Despite their tremendous diversity and their medical and veterinary importance, details of egg ultrastructure among the digenean trematodes has been studied rather little. The available literature is spread over several decades and several species, but has not been adequately reviewed to reveal patterns of similarity and divergence. We present this review to synthesize and analyse what is known from the available literature reporting studies using both transmission electron microscopy (TEM) and scanning electron microscopy (SEM). To support our general review of existing literature, we also have synthesized our own previously published descriptions, and present herein our new previously unpublished data. From these new electron micrographs, we provide a comparative analysis of the intrauterine eggs of four digenean species, representing four genera and three families of the superfamily Microphalloidea, collected from four different host wildlife species in four European countries: 1) Mediogonimus jourdanei (Prosthogonimidae) from Myodes glareolus (Mammalia: Rodentia), collected in France; 2) Maritrema feliui (Microphallidae) from Crocidura russula (Mammalia: Soricimorpha), collected in Spain; 3) Brandesia turgida (Pleurogenidae) from Pelophylax ridibundus (Amphibia: Anura: Ranidae), collected in Russia; and 4) Prosotocus confusus (Pleurogenidae) from Rana lessonae (Amphibia: Anura: Ranidae), collected in Belarus. All were studied by preparing whole worms by various techniques for TEM, so that eggs could be studied in situ within the uterus of the parent worm. Based on the literature review and the new data presented here, we describe basic similarities in patterns of embryogenesis and egg formation among all trematode species, but substantial variations in timing of larvigenesis, sculpturing of egg shell surfaces, and some other features, especially including accessory cocoon coverings outside the egg shells of B . turgida and P . confusus . In the future, many more studies are needed to explore egg ultrastructure in other digenean taxa, to explore potential phylogenetic patterns in egg development and structure, and to correlate structure with function in the life cycle.
Contents
- Invited Paper
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Requires Authentication UnlicensedUltrastructure of digenean trematode eggs (Platyhelminthes: Neoophora): A review emphasizing new comparative data on four European MicrophalloideaLicensedJanuary 17, 2018
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Requires Authentication UnlicensedPhylogeny and cocoon production in the parasitic leech Myzobdella lugubris Leidy, 1851 (Hirudinidae, Piscicolidae)LicensedJanuary 17, 2018
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Requires Authentication UnlicensedParasites in stray dogs from Italy: prevalence, risk factors and management concernsLicensedJanuary 17, 2018
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Requires Authentication UnlicensedA serological study of antibodies to Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato in the sera of healthy individuals collected two decades apartLicensedJanuary 17, 2018
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Requires Authentication UnlicensedChanges in the incidence of intestinal giardiosis in Mexican population during five years (2011-2015)LicensedJanuary 17, 2018
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Requires Authentication UnlicensedMolecular target analysis of stearoyl-CoA desaturase genes of protozoan parasitesLicensedJanuary 17, 2018
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Requires Authentication UnlicensedMolecular and morphological characterisation of Rhabdias picardiae Junker, Lhermitte-Vallarino et Bain, 2010 (Nematoda: Rhabdiasidae) from Delaland’s River Frog, Amietia delalandii (Duméril et Bibron, 1841) (Amphibia: Pyxicephalidae) in South AfricaLicensedJanuary 17, 2018
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Requires Authentication UnlicensedScanning electron microscopy study of Strabax monstrosus von Nordmann, 1864 (Copepoda: Chondracanthidae) from Tunisian waters and histopathological study of its effects on hostLicensedJanuary 17, 2018
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Requires Authentication UnlicensedCharacterization of phosphate transporter(s) and understanding their role in Leishmania donovani parasiteLicensedJanuary 17, 2018
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Requires Authentication UnlicensedTwo nematode species from freshwater and marine fishes in Thailand, including Ascarophis scatophagi sp. nov. (Cystidicolidae) from Scatophagus argus (Scatophagidae)LicensedJanuary 17, 2018
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Requires Authentication UnlicensedMetazoan parasite fauna of migrating common garfish, Belone belone (L.), in the Baltic SeaLicensedJanuary 17, 2018
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Requires Authentication UnlicensedMeasurement of binding strength between prey proteins interacting with Toxoplasma gondii SAG1 and SAG2 using isothermal titration calorimetry (ITC)LicensedJanuary 17, 2018
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Requires Authentication UnlicensedAsymmetric peptidomimetics containing L-tartaric acid core inhibit the aspartyl peptidase activity and growth of Leishmania amazonensis promastigotesLicensedJanuary 17, 2018
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Requires Authentication UnlicensedTranscriptional analysis of immune-relevant genes in the mucus of Labeo rohita, experimentally infected with Argulus siamensisLicensedJanuary 17, 2018
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Requires Authentication UnlicensedPrevalence of endoparasitic infections of birds in zoo gardens in SerbiaLicensedJanuary 17, 2018
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Requires Authentication UnlicensedContamination of swimming pools and hot tubs biofilms with AcanthamoebaLicensedJanuary 17, 2018
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Requires Authentication UnlicensedMorphological and molecular characterization of Seuratascaris numidica (Seurat, 1917) (Ascaridida: Ascarididae)LicensedJanuary 17, 2018
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Requires Authentication UnlicensedNematode Thelazia callipaeda is spreading across Europe. The first survey of red foxes from SlovakiaLicensedJanuary 17, 2018
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Requires Authentication UnlicensedA frequent roundworm Baylisascaris transfuga in overpopulated brown bears (Ursus arctos) in Slovakia: a problem worthy of attentionLicensedJanuary 17, 2018
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Requires Authentication UnlicensedNematode parasites of Duttaphrynus stomaticus (Lutken, 1864) (Amphibia: Anura) with description of a new species of Rhabdias Stiles and Hassall, 1905 (Nematoda: Rhabdiasidae) from Dehradun (Uttarakhand), IndiaLicensedJanuary 17, 2018
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Requires Authentication UnlicensedMolecular and serological investigation of infectious diseases in captive and free-range crab-eating fox (Cerdocyon thous – Linnaeus, 1776) from northeastern BrazilLicensedJanuary 17, 2018
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Requires Authentication UnlicensedA new species of Aplectana (Nematoda, Cosmocercidae) in Goniurosaurus bawanglingensis (Squamata, Eublepharidae), from Hainan Province, ChinaLicensedJanuary 17, 2018
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Requires Authentication UnlicensedSyphacia muris infection in rats attenuates colorectal carcinogenesis through oxidative stress and gene expression alterations. Implications for modulatory effects by Bryostatin-1LicensedJanuary 17, 2018
- Research Note
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Requires Authentication UnlicensedThe first case of Leporacarus gibbus infestation in a rabbit from PolandLicensedJanuary 17, 2018
- Research Note
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Requires Authentication UnlicensedPathological and molecular studies of the renal trematode Paratanaisia bragai in Indian peafowls (Pavo cristatus)LicensedJanuary 17, 2018