissue, with similarity to mammalian heart-type fabp or mammalian adipose-type fabp respectively) ...19989461533
characterization of toll-like receptor gene expression and the pathogen agonist response in the antarctic bullhead notothen notothenia coriiceps.notothenia coriiceps, a typical antarctic notothenioid teleost, has evolved to adapt to the extreme antarctic marine environment. we previously reported an extensive analysis of the antarctic notothenioid transcriptome. in this study, we focused on a key component of the innate immune system, the toll-like receptors (tlrs). we cloned the full-length sequence of 12 tlrs of n. coriiceps. the n. coriiceps transcriptome for tlr homologue (nctlr) genes encode a typical tlr structure, with multiple ex ...201425073429
microtubule assembly in cold-adapted organisms: functional properties and structural adaptations of tubulins from antarctic fishes.fishes native to the coastal waters of the antarctic have adapted to habitat and body temperatures in the range -1.8 to +2 degrees c. their cytoplasmic microtubules, unlike those of mammals and temperate poikilotherms, have evolved to assemble efficiently at these low temperatures. to learn about the underlying molecular adaptations, my laboratory is studying microtubule proteins [tubulin alpha beta dimers and microtubule-associated proteins (maps)] and tubulin genes from several antarctic fishe ...19979406432
inner and outer arm axonemal dyneins from the antarctic rockcod notothenia coriiceps.adaptive compensation of enzymatic activities is common among cold-living poikilotherms. their enzymes often demonstrate higher activities at low temperatures than do homologs from temperate or thermophilic species. to understand the molecular features necessary for cold adaptation of microtubule motor proteins, we have initiated studies of the flagellar dynein atpases of antarctic fishes (body temperature range = -1.8 to +2 degrees c). dyneins were isolated by high-salt extraction of demembrana ...19979063878
divergent neural beta tubulin from the antarctic fish notothenia coriiceps neglecta: potential sequence contributions to cold adaptation of microtubule assembly.the cytoplasmic microtubules of the cold-adapted antarctic fishes, unlike those of homeotherms and temperate poikilotherms, assemble and function at body temperatures in the range -1.8 to +2 degrees c. to determine whether alterations to the primary sequence of beta tubulin may contribute to enhancement of microtubule assembly at cold temperatures, we have cloned and sequenced a 1.8-kilobase neural beta-chain cdna, ncn beta 1, from an antarctic rockcod, notothenia coriiceps neglecta. based on nu ...19938467523
genomic remnants of alpha-globin genes in the hemoglobinless antarctic icefishes.alone among piscine taxa, the antarctic icefishes (family channichthyidae, suborder notothenioidei) have evolved compensatory adaptations that maintain normal metabolic functions in the absence of erythrocytes and the respiratory oxygen transporter hemoglobin. although the uniquely "colorless" or "white" condition of the blood of icefishes has been recognized since the early 20th century, the status of globin genes in the icefish genomes has, surprisingly, remained unexplored. using alpha- and b ...19957892183
polymerization of antarctic fish tubulins at low temperatures: role of carboxy-terminal domains.we have proposed previously that the efficient polymerization of tubulins from antarctic fishes at low, physiological temperatures (-1.8 to +2 degrees c) may result in part from adaptations (e.g., reductions in acidic residues) located in their carboxy-terminal (c-terminal) tails [detrich & overton (1986) j. biol. chem. 261, 10922-10930]. to test this hypothesis, we have examined the polymerization of antarctic fish neural tubulins modified at their c termini by proteolysis or by neutralization ...19947803402
hemoglobin from the antarctic fish notothenia coriiceps neglecta. 2. amino acid sequence of the alpha chain of hb1.the complete amino acid sequence of the alpha chain of the main hemoglobin of the antarctic fish notothenia coriiceps neglecta (family nototheniidae) has been determined. it consists of 142 residues; an acetylated seryl residue is at the amino terminal. the molecular mass is 15,519 da. in comparison with alpha-chain sequences of non-antarctic poikilothermic fish hemoglobins, the homology appears to be significantly lower than that existing among the latter species. a higher homology has been fou ...19892920735
hemoglobin from the antarctic fish notothenia coriiceps neglecta. 1. purification and characterisation.antarctic fishes live at a constant temperature of -1.8 degrees c, in an oxygen-rich environment. in comparison with fishes that live in temperate or tropical waters, their blood contains less erythrocytes and hemoglobin. a study was initiated on the structure and function of antarctic fish hemoglobin. the erythrocytes of the antarctic benthic teleost notothenia coriiceps neglecta, of the family nototheniidae, have been shown to contain two hemoglobins, accounting for about 90% and 5% of the tot ...19892920734
genome enablement of the notothenioidei: genome size estimates from 11 species and bac libraries from 2 representative taxa.the perciform suborder notothenoidei provides a compelling opportunity to study the adaptive radiation of a marine species flock in the cold southern ocean surrounding antarctica. to enable genome-level studies of these psychrophilic fishes, we estimated the sizes of the genomes of 11 antarctic species and generated high-quality bac libraries for 2, the notothen notothenia coriiceps and the icefish chaenocephalus aceratus. our results indicate that evolution of phylogenetically derived nototheni ...201020235119
polymerization of antarctic fish tubulins at low temperatures: energetic aspects.tubulins were purified from the brain tissues of three antarctic fishes, notothenia gibberifrons, notothenia coriiceps neglecta, and chaenocephalus aceratus, by ion-exchange chromatography and one cycle of temperature-dependent microtubule assembly and disassembly in vitro, and the functional properties of the protein were examined. the preparations contained the alpha- and beta-tubulins and were free of microtubule-associated proteins. at temperatures between 0 and 24 degrees c, the purified tu ...19892620064
an antifreeze glycopeptide gene from the antarctic cod notothenia coriiceps neglecta encodes a polyprotein of high peptide copy number.the antarctic fish notothenia coriiceps neglecta synthesizes eight antifreeze glycopeptides (afgp 1-8; mr 2600-34,000) to avoid freezing in its ice-laden freezing habitat. we report here the sequence of one of its afgp genes. the structural gene contains 46 tandemly repeated segments, each encoding one afgp peptide plus a 3-amino acid spacer. most of the repeats (44/46) code for peptides of afgp 8; the remaining 2 code for peptides of afgp 7. at least 2 of the 3 amino acids in the spacers could ...19902251271
brain and egg tubulins from antarctic fishes are functionally and structurally distinct.the multitubulin hypothesis proposes that chemically distinct tubulins may possess different polymerization properties or may form functionally different microtubules. to test this hypothesis, we have examined the functional properties and the structures of singlet-specific nonneural and neural tubulins from antarctic fishes. tubulins were purified from eggs of notothenia coriiceps neglecta, and from brain tissues of n. coriiceps neglecta or n. gibberifrons, by deae ion-exchange chromatography a ...19921527007
morphometry of retinal vasculature in antarctic fishes is dependent upon the level of hemoglobin in circulation.we quantitatively assessed ocular vascular patterns of six antarctic notothenioid fishes that vary in their expression of the circulating oxygen-binding protein, hemoglobin (hb). digital image analyses revealed marked differences in vessel morphometries among notothenioid species. hemoglobinless (-hb) icefishes display mean vessel length densities that are greater (chaenocephalus aceratus, 5.51+/-0.32 mm mm(-2); champsocephalus gunnari, 5.15+/-0.50 mm mm(-2)) than those observed in red-blooded ( ...200717297141
characterization of the cytoplasmic chaperonin containing tcp-1 from the antarctic fish notothenia coriiceps.the cytoplasmic chaperonin containing tcp-1 (cct) plays a critically important role in the folding and biogenesis of many cytoskeletal proteins, including tubulin and actin. for marine ectotherms, the chronically cold southern ocean (-2 to +2 degrees c) poses energetic challenges to protein folding, both at the level of substrate proteins and with respect to the chaperonin/chaperone folding system. here we report the partial functional and structural characterization of cct from an antarctic not ...200616770691
microscopical study of experimental wound healing in notothenia coriiceps (cabeçuda) at 0 degrees c.notothenia coriiceps (cabeçuda) is an antarctic benthic fish frequently found with lesions in the tegument caused by seal predation. we have investigated epidermal repair in these animals by means of a microscopic study of experimental wound healing at 0 degrees c. at 24--48 h after wound induction, mucous exudate and necrotic lining cells covered the wound. at 7--14 days, an epidermal "tongue" could be discerned, folded at the tip, with intercellular oedema between the tip and the wound border. ...200516012878
posttranslational modification of brain tubulins from the antarctic fish notothenia coriiceps: reduced c-terminal glutamylation correlates with efficient microtubule assembly at low temperature.we have shown previously that the tubulins of antarctic fish assemble into microtubules efficiently at low temperatures (-2 to +2 degrees c) due to adaptations intrinsic to the tubulin subunits. to determine whether changes in posttranslational glutamylation of the fish tubulins may contribute to cold adaptation of microtubule assembly, we have characterized c-terminal peptides from alpha- and beta-tubulin chains from brains of adult specimens of the antarctic rockcod notothenia coriiceps by mal ...200415379565
hibernation in an antarctic fish: on ice for winter.active metabolic suppression in anticipation of winter conditions has been demonstrated in species of mammals, birds, reptiles and amphibians, but not fish. this is because the reduction in metabolic rate in fish is directly proportional to the decrease in water temperature and they appear to be incapable of further suppressing their metabolic rate independently of temperature. however, the antarctic fish (notothenia coriiceps) is unusual because it undergoes winter metabolic suppression irrespe ...200818320061
solution structure of mt_nc, a novel metallothionein from the antarctic fish notothenia coriiceps.the structure of [113cd(7)]-metallothionein (mt_nc) of the antarctic fish notothenia coriiceps, the first three-dimensional structure of a fish metallothionein, was determined by homonuclear 1h nmr experiments and heteronuclear [1h, 113cd]-correlation spectroscopy. mt_nc is composed of an n-terminal beta domain with 9 cysteines and 3 metal ions and a carboxy-terminal alpha-domain with 11 cysteines and 4 metal ions. the position of the ninth cys of the alpha domain of mt_nc is different from the ...200312679021
positive darwinian selection operating on the immunoglobulin heavy chain of antarctic fishes.the cooling of the southern ocean to the freezing point of seawater (-1.9 degrees c) over the past 25 million years played a dominant selective role in the evolution of the antarctic fish fauna. during this period, the perciform suborder notothenioidei, which is largely endemic to the antarctic, diversified and developed numerous cold-adapted characters. in this report, we provide compelling evidence that the immunoglobulin heavy chain (igh) of the notothenioid fishes has undergone adaptive sele ...200312548542
high mitochondrial densities in the hearts of antarctic icefishes are maintained by an increase in mitochondrial size rather than mitochondrial biogenesis.we investigated the molecular mechanisms regulating differences in mitochondrial volume density between heart ventricles of antarctic notothenioids that vary in the expression of hemoglobin (hb) and myoglobin (mb). in mammals, peroxisome proliferator-activated receptor gamma coactivator-1alpha (pgc-1alpha) and nuclear respiratory factor 1 (nrf-1) stimulate mitochondrial biogenesis and maintain mitochondrial density in muscle tissues. we hypothesized that these factors would also maintain mitocho ...200818689417
hypercapnia induced shifts in gill energy budgets of antarctic notothenioids.mechanisms responsive to hypercapnia (elevated co(2) concentrations) and shaping branchial energy turnover were investigated in isolated perfused gills of two antarctic notothenioids (gobionotothen gibberifrons, notothenia coriiceps). branchial oxygen consumption was measured under normo- versus hypercapnic conditions (10,000 ppm co(2)) at high extracellular ph values. the fractional costs of ion regulation, protein and rna synthesis in the energy budgets were determined using specific inhibitor ...201019834716
control of branchial artery tone in fish: effects of environmental temperature and phylogeny.branchial artery vasoreactivity and nerve density were measured in teleosts of different phylogenetic relatedness from cold (-1.86 degrees to +1 degrees c) and temperate ( approximately 13 degrees c) environments. polar notothenia coriiceps and temperate paranotothenia angustata are closely related southern hemisphere nototheniids, and polar boreogadus saida and temperate myoxocephalus scorpius are northern hemisphere species that are phylogenetically distant from each other and the nototheniids ...201019938979
presence and distribution of persistent toxic substances in sediments and marine organisms of potter cove, antarctica.levels of butyltin compounds, polychlorinated biphenyls, and heavy metals were analyzed in marine sediments and organisms (notothenia coriiceps, laternula elliptica, and nacella concinna), each of which has a different feeding strategy, in potter cove, antarctica. pcbs were lower than detection limits in all samples. only butyltin compounds were detected in a restricted area near the scientific station. chromium, copper, magnesium, lead (pb), and zinc had similar behavior in the cove, probably b ...201020379707
phenylhydrazine-induced anemia causes nitric-oxide-mediated upregulation of the angiogenic pathway in notothenia coriiceps.antarctic icefishes possess several cardiovascular characteristics that enable them to deliver oxygen adequately in the absence of hemoglobin (hb). to gain insight into mechanisms driving development of these cardiovascular characteristics of icefish, we chemically induced severe anemia in a red-blooded notothenioid, notothenia coriiceps. after 10 days of treatment with phenylhydrazine hcl, the hematocrit and hb concentration of n. coriiceps decreased by >90% and >70%, respectively. anemic fish ...201020675556
antarctic notothenioid fishes: genomic resources and strategies for analyzing an adaptive radiation.the perciform suborder notothenoidei provides a compelling opportunity to study the adaptive radiation of a marine species-flock in the cold southern ocean that surrounds antarctica. to facilitate genome-level studies of the diversification of these fishes, we present estimates of the genome sizes of 11 antarctic species and describe the production of high-quality bacterial artificial chromosome (bac) libraries for two, the red-blooded notothen notothenia coriiceps and the white-blooded icefish ...201021082069
transcriptome analysis of immune response genes induced by pathogen agonists in the antarctic bullhead notothen notothenia coriiceps.fish are a representative population of lower vertebrates that serve as an essential link to early vertebrate evolution, and this has fueled academic interest in studying ancient vertebrate immune defense mechanisms in teleosts. notothenia coriiceps, a typical antarctic notothenioid teleost, has evolved to adapt to the cold and thermally stable antarctic sea. in this study, we examined adaptive signaling pathways and immune responses to bacterial and viral pathogenic exposure in n. coriiceps. us ...201627276114
molecular identification, morphological characterization and new insights into the ecology of larval pseudoterranova cattani in fishes from the argentine coast with its differentiation from the antarctic species, p. decipiens sp. e (nematoda: anisakidae).larvae of the genus pseudoterranova constitute a risk for human health when ingested through raw or undercooked fish. they can provoke pseudoterranovosis in humans, a fish-borne zoonotic disease whose pathogenicity varies with the species involved, making their correct specific identification a necessary step in the knowledge of this zoonosis. larvae of pseudoterranova decipiens s.l. have been reported in several fish species from off the argentine coasts; however, there are no studies dealing w ...201424161261
characterization of mitochondrial glycerol-3-phosphate acyltransferase in notothenioid fishes.hearts of antarctic icefishes (suborder notothenioidei, family channichthyidae) have higher densities of mitochondria, and mitochondria have higher densities of phospholipids, compared to red-blooded notothenioids. glycerol-3-phosphate acyltransferase (gpat) catalyzes the rate-limiting step in glycerolipid biosynthesis. there are four isoforms of gpat in vertebrates; gpat1 and gpat2 are localized to the outer mitochondrial membrane, whereas gpat3 and gpat4 are localized to the endoplasmic reticu ...201727836743
expansion of capacities for iron transport and sequestration reflects plasma volumes and heart mass among white-blooded notothenioid fishes.the family channichthyidae or "icefishes" (suborder notothenioidei) represents the only vertebrates lacking hemoglobin (hb) as adults. several icefish species also do not express cardiac myoglobin (mb). we address how levels of proteins involved in iron (fe) processing (transport, sequestration, and export) vary among white- and red-blooded notothenioids, and whether absence of hb and/or mb in channichthyids is accompanied by expansion of contents of fe-binding proteins to protect against unchap ...201627465736
genomic conservation of erythropoietic micrornas (erythromirs) in white-blooded antarctic icefish.white-blooded antarctic crocodile icefish are the only vertebrates known to lack functional hemoglobin genes and red blood cells throughout their lives. we do not yet know, however, whether extinction of hemoglobin genes preceded loss of red blood cells or vice versa, nor whether erythropoiesis regulators disappeared along with hemoglobin genes in this erythrocyte-null clade. several micrornas, which we here call erythromirs, are expressed primarily in developing red blood cells in zebrafish, mo ...201627189439
hyperoxia does not extend critical thermal maxima (ctmax) in white- or red-blooded antarctic notothenioid fishes.understanding what limits the capacity of organisms to tolerate increasing temperatures is a critical objective in comparative biology. using an experimental system of antarctic notothenioid fishes, we sought to determine whether a mismatch between oxygen demand and oxygen supply was responsible for setting thermal tolerance limits. previous studies have shown that antarctic icefishes (family channichthyidae), which lack hemoglobin, have lower critical thermal maxima (ctmax) than red-blooded not ...201627082520
transcriptomics and comparative analysis of three antarctic notothenioid fishes.for the past 10 to 13 million years, antarctic notothenioid fish have undergone extraordinary periods of evolution and have adapted to a cold and highly oxygenated antarctic marine environment. while these species are considered an attractive model with which to study physiology and evolutionary adaptation, they are poorly characterized at the molecular level, and sequence information is lacking. the transcriptomes of the antarctic fishes notothenia coriiceps, chaenocephalus aceratus, and pleura ...201222916302
thermal tolerance of antarctic notothenioid fishes correlates with level of circulating hemoglobin.the west antarctic peninsula region is experiencing some of the most rapid elevations in temperature of any marine environment. we assessed thermal tolerance of white- and red-blooded antarctic notothenioid fishes inhabiting these waters, using a modified critical thermal maximum (ct(max)) design. temperature was elevated acutely from ambient at a constant rate of 3.6°c h(-1), and ct(max) was defined as the temperature where animals lost righting response. ct(max) temperatures of white-blooded i ...201321743249
bloodthirsty, an rbcc/trim gene required for erythropoiesis in zebrafish.the antarctic icefishes (family channichthyidae, suborder notothenioidei) constitute the only vertebrate taxon that fails to produce red blood cells. these fishes can be paired with closely related, but erythrocyte-producing, notothenioids to discover erythropoietic genes via representational difference analysis. using a b30.2-domain-encoding dna probe so derived from the hematopoietic kidney (pronephros) of a red-blooded antarctic rockcod, notothenia coriiceps, we discovered a related, novel ge ...200515890331
myosin heavy chain genes expressed in juvenile and adult silver carp hypopthalmichthys molitrix: novel fast-type myosin heavy chain genes of silver carp.silver carp hypopthalmichthys molitrix is eurythermal temperate fish, whose muscle is considered to express several types of myosin heavy chain (myh) genes at different stages of its growth and to adjust to the environmental temperature. in this study, myh genes expressed in the muscles of juvenile and adult silver carp were investigated. five types of myh cdna clone were isolated from silver carp (h. molitrix) by race strategy using a set of fast-type myh specific primers, and termed scmyh(f1), ...200919100315
metabolic responses of the antarctic fishes notothenia rossii and notothenia coriiceps to sewage pollution.the present study aimed to assess the sewage effects of the brazilian antarctic station comandante ferraz, admiralty bay, king george island, on the hepatic metabolism (energetic, antioxidant, and arginase levels) and levels of plasma constituents of two antarctic fish species notothenia rossii and n. coriiceps. the bioassays were conducted under controlled temperature (0 °c) and salinity (35 psu), exposing the fish for 96 h, to sewage effluent diluted in seawater to 0.5 % (v/v). liver homogenat ...201526031510
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