Parasitology Research Today is a free monthly online journal that collates and summarizes the latest research about Parasitology, including details on parasites, worms, bacterial, fungal, medical, veterinary. | ||||||
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Abdominal sensory equipment involved in external host discrimination in a solitary parasitoid wasp.Goubault M, Cortesero AM, Paty C, Fourrier J, Dourlot S, Ralec AL IRBI UMR CNRS 6035, Université de Tours, Parc Grandmont, 37200 Tours, France. marlene.goubault@univ-tours.fr. Already parasitized hosts are often of poorer quality than healthy hosts. It is therefore usually advantageous for parasitoid females to recognize and reject them. Parasitized hosts can be identified on the basis of various physical or chemical marks present on the surface or inside the hosts or their surroundings in the case of concealed host. Here we studied host discrimination behaviors of females of a certain population of Pachycrepoideus vindemmiae, a solitary ectoparasitoid, which are known to reject large-sized parasitized hosts after an abdominal examination of their surface. We first investigated females' recognition behaviors of host parasitism status when confronted to small-sized hosts (Drosophila melanogaster pupae) as host size may influence the use of different cues for host selection. We showed that, in such a situation, females also discriminate parasitized hosts after an external host exploration with the tip of their ovipositor sheath (third valvulae). We then described the sense organs present on the different parts of the ovipositor by means of scanning and transmission electron microscopy analysis. As the extremity of the third valvulae bears only one type of sensilla that appears to be chemoreceptors, we considered these sensilla as highly likely to be involved in host discrimination in P. vindemmiae. To our knowledge, this is the first time that receptors located on the ovipositor sheath are described as implicated in host discrimination in parasitoid wasps. We discuss potential chemical markers that might be detected by these receptors. Microsc. Res. Tech., 2011. © 2011 Wiley-Liss, Inc. Published 12 May 2011 in Microsc Res Tech. Articles on Parasitology published 12 May 2011: Within-host parasite cooperation and the evolution of virulence. Proc Biol Sci. Infections by multiple genotypes are common in nature and are known to select for higher levels of virulence for some parasites. When parasites produce public goods (PGs) within the host, such co-infections have been predicted to select for lower levels of virulence. However, this prediction is based on simplifying assumptions regarding epidemiological feedbacks on the multiplicity of infections (MOI). Here, we analyse the case of parasites producing a PG (for example, siderophore-producing ... [Abstract] [Full-text] Alternative mechanisms of increased eggshell hardness of avian brood parasites relative to host species. J R Soc Interface. Obligate brood parasitic birds lay their eggs in nests of other species and parasite eggs typically have evolved greater structural strength relative to host eggs. Increased mechanical strength of the parasite eggshell is an adaptation that can interfere with puncture ejection behaviours of discriminating hosts. We investigated whether hardness of eggshells is related to differences between physical and chemical traits from three different races of the parasitic common cuckoo Cuculus canorus, ... [Abstract] [Full-text] Abstract This work describes associations of Thiara (Tarebia) granifera, its larval trematode community, and Chaetogaster limnaei limnaei at a freshwater reservoir in Jamaica. Larvae of 2 trematodes were present, i.e., a notocotylid (15.3%) and Philophthalmus sp. (1.3%), in 3,575 T. granifera examined. The prevalence of both infections increased with snail shell length (H = 56, P < 0.01, H = 23.1, P < 0.01, respectively). Only 3.0% (n = 595) of infected snails possessed reproductive ... [Abstract] [Full-text] Articles on Parasitology published 11 May 2011: Two Theileria parva CD8 T Cell Antigen Genes Are More Variable in Buffalo than Cattle Parasites, but Differ in Pattern of Sequence Diversity. PLoS One, 6(4): e19015. Intracellular eukaryotic parasites have a distinct unfolded protein response. PLoS One, 6(4): e19118. Insult to the endoplasmic reticulum (ER) activates the Unfolded Protein Response (UPR), a set of signaling pathways that protect the cell from the potential damage caused by improperly folded proteins. Accumulation of misfolded proteins in the ER lumen initiates a series of signal transduction events via activation of three transmembrane ER proteins: Ire1, Atf6 and PERK. Activation of these proteins results in the transcriptional up-regulation of the components of the folding, trafficking and ... [Abstract] [Full-text] Altered T cell memory and effector cell development in chronic lymphatic filarial infection that is independent of persistent parasite antigen. PLoS One, 6(4): e19197. Chronic lymphatic filarial (LF) infection is associated with suppression of parasite-specific T cell responses that persist even following elimination of infection. While several mechanisms have been implicated in mediating this T cell specific downregulation, a role for alterations in the homeostasis of T effector and memory cell populations has not been explored. Using multiparameter flow cytometry, we investigated the role of persistent filarial infection on the maintenance of T cell memory ... [Abstract] [Full-text] Outcomes of Brood Parasite-Host Interactions Mediated by Egg Matching: Common Cuckoos Cuculus canorus versus Fringilla Finches. PLoS One, 6(4): e19288. Quantitative time-course profiling of parasite and host cell proteins in the human malaria parasite Plasmodium falciparum. Mol Cell Proteomics. Studies of the P. falciparum transcriptome have shown that the tightly controlled progression of the parasite through the intraerythrocytic developmental cycle (IDC) is accompanied by a continuous gene expression cascade where most expressed genes exhibit a single transcriptional peak. Since the biochemical and cellular functions of most genes are mediated by the encoded proteins, understanding the relationship between mRNA and protein levels is crucial for inferring biological activity from ... [Abstract] [Full-text] © 2005-2011 Parasitology Research Today. All Rights Reserved. |
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