Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Steroids accumulation in recirculating aquaculture systems
    Mota, V.C. - \ 2015
    Wageningen University. Promotor(en): Johan Verreth, co-promotor(en): A.V.M. Cana´rio; C.I.M. Martins. - Wageningen : Wageningen University - ISBN 9789462575554 - 145
    steroïden - recirculatie aquacultuur systemen - prestatieniveau - bezettingsdichtheid - stress - ph - hydrocortison - testosteron - chemische communicatie - visteelt - viskwekerijen - steroids - recirculating aquaculture systems - performance - stocking density - stress - ph - hydrocortisone - testosterone - chemical communication - fish culture - fish farms
    Nutritional analysis and intervention in the captive woolly monkey (Lagothric lagotricha)
    Ange-van Heugten, K.D. - \ 2008
    Wageningen University. Promotor(en): Martin Verstegen, co-promotor(en): P. Ferket. - [S.l.] : S.n. - ISBN 9789085049012 - 191
    apen - diervoeding - diergezondheid - dierziekten - diëten - voedingsstoffen - levensverwachting - bloedserum - bloedchemie - diabetes mellitus - hydrocortison - voedselsupplementen - dierentuinen - dieren in gevangenschap - voeding en gezondheid - monkeys - animal nutrition - animal health - animal diseases - diets - nutrients - life expectancy - blood serum - blood chemistry - diabetes mellitus - hydrocortisone - food supplements - zoological gardens - captive animals - nutrition and health
    Woolly monkeys (Lagothrix ssp.) are a threatened species in the wild and are extremely difficult to breed and successfully maintain in captivity. The majority of health complications in woolly monkeys (WM) may be of nutritional origin. The objectives of this thesis were to: 1) determine the current status of the captive WM, 2) isolate potential nutritional causes for primary disorders in captive WM, and 3) investigate the effects that diet nutrients have on WM serum chemistry and cortisol concentrations. Our studies showed that the number of captive WM have decreased by 11% in the past 16 years. The number of institutions holding WM decreased and the birth to death ratio is 0.65 compared to 1.26 for their close relative the spider monkey (SM) (Ateles spp.). Lack of genetic diversity in captive WM also may negatively influence their success. Serum chemistry from 30 WM housed at two zoos were similar to previously reported concentrations for howler (Aloutta sp.) and SM; however, serum glucose was above the baseline range compared to humans and SM. Fasting concentrations of glucose, insulin, fructosamine, glycated hemoglobin, circulating lipids and urinary glucose were within normal ranges in six WM with known hypertension problems compared to other monkeys and humans. Potential stressors, such as unnatural diet, can contribute to the low success of endangered primates via noted health abnormalities. Fecal and salivary cortisol concentrations in WM and SM, at multiple zoological institutions showed that zoos with the highest dietary total carbohydrates, total sugars, glucose and fruit content had the highest cortisol. Supplementation of WM and SM diets with inulin-type fructans numerically decreased fecal cortisol after 4 weeks of supplementation, primarily in SM. The lifespan and reproductive success of captive primates will improve if stressors and negative effects of nutrition on the health status can be reduced and dietary nutrients can be optimized.
    Natuur, stress en cortiso l: experimenteel onderzoek naar de invloed van tuinieren en activiteiten in een groenkamer op het fysiologisch, affectief en cognitief herstel van stress
    Custers, M.H.G. ; Berg, A.E. van den - \ 2007
    Wageningen : Alterra (Alterra-rapport 1629) - 111
    mentale stress - tuinieren - hydrocortison - gezondheid - natuur - omgevingspsychologie - stress - welzijn - mental stress - gardening - hydrocortisone - health - nature - environmental psychology - stress - well-being
    In dit rapport wordt verslag gedaan van een literatuuronderzoek en twee experimentele studies naar de stressherstellende functie van natuur. Het literatuuronderzoek geeft een beschrijving van de kennis rondom stress, het omgaan met stress, en het meten van stress. Ook wordt een overzicht gegeven van eerder onderzoek naar de stressherstellende functie van natuur, en de mogelijke mechanismen die hieraan ten grondslag liggen. In de experimentele studies is de stressherstellende functie van natuur onderzocht met behulp van metingen van het cortisolniveau in het speeksel. Het eerste experiment richtte zich op de stressherstellende functie van tuinieren op een volkstuin. In het tweede experiment werden de stressherstellende effecten van een verblijf in een groenkamer in een zorgcentrum onderzocht. In beide experimenten zijn, in aanvulling op de cortisolmetingen, ook andere stressmaten, in de vorm concentratie- en/of stemmingstests, afgenomen. De resultaten van beide studies bieden ondersteuning voor de veronderstelling dat contact met natuur een gunstige invloed heeft op het herstel van stress
    Neuroendocrine-immune interactions in carp: a role for cortisol and interleukin-1
    Engelsma, M. - \ 2002
    Wageningen University. Promotor(en): W.B. van Muiswinkel; B.M.L. Verburg-van Kemenade. - S.l. : S.n. - ISBN 9789058086655 - 158
    karper - cyprinus - hydrocortison - interleukine 1 - endocrien systeem - immuunsysteem - leukocyten - interacties - stress - neurofysiologie - carp - cyprinus - hydrocortisone - interleukin 1 - endocrine system - immune system - leukocytes - interactions - stress - neurophysiology

    Maintaining a dynamic internal equilibrium, homeostasis, is crucial for survival of an organism. Disturbances in the environment may threaten the homeostasis and this will subsequently evoke an adaptive response in order to restore homeostasis. In vertebrates the adaptive response is mediated via the neuroendocrine system by adrenocortical and adrenergic activation. Glucocorticoids (GC) and catecholamines are the main actors in the response and can affect a whole range of processes, including those in the immune system. In response to pathogenic challenges the immune system is triggered, resulting in activation of components of innate and acquired immunity. Bi-directional communication between the Hypothalamus-Pituitary-Adrenal (HPA)-axis, sympathetic nervous system and the immune system is crucial to ensure homeostasis in mammals. Shared use of ligands and especially receptors forms a key component of this mutual interaction.

    The Hypothalamus-Pituitary-Interrenal (HPI)-axis is the teleost equivalent of the HPA-axis. Stress induced immuno-suppression in fish is mostly attributed to actions of cortisol, major GC in fish and end-product of the HPI-axis. Stress in aquaculture is one of the potential factors causing increased susceptibility of fish to pathogens and subsequently considerable losses in production.

    As part of a programme investigating adaptive strategies of carp ( Cyprinus carpio L.) after temperature stress, this study focuses on the possible neuroendocrine modulation of immune functioning during acute stress. We studied the effects of in vitro cortisol and in vivo acute temperature stress on carp leucocytes and functioning of these leucocytes. Moreover, the cortisol influence on gene expression of the cytokine interleukin-1b(IL-1b) was studied. IL-1bin mammals is part of the reciprocal signalling between neuroendocrine and immune system, therefore it may be an important candidate for modulating hormone secretion in carp.

    Cortisol acts upon lymphocytes differentially; in previous research it was demonstrated that in carp, in particular the B lymphocytes are affected. In vertebrates B lymphocytes play an important role in acquired immunity as precursors of antibody producing cells. Maturation and activation state of B lymphocytes may have consequences for the influence cortisol has on these cells. Therefore, carp B lymphocytes were isolated from different tissues and compared with regard to their proliferation, apoptosis and the effects of cortisol on these processes. Head kidney and spleen B lymphocytes were characterised by high basal proliferation. Peripheral blood B lymphocytes showed a low basal proliferation which could be up-regulated by stimulation with lipopolysaccharide (LPS), a major constituent of the cell wall of gram-negative bacteria. LPS could not alter proliferation of head kidney B lymphocytes. In addition, Ig-crosslinking induced higher intracellular calcium responses in circulating B lymphocytes compared with B lymphocytes from head kidney or spleen origin. With respect to apoptosis, stimulation could enhance cell viability in all organs. However, in combination with cortisol high levels of apoptosis were induced. Especially activated peripheral blood B lymphocytes were sensitive to cortisol-induced apoptosis. Also head kidney and to a lesser extent spleen B lymphocytes, although less sensitive than their equivalent in circulation, underwent cortisol-induced apoptosis irrespective of extra stimulation. Proliferation was suppressed by cortisol in blood and spleen B lymphocytes and to a more limited extent in head kidney, regardless of LPS stimulation. It is suggested that cortisol may be important for immunoregulation in both stress and non-stress conditions, because the relatively modest concentration of cortisol used (compared to plasma values measured during stress conditions) could induce a significant increase in apoptosis in all three populations of B lymphocytes. This implies an impact of stress on B lymphocyte development and activity.

    Stress-induced immunological changes that may contribute to a decreased disease resistance in carp were investigated. A 3 h drop in ambient water temperature was used as model for a relative mild and acute stressor for carp. After single or multiple temperature shocks, the relative number of circulating B lymphocytes decreased significantly within 4 h after the onset of the stressor, which was even more pronounced than after challenging the immune system. After a single temperature shock the relative number of B lymphocytes returned to control levels within 24 hours. In head kidney, an increase was measured in the relative number of B lymphocytes. Migration of B lymphocytes resulting in a redistribution of these cells to other body compartments may contribute to the relative drop in B lymphocytes in the circulation. Granulocyte numbers showed opposite reactions, doubling in circulation and decreasing significantly in head kidney. This demonstrates differential modulation of immune cells in vivo by a relative mild stressor. Freshly isolated blood lymphocytes from stressed carp showed a considerable higher number of apoptotic cells than lymphocytes from unstressed animals. Besides B lymphocytes, Ig -lymphocytes contributed significantly to this stress-induced apoptosis. Glucocorticoid receptors could be detected in the vast majority of the B lymphocytes and also part of the Ig -lymphocytes. As distribution of B lymphocytes was substantially affected by temperature stress, the effects of multiple temperature shocks on humoral antibody responses were determined. The kinetics of the antibody response to both, T lymphocyte independent (TI) antigens and T lymphocyte dependent (TD) antigens consistently showed a trend to decreased antibody response in stressed carp. In carp immunised with the TI-antigen TNP-LPS the antibody response was significantly slower in the stressed carp. These observations confirm the effect of temperature stress on the B lymphocyte population.

    These results show that even a mild stressor can affect distribution of B lymphocyte and granulocyte cell populations reversibly with differential effects and thus can have implications for a subsequent immune response. However, during acute stress, the role of cortisol is most probably not purely immunosuppressive but more immunomodulatory. A stress-induced enhancement of an innate type of response could facilitate a fast and effective reaction of the immune system.

    Cytokines, like IL-1b, play a pivotal role in the regulation of the immune system. Macrophages and a whole range of other cells release IL-1bas a response to infection or tissue damage. IL-1bhas pleiotropic effects as an immune and inflammatory mediator. Furthermore, IL-1bis an important candidate able to affect the HPI-axis by altering the release of corticotropin releasing hormone (CRH) and adrenocorticotropic hormone (ACTH).

    In fish, most interleukin molecules await identification but the IL-1bsequences of several teleost fishes were recently elucidated. In the tetraploid carp we describe gene organisation and expression of two IL-1bgenes: IL-1b1 and IL-1b2. The two carp mRNA sequences share about 74% amino acid identity. The existence of two IL-1bcopies in the carp genome probably originates from the tetraploid nature of the species. In contrast to carp IL-1b1, the IL-1b2 locus is represented by multiple sequences with 95-99% identity. Detection of up to 6 distinct IL-1b2 sequences within single homozygous fish suggests the presence of multiple copies of the IL-1b2 gene in the carp genome. Both IL-1b1 and IL-1b2 comprise seven exons with typical IL-1 characteristics as an IL-1 family motif and instability motifs in the 3'-untranslated region. A general discrepancy of teleost IL-1bsequences described thus far with mammalian IL-1b, is the lack of a clear caspase-1 (interleukin- 1b-converting enzyme; ICE) cleavage site. Three IL-1b1 RNA transcripts could be detected in carp: (1) a fully spliced product, (2) exon 1-7 with introns 5 and 6 and (3) exon 1-7 with intron 5 only. Intron-containing products were also detected for IL-1b2. These intron-containing products probably represent partially spliced transcripts.

    IL-1bmRNA expression in carp was semi-quantitatively analysed by RT-PCR in multiple organs, including brain and pituitary. In vivo , mRNA of both IL-1bsequences were constitutively expressed in healthy carp, for IL-1b1 this was predominantly in the immune organs head kidney and spleen. Furthermore, a scattered distribution of IL-1b1 producing cells was shown by in situ hybridisations of head kidney tissue. Administration of phorbol-myristate-acetate (PMA) or LPS to phagocytes isolated from the head kidney, resulted in up-regulation of IL-1b1 expression. Also IL-1b2 transcripts could be up-regulated by in vitro LPS stimulation of head kidney phagocytes. Interestingly, by determining the ratio of expression it was demonstrated that IL-1b2 is expressed at a maximum of one tenth of the amount of the IL-1b1 sequence. Together with the high number of amino acid substitutions in the IL-1b2 sequences this suggests either that IL-1b2 is approaching a pseudogene status or IL-1b2 is part of a complex receptor - ligand interaction network. The involvement of nuclear factor (NF)-kB in carp IL-1b1 expression was shown with suppression of the LPS-induced IL-1bexpression by the NF-kB inhibitor, pyrrolidine dithiocarbamate (PDTC). Data suggests also that carp IL-1b2 is regulated via NF-kB and consequently both IL-1bsequences appear to have similar promoter regions.

    Cortisol, as endocrine-derived factor potentially mediating carp IL-1bexpression, was able to inhibit constitutive expression of IL-1b1 as well as IL-1b2 transcripts in vitro. However, when cortisol was added in combination with LPS at a physiological dose, cortisol could not inhibit LPS-induced expression. Moreover, it appears that cortisol synergistically enhances LPS-induced IL-1bexpression in carp. Probably LPS overrules the glucocorticoid receptor mediated inhibition via the NF-kB pathway. This might imply that cortisol can not suppress IL-1bactivation during infection. At a tenfold higher cortisol dose, however, the expression is inhibited.

    In conclusion, data presented in this thesis show that carp leucocytes are differentially sensitive to cortisol and in vivo stress, with regard to cell type, location and maturation or activation state. This affects cell viability, replication and migration with subsequent consequences for the immune status of carp. Also interaction of the neuroendocrine system with immune regulating factors was demonstrated: cortisol affects carp IL-1bmRNA expression. IL-1bin carp consists of multiple forms and is part of an immune regulating mechanism which probably matches that of mammals in complexity.

    Stress and stress disorders in a teleost fish, the common carp Cyprinus carpio L.
    Ruane, N.M. - \ 2002
    Wageningen University. Promotor(en): E.A. Huisman; J. Komen. - S.l. : S.n. - ISBN 9789058087485 - 160
    karper - zoetwatervissen - stressreactie - stress - hydrocortison - fysiologie - dierenwelzijn - visteelt - afwijkingen - psychologische fysiologie - carp - freshwater fishes - stress response - stress - hydrocortisone - physiology - animal welfare - fish culture - abnormalities - psychological physiology

    Unlike research using mammalian animal models such as rats or mice, experimental fish often come from wild or commercial sources, leading to a lack of well defined experimental animal models. Isogenic carp offer us a well defined fish model for physiological research. The aim of this thesis was to, therefore, investigate the physiological stress response of isogenic strains of carp. Increased levels of stress in intensively reared animals results in large economical losses (due to disease mortalities, poor growth) and an increased understanding of the stress response is therefore relevant to the fish farming industry. Using a standard stressor, we aimed to examine the influence of environmental disturbances (e.g. high densities, restricted feeding levels) on the physiological response of the carp to this stressor. Fish showed a mild response to the period of crowding, although they appeared to recover physiologically, fish reared at a high density were more sensitive to an additional disturbance as seen by the higher levels of stress-hormones in the circulation. In addition, alternate periods of optimal or maintenance feeding levels were also found to affect the response to stress. An alternative method for measuring chronic stress in fish was also established through hormonal measurements in the water. A stress disorder was noted in one strain, these fish appear to suffer from a disorder similar to the 'chronic adrenal hyperplasia' which occurs in mammals. As this has never been described in a lower vertebrate, these fish may prove to be an important model for future studies on fish endocrinology.

    Selective breeding for stress response in common carp (Cyprinus carpio L.) using androgenesis
    Tanck, M. - \ 2000
    Agricultural University. Promotor(en): E.A. Huisman; E.W. Brascamp; J. Komen. - S.l. : S.n. - ISBN 9789058083470 - 185
    cyprinus - karper - selectief fokken - androgenese - stressreactie - genetica - hydrocortison - cyprinus - carp - selective breeding - androgenesis - stress response - genetics - hydrocortisone

    The aim of the thesis was to explore the genetic background of stress response in common carp ( Cyprinus carpio L.) and produce homozygous and heterozygous isogenic strains with divergent stress responses. As stressor a rapid temperature decrease (= cold shock) was used. As a preparatory step, a number of experiments were carried out to 1) investigate the validity of the cold shock as a stressor, 2) investigate the possible influences of environmental factors on the stress response, and 3) define a selection criterion for the selection experiment. The stress response of common carp was studied by evaluating plasma cortisol, glucose and lactate after single or multiple rapid temperature drops (ΔT: 7, 9 or 11 °C). All three amplitudes used induced a significant rise in plasma cortisol levels. Peaks occurred within 20 min after onset of the cold shock. No stress-related related secondary metabolic changes were observed in any of the experiments described: plasma glucose levels remained unaffected and plasma lactate levels dropped. Carp of 60 days old showed a significant stress response, although plasma cortisol levels were lower than those observed in carp of 120 days. Furthermore, fish that had experienced multiple cold shocks showed an overall lower cortisol response than fish experiencing a single cold shock, indicating that habituation to this stressor occurred. Based on these results, the plasma cortisol concentration at 20 min after onset of the cold shock was set as selection criterion in our selection experiment and fish were tested at a minimal age of 100 days post hatching.

    The first step in the actual selection experiment was the formation of the base population. This base population was an F 1 cross between six sires from a wild strain originating from the Anna Paulowna (AP) polder and a highly domesticated homozygous E4 dam already present in our laboratory. The six sires, caught in the water system surrounding the Anna Paulowna (AP) Polder in The Netherlands, were characterised using allozyme and microsatellite markers. At the sMDH-A1,2* loci an allele was found, which was previously only found in wild River Rhine and wild Vietnamese common carp. Microsatellite allele frequencies showed that these AP carp were significantly different from a group of carps originating from several different domesticated strains. Based on both allozyme and microsatellite data, the AP carp most likely originated from a wild or feral self-sustaining population.

    Thirty-three randomly picked sires from these six E4 × AP full-sib families (F 1 ) were androgenetically reproduced to create the F 2 generation, which thus consisted of 33 doubled haploids (DH) progeny groups. These 33 DH progeny groups (566 individuals) were subjected to the 9 °C cold shock, enabling us to estimate heritabilities for weight, length, condition factor (K), and plasma cortisol, glucose and lactate concentrations using Gibbs sampling and an animal model. Estimated heritabilities for the morphological traits weight and length were 0.09 (90% Highest Posterior Density range: 0.03 - 0.17) and 0.11 (0.04 - 0.21), respectively. The condition factor (K), showed a medium heritability of 0.37 (0.20 - 0.62). Heritabilities for basal plasma glucose and lactate were 0.19 (0.10 - 0.33) and 0.56 (0.33 - 0.85), respectively. For stress-related cortisol increase a high heritability estimate of 0.60 (0.37 - 0.90) was found. Although the height of this cortisol heritability has to be regarded with some reservation, due to confoundedness of some environmental effects with sire effects, the estimated heritability clearly shows that the stress response due to a cold shock is hereditary in the carp population used.

    Because the model used to estimate the h2 assumed a complete homozygous state of the DH individuals and to ensure that only homozygous individuals would be used for subsequent reproduction, all individuals within the 33 DH androgenetic progeny groups were analysed using 11 microsatellite markers to: 1) verify the homozygous status of the 566 androgenetic DH individuals, 2) analyse the microsatellite allele segregation, and 3) study possible association of microsatellite alleles with the phenotypic traits recorded. In total, 92% of the androgenetic DH individuals proved to be homozygous at all 11 loci. Forty-three out of the 47 heterozygous individuals were heterozygous at a single locus only. This heterozygosity was probably due to DNA fragments caused by UV-irradiation of the eggs, although the maternal origin of the fragments could not be proved beyond doubt. Screening with 11 microsatellites also revealed two linkage groups, a segregation distortion at two microsatellite loci and possible association of some microsatellites with weight, length, stress-related plasma cortisol levels and basal plasma glucose levels. The success of the linkage and association study could be explained by a low recombination frequency due to high chiasma interference. This would imply a relatively short genetic map length for common carp.

    Selection of individual fish from the 33 DH progeny groups based on the response at 4 months was not possible. Therefore, three DH progeny groups with a high (H1-3) and three with a low (L1-3) mean plasma cortisol concentration were selected. The 154 DH fish in these six groups were individually tagged, mixed and subjected to a second cold shock at an age of 15 months. For each individual fish, a breeding value was estimated (EBV 15 ) for stress-related cortisol using an animal model with a fixed h 2 of 0.60. Two homozygous sires (two high and two low) and dams (high and low) were selected based on their EBV 15 and used to produce four homozygous (HomIso) and eight heterozygous isogenic (HetIso) strains. These were used in two separate experiments to examine the genetic background of the stress-related cortisol response. In both experiments, the strains were subjected to the 9 °C cold shock at an age of 5 months. The ranking in plasma cortisol levels of the HomIso strains was identical to the ranking in EBV 15 of the sires and the maximal difference of 350 nmol.l -1 was similar to the expected difference based on these EBV 15 's. Differences between the HetIso strains were smaller than expected, and influence of non-additive genetic effects could not be detected ( PD×S = 0.14). Estimated breeding values based on the performance of the androgenetic progeny (EBV 5 ) in experiment 1 and general combining abilities (GCA) of the sires and dams calculated in experiment 2 were positively correlated with the EBV 15 ( r not significantly different from 1), providing no evidence that the stress response at 5 and 15 months are different traits.

    Apart from the isogenic strain used in the first experiments, no complete profiles of the cortisol, glucose and lactate dynamics had been examined in other isogenic strains. Therefore, an additional experiment, parallel to the selection experiment, was carried out to investigate the 'complete' cortisol, glucose and lactate dynamics during the cold shock in four, readily available, isogenic at two different ages. The experiments showed that stress-related cortisol response patterns can differ consistently between genotypes of common carp. Significant dam and sire effects on the total amount of cortisol measured during the cold shock were found, but no significant dam × sire interaction effect. Although no significant difference was found between the cortisol response dynamics at 5 or 7 months, the results justify further research into that field. The observed differences in plasma glucose and lactate dynamics between control and shocked fish were most likely temperature related. Age did not have any apparent influence on either plasma glucose or lactate dynamics in both control and shocked fish.

    Based on the results of the experiments described in this thesis, it can be argued that the best method to change the stress response of common carp would be through selective breeding (exploiting additive genetic effects) rather than through crossbreeding (exploiting non-additive genetic effects). The selection and the 'parallel' experiments resulted in several isogenic strains of common carp with at least two types of cortisol stress responses. Type I showed a relative short cortisol response with either a high or low peak at 20 min after onset of the shock. Type II showed a similar cortisol level at 20 min but no significant decrease in this level during the cold shock. These different isogenic strains will be valuable tools in future research into the stress response itself and its effects on other traits like growth, reproduction and health. This way, some of the problems related to the use of stress response as selection criterion in commercial breeding programmes in fish could be solved in the near future.

    Residual heterozygosity was demonstrated to occur in androgenetic progenies, most likely due to maternal DNA fragments induced by the UV irradiation of the eggs. Improved control measures were implemented in the androgenesis procedure, but androgenetic progenies destined for further reproduction purposes should be screened for residual heterozygosity. Androgenetic reproduction proved to be a useful tool for dissection of phenotypic variance and heritability estimations for traits, especially in combination with selection experiments aimed at development of isogenic strains for this trait. Androgenesis might result in reduced fertility in female progeny, but the advantages are such that inclusion of androgenetic reproduction within larger commercial breeding programmes for faster dissemination of genetic progress and product protection should be considered as a promising option.

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