Publications

respiratory characteristics of the hemoglobin-free fish chaenocephalus aceratus.		1970	5421990
oxygen uptake and circulation by a hemoglobinless antarctic fish (chaenocephalus aceratus lonnberg) compared with three red-blooded antartic fish.		1970	5426570
absence of porphyrin respiratory pigments in the blood in the antarctic icefish chaenocephalus aceratus.		1973	4747589
electrophoretic analysis of antarctic fish from south georgia.	white muscle samples of antarctic fish (notothenia rossii, n. neglecta, n. gibberifrons and chaenocephalus aceratus) were subjected to electrophoretic tests. isoelectric focusing of general muscle proteins provides a quick method of identifying species. six muscle enzymes were resolved by horizontal starch gel electrophoresis. these are presumed to be the products of ten independent gene loci. coefficients of genetic distance were calculated and substantially agree with the conventional taxonomy ...	1982	6214976
dimensions of respiratory surfaces of the gills and skin in the antarctic white-blooded fish, chaenocephalus aceratus lönnberg (chaenichthyidae).	gill arches of c. aceratus are long and bear a small number of filaments (9...11/cm). density of secondary lamellae on filaments decreases from 19.4/mm to 17.8/mm in the specimen examined (815...1820 g). in contrast to that, surface area of an average secondary lamella increases in larger specimens and is from 0.489 mm2 to 0.664 mm2, respectively. the total surface area of secondary lamellae per 1 g of body weight is from about 193 to 159 mm2. the skin vascularization of c. aceratus is abundant. ...	1982	7102033
a comparative study of protein synthesis in nototheniids and icefish at palmer station, antarctica.	protein synthetic rates were measured in tissues of notothenia corriceps, n. gibberifrons and chaenocephalus aceratus in vivo at 2 degrees c by a method in which high doses of 14c-phenylalanine are used for stabilization of specific radioactivity. rates in n. coriiceps, as per cent of tissue protein synthesized per day, were: liver 10.4, head kidney 3.5, testis 2.6, spleen 2.1, kidney 1.9, gill 1.6, heart 1.4, pectoral muscle 1.0, epaxial muscle 0.37, brain 0.42. with the exception of liver and ...	1983	6641175
the fine structure of endothelial cells of white-blooded fish chaenocephalus aceratus.	the fine structure of the arterial endothelial cells from an eye moving muscle--musculus obliquus inferior in an antarctic teleostean fish, chaenocephalus aceratus, is described. thin filaments of 4.6 nm in diameter occur in form of compact bundles situated just beneath the cell membranes, whereas the 9 nm thick filaments appeared in central part of the cell extensions. both types of filaments, as well as the numerous microtubules (25 nm) are oriented along the axis of the artery. a large number ...	1983	6686909
skeletal muscle capillary supply in a fish that lacks respiratory pigments.	the relationship between capillary density and mitochondrial volume density has been investigated for the slow trunk muscle of the haemoglobinless 'icefish', chaenocephalus aceratus lönnberg. in general, for teleost slow muscles capillary densities, na(c,f), are positively correlated with mitochondrial volume densities, vv(mit,f). however, the capillary density for the slow trunk muscle of the icefish is low (544 +/- 24 capillaries/mm2) when compared with teleosts of similar mitochondrial volume ...	1984	6494646
cardiac beat frequency and oxygen supply: a comparative study.	the length of diastole in mammals varies between approx 1 s (elephant) and 38 ms (shrew) which makes oxygen supply in high speed cardiac pumps in very small mammals precarious. high capillary density and high blood p50 are reported in mammals with high frequency cardiac cycle. both are probably insufficient when cardiac frequency is exceedingly high (shrew: 1000 min-1). high respiratory efficiency due to large relative mitochondrial volume per cell (greater than 50%) seems to be preferential sol ...	1984	6146429
myoglobin in the heart tissue of fishes lacking hemoglobin.	myoglobin has been identified in the heart tissue of three species of antarctic icefish, chaenocephalus aceratus, pseudochaenichthys georgianus and chaenodraco wilsoni. quantitative analysis shows myoglobin concentrations that are substantially lower than other teleost fish. a simple and accurate method for the direct measurement of myoglobin in tissue is described.	1985	2863077
evolutionary adaptation of muscle power output to environmental temperature: force-velocity characteristics of skinned fibres isolated from antarctic, temperate and tropical marine fish.	single fast fibres were isolated from the myotomal muscles of icefish (chaenocephalus aceratus lönnberg, antarctica), north sea cod (gadus morhua l.) and pacific blue marlin (makaira nigricans wakiya, hawaii). fibres were chemically skinned with the non-ionic detergent brij-58. maximum tensions (po, kn m-2) developed at the characteristic body temperature of each species are 231 for icefish (-1 degree c), 187 for cod (8 degrees c) and 156 for marlin (20 degrees c). at 0 degree c po is 7 times hi ...	1985	4059035
activities of chitinase and protease and concentration of fluoride in the digestive tract of antarctic fishes feeding on krill (euphausia superba dana).	studies on the digestion of krill by notothenia rossii marmorata, notothenia neglecta, champsocephalus gunnari and chaenocephalus aceratus showed that these antarctic fish species are well equipped to feed on krill, as indicated by their high levels of chitinase and protease activity. very high chitinolytic activities were determined in the stomach of the fish species. however, activities that were measured in intestine samples can be substantial, as well. very strong protease activities were de ...	1986	2878783
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 ...	1986	3733739
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 ...	1987	3597376
respiratory characteristics of muscle fibres in a fish (chaenocephalus aceratus) that lacks haem pigments.	1. oxygen consumption, mitochondrial content and enzyme activities were determined in identified muscle fibre types of the 'haemoglobin-less' icefish chaenocephalus aceratus lönnberg. 2. small bundles (2-12) of fast and slow fibres were isolated from the myotomal and superficial pectoral fin abductor muscles, respectively. at 0 degrees c the time to 50% peak force and the half-relaxation time of isometric twitches were, respectively, 18 +/- 1 and 38 +/- 4 ms for fast and 43 +/- 3 and 119 +/- 21 ...	1987	3430116
morphometrics and ultrastructure of myocardial tissue in notothenioid fishes.	antarctic fish of the family channichthyidae (icefishes) lack the respiratory pigments haemoglobin and myoglobin. the morphometrics and ultrastructure of the ventricular myocardium of a benthic icefish,chaenocephalus aceratus has been compared with that of a red-blooded notothenioid fish,notothenia neglecta, of similar habit.the mass of ventricular muscle as a percentage of bodyweight is 3 times greater in adultc. aceratus (0.32%) thann. neglecta (0.11%). myoglobin concentration in the ventricle ...	1987	24233247
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 ...	1988	3180738
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 ...	1989	2620064
microtubule-associated proteins from antarctic fishes.	microtubules and presumptive microtubule-associated proteins (maps) were isolated from the brain tissues of four antarctic fishes (notothenia gibberifrons, n. coriiceps neglecta, chaenocephalus aceratus, and a chionodraco sp.) by means of a taxol-dependent, microtubule-affinity procedure (cf. vallee: journal of cell biology 92:435-442, 1982). maps from these fishes were similar to each other in electrophoretic pattern. prominent in each preparation were proteins in the molecular weight ranges 41 ...	1990	1980093
purification and characterization of fatty acid-binding protein from aerobic muscle of the antarctic icefish chaenocephalus aceratus.	intracellular fatty acid-binding protein is purified and characterized from aerobic skeletal muscle of the antarctic icefish chaenocephalus aceratus. molecular mass of c. aceratus fabp (ca-fabp) is 14,936 da as estimated by electrospray mass spectrometry. ca-fabp is expressed at an intracellular concentration of 0.984 +/- 0.115 mg ca-fabp g-1 wet weight aerobic muscle and binds 0.859 +/- 0.013 moles oleic acid per mole of protein at a physiological temperature of 0 degrees c. dissociation consta ...	1995	7595283
binding site polarity and ligand affinity of homologous fatty acid-binding proteins from animals with different body temperatures.	binding affinity and binding-pocket polarity is determined for intracellular fatty acid-binding protein (fabp) from aerobic muscle of chaenocephalus aceratus, the antarctic icefish, and from rat heart. fabps bind fatty acids via weak-bond forces (both ionic and hydrophobic), and these bond forces are temperature sensitive, yet fabps are present in animals whose body temperatures range over nearly 40 degrees c. to investigate fabp's sensitivity to body temperature, fatty acid binding affinity (kd ...	1996	8813708
myoglobin enhances cardiac performance in antarctic icefish species that express the protein.	channichthyid icefishes of antarctica are unique among adult vertebrates. all icefish species lack hemoglobin and red blood cells in their circulating blood. all icefishes examined to date also lack the intracellular oxygen-binding protein myoglobin (mb) in their oxidative skeletal muscles. however, some icefish species do express mb in their heart ventricles. it is unknown whether mb in those species in which it is present represents an evolutionary relic or has functional significance. to addr ...	1997	9249538
conservation of the myoglobin gene among antarctic notothenioid fishes.	we determined the myoglobin cdna sequence for seven antarctic notothenioid fish species. these data identify mutations in the myoglobin gene for champsocephalus gunnari and pagetopsis macropterus, two icefish species that lack detectable quantities of the polypeptide but express myoglobin mrna. a third species lacking myoglobin polypeptide, chaenocephalus aceratus, is devoid of myoglobin mrna and accordingly failed to produce myoglobin products on polymerase chain reaction (pcr) amplification. m ...	1997	9284559
enzymes in antarctic fish: glucose-6-phosphate dehydrogenase and glutamate dehydrogenase.	glucose-6-phosphate dehydrogenase (g6pd) and l-glutamate dehydrogenase (gdh) from antarctic fish were isolated and characterized. g6pd was purified from the erythrocytes of red-blooded dissostichus mawsoni and from the colorless blood of the icefish chionodraco hamatus. structural and functional characterization showed that the two enzymes do not differ significantly from each other. gdh was purified from the liver of the icefish chaenocephalus aceratus. as in other fish odhs, it showed a marked ...	1997	9505417
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 ...	1998	9614073
a novel vertebrate myoglobin gene containing three a+t-rich introns is conserved among antarctic teleost species which differ in myoglobin expression.	this report presents the first teleost myoglobin (mb) genomic dna sequence, several features of which are distinct from mammalian mb genes. we have isolated and compared genomic clones of three closely related antarctic icefish: chionodraco rastrospinosus, which expresses mb mrna and functional polypeptide; champsocephalus gunnari, which transcribes the mb gene but does not produce polypeptide due to a 5-base pair (bp) frameshift insertion; and chaenocephalus aceratus, which lacks both mb protei ...	1998	9694664
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) ...	1998	9461533
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 ...	1999	10431726
antarctic fishes have a limited capacity for catecholamine synthesis.	to determine whether an attenuated stress response is a general feature of antarctic fish or is dependent on ecotype, the capacity for catecholamine synthesis within the head kidney and plasma levels of the primary stress hormones (catecholamines and cortisol) were determined in species with a range of activity patterns. tyrosine hydroxylase (th) activities were similar in both sluggish (gobionotothen gibberifons, 153+/-22 nmol g(-)(1 )h(-)(1), mean +/- s.e.m.) and active (notothenia rossii, 185 ...	1999	10574739
concentrations of myoglobin and myoglobin mrna in heart ventricles from antarctic fishes.	we used a combined immunochemical and molecular approach to ascertain the presence and concentrations of both the intracellular oxygen-binding hemoprotein myoglobin (mb) and its messenger rna (mrna) in 13 of 15 known species of antarctic channichthyid icefishes. mb protein is present in the hearts of eight species of icefishes: chionodraco rastrospinosus, chionodraco hamatus, chionodraco myersi, chaenodraco wilsoni, pseudochaenichthys georgianus, cryodraco antarcticus, chionobathyscus dewitti an ...	2000	10729277
the interplay among cardiac ultrastructure, metabolism and the expression of oxygen-binding proteins in antarctic fishes.	we examined heart ventricle from three species of antarctic fishes that vary in their expression of oxygen-binding proteins to investigate how some of these fishes maintain cardiac function despite the loss of hemoglobin (hb) and/or myoglobin (mb). we quantified ultrastructural features and enzymatic indices of metabolic capacity in cardiac muscle from gobionotothen gibberifrons, which expresses both hb and mb, chionodraco rastrospinosus, which lacks hb but expresses mb, and chaenocephalus acera ...	2000	10729278
quantification of diffusion distance within the spongy myocardium of hearts from antarctic fishes.	we developed a stereological method for quantifying diffusion distance within spongy myocardium. using this method we compared the hearts of three species of antarctic fishes that vary in expression of oxygen-binding proteins. we examined hearts from gobionotothen gibberifrons, a red-blooded species whose ventricle has myoglobin (mb), and hearts of two species of icefish that lack hemoglobin (hb) and vary in expression of cardiac mb; chionodraco rastrospinosus expresses mb, chaenocephalus acerat ...	2000	10936602
l-glutamate dehydrogenase from the antarctic fish chaenocephalus aceratus. primary structure, function and thermodynamic characterisation: relationship with cold adaptation.	in order to study the molecular mechanisms of enzyme cold adaptation, direct amino acid sequence, catalytic features, thermal stability and thermodynamics of the reaction and of heat inactivation of l-glutamate dehydrogenase (gdh) from the liver of the antarctic fish chaenocephalus aceratus (suborder notothenioidei, family channichthyidae) were investigated. the enzyme shows dual coenzyme specificity, is inhibited by gtp and the forward reaction is activated by adp and atp. the complete primary ...	2000	11087937
evolutionary and physiological variation in cardiac troponin c in relation to thermal strategies of fish.	striated muscle contraction is initiated when troponin c (tnc) binds ca(2+), which activates actinomyosin atpase. we investigated (i) the variation between cardiac tnc (ctnc) primary structure within teleost fish and (ii) the pattern of tnc expression in response to temperature acclimation. there were few differences between rainbow trout (oncorhynchus mykiss), yellowfin tuna (thunnus albacares), yellow perch (perca flavescens), goldfish (carassius auratus), white sucker (catostomus commersoni), ...	2000	11121357
peripheral oxygen transport in skeletal muscle of antarctic and sub-antarctic notothenioid fish.	transcellular oxygen flux was modelled mathematically in the aerobic skeletal muscles of perciform fish species living at widely different temperatures (antarctica, sub-antarctica and the mediterranean sea). using structural data derived from stereological analysis of electron micrographs, mean fibre p(o(2)) was calculated on the basis of temperature-corrected rates of mitochondrial respiration and oxygen diffusion. the mean muscle fibre diameter (mfd) among antarctic notothenioids was in the ra ...	2002	11914385
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 ...	2002	12037591
sscp-based identification of members within the pseudoterranova decipiens complex (nematoda: ascaridoidea: anisakidae) using genetic markers in the internal transcribed spacers of ribosomal dna.	the anisakid nematodes morphologically corresponding with pseudoterranova decipiens sensu lato (s.l.) (krabbe, 1878) from different seal or sea lion hosts and geographical origins, previously identified as pseudoterranova krabbei, p. decipiens (s.s.), p. bulbosa, p. azarasi and p. cattani by multilocus enzyme electrophoresis, were characterized using a dna approach. also a population of p. decipiens (s.l.) from chaenocephalus aceratus, the blackfin icefish, from antarctica and another from osmer ...	2002	12118717
notothenioid fish, krill and phytoplankton from antarctica contain a vitamin e constituent (alpha-tocomonoenol) functionally associated with cold-water adaptation.	the vitamin e (ve) content of tissues from the antarctic notothenioid fish, chaenocephalus aceratus, champsocephalus gunnari and gobionotothen gibberifrons, and extracts of antarctic krill euphausia superba and phytoplankton collected from the antarctic peninsula was examined. included in the ve composition was a newly described 'marine-derived' tocopherol (mdt), an unsaturated-isoprenoid derivative of alpha-tocopherol, that is attributed to enhancing antioxidant protection of cellular lipids at ...	2002	12431397
the myoglobin gene of the antarctic icefish, chaenocephalus aceratus, contains a duplicated tataaaa sequence that interferes with transcription.	six of the 16 known species of antarctic icefish (family channichthyidae) have lost the ability to express cardiac myoglobin (mb) via at least four independent events during radiation of these species. we report here that the lesion in chaenocephalus aceratus mb is a duplicated tataaaa element that blocks transcription. this lesion is distinct from those of other icefish species that do not express cardiac mb. the c. aceratus mb gene is nearly identical to that of chionodraco rastrospinosus, a c ...	2003	12456703
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, ...	2003	12477911
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 ...	2003	12548542
isolation, characterization and nucleotide sequence of the muscle isoforms of creatine kinase from the antarctic teleost chaenocephalus aceratus.	creatine kinase (ck) was isolated from the white muscle of the antarctic icefish chaenocephalus aceratus, which is deficient in glycolytic capacity. c. aceratus white myotomal creatine kinase (mmck) displayed an apparent k(m) at 0.5 degrees c of 0.06 mm for adp and 17 mm for phosphocreatine. these k(m) values are similar to those reported for other vertebrate mmcks at their physiologically relevant body temperatures. c. aceratus mmck exhibited optimal activity at ph of 7.6-7.7 at 0.5 degrees c, ...	2003	12670791
mitochondrial dna, morphology, and the phylogenetic relationships of antarctic icefishes (notothenioidei: channichthyidae).	the channichthyidae is a lineage of 16 species in the notothenioidei, a clade of fishes that dominate antarctic near-shore marine ecosystems with respect to both diversity and biomass. among four published studies investigating channichthyid phylogeny, no two have produced the same tree topology, and no published study has investigated the degree of phylogenetic incongruence between existing molecular and morphological datasets. in this investigation we present an analysis of channichthyid phylo ...	2003	12801473
reduction in muscle fibre number during the adaptive radiation of notothenioid fishes: a phylogenetic perspective.	the fish fauna of the continental shelf of the southern ocean is dominated by a single sub-order of perciformes, the notothenioidei, which have unusually large diameter skeletal muscle fibres. we tested the hypothesis that in fast myotomal muscle a high maximum fibre diameter (fd(max)) was related to a reduction in the number of muscle fibres present at the end of the recruitment phase of growth. we also hypothesized that the maximum fibre number (fn(max)) would be negatively related to body siz ...	2003	12819266
persistent organic pollutants (pops) in antarctic fish: levels, patterns, changes.	organochlorine compounds were analysed in three fish species of different feeding types from the area of elephant island in the antarctic. in 1996, hexachlorobenzene (hcb) (means: 15-20 ng/g lipid), p,p'-dde (5-13 ng/g lipid) and mirex (1-7 ng/g lipid) predominated, while pcbs were minor components (pcb 153: 0.4-2 ng/g lipid). concentration patterns were species-dependent: pcb 180, pcb 153, mirex, nonachlor iii, trans-nonachlor and the toxaphene compound b8-1413 were highest in the bottom invert ...	2003	12962716
increasing levels and biomagnification of persistent organic pollutants (pops) in antarctic biota.	representatives of the antarctic food web (krill, cephalopod, fish, penguin, seal) of the area around elephant island and from the weddell sea were analysed for the most recalcitrant organochlorine compounds. due to sorption of the compounds to sinking particles and accumulation in sediments, two benthic fish species (gobionotothen gibberifrons, chaenocephalus aceratus) feeding on benthos invertebrates and fish reflected significantly increasing concentrations within a decade (1987-1996), while ...	2004	14972581
decreases in activation energy and substrate affinity in cold-adapted a4-lactate dehydrogenase: evidence from the antarctic notothenioid fish chaenocephalus aceratus.	enzyme function is strongly affected by temperature, and orthologs from species adapted to different thermal environments often show temperature compensation in kinetic properties. antarctic notothenioid fishes live in a habitat of constant, extreme cold (-1.86 +/- 2 degrees c), and orthologs of the enzyme a4-lactate dehydrogenase (a4-ldh) in these species have adapted to this environment through higher catalytic rates, lower arrhenius activation energies (ea), and increases in the apparent mich ...	2004	15317880
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 ...	2004	15364288
temperature sensitivity of calcium binding for parvalbumins from antarctic and temperate zone teleost fishes.	parvalbumin (pv) is a soluble calcium-binding protein that is especially abundant in fast-twitch muscles of fish and other lower vertebrates. despite its prevalence in ectothermic taxa, few data address the effects of temperature on pv binding function. in this study, calcium dissociation constants (kd) were measured as a function of temperature (0-25 degrees c) for pv from two antarctic (gobionotothen gibberifrons and chaenocephalus aceratus) and two temperate zone fish species (cyprinus carpio ...	2005	15748857
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 ...	2005	15890331
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 ( ...	2007	17297141
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 ...	2008	18689417
morphological and physiological study of the cardiac nos/no system in the antarctic (hb-/mb-) icefish chaenocephalus aceratus and in the red-blooded trematomus bernacchii.	the nitric oxide synthase (nos)/nitric oxide (no) system integrates cellular biochemical machinery and energetics. in heart microenvironment, dynamic no behaviour depends upon the presence of superoxide anions, haemoglobin (hb), and myoglobin (mb), being hemoproteins are major players disarming no bioactivity. the antarctic icefish, which lack hb and, in some species, also cardiac mb, represent a unique model for exploring hb and mb impact on nos/no function. we report in the (hb(-)/mb(-)) icefi ...	2009	19027084
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 ...	2009	19472032
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, ...	2010	20053275
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 ...	2010	21082069
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 ...	2010	20235119
gene cloning and mrna expression of glutamate dehydrogenase in the liver, brain, and intestine of the swamp eel, monopterus albus (zuiew), exposed to freshwater, terrestrial conditions, environmental ammonia, or salinity stress.	the swamp eel, monopterus albus, is an obligatory air-breathing teleost which can undergo long period of emersion, has high environmental and tissue ammonia tolerance, and can survive in brackish water. we obtained a cdna sequence of glutamate dehydrogenase (gdh), which consisted of a 133-bp 5' utr, a complete coding sequence region spanning 1629 bp and a 3' utr of approximately 717 bp, from the liver, intestine, and brain of m. albus. the translated gdh amino acid sequence had 542 residues, and ...	2011	22319499
structure and dynamics of antarctic fish neuroglobin assessed by computer simulations.	neuroglobin (ngb) is a heme protein, highly conserved along evolution, predominantly found in the nervous system. it is upregulated by hypoxia and ischemia and may have a neuroprotective role under hypoxic stress. although many other roles have been proposed, the physiological function is still unclear. antarctic icefishes lack hemoglobin and some species also lack myoglobin, but all have ngb and thus may help the elucidation of ngb function. we present the first theoretically derived structure ...	2011	21445852
biophysical characterisation of neuroglobin of the icefish, a natural knockout for hemoglobin and myoglobin. comparison with human neuroglobin.	the antarctic icefish chaenocephalus aceratus lacks the globins common to most vertebrates, hemoglobin and myoglobin, but has retained neuroglobin in the brain. this conserved globin has been cloned, over-expressed and purified. to highlight similarities and differences, the structural features of the neuroglobin of this colourless-blooded fish were compared with those of the well characterised human neuroglobin as well as with the neuroglobin from the retina of the red blooded, hemoglobin and m ...	2012	23226490
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 ...	2012	22916302
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 ...	2013	21743249
is the heme pocket region modulated by disulfide-bridge formation in fish and amphibian neuroglobins as in humans?	neuroglobin, a globin characterized by a bis-histidine ligation of the heme iron, has been identified in mammalian and non-mammalian vertebrates, including fish, amphibians and reptiles. in human neuroglobin, the presence of an internal disulfide bond in the cd loop (cd7-d5) is found to modulate the ligand binding through a change in the heme pocket structure. although the neuroglobin sequences mostly display conserved cys at positions cd7, d5 and g18/19, a number of exceptions are known. in thi ...	2013	23403147
population divergences despite long pelagic larval stages: lessons from crocodile icefishes (channichthyidae).	dispersal via pelagic larval stages plays a key role in population connectivity of many marine species. the degree of connectivity is often correlated with the time that larvae spend in the water column. the antarctic notothenioid fishes develop through an unusually long pelagic larval phase often exceeding 1 year. notothenioids thus represent a prime model system for studying the influence of prolonged larval phases on population structure in otherwise demersal species. here, we compare the pop ...	2014	24372945
cardiovascular oxygen transport limitations to thermal niche expansion and the role of environmental po2 in antarctic notothenioid fishes.	the notothenioid fishes of the southern ocean possess some of the lowest upper thermal thresholds of any species and display a range of cardiovascular features that distinguish them from other fishes. some species lack hemoglobin, and it has been posited that the inability to deliver sufficient oxygen at elevated temperature may in part determine upper thermal thresholds. here, we provide an analysis of systemic o2 transport based on circulatory resistance, cardiac outputs, and cardiac power for ...	2014	24940914
complete mitochondrial genome of the antarctic icefish, chaenocephalus aceratus (perciforms, channichthyidae).	the complete sequence of the mitochondrial genome of the antarctic icefish chaenocephalus aceratus was determined to be 17311 bp in length, and to contain 13 protein coding genes (pcgs), 22 trna genes and 2 rrna genes. the total a+t content is 52.8%. the notothenioid-exclusive nd6/trnaglu translocation was observed in the mitogenome of c. aceratus. generally, the order and contents of the other genes are identical with those of other fishes. antarctic icefishes, the only vertebrates which do not ...	2015	24409864
benzo(a)pyrene metabolism and erod and gst biotransformation activity in the liver of red- and white-blooded antarctic fish.	climate change and anthropogenic pollution are of increasing concern in remote areas such as antarctica. the evolutionary adaptation of antarctic notothenioid fish to the cold and stable southern ocean led to a low plasticity of their physiological functions, what may limit their capacity to deal with altered temperature regimes and pollution in the antarctic environment. using a biochemical approach, we aimed to assess the hepatic biotransformation capacities of antarctic fish species by determ ...	2015	25965896
aortic blood flow and cardiac output in the hemoglobin-free fish chaenocephalus aceratus.		2015	4405337
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 ...	2016	27465736
persistent organic pollutants in tissues of the white-blooded antarctic fish champsocephalus gunnari and chaenocephalus aceratus.	the global occurrence of persistent organic pollutants (pops) continuously contributes to their accumulation also in remote areas such as the antarctic ocean. antarctic fish, which hold high trophic positions but appear to possess low endogenous elimination rates for chemicals, are expected to bioaccumulate pops with rising anthropogenic pollution. using a chemical-analytical method, we measured concentrations of pcbs, pbdes, hcbs, hch and ddts and determined toxic equivalents (teqs) and bioanal ...	2016	27198544
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 ...	2016	27189439
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 ...	2016	27082520
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 ...	2017	27836743