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  • 1.
    Abbey-Lee, Robin N.
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Kreshchenko, Anastasia
    Mechanical and Aeronautical Engineering Division L5, Department of Mechanical, Aerospace & Civil Engineering, Dalton Nuclear Institute, FSE Research Institutes,The University of Manchester, UK.
    Fernandez Sala, Xavier
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Petkova, Irina
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. School of Biological Sciences, Centre for Ecology,Evolution and Behaviour, Royal Holloway University of London, Egham UK.
    Løvlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Effects of monoamine manipulations on the personality and gene expression of three-spined sticklebacks2019Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 222, nr 20, artikel-id jeb211888Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Among-individual behavioral differences (i.e. animal personality) are commonly observed across taxa, although the underlying, causal mechanisms of such differences are poorly understood. Animal personality has been correlated with physiological functions as well as fitness-related traits. Variation in many aspects of monoamine systems, such as metabolite levels and gene polymorphisms, has been linked to behavioral variation. Therefore, here we experimentally investigated the potential role of monoamines in explaining individual variation in personality, using two common pharmaceuticals that respectively alter the levels of serotonin and dopamine in the brain: fluoxetine and ropinirole. We exposed three-spined sticklebacks, a species that shows animal personality, to either chemical alone or to a combination of the two chemicals, for 18 days. During the experiment, fish were assayed at four time points for the following personality traits: exploration, boldness, aggression and sociability. To quantify brain gene expression on short- and longer-term scales, fish were sampled at two time points. Our results show that monoamine manipulations influence fish behavior. Specifically, fish exposed to either fluoxetine or ropinirole were significantly bolder, and fish exposed to the two chemicals together tended to be bolder than control fish. Our monoamine manipulations did not alter the gene expression of monoamine or stress-associated neurotransmitter genes, but control, untreated fish showed covariation between gene expression and behavior. Specifically, exploration and boldness were predicted by genes in the dopaminergic, serotonergic and stress pathways, and sociability was predicted by genes in the dopaminergic and stress pathways. These results add further support to the links between monoaminergic systems and personality, and show that exposure to monoamines can causally alter animal personality.

  • 2.
    Aldred, Nick
    et al.
    Newcastle University, England .
    Gohad, Neeraj V.
    Clemson University, SC USA .
    Petrone, Luigi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Orihuela, Beatriz
    Duke University, NC USA .
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Ederth, Thomas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Mount, Andrew
    Clemson University, SC USA .
    Rittschof, Dan
    Duke University, NC USA .
    Clare, Anthony S.
    Newcastle University, England .
    Confocal microscopy-based goniometry of barnacle cyprid permanent adhesive2013Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 216, nr 11, s. 1969-1972Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biological adhesives are materials of particular interest in the fields of bio-inspired technology and antifouling research. The adhesive of adult barnacles has received much attention over the years; however, the permanent adhesive of the cyprid - the colonisation stage of barnacles - is a material about which very little is presently known. We applied confocal laser-scanning microscopy to the measurement of contact angles between the permanent adhesive of barnacle cyprid larvae and self-assembled monolayers of OH- and CH3-terminated thiols. Measurement of contact angles between actual bioadhesives and surfaces has never previously been achieved and the data may provide insight into the physicochemical properties and mechanism of action of these functional materials. The adhesive is a dual-phase system post-secretion, with the behaviour of the components governed separately by the surface chemistry. The findings imply that the cyprid permanent adhesion process is more complex than previously thought, necessitating broad re-evaluation of the system. Improved understanding will have significant implications for the production of barnacle-resistant coatings as well as development of bio-inspired glues for niche applications.

  • 3.
    Altimiras, Jordi
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Zoologi. Linköpings universitet, Tekniska högskolan.
    Axelsson, Michael
    Department of Zoology University of Göteborg.
    Intrinsic autoregulation of cardiac output in rainbow trout (Oncorhynchus mykiss) at different heart rates2004Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 207, s. 195-201Artikel i tidskrift (Refereegranskat)
  • 4.
    Crossley II, Dane A.
    et al.
    University of California Irvine, USA.
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Zoologi. Linköpings universitet, Tekniska högskolan.
    Cardiovascular development in embryos of the American alligator Alligator mississippiensis: effects of chronic and acute hypoxia2005Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 208, s. 31-39Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Chronic hypoxic incubation is a common tool used to address the plasticity of morphological and physiological characteristics during vertebrate development. In this study chronic hypoxic incubation of embryonic American alligators resulted in both morphological (mass) and physiological changes. During normoxic incubation embryonic mass, liver mass and heart mass increased throughout the period of study, while yolk mass fell. Chronic hypoxia (10%O2) resulted in a reduced embryonic mass at 80% and 90% of incubation. This reduction in embryonic mass was accompanied by a relative enlargement of the heart at 80% and 90% of incubation, while relative embryonic liver mass was similar to the normoxic group. Normoxic incubated alligators maintained a constant heart rate during the period of study, while mean arterial pressure rose continuously. Both levels of hypoxic incubation (15% and 10%O2) resulted in a lower mean arterial pressure at 90% of incubation, while heart rate was lower in the 10%O2 group only. Acute (5 min) exposure to 10%O2 in the normoxic group resulted in a biphasic response, with a normotensive bradycardia occurring during the period of exposure and a hypertensive tachycardic response occurring during recovery. The embryos incubated under hypoxia also showed a blunted response to acute hypoxic stress. In conclusion, the main responses elicited by chronic hypoxic incubation, namely, cardiac enlargement, blunted hypoxic response and systemic vasodilation, may provide chronically hypoxic embryos with a new physiological repertoire for responding to hypoxia.

  • 5.
    Crossley, II, Dane A.
    et al.
    University of California at Irvine.
    Hicks, James W.
    University of California at Irvine.
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Zoologi. Linköpings universitet, Tekniska högskolan.
    Ontogeny of baroreflex control in the American alligator Alligator mississippiensis2003Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 206, s. 2895-2902Artikel i tidskrift (Refereegranskat)
    Abstract [en]

     Baroreflex regulation appears in different species at different points in embryonic development. This study was designed to understand the development of the baroreflex in embryos of the American alligator at four different points of embryonic development (60%, 70%, 80% and 90% of a total incubation period of 72 days) and in 1-week-old hatchlings. Data from a separate study on 1-year-old alligators were included for comparison. The gain of the cardiac limb of the baroreflex was calculated from heart rate changes triggered by pharmacological manipulation of arterial pressure with sodium nitroprusside and phenylephrine. The results demonstrated that a vagally mediated hypertensive baroreflex was present during the final 30% of alligator development. A hypotensive baroreflex was not present in embryos but appeared in hatchlings, mediated by a combined effect of vagal and sympathetic efferents. Absolute baroreflex gain was maximal at 80% of incubation (41.22 beats kPa–1 min–1) and dropped thereafter, reaching a minimum in 1-year-old alligators (9.69 beats kPa–1 min–1). When the baroreflex gain was normalized to resting arterial pressure and heart rate, the maximum gain was observed in 1-year-old alligators (normalized index of 2.12 versus 0.75 in hatchlings and 0.69 as the highest gain in embryos). In conclusion, baroreflex regulation appeared during embryonic development with a substantial gain. These findings indicate that embryonic development is a period of preparation for cardiovascular regulatory mechanisms that will be necessary in adult life and that the baroreflex control mechanism is required for cardiovascular control during ontogeny.   

  • 6.
    Farrell, Anthony P.
    et al.
    Faculty of Agricultural Sciences and Department of Zoology University of British Columbia, Vancouver, Canada.
    Axelsson, Michael
    Department of Zoology Göteborg University.
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Zoologi. Linköpings universitet, Tekniska högskolan.
    Sandblom, Erik
    Department of Zoology Göteborg University.
    Claireaux, Guy
    Département de Biologie Intégrative 1 Quai de la Daurade, 34200 Sète, France.
    Maximum cardiac performance and adrenergic sensitivity of the sea bass Dicentrarchus labrax at high temperatures2007Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 210, s. 1216-1224Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We examined maximum cardiac performance of sea bass Dicentrarchus labrax acclimated to 18°C and 22°C, temperatures near the optimum for growth of this species. Our aim was to study whether cardiac performance, especially the effect of adrenergic stimulation, differed when compared to salmonids. Sea bass and salmonids are both athletic swimmers but their cardiac anatomy differs markedly. The sea bass ventricle does not receive any oxygenated blood via a coronary circulation while salmonids have a well-developed arterial supply of oxygen to the compact layer of the ventricle. Using in situ perfused heart preparations, maximum cardiac performance of 18°C-acclimated sea bass (i.e. cardiac output=90.8± 6.6 ml min–1 kg–1 and power output=11.41±0.83 mW g–1) was found to be comparable to that previously reported for rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta at similar temperatures and with tonic adrenergic (5 nmol l–1 adrenaline) stimulation. For 22°C-acclimated sea bass, heart rate was significantly higher, but maximum stroke volume was reduced by 22% (1.05±0.05 ml kg–1) compared with 18°C (1.38± 0.11 ml kg–1). As a result, maximum cardiac output (99.4±3.9 ml min–1 kg–1) was not significantly different at 22°C. Instead, maximum power output was 27% higher at 22°C (14.95±0.96 mW g–1) compared with 18°C, primarily because of the smaller relative ventricular mass in 22°C-acclimated sea bass. Compared with tonic adrenergic stimulation with 5 nmol l–1 adrenaline, maximum adrenergic stimulation of the sea bass heart produced only modest stimulatory effects at both temperatures (12–13% and 14–15% increases in maximum cardiac output and power output, respectively, with no chronotropic effect). Adrenergic stimulation also increased the cardiac sensitivity to filling pressure, with the maximum left-shift in the Starling curve being produced by 50–100 nmol l–1 adrenaline at 18°C and 10–50 nmol l–1 adrenaline at 22°C. We show that the sea bass, which lacks a coronary arterial oxygen supply to the ventricle, has a powerful heart. Its maximum performance is comparable to a salmonid heart, as is the modest stimulatory effect of adrenaline at high temperature.

  • 7.
    Franklin, Craig E.
    et al.
    University of Queensland, Brisbane, Australia.
    Farrell, Anthony P.
    University of British Columbia, Vancouver, Canada.
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Zoologi. Linköpings universitet, Tekniska högskolan.
    Axelsson, Michael
    University of Gothenburg, Sweden.
    Thermal dependence of cardiac function in arctic fish: implications of a warming world2013Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 216, s. 4251-4255Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the Arctic experiencing one of the greatest and most rapid increases in sea temperatures in modern time, predicting how Arctic marine organisms will respond to elevated temperatures has become crucial for conservation biology. Here, we examined the thermal sensitivity of cardiorespiratory performance for three closely related species of sculpins that inhabit the Arctic waters, two of which, Gymnocanthus tricuspis and Myoxocephalus scorpioides, have adapted to a restricted range within the Arctic, whereas the third species, Myoxocephalus scorpius, has a wider distribution. We tested the hypothesis that the fish restricted to Arctic cold waters would show reduced cardiorespiratory scope in response to an increase in temperature, as compared with the more eurythermal M. scorpius. As expected from their biogeography, M. scorpioides and G. tricuspis maximised cardiorespiratory performance at temperatures between 1 and 4 degrees C, whereas M. scorpius maximised performance over a wider range of temperatures (1-10 degrees C). Furthermore, factorial scope for cardiac output collapsed at elevated temperature for the two high-latitude species, negatively impacting their ability to support aerobically driven metabolic processes. Consequently, these results concurred with our hypothesis, suggesting that the sculpin species restricted to the Arctic are likely to be negatively impacted by increases in ocean temperatures.

  • 8.
    Jensen, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska högskolan.
    Adding ‘epi-’ to behaviour genetics: implications for animaldomestication2015Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 218, nr 1-5, s. 32-40Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    In this review, it is argued that greatly improved understanding ofdomestication may be gained from extending the field of behaviourgenetics to also include epigenetics. Domestication offers aninteresting framework of rapid evolutionary changes caused by welldefinedselection pressures. Behaviour is an important phenotype inthis context, as it represents the primary means of response toenvironmental challenges. An overview is provided of the evidencefor genetic involvement in behavioural control and the presently usedmethods for finding so-called behaviour genes. This shows thatevolutionary changes in behaviour are to a large extent correlated tochanges in patterns of gene expression, which brings epigenetics intothe focus. This area is concerned with the mechanisms controllingthe timing and extent of gene expression, and a lot of focus has beenplaced on methylation of cytosine in promoter regions, usuallyassociated with genetic downregulation. The review considers theavailable evidence that environmental input, for example stress, canmodify methylation and other epigenetic marks and subsequentlyaffect behaviour. Furthermore, several studies are reviewed,demonstrating that acquired epigenetic modifications can be inheritedand cause trans-generational behaviour changes. In conclusion,epigenetics may signify a new paradigm in this respect, as it showsthat genomic modifications can be caused by environmental signals,and random mutations in DNA sequence are therefore not the onlysources of heritable genetic variation.

  • 9.
    Joyce, William
    et al.
    Department of Zoophysiology, Aarhus University, Aarhus, Denmark.
    Axelsson, Michael
    Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden..
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Wang, Tobias
    Department of Zoophysiology, Aarhus University, Aarhus, Denmark..
    In situ cardiac perfusion reveals interspecific variation of intraventricular flow separation in reptiles2016Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 219, nr pt 14, s. 2220-2227Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ventricles of non-crocodilian reptiles are incompletely dividedand provide an opportunity for mixing of oxygen-poor blood andoxygen-rich blood (intracardiac shunting). However, both cardiacmorphology and in vivo shunting patterns exhibit considerableinterspecific variation within reptiles. In the present study, wedevelop an in situ double-perfused heart approach to characterisethe propensity and capacity for shunting in five reptile species: theturtle Trachemys scripta, the rock python Python sebae, the yellowanaconda Eunectes notaeus, the varanid lizard Varanusexanthematicus and the bearded dragon Pogona vitticeps. Tosimulate changes in vascular bed resistance, pulmonary andsystemic afterloads were independently manipulated and changesin blood flow distribution amongst the central outflow tracts weremonitored. As previously demonstrated in Burmese pythons, rockpythons and varanid lizards exhibited pronounced intraventricularflow separation. As pulmonary or systemic afterload was raised, flowin the respective circulation decreased. However, flow in the othercirculation, where afterload was constant, remained stable. Thiscorrelates with the convergent evolution of intraventricular pressureseparation and the large intraventricular muscular ridge, whichcompartmentalises the ventricle, in these species. Conversely, inthe three other species, the pulmonary and systemic flows werestrongly mutually dependent, such that the decrease in pulmonaryflow in response to elevated pulmonary afterload resulted inredistribution of perfusate to the systemic circuit (and vice versa).Thus, in these species, the muscular ridge appeared labile and bloodcould readily transverse the intraventricular cava. We conclude thatrelatively minor structural differences between non-crocodilianreptiles result in the fundamental changes in cardiac function.Further, our study emphasises that functionally similar intracardiacflow separation evolved independently in lizards (varanids) andsnakes (pythons) from an ancestor endowed with the capacity forlarge intracardiac shunts.

  • 10.
    Laska, Matthias
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Zoologi. Linköpings universitet, Tekniska högskolan.
    Rivas Bautista, Rosa Mariela
    2Instituto de Neuro-Etologia Universidad Veracruzana, Mexico.
    Höfelmann, Daniela
    Department of Medical Psychology University of Munich, Germany.
    Sterlemann, Vera
    3Department of Medical Psychology University of Munich, Germany.
    Hernandez Salazar, Laura Teresa
    2Instituto de Neuro-Etologia Universidad Veracruzana, Mexico.
    Olfactory sensitivity for putrefaction-associated thiols and indols in three species of non-human primate2007Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 210, nr 23, s. 4169-4178Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Using a conditioning paradigm, the olfactory sensitivity of four spider monkeys, three squirrel monkeys and three pigtail macaques to four thiols and two indols, substances characteristic of putrefaction processes and faecal odours, was assessed. With all odorants, the animals significantly discriminated concentrations below 1 p.p.m. (part per million) from the odourless solvent, and in several cases individual animals even demonstrated thresholds below 1 p.p.t. (part per trillion). The detection thresholds of 0.03 p.p.t. for indol in Saimiri sciureus and Macaca nemestrina and 0.96 p.p.t. for ethanethiol in Ateles geoffroyi represent the lowest values among the more than 50 odorants tested so far with these species and are in the same order of magnitude as the lowest detection thresholds reported so far in the rat and the mouse. The results showed (a) all three species of non-human primate to have a highly developed olfactory sensitivity for putrefaction-associated odorants, and (b) a significant correlation between perceptibility in terms of olfactory detection threshold and carbon chain length of the thiols, and a marked effect of the presence vs absence of a methyl group on perceptibility of the indols tested in two of the three species. The results support the hypotheses that (a) between-species differences in neuroanatomical or genetic features may not be indicative of olfactory sensitivity, and (b) within-species differences in olfactory sensitivity may reflect differences in the behavioural relevance of odorants.

  • 11.
    Nachtigal, Paul E.
    et al.
    Hawaii Institute of Marine Biology, University of Hawaii.
    Supin, Alexander Y.
    Russian Academy of Sciences, Moscow.
    Amundin, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Zoologi. Linköpings universitet, Tekniska högskolan.
    Röken, Bengt
    Kolmårdens Djurpark .
    Möller, Thorsten
    Kolmårdens Djurpark .
    Mooney, T. Aran
    Hawaii Institute of Marine Biology, University of Hawaii.
    Taylor, Kristen A.
    Hawaii Institute of Marine Biology, University of Hawaii.
    Yuen, Michelle
    Pacific Islands Regional Office, Honolulu.
    Polar bear Ursus maritimus hearing measured with auditory evoked potentials2007Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 210, s. 1116-1122Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    While there has been recent concern about the effects of sound on marine mammals, including polar bears, there are no data available measuring the hearing of any bear. The in-air hearing of three polar bears was measured using evoked auditory potentials obtained while tone pips were played to three individually anaesthetized bears at the Kolmården Djurpark. Hearing was tested in half-octave steps from 1 to 22.5 kHz. Measurements were not obtainable at 1 kHz and best sensitivity was found in the range from 11.2–22.5 kHz. Considering the tone pips were short and background noise measurements were available, absolute measurements were estimated based on an assumed mammalian integration time of 300 ms. These data show sensitive hearing in the polar bear over a wide frequency range and should cause those concerned with the introduction of anthropogenic noise into the polar bear's environment to operate with caution.

  • 12.
    Nespolo, Roberto F.
    et al.
    University of Austral Chile, Chile; University of Catolica Chile, Chile.
    Gonzalez-Lagos, Cesar
    University of Catolica Chile, Chile; University of Bernardo OHiggins, Chile.
    Solano-Iguaran, Jaiber J.
    University of Austral Chile, Chile.
    Elfwing, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Garitano-Zavala, Alvaro
    University of Mayor San Andres, Bolivia.
    Manosa, Santiago
    University of Barcelona, Spain.
    Carlos Alonso, Juan
    CSIC, Spain.
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Aerobic power and flight capacity in birds: a phylogenetic test of the heart-size hypothesis2018Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 221, nr 1, artikel-id UNSP jeb175208Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Flight capacity is one of the most important innovations in animal evolution; it only evolved in insects, birds, mammals and the extinct pterodactyls. Given that powered flight represents a demanding aerobic activity, an efficient cardiovascular system is essential for the continuous delivery of oxygen to the pectoral muscles during flight. It is well known that the limiting step in the circulation is stroke volume (the volume of blood pumped from the ventricle to the body during each beat), which is determined by the size of the ventricle. Thus, the fresh mass of the heart represents a simple and repeatable anatomical measure of the aerobic power of an animal. Although several authors have compared heart masses across bird species, a phylogenetic comparative analysis is still lacking. By compiling heart sizes for 915 species and applying several statistical procedures controlling for body size and/or testing for adaptive trends in the dataset (e.g. model selection approaches, phylogenetic generalized linear models), we found that (residuals of) heart size is consistently associated with four categories of flight capacity. In general, our results indicate that species exhibiting continuous hovering flight (i.e. hummingbirds) have substantially larger hearts than other groups, species that use flapping flight and gliding show intermediate values, and that species categorized as poor flyers show the smallest values. Our study reveals that on a broad scale, routine flight modes seem to have shaped the energetic requirements of birds sufficiently to be anatomically detected at the comparative level.

  • 13.
    Pertille, Fabio
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. University of Sao Paulo, Brazil.
    Brantsaeter, Margrethe
    Norwegian University of Life Science, Norway.
    Nordgreen, Janicke
    Norwegian University of Life Science, Norway.
    Lehmann Coutinho, Luiz
    University of Sao Paulo, Brazil.
    Janczak, Andrew M.
    Norwegian University of Life Science, Norway.
    Jensen, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Guerrero Bosagna, Carlos
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    DNA methylation profiles in red blood cells of adult hens correlate with their rearing conditions2017Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 220, nr 19, s. 3579-3587Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Stressful conditions are common in the environment where production animals are reared. Stress in animals is usually determined by the levels of stress-related hormones. A big challenge, however, is in determining the history of exposure of an organism to stress, because the release of stress hormones can show an acute (and recent) but not a sustained exposure to stress. Epigenetic tools provide an alternative option to evaluate past exposure to long-termstress. Chickens provide a unique model to study stress effects in the epigenome of red blood cells (RBCs), a cell type of easy access and nucleated in birds. The present study investigated whether two different rearing conditions in chickens can be identified by looking at DNA methylation patterns in their RBCs later in life. These conditions were rearing in open aviaries versus in cages, which are likely to differ regarding the amount of stress they generate. Our comparison revealed 115 genomic windows with significant changes in RBC DNA methylation between experimental groups, which were located around 53 genes and within 22 intronic regions. Our results set the ground for future detection of long-term stress in live production animals by measuring DNA methylation in a cell type of easy accessibility.

  • 14.
    Sandbom, Erik
    et al.
    Department of Zoology, Göteborg University.
    Farrell, Anthony P
    University of British Columbia, Canada.
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Zoologi. Linköpings universitet, Tekniska högskolan.
    Axelsson, Michael
    Department of Zoology, Göteborg University.
    Claireau, Guy
    Place du Séminaire, L'Houmeau, France .
    Cardiac preload and venous return in swimming sea bass (Dicentrarchus labrax L.)2005Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 208, s. 1927-1935Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cardiac preload (central venous pressure, P(CV), mean circulatory filling pressure (MCFP), dorsal aortic blood pressure (P(DA)) and relative cardiac output (Q) were measured in sea bass (Dicentrarchus labrax) at rest and while swimming at 1 and 2 BL s(-1). MCFP, an index of venous capacitance and the upstream venous pressure driving the return of venous blood to the heart, was measured as the plateau in Pcv during ventral aortic occlusion. Compared with resting values, swimming at 1 and 2 BL s(-1) increased Q (by 15+/-1.5 and 38+/-6.5%, respectively), P(CV) (from 0.11+/-0.01 kPa to 0.12+/-0.01 and 0.16+/-0.02 kPa, respectively), MCFP (from 0.27+/-0.02 kPa to 0.31+/-0.02 and 0.40+/-0.04 kPa, respectively) and the calculated pressure gradient for venous return (DeltaP(V), from 0.16+/-0.01 kPa to 0.18+/-0.02 and 0.24+/-0.02 kPa, respectively), but not P(DA). In spite of an increased preload, the increase in Q was exclusively mediated by an increased heart rate (f(H), from 80+/-4 beats min(-1) to 88+/-4 and 103+/-3 beats min(-1), respectively), and stroke volume (Vs) remained unchanged. Prazosin treatment (1 mg kg(-1) Mb) abolished pressure and flow changes during swimming at 1 BL s(-1), but not 2 BL s(-1), indicating that other control systems besides an alpha-adrenoceptor control are involved. This study is the first to address the control of venous capacitance in swimming fish. It questions the generality that increased Q during swimming is regulated primarily through Vs and shows that an increased cardiac filling pressure does not necessarily lead to an increased Vs in fish, but may instead compensate for a reduced cardiac filling time.

  • 15.
    Wang, Tobias
    et al.
    Department of Zoophysiology University of Aarhus, Denmark.
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Zoologi. Linköpings universitet, Tekniska högskolan.
    Klein, Wilfried
    Institute of Zoology University of Bonn, Germany.
    Axelsson, Michael
    Department of Zoology University of Gothenburg.
    Ventricular haemodynamics in Python molurus: Separation of pulmonary and systemic pressures2003Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 206, nr 23, s. 4241-4245Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Vascular pressure separation by virtue of a two-chambered ventricle evolved independently in mammals and birds from a reptilian ancestor with a single ventricle, and allowed for high systemic perfusion pressure while protecting the lungs from oedema. Within non-crocodilian reptiles, ventricular pressure separation has only been observed in varanid lizards and has been regarded as a unique adaptation to an active predatory life style and high metabolic rate. The systemic and pulmonary sides of the ventricle in Python molurus are well separated by the muscular ridge, and a previous study using in situ perfusion of the heart revealed a remarkable flow separation and showed that the systemic side can sustain higher output pressures than the pulmonary side. Here we extend these observations by showing that systemic blood pressure Psys exceeded pulmonary pressure Ppul almost seven times (75.7±4.2 versus 11.6±1.1 cm H2O). The large pressure difference between the systemic and pulmonary circulation persisted when Psys was altered by infusion of sodium nitroprusside or phenylephrine. Intraventricular pressures, measured in anaesthetised snakes, showed an overlap in the pressure profile between the pulmonary side of the ventricle (cavum pulmonale) and the pulmonary artery, while the higher pressure in the systemic side of the ventricle (cavum arteriosum) overlapped with the pressure in the right aortic arch. This verifies that the pressure differences originate within the ventricle, indicating that the large muscular ridge separates the ventricle during cardiac contraction.

  • 16.
    Wu, Chi-Chih
    et al.
    Uppsala Univ, Sweden.
    Klaesson, Axel
    Uppsala Univ, Sweden.
    Buskas, Julia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Uppsala Univ, Sweden.
    Ranefall, Petter
    Uppsala Univ, Sweden.
    Mirzazadeh, Reza
    Karolinska Inst, Sweden.
    Soderberg, Ola
    Uppsala Univ, Sweden.
    Wolf, Jochen B. W.
    Uppsala Univ, Sweden; Ludwig Maximilians Univ Munchen, Germany.
    In situ quantification of individual mRNA transcripts in melanocytes discloses gene regulation of relevance to speciation2019Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 222, nr 5, artikel-id UNSP jeb194431Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Functional validation of candidate genes involved in adaptation and speciation remains challenging. Here, we exemplify the utility of a method quantifying individual mRNA transcripts in revealing the molecular basis of divergence in feather pigment synthesis during early-stage speciation in crows. Using a padlock probe assay combined with rolling circle amplification, we quantified cell-typespecific gene expression in the histological context of growing feather follicles. Expression of Tyrosinase Related Protein 1 (TYRP1), Solute Carrier Family 45 member 2 (SLC45A2) and Hematopoietic Prostaglandin D Synthase (HPGDS) was melanocyte-limited and significantly reduced in follicles from hooded crow, explaining the substantially lower eumelanin content in grey versus black feathers. The central upstream Melanocyte Inducing Transcription Factor (MITF) only showed differential expression specific to melanocytes - a feature not captured by bulk RNA-seq. Overall, this study provides insight into the molecular basis of an evolutionary young transition in pigment synthesis, and demonstrates the power of histologically explicit, statistically substantiated single-cell gene expression quantification for functional genetic inference in natural populations.

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