We evaluated the effects of the protozoan parasite Ophryocystis elektroscirrha on the survival and reproduction of monarch butterflies. Because larvae in natural populations are likely to experience a wide range of natural parasite population densities, we examined the effects of increasing spore density (0, 10, 100, or 1000 spores per larva) on host fitness. Parasites had little effect on mona...

BACKGROUND Uncoupling protein 2 (UCP2) is a mitochondrial transporter that has been shown to lower the production of reactive oxygen species (ROS). Intracellular pathogens such as Leishmania upregulate UCP2 and thereby suppress ROS production in infected host tissues, allowing the multiplication of parasites within murine phagocytes. This makes host UCP2 and ROS production potential targets in ...

Despite growing interest in ecological consequences of parasitism in food webs, relatively little is known about effects of parasites on long-term population dynamics of non-host species or about whether such effects are density or trait mediated. We studied a tri-trophic food chain comprised of (i) a bacterial basal resource (Serratia fonticola), (ii) an intermediate consumer (Paramecium cauda...

Natural selection should strongly favour hosts that can protect themselves against parasites. Most studies on animals so far have focused on resistance, a series of mechanisms through which hosts prevent infection, reduce parasite growth or clear infection. However, animals may instead evolve tolerance, a defence mechanism by which hosts do not reduce parasite infection or growth, but instead a...

INTRODUCTION Association between Ascaris lumbricoides infection and asthma is a controversial subject that has been studied by several authors based on the hygiene theory. This work contributes to better understanding this issue. METHODOLOGY This was a cross-sectional study involving 1,004 children from a neighborhood of low socioeconomic status in Campina Grande, Paraíba, northeastern Brazil...

The extent to which genotypic variation at a priori identified candidate genes can explain variation in complex phenotypes is a major debate in evolutionary biology. Whereas some high-profile genes such as the MHC or MC1R clearly do account for variation in ecologically relevant characters, many complex phenotypes such as response to parasite infection may well be underpinned by a large number ...

A central issue in ecology is in understanding the relative influences of intrinsic and extrinsic effects on population regulation. Previous studies on the cyclic population dynamics of red grouse (Lagopus lagopus scoticus) have emphasized the destabilizing effects of either nematode parasites or territorial behaviour and aggression. The potential interacting effects of these processes, mediate...

Theileria orientalis (Ikeda) was first detected in New Zealand 2012, becoming endemic most of the North Island, and can cause incidences anaemia death. Research has been performed on incidence severity infection. Through this research anecdotal evidence found to suggest a potential genetic susceptibility component response host parasite. To investigate cattle T. (Ikeda), 99 calves born 2016 as ...

Host movement and spatial structure can strongly influence the ecology and evolution of infectious diseases, with limited host movement potentially leading to high spatial heterogeneity in infection. Monarch butterflies (Danaus plexippus) are best known for undertaking a spectacular long-distance migration in eastern North America; however, they also form non-migratory populations that breed ye...

BACKGROUND Here we report the monitoring of the digestive tract colonization of Rhodnius prolixus by Trypanosoma cruzi using an accurate determination of the parasite load by qPCR coupled with fluorescence and bioluminescence imaging (BLI). These complementary methods revealed critical steps necessary for the parasite population to colonize the insect gut and establish vector infection. METHO...