599 research outputs found
Halophilanema prolata n. gen., n. sp. (Nematoda: Allantonematidae), a parasite of the intertidal bug, Saldula laticollis (Reuter)(Hemiptera: Saldidae) on the Oregon coast
This is the publisherâs final pdf. The published article is copyrighted by BioMed Central and can be found at: http://www.biomedcentral.com/.Background: It is rare to find terrestrial nematode lineages parasitizing arthropods inhabiting the intertidal or\ud
littoral zone of the oceans. During an ecological study along the Oregon dunes, an allantonematid nematode\ud
(Tylenchomorpha: Allantonematidae) was discovered parasitizing the intertidal shore bug, Saldula laticollis (Reuter)\ud
(Hemiptera: Saldidae). This shore bug is adapted to an intertidal environment and can survive short periods of\ud
submergence during high tides. The present study describes the nematode parasite and discusses aspects of its\ud
development, ecology and evolution.\ud
Methods: Adults and last instar nymphs of S. laticollis (Hemiptera: Saldidae) were collected from the high intertidal\ud
zone among clumps of Juncus L. (Juncaceae) plants at Waldport, Oregon on October 3, 2011. The bugs were\ud
dissected in 1% saline solution and the nematodes killed in 1% Ringers solution and immediately fixed in 5%\ud
formalin (at 20°C). Third stage juveniles removed from infected hosts were maintained in 1% saline solution until\ud
they matured to the adult stage, molted and mated.\ud
Results: Halophilanema prolata n. gen., n. sp. (Nematoda: Allantonematidae) is described from last instar nymphs\ud
and adults of the intertidal bug, Saldula laticollis on the Oregon coast. The new genus can be distinguished from\ud
other genera in the Allantonematidae by a stylet lacking basal knobs in both sexes, an excretory pore located\ud
behind the nerve ring, ribbed spicules, a gubernaculum, the absence of a bursa and the elongate-tubular shape of\ud
the ovoviviparous parasitic females. Studies of the organogenesis of Halophilanema showed development to third\ud
stage juveniles in the uterus of parasitic females. Maturation to the free-living adults and mating occurred in the\ud
environment. The incidence of infection of S. laticollis ranged from 0% to 85% depending on the microhabitat in\ud
the intertidal zone.\ud
Conclusions: Based on the habitat and morphological characters, it is proposed that Halophilanema adapted a\ud
parasitic existence fairly recently, evolutionarily speaking. It was probably a free-living intertidal or shore nematode\ud
that fed on microorganisms, especially fungi, in the intertidal habitat and became parasitic after saldids entered the\ud
environment. Halophilanema represents the first described nematode parasite of an intertidal insect
Lutzomyia adiketis sp. n. (Diptera: Phlebotomidae), a vector of Paleoleishmania neotropicum sp. n. (Kinetoplastida: Trypanosomatidae) in Dominican amber
<p>Abstract</p> <p>Background</p> <p>Amber fossils can be used to trace the history of disease-vector associations because microorganisms are preserved "in situ" inside the alimentary tract and body cavity of blood-sucking insects.</p> <p>Results</p> <p><it>Lutzomyia adiketis </it>sp. n. (Phlebotomidae: Diptera) is described from Dominican amber as a vector of <it>Paleoleishmania neotropicum </it>sp. n. (Kinetoplastida: Trypanosomatidae). The fossil sand fly differs from all previously described extinct and extant members of the genus by the following combination of characters: Sc forked with the branches meeting the costa and radius veins; wing L/W value of 4.1; a ÎŽ value of 18; a ratio ÎČ/α value of 0.86, and the shape and size of the spatulate rods on the ninth sternite. The trypanosomatid is characterized by the structure of its promastigotes, amastigotes and paramastigotes and its transmission by an extinct species of sand fly.</p> <p>Conclusion</p> <p>Morphological characters show that the fossil sand fly is a new extinct species and that it is host to a digenetic species of trypanosomatid. This study provides the first fossil evidence that Neotropical sand flies were vectors of trypanosomatids in the mid-Tertiary (20â30 mya).</p
Screening Surface Contamination with BetaCage
Existing screening facilities are insufficiently sensitive to meet the needs of rareâevent experiments for lowâenergy electron emitters and alphaâdecaying isotopes. To provide such screening, the BetaCage will be a lowâbackground, atmosphericâpressure neon drift chamber with unprecedented sensitivity to emitters of lowâenergy electrons and alpha particles. Minimization of the detector mass and use of radiopure materials reduce background events. The chamber design accepts nearly all alphas and lowâenergy electrons from the sample surface while allowing excellent rejection of residual backgrounds. A nonâradiopure prototype is under construction to test the design. The BetaCage will provide new infrastructure for rareâevent science as well as for a wider community that uses radioactive screening for areas including archaeology, biology, climatology, environmental science, geology, planetary science, and integratedâcircuit quality control
Some properties of three related viruses: Andean potato latent, dulcamara mottle, and Ononis yellow mosaic
RESP-544
Chronogaster troglodytes sp n (Nemata, Chronogasteridae) from Mobile cave, with a review of cavernicolous nematodes
Summary -Chronogaster lroglodytes sp. n. (Nemata : Chronogasteridae) is described as the first true cavernicolous nematode which was recovered from Movile Cave in Romania. This species is adapted for survival in floating fungal mats growing in hydrogen sulfide-rich thermomineral waters. Populations are composed of hermaphroditic females which feed on bacteria associated with the fungal mats. A review of cavernicolous nematodes, and their relationship to epigean freshwater and soil forms, is presented
Nematode endoparasites do not codiversify with their stick insect hosts.
Host-parasite coevolution stems from reciprocal selection on host resistance and parasite infectivity, and can generate some of the strongest selective pressures known in nature. It is widely seen as a major driver of diversification, the most extreme case being parallel speciation in hosts and their associated parasites. Here, we report on endoparasitic nematodes, most likely members of the mermithid family, infecting different Timema stick insect species throughout California. The nematodes develop in the hemolymph of their insect host and kill it upon emergence, completely impeding host reproduction. Given the direct exposure of the endoparasites to the host's immune system in the hemolymph, and the consequences of infection on host fitness, we predicted that divergence among hosts may drive parallel divergence in the endoparasites. Our phylogenetic analyses suggested the presence of two differentiated endoparasite lineages. However, independently of whether the two lineages were considered separately or jointly, we found a complete lack of codivergence between the endoparasitic nematodes and their hosts in spite of extensive genetic variation among hosts and among parasites. Instead, there was strong isolation by distance among the endoparasitic nematodes, indicating that geography plays a more important role than host-related adaptations in driving parasite diversification in this system. The accumulating evidence for lack of codiversification between parasites and their hosts at macroevolutionary scales contrasts with the overwhelming evidence for coevolution within populations, and calls for studies linking micro- versus macroevolutionary dynamics in host-parasite interactions
Cephalobellus lobulata n. sp. (Oxyurida:Thelastomatidae) a parasite of Neocurtilla claraziana Saussure (Orthoptera: Gryllotalpidae) from Argentina
Burmese amber fossils bridge the gap in the Cretaceous record of polypod ferns
publisher: Elsevier articletitle: Burmese amber fossils bridge the gap in the Cretaceous record of polypod ferns journaltitle: Perspectives in Plant Ecology, Evolution and Systematics articlelink: http://dx.doi.org/10.1016/j.ppees.2016.01.003 content_type: article copyright: Copyright © 2016 Elsevier GmbH. All rights reserved.Copyright © 2016 Elsevier GmbH. All rights reserved. This document is the authors' final accepted version of the journal article. You are advised to consult the publisher's version if you wish to cite from it
Infection by the castrating parasitic nematode <i>Sphaerularia bombi </i>changes gene expression in <i>Bombus terrestris </i>bumblebee queens
Parasitism can result in dramatic changes in host phenotype, which are themselves
underpinned by genes and their expression. Understanding how hosts respond at the molecular
level to parasites can therefore reveal the molecular architecture of an altered host phenotype.
The entomoparasitic nematode Sphaerularia bombi is a parasite of bumblebee (Bombus) hosts
where it induces complex behavioural changes and host castration. To examine this interaction
at the molecular level, we performed genome-wide transcriptional profiling using RNA-Seq of S.
bombi-infected Bombus terrestris queens at two critical time-points: during and just after
overwintering diapause. We found that infection by S. bombi affects the transcription of genes
underlying host biological processes associated with energy usage, translation, and circadian
rhythm. We also found that the parasite affects the expression of immune genes, including
members of the Toll signaling pathway providing evidence for a novel interaction between the
parasite and the host immune response. Taken together, our results identify host biological
processes and genes affected by an entomoparasitic nematode providing the first steps towards
a molecular understanding of this ecologically important host-parasite interaction
- âŠ