0000000000114443
AUTHOR
Ilmari Jokinen
Manipulation of offspring number and size: benefits of large body size at birth depend upon the rearing environment
Summary 1. Allocation of reproductive effort between the number and size of offspring determines the immediate rearing environment for the growing young. As the number of offspring increases, the amount of parental investment per individual offspring decreases, and the quality of the rearing environment is expected to decrease. This may result in a lower quality of offspring reared in such conditions. 2. We studied the effects of the rearing environment on the quality of juvenile bank voles, Clethrionomys glareolus , with different initial body sizes at birth in a 2 〈 2 factorial experiment. The rearing environment was manipulated by enlarging both the litter size by two extra pups, and mea…
Loss of density-dependence and incomplete control by dominant breeders in a territorial species with density outbreaks
Abstract Background A territory as a prerequisite for breeding limits the maximum number of breeders in a given area, and thus lowers the proportion of breeders if population size increases. However, some territorially breeding animals can have dramatic density fluctuations and little is known about the change from density-dependent processes to density-independence of breeding during a population increase or an outbreak. We suggest that territoriality, breeding suppression and its break-down can be understood with an incomplete-control model, developed for social breeders and social suppression. Results We studied density dependence in an arvicoline species, the bank vole, known as a terri…
Long-term UVB irradiation affects the immune functions of carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss).
The effects of long-term, low-dose ultraviolet B (UVB) radiation on immune functions of two fish species representing different taxonomic groups, carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss), were assessed in this study. The fish were exposed to 7, 20 or 60 mJ cm(-2) UVB three times per week, for 6 weeks. In carp, UVB exposure affected the respiratory burst activity of blood and head kidney phagocytes, differential blood leukocyte counts and blood chemistry. Phytohemagglutinin (PHA)-stimulated in vitro proliferation responses of blood and head kidney lymphocytes, however, remained unchanged. Rainbow trout tolerated the irradiations with fewer alterations, but significant c…
Do pheromones reveal male immunocompetence?
Pheromones function not only as mate attractors, but they may also relay important information to prospective mates. It has been shown that vertebrates can distinguish, via olfactory mechanisms, major histocompatibility complex types in their prospective mates. However, whether pheromones can transmit information about immunocompetence is unknown. Here, we show that female mealworm beetles (Tenebrio molitor) prefer pheromones from males with better immunocompetence, indicated by a faster encapsulation rate against a novel antigen, and higher levels of phenoloxidase in haemolymph. Thus, the present study indicates that pheromones could transmit information about males' parasite resistance ab…
GENETIC AND ENVIRONMENTAL VARIATION IN ANTIBODY AND T-CELL MEDIATED RESPONSES IN THE GREAT TIT
Host parasite coevolution assumes pathogen specific genetic variation in host immune defense. Also, if immune function plays a role in the evolution of life history, allocation to immune function should be heritable. We conducted a cross-fostering experiment to test the relative importance of genetic and environmental sources of variation in T-cell mediated inflammatory response and antigen specific antibody responses in the great tits Parus major. Cell mediated response was measured during the nestling period and antibody response against two novel antigens was measured in two-month-old juveniles raised in a laboratory. We found no effect of nest of origin, but a strong effect of rearing e…
IGF-I, IgA, and IgG responses to bovine colostrum supplementation during training.
This study examined the effect of bovine colostrum (Dynamic colostrum) supplementation on blood and saliva variables ( study 1) and the absorption of orally administered human recombinant insulin-like growth factor (IGF)-I (rhIGF-I) labeled with 123I (123I-rhIGF-I) ( study 2). In study 1, adult male and female athletes were randomly assigned in a double-blind fashion to either an experimental (Dynamic; n = 19) or a control (Placebo; n = 11) group. The former consumed daily 20 g of Dynamic supplement, and the latter 20 g of maltodextrin during a 2-wk training period. After bovine colostrum supplementation, significant increases were noticed in serum IGF-I ( P < 0.01) and saliva IgA ( P &…
Additive effects of enhanced ambient ultraviolet B radiation and increased temperature on immune function, growth and physiological condition of juvenile (parr) Atlantic Salmon, Salmo salar.
Climate change models predict increased ultraviolet B (UVB) radiation levels due to stratospheric ozone depletion and global warming. In order to study the impact of these two environmental stressors acting simultaneously on the physiology of fish, Atlantic salmon parr were exposed, for 8 weeks in outdoor tanks, to different combinations of UVB radiation (depleted and enhanced) and temperature (standard rearing temperature of 14 °C or 19 °C). The immune function (plasma IgM, lysozyme activity and complement bacteriolytic activity), growth (body weight) and physiological condition (haematocrit and plasma protein concentration) of the fish were determined. Increased UVB level, regardless of w…
Testosterone-Mediated Effects on Fitness-Related Phenotypic Traits and Fitness
International audience; The physiological and behavioral mechanisms underlying life-history trade-offs are a continued source of debate. Testosterone (T) is one physiological factor proposed to mediate the trade-off between reproduction and survival. We use phenotypic engineering and multiple laboratory and field fitness-related phenotypic traits to test the effects of elevated T between two bank vole Myodes glareolus groups: dominant and subordinate males. Males with naturally high T levels showed higher social status (laboratory dominance) and mobility (distance between capture sites) than low-T males, and the effect of T on immune response was also T group specific, suggesting that behav…
Effects of UV Radiation and Diet on Polyunsaturated Fatty Acids in the Skin, Ocular Tissue and Dorsal Muscle of Atlantic Salmon (Salmo salar) Held in Outdoor Rearing Tanks
Article published in Photochemistry and Photobiology, 86 (4): 909-919 JUL-AUG 2010 The effect of UV radiation (UVR) on juvenile Atlantic salmon (Salmo salar) was assessed by measuring the fatty acid (FA) profiles of muscle, dorsal and ventral skin, and ocular tissues following 4-month long exposures to four different UVR treatments in outdoor rearing tanks. Fish were fed two different diets (Anchovy- and Herring-oil based) that differed in polyunsaturated fatty acid (PUFA) concentrations. Anchovy-fed salmon had higher concentrations of ALA (alpha-linoleic acid; 18:3n-3), EPA (eicosapentaenoic acid; 20:5n-3) and DPA (docosapentaenoic acid, 22:5n-3) in their muscle tissues than fish fed the H…
Breeding-related seasonal changes in immunocompetence, health state and condition of the cyprinid fish, Rutilus rutilus, L.
Seasonal changes in immunocompetence are predicted by the hypothesized trade-off between reproduction and self-maintenance, whereby immune function is a measure of self-maintenance and reproductive effort is seasonally dependent. We examined seasonal patterns in immunological, haematological and body condition parameters for male and female freshwater fish. In two different populations, the relative size of the spleen and the chemotaxic migration activity of head kidney granulocytes decreased immediately before and after spawning, respectively. Those decreases were accompanied by an increase in haematocrit values shortly before and after spawning in both populations and a decrease in the re…
Intra‐ and Intersexual Trade‐Offs between Testosterone and Immune System: Implications for Sexual and Sexually Antagonistic Selection
International audience; Parasites indirectly affect life-history evolution of most species. Combating parasites requires costly immune defenses that are assumed to trade off with other life-history traits. In vertebrate males, immune defense is thought to trade off with reproductive success, as androgens enhancing sexual signaling can suppress immunity. The phenotypic relationship between male androgen levels and immune function has been addressed in many experimental studies. However, these do not provide information on either intra- or intersex genetic correlations, necessary for understanding sexual and sexually antagonistic selection theories. We measured male and female humoral antibod…
FITNESS TRADE-OFFS MEDIATED BY IMMUNOSUPPRESSION COSTS IN A SMALL MAMMAL
International audience; Trade-offs are widespread between life-history traits, such as reproduction and survival. However, their underlying physiological and behavioral mechanisms are less clear. One proposed physiological factor involves the trade-off between investment in male reproductive effort and immunity. Based on this hypothesis, we investigated differences in fitness between artificially selected immune response bank vole groups, Myodes glareolus. Significant heritability of immune response was found and a correlated response in testosterone levels to selection on immune function. Male reproductive effort, reproductive success, and survival of first generation offspring were assess…
Optimal diet composition for European whitefish (Coregonus lavaretus): carbohydrate stress and immune parameter responses
Abstract A feeding trial was conducted on the European whitefish to study the effects of replacing fish meal with fish oil and corn starch on the stress response and immune system parameters. Nine diets with varying levels of fish meal (FM; 38–86%), fish oil (FO; 2–22%) and corn starch (CS; 0–33%), and fixed levels of wheat meal (10%) and vitamin–mineral premix (2%) were formulated and replicates were allocated among 25 tanks following the D-optimality criteria. Fish were fed the extruded diets to satiation for 10 weeks in a flow-through freshwater system at 15 °C. The liver and plasma were sampled at the termination of the trial, and the response surfaces were modeled as Scheffe polynomial…
Lysosomal trafficking in rat cardiac myocytes.
By immunolabeling of cryosections, we have characterized in rat cardiac myocytes the cation-independent mannose-6-phosphate receptor (MPR), a lysosomal membrane glycoprotein, lgp120, and a lysosomal enzyme, MEP (homologous to cathepsin L). Most of the MPR label was located in large membrane-filled structures (MPR structures) in large clusters of mitochondria adjacent to but distinct from the Golgi complex. Lpg120 and MEP showed typical lysosomal localization throughout the cell, often associated with regions that appeared to contain autophagosome-like structures. In addition, MEP and lgp120 co-localized within MPR structures. MEP and MPR were localized inside the lumen of MPR structures. M…
Biomarker responses along a pollution gradient: Effects of pulp and paper mill effluents on caged whitefish
Abstract Lake Saimaa (SE Finland) is a large oligotrophic lake receiving biologically treated effluent from a bleached kraft pulp and paper mill. Hatchery-reared juvenile whitefish ( Coregonus lavaretus L. s.l.), a species known to feed on plankton and other particulates, were caged using a technique developed and optimized for this species and were exposed for one month in five downstream stations (3.3–16 km). Two reference stations (4.5–8.5 km) upstream from the effluent outlet were used. An exposure gradient of chlorinated organics was assessed by determining concentrations of conjugated chlorophenolics (CPs) in bile and CPs as well as extractable organic halogens (EOX) in gut lipids. Ac…
Exposure to increased ambient ultraviolet B radiation has negative effects on growth, condition and immune function of juvenile Atlantic salmon (Salmo salar).
Atlantic salmon (Salmo salar) parr were exposed in two outdoor experiments, ranging in duration from 52 to 137 days, to spectral treatments: (1) natural sunlight (=present ambient UVB level), (2) solar radiation supplemented with enhanced UVB radiation from lamps simulating 20% or 8% stratospheric ozone loss or (3) UVB-depleted sunlight achieved by screening with Mylar-D film. The growth, condition and immune function of the salmon were quantified after treatments. Exposure to enhanced UVB radiation retarded growth, and decreased hematocrit value and plasma protein concentration. Further, enhanced UVB radiation affected plasma immunoglobulin concentration. The results demonstrate that juven…
Effects of gender, diet, exogenous melatonin and subchronic PCB exposure on plasma immunoglobulin G in mink
Abstract Effects of different fish-based diets (freshwater smelt, Baltic herring, marine herring/cod offal or their mixtures), gender, β-glucan supplement, exogenous melatonin, and PCB exposure (Aroclor 1242®, 1 mg per animal per day in feed) on plasma immunoglobulin G (IgG) in the mink (Mustela vison) were studied. The aims of the study were to find out whether plasma IgG of the mink is affected by the subchronic PCB exposure, and whether biological, nutritional and hormonal effects are large enough to mask the possible IgG response. The concentration of IgG was determined using enzyme-linked immunosorbent assay (ELISA). Sexual dimorphism was detected, the males having higher levels of pla…
The efficacy of two immunostimulants against Flavobacterium columnare infection in juvenile rainbow trout (Oncorhynchus mykiss).
Abstract Bacterium Flavobacterium columnare is the causative agent of columnaris disease in many wild and farmed fish species. Immunostimulants are used with success in aquaculture against many pathogens, but the ability to improve innate resistance to columnaris disease has not been studied. Fingerling rainbow trout were treated with two immunostimulants, yeast β-glucan and β-hydroxy-β-methylbutyrate (HMB). Selected innate immune function parameters, the production of reactive oxygen species (ROS) by whole blood and by isolated head kidney leukocytes, plasma lysozyme activity and complement bacteriolytic activity, were determined to assess the immune status of fish. The fish were then bath…