| 1. |
- Mayer, Gregory D., et al.
(författare)
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Activation of the rainbow trout metallothionein-A promoter by silver and zinc
- 2003
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Ingår i: Comparative Biochemistry and Physiology - Part B. - 1096-4959 .- 1879-1107. ; 134:1, s. 181-188
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Tidskriftsartikel (refereegranskat)abstract
- In fish, the synthesis of metallothionein (MT) is increased by a number of heavy metals. The rainbow trout MT-A gene promoter region contains six known metal responsive elements (MREs), that mediate promoter activation by metals. In the present study, two fish cell lines differing in their ability to produce MT, RTG-2 (produce MT protein) and CHSE-214 (produce no detectable MT protein), were used to help elucidate the roles of Zn, Ag and MT in the activation of the MT promoter. The hypothesis tested was that Ag activates the MT-A promoter indirectly by displacing Zn from pre-existing Zn-MT and that this liberated Zn subsequently induces MT synthesis. Both cell lines were transfected with a luciferase reporter gene construct containing the rainbow trout MT-A promoter, exposed to various concentrations of Zn or Ag, and assayed for luciferase activity. CHSE-214 cells showed five times greater production of luciferase than RTG-2 cells when exposed to identical concentrations of Ag. Thus, Ag can likely induce MT transcription without displacing Zn from pre-existing Zn-MT. Furthermore, Ag activated the MT promoter at concentrations 100-fold lower than those required for Zn to initiate transcription, suggesting that zinc displaced from other sites by such low concentrations of Ag would not be sufficient to initiate MT transcription. This interpretation was further supported by radiotracer studies indicating that Ag did not cause a redistribution of 65Zn within either of the two cell types. These combined results indicate that Ag may be a direct inducer of MT.
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| 2. |
- Westermark, Gunilla, 1958-, et al.
(författare)
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Islet amyloid polypeptide is expressed in the pancreatic islet parenchyma of the teleostean fish, Myoxocephalus (cottus) scorpius
- 2002
-
Ingår i: Comparative Biochemistry and Physiology - Part B. - 1096-4959 .- 1879-1107. ; 133, s. 119-
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Tidskriftsartikel (refereegranskat)abstract
- The comparative endocrinology of the 37-amino-acid-residue islet amyloid polypeptide (IAPP) is poorly known, possibly due to the fact that available antisera, raised against mammalian IAPP, fail to give immunoreactivity with islet parenchymal cells of non-mammalian vertebrates. Using reverse transcriptase-linked polymerase chain reaction with degenerate primers, IAPP was identified, and its deduced amino-acid sequence partially characterized, in three species of teleostean fish, i.e. Danio rerio (zebrafish), Salmo salar (Atlantic salmon), and Myoxocephalus (cottus) scorpius (daddy sculpin). The daddy sculpin is a species where the histophysiology of the pancreatic islet parenchyma has previously been comprehensively studied. From the deduced amino-acid sequence, a synthetic peptide, corresponding to positions 20-29 of Salmo IAPP, was synthesized. A mouse antiserum to this peptide gave a distinct immunoreactivity with the insulin-producing beta cells of the sculpin Brockmann bodies and salmon endocrine pancreas. Thus, IAPP belongs to the group of peptide hormones expressed by the islet parenchymal cells in both mammals and non-mammalian vertebrates. Salmo salar IAPP(20-29) was found to give rise to amyloid-like fibrils in vitro.
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| 3. |
- Abro, Rani, et al.
(författare)
-
Evaluation of chitinolytic activities and membrane integrity in gut tissues of Arctic charr (Salvelinus alpinus) fed fish meal and zygomycete biomass.
- 2014
-
Ingår i: Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. - : Elsevier BV. - 1096-4959 .- 1879-1107. ; 175, s. 1-8
-
Tidskriftsartikel (refereegranskat)abstract
- Chitinolytic activity, nutrient uptake and intestinal barrier functions were investigated in gut tissues of Arctic charr (Salvelinus alpinus) fed iso-nitrogenous diets based on fish meal, with or without inclusion of zygomycetes (Rhizopus oryzae). We found that gut tissue of Arctic charr had significant chitinase activity, of both endo- and exo-chitinase iso-forms. Moreover, the distribution pattern along the GI tract of Arctic charr differed between endo-chitinase and exo-chitinase. The endo-chitinase activity in stomach tissue and in the distal intestine was several hundred-fold higher than the exo-chitinase activity in stomach tissue. The greatest exo-chitinase activity was found in the distal intestine. The zygomycete-based diet resulted in higher chitinolytic activity in gut tissue compared to the fish meal-based diet. Disturbed intestinal integrity and increased uptake rate of the amino acid lysine were observed in the distal, but not proximal, intestine of fish fed the zygomycete-based feed.
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| 4. |
- Dave, Göran, 1945, et al.
(författare)
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Metabolic and hematological effects of starvation in the european eel, Anguilla anguilla L.—III. Fatty acid composition
- 1976
-
Ingår i: Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. - 1096-4959 .- 1879-1107. ; 53:4, s. 509-515
-
Tidskriftsartikel (refereegranskat)abstract
- 1.1. Fatty acid composition in liver and muscle was studied in the European eel (Anguilla anguilla L.) after 11, 47, 96 and 164 days of starvation during the winter season. 2.2. The changes in muscle were small compared with those in liver. 3.3. In both liver and muscle there was a marked decrease in 14:0.∗ 4.4. In the liver starvation caused a decrease in 16:1, 18:1, 20:1 and/or 18:3 and an increase in 20:4, 20:5, 22:4 and 22:5. 5.5. The observed changes are discussed in relation to differences in distributional pattern among the lipid classes, to α- and β-positional preferences and to environmental temperature.
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| 5. |
- Dave, Göran, 1945, et al.
(författare)
-
Metabolic and hematological studies on the yellow and silver phases of the European eel, Anguilla anguilla L.—II. Fatty acid composition
- 1974
-
Ingår i: Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. - 1096-4959 .- 1879-1107. ; 43:3, s. 583-591
-
Tidskriftsartikel (refereegranskat)abstract
- 1.1. Fatty acid composition in liver, muscle and gonads of yellow and silver phases of the European eel (Anguilla anguilla L.) was determined by gas-liquid chromatography (GLC). 2.2. Significantly higher amounts of were found in the gonads of silver eels compared to yellow eels. 3.3. In the gonads of silver eels the amounts of the unsaturated acids, palmitoleic (16:1), oleic (18:1) and linoleic (18:2), were significantly higher while the amount of palmitic acid (16:0) was significantly lower. 4.4. In the liver the amount of stearic (18:0) and arachidonic acid (20:4) was significantly lower, while the amount of linoleic acid (18:2) was significantly higher in the silver phase.
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| 6. |
- Fällmar, Helena, 1980-, et al.
(författare)
-
Neuropeptide Y/peptide YY receptor Y2 duplicate in zebrafish with unique introns displays distinct peptide binding properties
- 2011
-
Ingår i: Comparative Biochemistry and Physiology - Part B. - : Elsevier BV. - 1096-4959 .- 1879-1107. ; 160:4, s. 166-173
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The neuropeptide Y-family peptides and receptors are involved in a broad range of functions including appetite regulation. Both the peptide genes and the receptor genes are known to have duplicated in early vertebrate evolution. The ancestral jawed vertebrate had 7 NPY receptors but the number varies between 4 and 7 in extant vertebrates. Herein we describe the identification of an additional NPY receptor in two fish species, zebrafish and medaka. They cluster together with the Y2 receptors in phylogenetic analyses and seem to be orthologous to each other that is why we have named them Y2-2. Their genes differ from Y2 in having introns in the coding region. Binding studies with zebrafish Y2-2 receptors show that the three endogenous peptides NPY, PYYa and PYYb have similar affinities, 0.15-0.66nM. This is in contrast to the Y2 receptor where they differed considerably from one another. N-terminally truncated NPY binds poorly and the Y2 antagonist BIIE0246 binds well to Y2-2, results that are reversed in comparison to Y2. Zebrafish Y2-2 mRNA was detected by PCR in the intestine and the eye, but not in the brain. In conclusion, we have found a novel Y2-like NPY/PYY receptor that probably arose in early teleost fish evolution.
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| 7. |
- Gaudry, Michael J., et al.
(författare)
-
Comparative functional analyses of UCP1 to unravel evolution, ecophysiology and mechanisms of mammalian thermogenesis
- 2021
-
Ingår i: Comparative Biochemistry and Physiology - Part B. - : Elsevier BV. - 1096-4959 .- 1879-1107. ; 255
-
Tidskriftsartikel (refereegranskat)abstract
- Brown adipose tissue (BAT), present in many placental mammals, provides adaptive nonshivering thermogenesis (NST) for body temperature regulation and has facilitated survival in diverse thermal niches on our planet. Intriguingly, several key details on the molecular mechanisms of NST and their potential ecophysiological adaptations are still unknown. Comparative studies at the whole animal level are unpragmatic, due to the diversity and complexity of thermoregulation among different species. We propose that the molecular evolution of mitochondrial uncoupling protein 1 (UCP1), a central component for BAT thermogenesis, represents a powerful opportunity to unravel key questions of mammalian thermoregulation. Comparative analysis of UCP1 may elucidate how its thermogenic function arose, how environmental selection has shaped protein function to support ecophysiological requirements, and how the enigmatic molecular mechanism of proton leak is governed. Several approaches for the assessment of UCP1 function in vitro have been introduced over the years. For comparative characterization of UCP1, we put forward the overexpression of UCP1 orthologues and mutated variants in a mammalian cell system as a primary strategy and discuss advantageous aspects in contrast to other experimental systems. In turn, we suggest how remaining experimental caveats can be solved by complimentary test systems before physiological consolidation in the animal model. Furthermore, we highlight the appropriate bioenergetic techniques to perform the functional analyses on UCP1. The comparative characterizations of diverse UCP1 variants may enable key insights into open questions surrounding the molecular basis of NST.
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| 8. |
- Håkansson, Katarina, et al.
(författare)
-
Mouse and rat cystatin C: Escherichia coli production, characterization and tissue distribution
- 1996
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Ingår i: Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. - : Elsevier BV. - 1879-1107 .- 1096-4959. ; 114:3, s. 303-311
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Tidskriftsartikel (refereegranskat)abstract
- Recombinant mouse (Mus musculus) and rat (Rattus norvegicus) cystatin C were produced by expression in Escherichia coli, isolated and functionally characterized. The mouse and rat inhibitors were both fully active in titrations of papain. Determination of equilibrium constants for dissociation (Ki) for their complexes with the target proteinase, cathepsin B, produced values not largely different from that for human cystatin C (Ki 0.07-0.13 nM). Rabbit antisera against mouse and rat cystatin C were produced and used for improved affinity purification of the recombinant inhibitors. Affinity purified immunoglobulins isolated from the antiserum against mouse cystatin C were used for construction of a sensitive enzyme-linked immunosorbent assay. The assay was used to demonstrate a high degree of immunological cross-reactivity between mouse and rat cystatin C and could be used for cystatin C quantification in mouse and rat tissue homogenates. All tissues analyzed contained cystatin C, with a relative content very similar to that of human tissues. For all species, brain tissue contained the highest cystatin C amounts and liver the lowest, whereas kidney, spleen and muscle tissues were intermediate in content. In the mouse, a notable high cystatin C content in parotid gland tissue was observed. The high degree of similarity in distribution pattern and functional properties for mouse, rat and human cystatin C indicates that a murine model should be relevant for studies of the human disease, hereditary cystatin C amyloid angiopathy.
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| 9. |
- Jönsson, K. Ingemar, 1959-, et al.
(författare)
-
Induction of Hsp70 by desiccation, ionising radiation and heat-shock in the eutardigrade Richtersius coronifer
- 2007
-
Ingår i: Comparative Biochemistry and Physiology - Part B. - 1096-4959 .- 1879-1107. - 1096-4959 ; 146:4, s. 456-460
-
Tidskriftsartikel (refereegranskat)abstract
- The physiology and biochemistry behind the extreme tolerance to desiccation shown by the so-called anhydrobiotic animals represents an exciting challenge to biology. The current knowledge suggests that both carbohydrates and proteins are often involved in protecting the dry cell from damage, or in the repair of induced damage. Tardigrades belong to the most desiccation-tolerant multicellular organisms, but very little research has been reported on the biochemistry behind desiccation tolerance in this group. We quantified the induction of the heat-shock protein Hsp70, a very wide-spread stress protein, in response to desiccation, ionising radiation, and heating, in the anhydrobiotic tardigrade Richtersius coronifer using an immuno-westemblot method. Elevated levels of Hsp70 were recorded after treatment of both heat and ionising radiation, and also in rehydrated tardigrades after a period of desiccation. In contrast, tardigrades in the desiccated (dry) state had reduced Hsp70 levels compared to the non-treated control group. Our results suggest that Hsp70 may be involved in the physiological and biochemical system underlying desiccation (and radiation) tolerance in tardigrades, and that its role may be connected to repair processes after desiccation rather than to biochemical stabilization in the dry state.
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| 10. |
- Lewander, Kerstin, et al.
(författare)
-
Metabolic and hematological studies on the yellow and silver phases of the European eel, Anguilla anguilla L.—I. Carbohydrate, lipid, protein and inorganic ion metabolism
- 1974
-
Ingår i: Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. - 1096-4959 .- 1879-1107. ; 47:3, s. 571-581
-
Tidskriftsartikel (refereegranskat)abstract
- 1.1. The contents of different metabolites were determined in white and dark muscle, liver, blood and gonads of the yellow and silver phases of the European eel, Anguilla anguilla L. 2.2. The plasma cortisol level in the silver eels was lower than in the yellow eels. 3.3. The silver eels also showed an increased redistribution and utilization of fat as well as a changed carbohydrate and protein metabolism. 4.4. An enhanced content of dark muscle was found in the silver eels, indicating an adaptation for spawning migration.
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| 11. |
- Michael, Katharina, et al.
(författare)
-
Adjustments of molecular key components of branchial ion and pH regulation in Atlantic cod (Gadus morhua) in response to ocean acidification and warming
- 2016
-
Ingår i: Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. - : Elsevier BV. - 1096-4959 .- 1879-1107. ; 193, s. 33-46
-
Tidskriftsartikel (refereegranskat)abstract
- Marine teleost fish sustain compensation of extracellular pH after exposure to hypercapnia by means of efficient ion and acid-base regulation. Elevated rates of ion and acid-base regulation under hypercapnia may be stimulated further by elevated temperature. Here, we characterized the regulation of transepithelial ion transporters (NKCC1, NBC1, SLC26A6, NHE1 and 2) and ATPases (Na+/K+ ATPase and V-type H+ ATPase) in gills of Atlantic cod (Gadus morhua) after 4weeks of exposure to ambient and future PCO2 levels (550μatm, 1200μatm, 2200μatm) at optimum (10°C) and summer maximum temperature (18°C), respectively. Gene expression of most branchial ion transporters revealed temperature- and dose-dependent responses to elevated PCO2. Transcriptional regulation resulted in stable protein expression at 10°C, whereas expression of most transport proteins increased at medium PCO2 and 18°C. mRNA and protein expression of distinct ion transport proteins were closely co-regulated, substantiating cellular functional relationships. Na+/K+ ATPase capacities were PCO2 independent, but increased with acclimation temperature, whereas H+ ATPase capacities were thermally compensated but decreased at medium PCO2 and 10°C. When functional capacities of branchial ATPases were compared with mitochondrial F1Fo ATP-synthase strong correlations of F1Fo ATP-synthase and ATPase capacities generally indicate close coordination of branchial aerobic ATP demand and supply. Our data indicate physiological plasticity in the gills of cod to adjust to a warming, acidifying ocean within limits. In light of the interacting and non-linear, dose-dependent effects of both climate factors the role of these mechanisms in shaping resilience under climate change remains to be explored. © 2015 The Authors.
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| 12. |
- Ozerov, Mikhail, et al.
(författare)
-
Differential expression and alternative splicing analyses of multiple tissues reveal albinism-associated genes in the Wels catfish (Silurus glanis)
- 2024
-
Ingår i: Comparative Biochemistry and Physiology - Part B: Biochemistry and Molecular Biology. - 1096-4959 .- 1879-1107. ; 271
-
Tidskriftsartikel (refereegranskat)abstract
- Albinism is a widespread departure from a typical body colouration due to altered melanin production. The Wels catfish (Silurus glanis) is among the largest freshwater fish species in the world, and albino individuals occur both in the wild and in aquaculture. Here, we performed transcriptome-wide analysis of albino and normally pigmented S. glanis using four tissues (skin, dorsal fin, whole eye and liver) to identify genes associated with albinism by exploring patterns of differential expression (DE) and differential alternative splicing (DAS). Multitissue analyses revealed a large number of genes in skin (n = 1355) and fin (n = 614) tissue associated with the albino phenotype in S. glanis, while the number of DE genes in eye and liver tissues was lower (n = 188, n = 189, respectively). Several DE genes across multiple tissues were detected as the most promising candidates (e.g., hsp4, hsp90b1, raph1, uqcrfs1, adcy-family and wnt-family) potentially causally linked to the albino phenotype in Wels catfish. Moreover, our findings supported earlier observations of physiological differences between albino and normally pigmented individuals, particularly in energy metabolism and immune response. In contrast, there were only a few pigmentation-related genes observed among DAS genes (4 in skin, 2 in fin), the overlap between DAS and DE genes was low (n = 25) and did not include known pigmentation-related genes. This suggests that DAS and DE in Wels catfish are, to a large extent, independent processes, and the observed alternative splicing cases are probably not causally linked with albinism in S. glanis. This work provides the first transcriptome-wide multi-tissue insights into the albinism of Wels catfish and serves as a valuable resource for further understanding the genetic mechanisms of pigmentation in fish.
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| 13. |
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| 14. |
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| 15. |
- Carney Almroth, Bethanie, 1974, et al.
(författare)
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Early-age changes in oxidative stress in brown trout, Salmo trutta
- 2010
-
Ingår i: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY. - 1096-4959. ; 155:4, s. 442-448
-
Tidskriftsartikel (refereegranskat)abstract
- Fish are often used as models for studies investigating the ability of xenobiotics to induce oxidative stress, though age or developmental stage of the individuals studied has been given little attention. Oxidative stress in other organisms is associated with aging as well as with periods of rapid growth, which occurs in young brown trout. We measured protein carbonyls, 20S proteosome activity and glutathione (GSH) levels in farmed Salmo trutta in four different age groups from 5 months to 3 years. We found an increase in protein carbonyls and a decrease in 20S proteosome activity in both brain and liver tissues of the fish with increasing size and age. Total GSH levels in liver tissue declined as fish aged and the GSSG:GSH ratio increased. Five month and 1 year old trout were treated with paraquat (PQ) to induce oxidative stress. Five month old fish showed no changes in the measured parameters while 1 year old fish had both an increase in protein carbonylation in liver tissue and a decrease in 20S proteosome activity in brain tissue. These results indicate that oxidative stress biomarkers are affected by age or rapid growth in brown trout, and that individuals of different ages respond differently to oxidative stress induced by PQ.
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| 16. |
- Carney Almroth, Bethanie, 1974, et al.
(författare)
-
Oxidative stress and biomarker responses in the Atlantic halibut after long term exposure to elevated CO2 and a range of temperatures
- 2019
-
Ingår i: Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology. - : Elsevier BV. - 1096-4959. ; 238
-
Tidskriftsartikel (refereegranskat)abstract
- CO2 emissions from human activities are increasing, resulting in greater rates of change in the oceans, exceeding any other event in geological and historical records over the past 300 million years. Oceans are warming and pH levels are decreasing. Marine organisms will need to respond to multiple stressors and the potential consequences of global change-related effects in fish needs to be investigated. Fish are affected by many biotic and abiotic environmental variables, including temperature and CO2 fluctuations, and it is therefore critical to investigate how these variables may affect physiological and biochemical processes. We investigated the effects of elevated CO2 levels (pH of 8.0, which served as a control, or 7.6, which is predicted for the year 2100) combined with exposure to different temperatures (5, 10, 12, 14, 16, and 18 degrees C) in the Atlantic halibut (Hippoglossus hippoglossus) during a three month experiment. Since regulation of reactive oxygen species (ROS) is crucial for physiological processes the focus was on the antioxidant defense system and we assessed the effects on catalytic activities of antioxidant enzymes (SOD, CAT, GR, GST, GPx). In addition we also analyzed effects on cholinesterase enzymes (AChE and BChE), and CYP1A enzyme activities (EROD). The treatments resulted in oxidative stress, and damage was evident in the form of protein carbonyls which were consistently higher in the elevated CO2 -treated fish at all temperatures. Analyses of antioxidant enzymes did not show the same results, suggesting that the exposure to elevated CO2 increased ROS formation but not defences. The antioxidant defense system was insufficient, and the resulting oxidative damage could impact physiological function of the halibut on a cellular level.
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| 17. |
- Cobb, Christopher S., et al.
(författare)
-
Angiotensin I-converting enzyme-like activity in tissues from the Atlantic hagfish (Myxine glutinosa) and detection of immunoreactive plasma angiotensins
- 2004
-
Ingår i: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology. - : Elsevier BV. - 1096-4959. ; 138,:4, s. 357-364
-
Tidskriftsartikel (refereegranskat)abstract
- Using a highly sensitive fluorimetric assay, significant levels of angiotensin I -converting enzyme-like activity (ACELA) were detected in a range of tissues (branchial heart, gill, kidney with associated vasculature and archinephric duct, liver, whole brain and gut) from the Atlantic hagfish (Myxine glutinosa). The highest ACELA occurred in heart and gill (1.8 and 1.5 nmol His–Leu min−1 mg protein−1, respectively). The mammalian angiotensin I-converting enzyme (ACE) inhibitor, captopril, at 10−5 M was a potent inhibitor of the ACELA found in all hagfish tissues. Radioimmunoassay showed that immunoreactive angiotensins (251.8±11.8 pM) were detectable in hagfish plasma. The validity of the assay for measurement of hagfish angiotensins was indicated by the parallelism of the angiotensin II standard curve against serially diluted hagfish plasma. Measurement of immunoreactive plasma angiotensins and detection of significant levels of ACELA in a wide range of tissues gives indirect evidence for the presence of a renin–angiotensin system in hagfishes, the earliest evolved group of craniates
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| 18. |
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| 19. |
- Hildahl, Jon, 1976, et al.
(författare)
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Identification of two isoforms of Atlantic halibut insulin-like growth factor-I receptor genes and quantitative gene expression during metamorphosis
- 2007
-
Ingår i: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology. - : Elsevier BV. - 1096-4959. ; 147:3, s. 395-401
-
Tidskriftsartikel (refereegranskat)abstract
- Insulin-like growth factor-I (IGF-I) is an important regulator of growth and development in vertebrates. Both the endocrine and paracrine actions of IGF-I are mediated through ligand-binding to a membrane-bound IGF-I receptor (IGF-IR). The characterization of this receptor and subsequent expression studies thus help elucidate the endocrine regulation of developmental processes. As other flatfish species, the Atlantic halibut (Hippoglossus hippoglossus) undergoes a dramatic larval metamorphosis. This process is largely under endocrine control, and data indicate that IGF-I could be a key regulator. IGF-I content increases up to late pre-metamorphosis and decreases during metamorphosis. The IGF-IR has, however, not been studied during flatfish metamorphosis. To examine IGF-IR gene expression, two IGF-IR mRNA were cloned and sequenced. These partial sequences share high identity (≥ 95%) and similarity (≥ 97%) with other fish IGF-IR and lower identity (≥ 77%) and similarity (≥ 83.5%) with Japanese flounder insulin receptors. The expression of mRNA for both IGF-IR was analyzed by quantitative real-time RT-PCR during six larval developmental stages from pre- to post-metamorphosis. IGF-IR1 and IGF-IR2 mRNA are differentially expressed during metamorphosis, but if this indicates an isoform-specific regulation of developmental processes by circulating and/or locally-secreted IGF-I is unclear. Both IGF-IR genes are down-regulated in halibut larvae experiencing arrested metamorphosis, suggesting the IGF-I system is critical for metamorphic success in halibut.
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| 20. |
- Jönsson, K. Ingemar, et al.
(författare)
-
Induction of Hsp70 by desiccation, ionising radiation and heat-shock in the eutardigrade Richtersius coronifer
- 2007
-
Ingår i: Comparative Biochemistry and Physiology - Part BBiochemistry & Molecular Biology. - : Elsevier BV. - 1096-4959. ; 146:4, s. 456-460
-
Tidskriftsartikel (refereegranskat)abstract
- The physiology and biochemistry behind the extreme tolerance to desiccation shown by the so-called anhydrobiotic animals represents an exciting challenge to biology. The current knowledge suggests that both carbohydrates and proteins are often involved in protecting the dry cell from damage, or in the repair of induced damage. Tardigrades belong to the most desiccation-tolerant multicellular organisms, but very little research has been reported on the biochemistry behind desiccation tolerance in this group. We quantified the induction of the heat-shock protein Hsp70, a very wide-spread stress protein, in response to desiccation, ionising radiation, and heating, in the anhydrobiotic tardigrade Richtersius coronifer using an immuno-westemblot method. Elevated levels of Hsp70 were recorded after treatment of both heat and ionising radiation, and also in rehydrated tardigrades after a period of desiccation. In contrast, tardigrades in the desiccated (dry) state had reduced Hsp70 levels compared to the non-treatedcontrol group. Our results suggest that Hsp70 may be involved in the physiological and biochemical system underlying desiccation (and radiation) tolerance in tardigrades, and that its role may be connected to repair processes after desiccation rather than to biochemical stabilization in the dry state.
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| 21. |
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| 22. |
- Oxley, A., et al.
(författare)
-
Sn-2-monoaglycerol, not glycerol, is preferentially utilized for triacylglycerols and phosphatidylcholine biosynthesis in Atlantic salmon (Salmo salar L.) intestine.
- 2006
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Ingår i: Comparative Biochemistry and Physiology. Part B: Biochemistry & Molecular Biology. - : Elsevier BV. - 1096-4959. ; 146:1, s. 115-123
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Tidskriftsartikel (refereegranskat)abstract
- Pathways of lipid resynthesis in the intestine of fish are relatively unknown. Various reports have suggested the existence of both sn-1,3-specific (pancreatic) and non-specific (bile salt-activated) lipase activity operating on dietary triacylglycerol (TAG) in the intestinal lumen of fish during digestion. Thus, sn-2-monoacylglycerol (2-MAG) and glycerol, respective hydrolytic products of each lipase, are absorbed and utilised for glycerolipid synthesis in enterocytes via two alternative routes: monoacylglycerol (MAG) and glycerol-3-phosphate (G3P) pathways. Despite different precursors, both pathways converge at the production of sn-1,2-diacylglycerol (1,2-DAG) where TAG or phosphatidylcholine (PC) synthesis can occur. To elucidate the relative activities of MAG and G3P pathways in Atlantic salmon enterocytes, intestinal segments were mounted in Ussing chambers where equimolar mixtures of sn-2-oleoyl-[1,2,3-3H]glycerol (2-MAG) and [14C(U)]glycerol, plus unlabelled 16:0 and 18:2n-6 as exogenous fatty acid sources, were delivered in bile salt-containing Ringer solution to the mucosa. The MAG pathway predominated, over the G3P pathway, synthesizing ca. 95% of total TAG and ca. 80% of total PC after a 3 h incubation period at 10 °C. Further, the 1,2-DAG branch point into TAG or PC was polarised towards TAG synthesis (6:1) via the MAG pathway but more evenly distributed between TAG and PC (1:1) via the G3P pathway. Effect of long-chain saturated, monounsaturated and polyunsaturated fatty acids on the synthesized TAG/PC ratio was assessed by individually exchanging 16:0, 18:1n-9 or 18:2n-6, for 16:0 + 18:2n-6, in mucosal solutions. TAG synthesis was influenced considerably more than PC synthesis, via either pathway, by exogenous fatty acids utilised. 18:1n-9 significantly stimulated TAG synthesis via the MAG pathway yielding a TAG/PC ratio of 12:1. Alternatively, 18:2n-6 stimulated TAG synthesis the most via the G3P pathway (TAG/PC = 4:1). 16:0 significantly attenuated TAG synthesis via either pathway. Micellar fatty acid species also significantly affected intestinal active transport mechanisms as shown by decreasing transepithelial potential (TEP) and short-circuit current (SSC) with increasing fatty acid unsaturation. The epithelial integrity was, however, not compromised after 3 h of exposure to any of the fatty acids. The implications of these findings on dietary fatty acid composition and enterocytic lipid droplet accumulation are discussed.
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| 23. |
- Prager, Maria, 1973, et al.
(författare)
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Differential ability of carotenoid C4-oxygenation in yellow and red bishop species (Euplectes spp.)
- 2009
-
Ingår i: Comparative Biochemistry And Physiology B-Biochemistry & Molecular Biology. - : Elsevier BV. ; 154, s. 373-380
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Tidskriftsartikel (refereegranskat)abstract
- Male breeding plumages of African widowbirds and bishops (Euplectes spp.) show striking variation in carotenoid-based plumage coloration, with saturated yellow or orange-red patches of different size. Yet, from observations and experiments, agonistic signaling appears to have been a generalized sexual selection pressure for redness in the genus. Recent results show that yellow and red widowbird colors derive from distinctly different pigment profiles, and suggest that species vary in their ability to metabolize ingested carotenoids. We used reflectance spectrometry and High Performance Liquid Chromatography (HPLC) to describe the species-specific colors and plumage carotenoids of the congeneric yellow-crowned bishop (E. afer) and southern red bishop (E. orix). Results show that the yellow rump color of E. afer primarily derives from direct-deposited, dietary yellow pigments, i.e. lutein and zeaxanthin. In the red breast of E. orix, these are complemented by smaller amounts of derived red C4-keto-carotenoids: mainly α-doradexanthin, but also β-doradexanthin, canthaxanthin, astaxanthin and adonirubin. We also performed a diet supplementation experiment to investigate the relative importance of nutritional and metabolic constraints in determining the differential occurrence of C4-keto-carotenoids, and thus red plumage color, in the two species. Our results indicate that E. orix, but not E. afer, can manufacture red C4-keto-carotenoids (α-doradexanthin and canthaxanthin) from yellow dietary precursors (lutein and β-carotene).
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| 25. |
- Ratasvuori, Maire, et al.
(författare)
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Insight opinion to surgically treated metastatic bone disease: Scandinavian Sarcoma Group Skeletal Metastasis Registry report of 1195 operated skeletal metastasis
- 2013
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Ingår i: Surgical Oncology. - : Elsevier BV. - 0960-7404 .- 1879-3320. ; 22:2, s. 132-138
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Forskningsöversikt (refereegranskat)abstract
- The number of cancer patients living with metastatic disease is growing. The increased survival has led to an increase in the number of cancer-induced complications, such as pathologic fractures due to bone metastases. Surgery is most commonly needed for mechanical complications, such as fractures and intractable pain. We determined survival, disease free interval and complications in surgically treated bone metastasis. Data were collected from the Scandinavian Skeletal Metastasis Registry for patients with extremity skeletal metastases surgically treated at eight major Scandinavian referral centres between 1999 and 2009 covering a total of 1195 skeletal metastases in 1107 patients. Primary breast, prostate, renal, lung, and myeloma tumors make up 78% of the tumors. Number of complications is tolerable and is affected by methods of surgery as well as preoperative radiation therapy. Overall 1-year patient survival was 36%; however, mean survival was influenced by the primary tumor type and the presence of additional visceral metastases. Patients with impending fracture had more systemic complications than those with complete fracture. Although surgery is usually only a palliative treatment, patients can survive for years after surgery. We developed a simple, useful and reliable scoring system to predict survival among these patients. This scoring system gives good aid in predicting the prognosis when selecting the surgical method. While it is important to avoid unnecessary operations, operating when necessary can provide benefit. (C) 2013 Elsevier Ltd. All rights reserved.
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| 26. |
- Hansson, Maria, et al.
(författare)
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Characterization of two distinct aryl hydrocarbon receptor (AhR2) genes in Atlantic salmon (Salmo salar) and evidence for multiple AhR2 gene lineages in salmonid fish
- 2003
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Ingår i: Gene. - 1879-0038. ; 303, s. 197-206
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Tidskriftsartikel (refereegranskat)abstract
- The aryl hydrocarbon receptor (AhR) mediates the toxicity of several environmental contaminants, e.g. 2,3,7,8-tetrachlorodibenzo-p-dioxin, and other halogenated hydrocarbons in vertebrates. This receptor initiates the transcription of several biotransformation enzymes, which in turn are responsible for causing severe harm to biological tissue. Here we describe the isolation and complete characterization of the first two AhR genes from the teleost fish Atlantic salmon (Salmo salar). The predicted amino acid sequences contain regions characteristic of other vertebrate AhRs including basic helix-loop-helix (bHLH) and PER-ARNT-SIM (PAS) domains but show little similarity to other vertebrate AhRs across the C-terminal half. Furthermore, they do not contain distinct Q-rich domains as found in the mammalian AhR, which is in line with previously described fish AhR genes. The salmon cDNAs encode 1106 and 1107 putative residues, respectively, approximately 50 amino acids longer than previously characterized AhR genes. Phylogenetic analyses demonstrated that the two salmon AhR sequences cluster within the AhR subfamily of the bHLH-PAS family, in a clade containing fish AhR2 genes. Although the two AbR2 forms are 92% identical at the amino acid level, the distribution of sequence differences and the presence of both forms in 30 tested individuals suggest that they are not allelic but derived from separate loci. Interestingly, they are not orthologs of the rainbow trout (Oncorhynchus mykiss) AhR2alpha and beta genes and the new salmon loci are therefore here designated AhR2gamma and AhR2delta. In line with this, PCR with DNA from rainbow trout revealed a new trout AhR locus that was more similar to the two salmon genes than to the trout AhR2alpha and beta genes, suggesting that the rainbow trout possesses at least three distinct AhR2 genes. The presence of multiple AhR genes in these species is probably a consequence of the genome duplications that occurred in the early evolution of fish and later also specifically in the salmonid lineage. Reverse transcription-PCR analyses revealed that both AhR2gamma and AhR2delta are transcribed in the liver, spleen and muscles of adult salmon.
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