Diplomonorchis fallax n. sp. (Digenea: Monorchiidae) from the northern Gulf of Mexico with evaluation of sympatric congeners.

Diplomonorchis micropogoni Nahhas & Cable, 1964 was considered a junior subjective synonym of Diplomonorchis leiostomi Hopkins, 1941 in 1969. Diplomonorchis leiostomi has since been widely reported from the coastal Western Atlantic between Delaware Bay and southern Brazil. Until now, taxonomically verifiable DNA sequence data for D.

Muscular remodeling and anteroposterior patterning during tapeworm segmentation.

Background: Tapeworms are parasitic flatworms that independently evolved a segmented body plan, historically confounding comparisons with other animals. Anteroposterior (AP) patterning in free-living flatworms and in tapeworm larvae is associated with canonical Wnt signaling and positional control genes (PCGs) are expressed by their musculature in regionalized domains along the AP axis. Here, we extend investigations of PCG expression to the adult of the mouse bile-duct tapeworm Hymenolepis microstoma, focusing on the growth zone of the neck region and the initial establishment of segmental patterning.

Jumping continents and major host lineages: phylogeny and diversity of the enigmatic Cryptotropidae (Platyhelminthes: Digenea).

Members of several genera in the digenean superfamily Microphalloidea, namely , , , and , are characterized by an unusual dorsal position of the genital atrium. In the absence of phylogenetic data, their systematic position has been unstable. In the most recent taxonomic revision of the Microphalloidea, they were housed in three different families.

Complete representation of a tapeworm genome reveals chromosomes capped by centromeres, necessitating a dual role in segregation and protection.

Background: Chromosome-level assemblies are indispensable for accurate gene prediction, synteny assessment, and understanding higher-order genome architecture. Reference and draft genomes of key helminth species have been published, but little is yet known about the biology of their chromosomes. Here, we present the complete genome of the tapeworm Hymenolepis microstoma, providing a reference quality, end-to-end assembly that represents the first fully assembled genome of a spiralian/lophotrochozoan, revealing new insights into chromosome evolution.

The tapeworm interactome: inferring confidence scored protein-protein interactions from the proteome of Hymenolepis microstoma.

Background: Reference genome and transcriptome assemblies of helminths have reached a level of completion whereby secondary analyses that rely on accurate gene estimation or syntenic relationships can be now conducted with a high level of confidence. Recent public release of the v.3 assembly of the mouse bile-duct tapeworm, Hymenolepis microstoma, provides chromosome-level characterisation of the genome and a stabilised set of protein coding gene models underpinned by bioinformatic and empirical data.

Molecular circumscription of new species of Gyrocotyle Diesing, 1850 (Cestoda) from deep-sea chimaeriform holocephalans in the North Atlantic.

Chimaeras, or ratfishes, are the only extant group of holocephalan fishes and are the sole host group of gyrocotylidean cestodes, which represent a sister group of the true tapeworms (Eucestoda). These unique, non-segmented cestodes have been known since the 1850s and multiple species and genera have been erected despite a general agreement that the delineation of species on the basis of morphology is effectively impossible. Thus, in the absence of molecular studies, the validity of gyrocotylid taxa and their specific host associations has remained highly speculative.

Identification and expression profiling of microRNAs in Hymenolepis.

Tapeworms (cestodes) of the genus Hymenolepis are the causative agents of hymenolepiasis, a neglected zoonotic disease. Hymenolepis nana is the most prevalent human tapeworm, especially affecting children. The genomes of Hymenolepis microstoma and H.

Genome-wide transcriptome profiling and spatial expression analyses identify signals and switches of development in tapeworms.

Background: Tapeworms are agents of neglected tropical diseases responsible for significant health problems and economic loss. They also exhibit adaptations to a parasitic lifestyle that confound comparisons of their development with other animals. Identifying the genetic factors regulating their complex ontogeny is essential to understanding unique aspects of their biology and for advancing novel therapeutics.

Australian spiny mountain crayfish and their temnocephalan ectosymbionts: an ancient association on the edge of coextinction?

Australian spiny mountain crayfish (Euastacus, Parastacidae) and their ecotosymbiotic temnocephalan flatworms (Temnocephalida, Platyhelminthes) may have co-occurred and interacted through deep time, during a period of major environmental change. Therefore, reconstructing the history of their association is of evolutionary, ecological, and conservation significance. Here, time-calibrated Bayesian phylogenies of Euastacus species and their temnocephalans (Temnohaswellia and Temnosewellia) indicate near-synchronous diversifications from the Cretaceous.

Protecting Free-Living Dormice: Molecular Identification of Cestode Parasites in Captive Dormice (Muscardinus avellanarius) Destined for Reintroduction.

The success of any population translocation programme relies heavily on the measures implemented to control and monitor the spread of disease. Without these measures, programmes run the risk of releasing immunologically naïve species or, more dangerously, introducing novel infectious agents to native populations. As a precaution, a reintroduction programme for the common or hazel dormouse, Muscardinus avellanarius, in England screens dormice before release following captive breeding.

Comparative analysis of Wnt expression identifies a highly conserved developmental transition in flatworms.

Background: Early developmental patterns of flatworms are extremely diverse and difficult to compare between distant groups. In parasitic flatworms, such as tapeworms, this is confounded by highly derived life cycles involving indirect development, and even the true orientation of the tapeworm antero-posterior (AP) axis has been a matter of controversy. In planarians, and metazoans generally, the AP axis is specified by the canonical Wnt pathway, and we hypothesized that it could also underpin axial formation during larval metamorphosis in tapeworms.

Independent host switching events by digenean parasites of cetaceans inferred from ribosomal DNA.

Cetaceans harbour a unique fauna of digeneans whose origin and relationships have sparked considerable debate during recent decades. Disparity in the species reported indicates that they do not share close affinities, but their unusual morphology has made their taxonomic identities and phylogenetic positions uncertain. Here we use sequence data to investigate the phylogenetic relationships of the main species of flukes infecting cetaceans.

Spathebothriidea: survey of species, scolex and egg morphology, and interrelationships of a non-segmented, relictual tapeworm group (Platyhelminthes: Cestoda).

Tapeworms of the order Spathebothriidea Wardle et McLeod, 1952 (Cestoda) are reviewed. Molecular data made it possible to assess, for the first time, the phylogenetic relationships of all genera and to confirm the validity of Bothrimonus Duvernoy, 1842, Diplocotyle Krabbe, 1874 and Didymobothrium Nybelin, 1922. A survey of all species considered to be valid is provided together with new data on egg and scolex morphology and surface ultrastructure (i.

Orders out of chaos--molecular phylogenetics reveals the complexity of shark and stingray tapeworm relationships.

Novel molecular data are presented to resolve the long-standing issue of the non-monophyly of the elasmobranch-hosted tapeworm order Tetraphyllidea relative to the other acetabulate eucestode orders. Bayesian inference analyses of various combinations of full ssrDNA, and full or partial lsrDNA (D1-D3), sequence data, which included 134 species representing 97 genera across the 15 eucestode orders, were conducted. New ssrDNA data were generated for 82 species, partial lsrDNA data for 53 species, and full lsrDNA data for 29 species.

RNA-mediated gene suppression and in vitro culture in Hymenolepis microstoma.

Hymenolepis microstoma, the mouse bile-duct tapeworm, is a classical rodent-hosted model that provides easy laboratory access to all stages of the life cycle. Recent characterisation of its genome has greatly advanced its utility for molecular research, albeit contemporary techniques such as those for assaying gene function have yet to be developed in the system. Here we present research on the development of RNA-mediated gene suppression via RNA interference (RNAi), and on in vitro culture of the enteric, adult phase of the life cycle to support this work.

The genomes of four tapeworm species reveal adaptations to parasitism.

Tapeworms (Cestoda) cause neglected diseases that can be fatal and are difficult to treat, owing to inefficient drugs. Here we present an analysis of tapeworm genome sequences using the human-infective species Echinococcus multilocularis, E. granulosus, Taenia solium and the laboratory model Hymenolepis microstoma as examples.

Life cycles, molecular phylogeny and historical biogeography of the 'pygmaeus' microphallids (Digenea: Microphallidae): widespread parasites of marine and coastal birds in the Holarctic.

The 'pygmaeus' microphallids (MPG) are a closely related group of 6 digenean (Platyhelminthes: Trematoda) Microphallus species that share a derived 2-host life cycle in which metacercariae develop inside daughter sporocysts in the intermediate host (intertidal and subtidal gastropods, mostly of the genus Littorina) and are infective to marine birds (ducks, gulls and waders). Here we investigate MPG transmission patterns in coastal ecosystems and their diversification with respect to historical events, host switching and host-parasite co-evolution. Species phylogenies and phylogeographical reconstructions are estimated on the basis of 28S, ITS1 and ITS2 rDNA data and we use a combination of analyses to test the robustness and stability of the results, and the likelihood of alternative biogeographical scenarios.

Substitution saturation and nuclear paralogs of commonly employed phylogenetic markers in the Caryophyllidea, an unusual group of non-segmented tapeworms (Platyhelminthes).

Caryophyllidean cestodes (Platyhelminthes) represent an unusual group of tapeworms lacking serially repeated body parts that potentially diverged from the common ancestor of the Eucestoda prior to the evolution of segmentation. Here we evaluate the utility of two nuclear and two mitochondrial molecular markers (ssrDNA and lsrDNA, nad3 and cox1) for use in circumscribing generic boundaries and estimating interrelationships in the group. We show that these commonly employed markers do not contain sufficient signal to infer well-supported phylogenetic estimates due to substitution saturation.

Spatial and temporal consistency of putative reference genes for real-time PCR in a model tapeworm.

Relative quantification of gene expression by real-time PCR relies on the use of reference genes whose expressed levels remain consistent across experimental conditions. Here we compare expression levels of commonly employed endogenous housekeeping genes against a developmental regulatory gene in the model tapeworm Hymenolepis microstoma, examining variation both spatially across regions of the adult worm and temporally through the course of larval metamorphosis. β-Tubulin, RNA polymerase II and 60S ribosomal subunit L28 showed the most variance among candidate reference genes when comparing changes in expression along the anteroposterior gradient of development represented by the adult body, whereas expression of 18S rDNA and cyclic AMP were highly consistent and could be used reliably for relative quantification.

Wnt gene loss in flatworms.

Wnt genes encode secreted glycoproteins that act in cell-cell signalling to regulate a wide array of developmental processes, ranging from cellular differentiation to axial patterning. Discovery that canonical Wnt/β-catenin signalling is responsible for regulating head/tail specification in planarian regeneration has recently highlighted their importance in flatworm (phylum Platyhelminthes) development, but examination of their roles in the complex development of the diverse parasitic groups has yet to be conducted. Here, we characterise Wnt genes in the model tapeworm Hymenolepis microstoma and mine genomic resources of free-living and parasitic species for the presence of Wnts and downstream signalling components.

Molecular and morphological circumscription of Mesocestoides tapeworms from red foxes (Vulpes vulpes) in central Europe.

Here we examine 3157 foxes from 6 districts of the Slovak Republic in order to determine for the first time the distribution, prevalence and identity of Mesocestodes spp. endemic to this part of central Europe. During the period 2001-2006, an average of 41.

Description of Hymenolepis microstoma (Nottingham strain): a classical tapeworm model for research in the genomic era.

Background: Hymenolepis microstoma (Dujardin, 1845) Blanchard, 1891, the mouse bile duct tapeworm, is a rodent/beetle-hosted laboratory model that has been used in research and teaching since its domestication in the 1950s. Recent characterization of its genome has prompted us to describe the specific strain that underpins these data, anchoring its identity and bringing the 150+ year-old original description up-to-date.

Results: Morphometric and ultrastructural analyses were carried out on laboratory-reared specimens of the 'Nottingham' strain of Hymenolepis microstoma used for genome characterization.