Immunological Responses Elicited by Different Infection Regimes with Strongyloides ratti

Nematode infections are a ubiquitous feature of vertebrate life. In nature, such nematode infections are acquired by continued exposure to infective stages over a prolonged period of time. By contrast, experimental laboratory infections are typically induced by the administration of a single (and often large) dose of infective stages. Previous work has shown that the size of an infection dose can have significant effects on anti-nematode immune responses. Here we investigated the effect of different infection regimes of Strongyloides ratti, comparing single and repeated dose infections, on the host immune response that was elicited. We considered and compared infections of the same size, but administered in different ways. We considered infection size in two ways: the maximum dose of worms administered and the cumulative worm exposure time. We found that both infection regimes resulted in Th2-type immune response, characterised by IL4 and IL13 produced by S. ratti stimulated mesenteric lymph node cells, anti-S. ratti IgG1 and intestinal rat mast cell protease II (RMCPII) production. We observed some small quantitative immunological differences between different infection regimes, in which the concentration of IL4, IL13, anti-S. ratti IgG1 and IgG2a and RMCPII were affected. However, these differences were quantitatively relatively modest compared with the temporal dynamics of the anti-S. ratti immune response as a whole

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 December 2010-31 January 2011

This article documents the addition of 238 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alytes dickhilleni, Arapaima gigas, Austropotamobius italicus, Blumeria graminis f. sp. tritici, Cobitis lutheri, Dendroctonus ponderosae, Glossina morsitans morsitans, Haplophilus subterraneus, Kirengeshoma palmata, Lysimachia japonica, Macrolophus pygmaeus, Microtus cabrerae, Mytilus galloprovincialis, Pallisentis (Neosentis) celatus, Pulmonaria officinalis, Salminus franciscanus, Thais chocolata and Zootoca vivipara. These loci were cross-tested on the following species: Acanthina monodon, Alytes cisternasii, Alytes maurus, Alytes muletensis, Alytes obstetricans almogavarii, Alytes obstetricans boscai, Alytes obstetricans obstetricans, Alytes obstetricans pertinax, Cambarellus montezumae, Cambarellus zempoalensis, Chorus giganteus, Cobitis tetralineata, Glossina fuscipes fuscipes, Glossina pallidipes, Lysimachia japonica var. japonica, Lysimachia japonica var. minutissima, Orconectes virilis, Pacifastacus leniusculus, Procambarus clarkii, Salminus brasiliensis and Salminus hilarii

Cracks, microcracks and fracture in polymer structures: Formation, detection, autonomic repair

The first author would like to acknowledge the financial support from the European Union under the FP7 COFUND Marie Curie Action. N.M.P. is supported by the European Research Council (ERC StG Ideas 2011 n. 279985 BIHSNAM, ERC PoC 2015 n. 693670 SILKENE), and by the EU under the FET Graphene Flagship (WP 14 “Polymer nano-composites” n. 696656)

Processes of incipient speciation : the formation and maintenance of alternative strategies in the side blotched lizard, Uta stansburiana

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Previous experiences shape adaptive mate preferences

Existing models of mate choice assume that individuals have perfect knowledge of their own ability to attract a mate and can adjust their preferences accordingly. However, real animals will typically be uncertain of their own attractiveness. A potentially useful source of information on this is the feedback from previous encounters with potential mates. Here, we develop a dynamic model of mutual mate choice in which both males and females are initially ignorant of their own attractiveness. Individuals sequentially sample potential mates and retain some information about the outcome of these encounters (e.g., the number of times they are accepted or rejected). We use a simplified process of mutation and selection to evolve an adaptive strategy for mate choice under these conditions. The stable strategy we find is the one in which individuals are sensitive to this previous experience, adjusting their mate preferences according to the interest received from members of the opposite sex. In general, experiences of rejection tend to reduce choosiness, whereas experiences of acceptance tend to increase it. Sensitivity to previous experiences allows individuals to exercise a prudent mate-choice strategy in which their preferences are gradually tuned to their prospects on the mating market. This flexibility is based on simple rules and does not require sophisticated cognitive abilities. Our basic predictions can be tested in systems where both males and females are choosy, and it is possible to manipulate the level of interest shown by potential mates

Density-dependent immune responses against the gastrointestinal nematode Strongyloides ratti

Negative density-dependent effects on the fitness of parasite populations are an important force in their population dynamics. For the parasitic nematode Strongyloides ratti, density-dependent fitness effects require the rat host immune response. By analysis of both measurements of components of parasite fitness and of the host immune response to different doses of S. ratti infection, we have identified specific parts of the host immune response underlying the negative density-dependent effects on the fitness of S. ratti. The host immune response changes both qualitatively from an inflammatory Th1- to a Th2-type immune profile and the Th2-type response increases quantitatively, as the density of S. ratti infection increases. Parasite survivorship was significantly negatively related to the concentration of parasite-specific IgG1 and IgA, whereas parasite fecundity was significantly negatively related to the concentration of IgA only

The association between <i>per capita</i> fecundity and the concentration of IL13 produced by MLN stimulated with parasite antigen.

<p>AIC = 536.4, k = 1.57±0.31, residual df = 54.</p

Diagrammatic illustration of infective dose measured as the number of worms received and as the worm exposure time.

<p>Host A receives 100 infective L3s (iL3s) in a single day, host B receives 10 iL3s every day for 10 days and host C receives 20 iL3s every day for 10 days. Therefore, hosts A and B both receive 100 worms but host A has twice the worm exposure time compared with host B. Hosts A and C both have the same worm exposure time (1000 worm days) but host C received twice the number of worms compared with host A.</p

The association between <i>per capita</i> fecundity and the concentration of RMCPII in intestinal tissue.

<p>AIC = 532.4, k 1.61±0.32, residual df = 54</p