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Novel Antigen (novel + antigen)
Selected AbstractsDevelopmental, metabolic and immunological costs of flea infestation in the common voleFUNCTIONAL ECOLOGY, Issue 6 2008Godefroy Devevey Summary 1Parasites use resources from their hosts, which can indirectly affect a number of host functions because of trade-offs in resource allocation. In order to get a comprehensive view of the costs imposed by blood sucking parasites to their hosts, it is important to monitor multiple components of the development and physiology of parasitized hosts over long time periods. 2The effect of infestation by fleas on body mass, body length growth, haematocrit, resistance to oxidative stress, resting metabolic rate and humoral immune response were experimentally evaluated. During a 3-month period, male common voles, Microtus arvalis, were either parasitized by rat fleas (Nosopsyllus fasciatus), which are naturally occurring generalist ectoparasites of voles, or reared without fleas. Then voles were challenged twice by injecting Keyhole Limpet Haemocyanin (KLH) to assess whether the presence of fleas affects the ability of voles to produce antibodies against a novel antigen. During the immune challenge we measured the evolution of body mass, haematocrit, resistance to oxidative stress and antibody production. 3Flea infestation negatively influenced the growth of voles. Moreover, parasitized voles had reduced haematocrit, higher resting metabolic rate and lower production of antibodies against the KLH. Resistance to oxidative stress was not influenced by the presence of fleas. 4During the immune challenge with KLH, body mass decreased in both groups, while the resistance to oxidative stress remained stable. In contrast, the haematocrit decreased only in parasitized voles. 5Our experiment shows that infestation by a haematophageous parasite negatively affects multiple traits like growth, energy consumption and immune response. Fleas may severely reduce the survival probability and reproductive success of their host in natural conditions. [source] Effects of inbreeding on immune response and body size in a social insect, Bombus terrestrisFUNCTIONAL ECOLOGY, Issue 5 2003C. U. Gerloff Summary 1Inbreeding can negatively affect various fitness components. Here we examine how immune response and body size of a social insect are affected by inbreeding, sex and ploidy. 2In the bumble-bee, Bombus terrestris (L.), the offspring of colonies resulting from brother,sister matings were compared with that of outbred colonies. Immune response was measured as the degree of encapsulation of a novel antigen, body size as the length of the radial cell in the forewings. 3Inbreeding affected neither immune response nor body size in either workers or haploid males under laboratory conditions. However, fitness characteristics varied significantly among maternal families and colonies. The lack of detectable inbreeding depression for two fitness components might help explain why B. terrestris is a good colonizer in nature. 4In addition, sex and ploidy strongly affected the fitness components studied: diploid males had a significantly lower immune response than haploid males, who in turn had a significantly lower immune response than workers of the same colony. The body size of diploid males was intermediate between the body size of workers and haploid males. [source] Manipulation of offspring number and size: benefits of large body size at birth depend upon the rearing environmentJOURNAL OF ANIMAL ECOLOGY, Issue 2 2003Tuula A. Oksanen Summary 1Allocation 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. 2We 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 mean offspring body size at birth by replacing the original litter with heavier pups from smaller litters. Offspring quality was estimated from body size measurements, parasitic infection with Eimeria spp. and the level of immune response to a novel antigen. 3The analyses revealed that large body size at birth was an advantage in ,normal' rearing environments, but a disadvantage in poor ones. The initially normal sized offspring grown in enlarged litters had a relatively good capacity for growth and high immune function confirming that a poor rearing environment alone does not reduce their quality. 4Our findings that the benefits of large body size depend on the rearing environment suggest that offspring body size is adjusted in relation to litter size, and thus the evolution of these two traits is combined. [source] Effects of hybridization on the immunity of collared Ficedula albicollis and pied flycatchers F. hypoleuca, and their infection by haemosporidiansJOURNAL OF AVIAN BIOLOGY, Issue 4 2009Chris Wiley Because they are ubiquitous and typically reduce the fitness of hosts, parasites may play important roles in hybrid zone dynamics. Despite much work on herbivores and hybrid plants, the effect of parasites on the fitness of animal hybrids is poorly known. In an attempt to partly fill this gap, we examined the prevalence of avian haemosporidians Haemoproteus in a hybrid zone between collared Ficedula albicollis and pied flycatchers F. hypoleuca. 40 species-informative genetic markers allowed us to identify F1 hybrids, thus avoiding problems inherent in many studies that group hybrid genotypes. Furthermore, naturally occurring extra-pair paternity allowed us to test the immune responses of pure and hybrid nestlings to a novel antigen (phytohaemagglutinin) in a shared environment. In contrast to previous suggestions that animal hybrids may more often display resistance against parasites than plant hybrids, F1 hybrids exhibited prevalence of parasitism and immune responses that were intermediate between the two parental species. We also detected differences between the two parental species in their prevalence of infection, with the competitively dominant species (collared flycatcher) being less often infected by Haemoproteus. Overall, our results contribute to other recent data supporting the idea that the resistance of animals to parasites is variously and unpredictably affected by hybridization, and that there is a concordance in the general patterns observed in plants and animals. Haemosporidians in avian hybrids provide a useful system for investigating the interactions between hosts and parasites that characterize host contact zones. [source] | ||||||||||