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Sample records for mesocestoides corti platyhelminthes

  1. Hox genes in the parasitic platyhelminthes Mesocestoides corti, Echinococcus multilocularis, and Schistosoma mansoni: evidence for a reduced Hox complement.

    PubMed

    Koziol, Uriel; Lalanne, Ana I; Castillo, Estela

    2009-02-01

    Little is known about the Hox gene complement in parasitic platyhelminthes (Neodermata). With the aim of identifying Hox genes in this group we performed two independent strategies: we performed a PCR survey with degenerate primers directed to the Hox homeobox in the cestode Mesocestoides corti, and we searched genomic assemblies of Echinococcus multilocularis and Schistosoma mansoni. We identified two Hox genes in M. corti, seven in E. multilocularis, and nine in S. mansoni (including five previously reported). The affinities of these sequences, and other previously reported Hox sequences from flatworms, were determined according to phylogenetic analysis, presence of characteristic parapeptide sequences, and unusual intron positions. Our results suggest that the last common ancestor of triclads and neodermatans had a Hox gene complement of at least seven genes, and that this was probably derived by gene loss from a larger ancestral Hox complement in lophotrochozoans.

  2. Expression of the histone chaperone SET/TAF-Iβ during the strobilation process of Mesocestoides corti (Platyhelminthes, Cestoda).

    PubMed

    Costa, Caroline B; Monteiro, Karina M; Teichmann, Aline; da Silva, Edileuza D; Lorenzatto, Karina R; Cancela, Martín; Paes, Jéssica A; Benitz, André de N D; Castillo, Estela; Margis, Rogério; Zaha, Arnaldo; Ferreira, Henrique B

    2015-08-01

    The histone chaperone SET/TAF-Iβ is implicated in processes of chromatin remodelling and gene expression regulation. It has been associated with the control of developmental processes, but little is known about its function in helminth parasites. In Mesocestoides corti, a partial cDNA sequence related to SET/TAF-Iβ was isolated in a screening for genes differentially expressed in larvae (tetrathyridia) and adult worms. Here, the full-length coding sequence of the M. corti SET/TAF-Iβ gene was analysed and the encoded protein (McSET/TAF) was compared with orthologous sequences, showing that McSET/TAF can be regarded as a SET/TAF-Iβ family member, with a typical nucleosome-assembly protein (NAP) domain and an acidic tail. The expression patterns of the McSET/TAF gene and protein were investigated during the strobilation process by RT-qPCR, using a set of five reference genes, and by immunoblot and immunofluorescence, using monospecific polyclonal antibodies. A gradual increase in McSET/TAF transcripts and McSET/TAF protein was observed upon development induction by trypsin, demonstrating McSET/TAF differential expression during strobilation. These results provided the first evidence for the involvement of a protein from the NAP family of epigenetic effectors in the regulation of cestode development.

  3. Identification and profiling of microRNAs in two developmental stages of the model cestode parasite Mesocestoides corti.

    PubMed

    Basika, Tatiana; Macchiaroli, Natalia; Cucher, Marcela; Espínola, Sergio; Kamenetzky, Laura; Zaha, Arnaldo; Rosenzvit, Mara; Ferreira, Henrique B

    MicroRNAs (miRNAs), a class of small non-coding RNAs, are key regulators of gene expression at post-transcriptional level and play essential roles in fundamental biological processes such as metabolism and development. The particular developmental characteristics of cestode parasites highlight the importance of studying miRNA gene regulation in these organisms. Here, we performed a comprehensive analysis of miRNAs in two developmental stages of the model cestode Mesocestoides corti. Using a high-throughput sequencing approach, we found transcriptional evidence of 42 miRNA loci in tetrathyridia larvae and strobilated worms. Tetrathyridium and strobilated worm-specific miRNAs were found, as well as differentialy expressed miRNAs between these developmental stages, suggesting miRNA regulation of stage-specific features. Moreover, it was shown that uridylation is a differential mechanism of post-transcriptional modification of M. corti miRNAs. The whole set of M. corti miRNAs represent 33 unique miRNA families, and confirm the remarkable loss of conserved miRNA families within platyhelminth parasites, reflecting their relatively low morphological complexity and high adaptation to parasitism. Overall, the presented results provide a valuable platform to studies aiming to identify and characterize novel miRNA-based molecular mechanisms of post-transcriptional gene regulation in cestodes, necessary for the elucidation of developmental aspects of the complex biology of these parasites.

  4. In vitro culture of Mesocestoides corti metacestodes and isolation of immunomodulatory excretory-secretory products.

    PubMed

    Vendelova, E; Hrčková, G; Lutz, M B; Brehm, K; Nono Komguep, J

    2016-07-01

    Cestode-mediated diseases hold the interesting feature of persisting metacestode larvae dwelling within the host tissues, in the midst of the immune response. Excretory-secretory (ES) products of the metacestode larval stage modulate the host immune response and modify the outcome of the disease. Therefore, isolation and analysis of axenic metacestode ES products are crucial to study their properties. Here, we report the development of a system for long-term in vitro cultivation of the metacestode of the parasitic cestode Mesocestoides corti (syn. Mesocestoides vogae). Although feeder cells and host serum supported the early growth of the parasite, long-term survival was not dependent on host serum or host-derived factors enabling the collection of parasite released products in serum-free medium. Functionally, these axenic ES products recapitulated M. corti tetrathyridia's ability to inhibit LPS-driven IL-12p70 secretion by dendritic cells. Thus, our new axenic culture system will simplify the identification and characterization of M. corti-derived immunomodulatory factors that will indirectly enable the identification and characterization of corresponding factors in the metacestode larvae of medically relevant cestodes such as Echinococcus multilocularis that are not yet amenable to serum-free cultivation.

  5. Antibody response in mice infected with Mesocestoides vogae (syn. Mesocestoides corti) tetrathyridia after treatment with praziquantel and liposomised glucan.

    PubMed

    Hrckova, Gabriela; Velebný, Samuel; Kogan, Grigorij

    2007-05-01

    The therapeutic effect of praziquantel (PZQ) involves synergy with the humoral immune response during helminth infections, which is modulated by parasitic antigens. During experimental murine infections with the larval stage of cestoda Mesocestoides vogae (syn. M. corti), dynamic changes in the IgG and IgM antibody serum levels to both soluble somatic and secretory larval antigens were investigated after administration of PZQ alone and after its co-administration with the immunomodulator (l-->3)-beta-D-glucan entrapped in liposomes (lip.glucan). During the 2 weeks of follow-up after termination of therapy, specific IgG and IgM serum levels to the somatic antigens (enzyme-linked immunosorbent assay test) significantly decreased, whereas concentrations of the antibodies to the secretory antigens moderately increased, both in comparison with the control. Moreover, the number of immunogenic larval antigens (analysed by Western blot) was higher after combined therapy in comparison with single drug administration, which correlated with the intensity of reduction of the larval counts in the liver and peritoneal cavity of mice. Our data showed that administration of PZQ alone and in combination with lip.glucan resulted in marked changes in the dynamics of IgG and IgM antibodies to the somatic larval antigens, which were probably induced by the newly exposed antigens. In this respect, glucan can enhance chemotherapeutic activity of PZQ against larval cestodes by means of stimulation of the macrophage/monocyte effector functions, which seemed to contribute to the more intense larval damage.

  6. Proteomic Analysis of Excretory-Secretory Products of Mesocestoides corti Metacestodes Reveals Potential Suppressors of Dendritic Cell Functions.

    PubMed

    Vendelova, Emilia; Camargo de Lima, Jeferson; Lorenzatto, Karina Rodrigues; Monteiro, Karina Mariante; Mueller, Thomas; Veepaschit, Jyotishman; Grimm, Clemens; Brehm, Klaus; Hrčková, Gabriela; Lutz, Manfred B; Ferreira, Henrique B; Nono, Justin Komguep

    2016-10-01

    Accumulating evidences have assigned a central role to parasite-derived proteins in immunomodulation. Here, we report on the proteomic identification and characterization of immunomodulatory excretory-secretory (ES) products from the metacestode larva (tetrathyridium) of the tapeworm Mesocestoides corti (syn. M. vogae). We demonstrate that ES products but not larval homogenates inhibit the stimuli-driven release of the pro-inflammatory, Th1-inducing cytokine IL-12p70 by murine bone marrow-derived dendritic cells (BMDCs). Within the ES fraction, we biochemically narrowed down the immunosuppressive activity to glycoproteins since active components were lipid-free, but sensitive to heat- and carbohydrate-treatment. Finally, using bioassay-guided chromatographic analyses assisted by comparative proteomics of active and inactive fractions of the ES products, we defined a comprehensive list of candidate proteins released by M. corti tetrathyridia as potential suppressors of DC functions. Our study provides a comprehensive library of somatic and ES products and highlight some candidate parasite factors that might drive the subversion of DC functions to facilitate the persistence of M. corti tetrathyridia in their hosts.

  7. Proteomic Analysis of Excretory-Secretory Products of Mesocestoides corti Metacestodes Reveals Potential Suppressors of Dendritic Cell Functions

    PubMed Central

    Vendelova, Emilia; Camargo de Lima, Jeferson; Lorenzatto, Karina Rodrigues; Monteiro, Karina Mariante; Mueller, Thomas; Veepaschit, Jyotishman; Grimm, Clemens; Brehm, Klaus; Hrčková, Gabriela; Lutz, Manfred B.; Ferreira, Henrique B.

    2016-01-01

    Accumulating evidences have assigned a central role to parasite-derived proteins in immunomodulation. Here, we report on the proteomic identification and characterization of immunomodulatory excretory-secretory (ES) products from the metacestode larva (tetrathyridium) of the tapeworm Mesocestoides corti (syn. M. vogae). We demonstrate that ES products but not larval homogenates inhibit the stimuli-driven release of the pro-inflammatory, Th1-inducing cytokine IL-12p70 by murine bone marrow-derived dendritic cells (BMDCs). Within the ES fraction, we biochemically narrowed down the immunosuppressive activity to glycoproteins since active components were lipid-free, but sensitive to heat- and carbohydrate-treatment. Finally, using bioassay-guided chromatographic analyses assisted by comparative proteomics of active and inactive fractions of the ES products, we defined a comprehensive list of candidate proteins released by M. corti tetrathyridia as potential suppressors of DC functions. Our study provides a comprehensive library of somatic and ES products and highlight some candidate parasite factors that might drive the subversion of DC functions to facilitate the persistence of M. corti tetrathyridia in their hosts. PMID:27736880

  8. Infection of IL5 transgenic mice with Mesocestoides corti induces very high levels of IL5 but depressed production of eosinophils.

    PubMed

    Strath, M; Dent, L; Sanderson, C

    1992-02-01

    Transgenic mice expressing interleukin 5 (IL5) have been demonstrated to show a lifelong high level eosinophilia. These mice were produced using a construct in which the dominant control region (DCR) of the human CD2 gene was ligated to a 10-kb fragment containing the mouse IL5 gene. The construct allows the expression of the IL5 gene under the control of its own promoter, but the DCR ensures constitutive expression by all T cells. Infection of these transgenic mice with Mesocestoides corti, which is itself a potent inducer of eosinophilia, increases serum IL5 to very high levels. This demonstrates that the transgenes retain inducibility, which is a feature of the endogenous gene. However, despite the high levels of IL5, the numbers of eosinophils in the blood, marrow, and spleen decrease during the period 1-4 weeks after infection. Furthermore, there is a decrease in eosinophil precursors, as assessed by the capacity of bone marrow to produce eosinophils in culture. After this decrease eosinophils return to their previous high levels, although the levels of IL5 remain high. These results suggest that a control mechanism is operating to limit the numbers of eosinophils produced. This control appears to act at the level of the precursor production and may not be directly related to the high levels of IL5.

  9. Effects of free and liposomized praziquantel on the surface morphology and motility of Mesocestoides vogae tetrathyridia (syn. M. corti; Cestoda: Cyclophyllidea) in vitro.

    PubMed

    Hrcková, G; Velebný, S; Corba, J

    1998-01-01

    The effects of in vitro exposure to praziquantel (PZQ), liposomized PZQ (lip.PZQ), and empty liposomes on the surface morphology and motility of Mesocestoides vogae tetrathyridia were investigated using scanning electron microscopy (SEM) and a motility apparatus. Examination of treated larvae showed an effect that was concentration- and time-dependent, involving morphological damage that was similar in character for all of the treated groups. The most marked effects were a flattening and elongation of the larval body accompanied by irregularities in the surface architecture involving the development of tegumental protuberances and depressions. Erosion of the surface microvillous layer occurred only after overnight incubation, being most pronounced after treatment with lip.PZQ. The motility index of treated tetrathyridia corresponded well to the SEM observations. The frequency of contractions was maximal in worms treated with free PZQ at 25 micrograms/ml in both regimens. However, after incubation with lip.PZQ the increase in motility was concentration-dependent and of a greater extent. Empty liposomes and lipid mixtures of the same concentration and composition resulted in increased motility in treated larvae as compared with controls. More extensive tegumental damage and higher motility of larvae occurred after lip.PZQ treatment, perhaps resulting from a synergistic action of the drug and its associated lipid.

  10. Mesocestoides lineatus (Goeze, 1782) (Mesocestoididae): new data on sperm ultrastructure.

    PubMed

    Miquel, Jordi; Eira, Catarina; Swiderski, Zdzisław; Conn, David Bruce

    2007-06-01

    Spermiogenesis and the ultrastructural characters of the spermatozoon of Mesocestoides lineatus are described by means of transmission electron microscopy, including cytochemical analysis for glycogen. Materials were obtained from a golden hamster (Mesocricetus auratus) after experimental infection with tetrathyridia metacestodes obtained from naturally infected lizards (Anolis carolinensis) from Louisiana. Spermiogenesis in M. lineatus is characterized by the orthogonal growth of a free flagellum, a flagellar rotation, and a proximodistal fusion. The zone of differentiation contains 2 centrioles associated with striated rootlets and a reduced intercentriolar body. The mature spermatozoon of M. lineatus lacks a mitochondrion, and it is characterized by the presence of (1) a single, spiraled, crested body 150 nm thick; (2) a single axoneme of the 9+'1' pattern of trepaxonematan Platyhelminthes; (3) a parallel and reduced row of submembranous cortical microtubules; (4) a spiraled cordon of glycogen granules; and (5) a spiraled nucleus encircling the axoneme.

  11. Occurrence of Mesocestoides canislagopodis (Rudolphi, 1810) (Krabbe, 1865) in mammals and birds in Iceland and its molecular discrimination within the Mesocestoides species complex.

    PubMed

    Skirnisson, Karl; Jouet, Damien; Ferté, Hubert; Nielsen, Ólafur K

    2016-07-01

    The life cycle of Mesocestoides tapeworms (Cestoda: Cyclophyllidea: Mesocestoididae) requires three hosts. The first intermediate host is unknown but believed to be an arthropod. The second intermediate host is a vertebrate. The primary definitive host is a carnivore mammal, or a bird of prey, that eats the tetrathyridium-infected second intermediate host. One representative of the genus, Mesocestoides canislagopodis, has been reported from Iceland. It is common in the arctic fox (Vulpes lagopus) and has also been detected in domestic dogs (Canis familiaris) and cats (Felis domestica). Recently, scolices of a non-maturing Mesocestoides sp. have also been detected in gyrfalcon (Falco rusticolus) intestines, and tetrathyridia in the body cavity of rock ptarmigan (Lagopus muta). We examined the taxonomic relationship of Mesocestoides from arctic fox, gyrfalcon, and rock ptarmigan using molecular methods, both at the generic level (D1 domain LSU ribosomal DNA) and at the specific level (cytochrome c oxidase subunit I (COI) and 12S mitochondrial DNA). All stages belonged to Mesocestoides canislagopodis. Phylogenetic analysis of the combined 12S-COI at the specific level confirmed that M. canislagopodis forms a distinct clade, well separated from three other recognized representatives of the genus, M. litteratus, M. lineatus, and M. corti/vogae. This is the first molecular description of this species. The rock ptarmigan is a new second intermediate host record, and the gyrfalcon a new primary definitive host record. However, the adult stage seemed not to be able to mature in the gyrfalcon, and successful development is probably restricted to mammalian hosts.

  12. Towards an understanding of Mesocestoides vogae fatty acid binding proteins' roles.

    PubMed

    Alvite, Gabriela; Garrido, Natalia; Kun, Alejandra; Paulino, Margot; Esteves, Adriana

    2014-01-01

    Two fatty acid binding proteins, MvFABPa and MvFABPb were identified in the parasite Mesocestoides vogae (Platyhelmithes, Cestoda). Fatty acid binding proteins are small intracellular proteins whose members exhibit great diversity. Proteins of this family have been identified in many organisms, of which Platyhelminthes are among the most primitive. These proteins have particular relevance in flatworms since de novo synthesis of fatty acids is absent. Fatty acids should be captured from the media needing an efficient transport system to uptake and distribute these molecules. While HLBPs could be involved in the shuttle of fatty acids to the surrounding host tissues and convey them into the parasite, FABPs could be responsible for the intracellular trafficking. In an effort to understand the role of MvFABPs in fatty acid transport of M. vogae larvae, we analysed the intracellular localization of both MvFABPs and the co-localization with in vivo uptake of fatty acid analogue BODIPY FL C16. Immunohistochemical studies on larvae sections using specific antibodies, showed a diffuse cytoplasmic distribution of each protein with some expression in nuclei and mitochondria. MvFABPs distribution was confirmed by mass spectrometry identification from 2D-electrophoresis of larvae subcellular fractions. This work is the first report showing intracellular distribution of MvFABPs as well as the co-localization of these proteins with the BODIPY FL C16 incorporated from the media. Our results suggest that fatty acid binding proteins could target fatty acids to cellular compartments including nuclei. In this sense, M. vogae FABPs could participate in several cellular processes fulfilling most of the functions attributed to vertebrate's counterparts.

  13. Towards an Understanding of Mesocestoides vogae Fatty Acid Binding Proteins’ Roles

    PubMed Central

    Alvite, Gabriela; Garrido, Natalia; Kun, Alejandra; Paulino, Margot; Esteves, Adriana

    2014-01-01

    Two fatty acid binding proteins, MvFABPa and MvFABPb were identified in the parasite Mesocestoides vogae (Platyhelmithes, Cestoda). Fatty acid binding proteins are small intracellular proteins whose members exhibit great diversity. Proteins of this family have been identified in many organisms, of which Platyhelminthes are among the most primitive. These proteins have particular relevance in flatworms since de novo synthesis of fatty acids is absent. Fatty acids should be captured from the media needing an efficient transport system to uptake and distribute these molecules. While HLBPs could be involved in the shuttle of fatty acids to the surrounding host tissues and convey them into the parasite, FABPs could be responsible for the intracellular trafficking. In an effort to understand the role of MvFABPs in fatty acid transport of M. vogae larvae, we analysed the intracellular localization of both MvFABPs and the co-localization with in vivo uptake of fatty acid analogue BODIPY FL C16. Immunohistochemical studies on larvae sections using specific antibodies, showed a diffuse cytoplasmic distribution of each protein with some expression in nuclei and mitochondria. MvFABPs distribution was confirmed by mass spectrometry identification from 2D-electrophoresis of larvae subcellular fractions. This work is the first report showing intracellular distribution of MvFABPs as well as the co-localization of these proteins with the BODIPY FL C16 incorporated from the media. Our results suggest that fatty acid binding proteins could target fatty acids to cellular compartments including nuclei. In this sense, M. vogae FABPs could participate in several cellular processes fulfilling most of the functions attributed to vertebrate’s counterparts. PMID:25347286

  14. Modelling motions within the organ of Corti

    NASA Astrophysics Data System (ADS)

    Ni, Guangjian; Baumgart, Johannes; Elliott, Stephen

    2015-12-01

    Most cochlear models used to describe the basilar membrane vibration along the cochlea are concerned with macromechanics, and often assume that the organ of Corti moves as a single unit, ignoring the individual motion of different components. New experimental technologies provide the opportunity to measure the dynamic behaviour of different components within the organ of Corti, but only for certain types of excitation. It is thus still difficult to directly measure every aspect of cochlear dynamics, particularly for acoustic excitation of the fully active cochlea. The present work studies the dynamic response of a model of the cross-section of the cochlea, at the microscopic level, using the finite element method. The elastic components are modelled with plate elements and the perilymph and endolymph are modelled with inviscid fluid elements. The individual motion of each component within the organ of Corti is calculated with dynamic pressure loading on the basilar membrane and the motions of the experimentally accessible parts are compared with measurements. The reticular lamina moves as a stiff plate, without much bending, and is pivoting around a point close to the region of the inner hair cells, as observed experimentally. The basilar membrane shows a slightly asymmetric mode shape, with maximum displacement occurring between the second-row and the third-row of the outer hair cells. The dynamics responses is also calculated, and compared with experiments, when driven by the outer hair cells. The receptance of the basilar membrane motion and of the deflection of the hair bundles of the outer hair cells is thus obtained, when driven either acoustically or electrically. In this way, the fully active linear response of the basilar membrane to acoustic excitation can be predicted by using a linear superposition of the calculated receptances and a defined gain function for the outer hair cell feedback.

  15. Ants as first intermediate hosts of Mesocestoides on San Miguel Island, USA.

    PubMed

    Padgett, K A; Boyce, W M

    2005-03-01

    This study tested the hypotheses that ants (Formicidae) function as a first intermediate host of Mesocestoides (Cestoda: Mesocestoididae) and that deer mice (Peromyscus maniculatus) develop metacestode infections after ingesting cysticercoid or procercoid-infected ants. Field studies were conducted at an island fox (Urocyon littoralis littoralis) breeding facility located on San Miguel Island, California Channel Islands National Park, USA, where > 40% of captive foxes were infected with adult Mesocestoides. Eight percent (8%) of deer mice at the fox pen site were infected with Mesocestoides metacestodes while none were infected at a distant site where foxes were absent (campground), thereby indicating the potential localized presence of a first intermediate host. To test whether ants from San Miguel Island contained Mesocestoides DNA, a polymerase chain reaction (PCR)-based diagnostic assay was developed using nested primers that could detect a single hexacanth larva within pooled samples of ten ants. Ants (Lasius niger and Tapinoma sessile) collected near the fox breeding facility were tested using the nested-PCR assay. Seven of 223 pooled samples of L. niger (3.1%) and 2 of 84 pooled samples of T. sessile (2.4%) tested positive for Mesocestoides DNA, while none of the ants were positive at the campground site. Positive samples were sequenced and found to match DNA sequences from Mesocestoides obtained from island fox and deer mice. Finally, to determine whether ants function as a first intermediate host for Mesocestoides, colony-raised deer mice (n = 47) were fed L. niger (n = 3860) or T. sessile (n = 339) collected from the San Miguel Island fox breeding facility. No mouse became infected with Mesocestoides metacestodes after ingesting ants. While both L. niger and T. sessile from SMI were positive for Mesocestoides DNA, they were not infective to deer mice in the laboratory.

  16. [Canine peritoneal larval cestodosis caused by Mesocestoides spp. larval stages].

    PubMed

    Häußler, T C; Peppler, C; Schmitz, S; Bauer, C; Hirzmann, J; Kramer, M

    2016-01-01

    In a female dog with unspecific clinical symptoms, sonography detected a hyperechoic mass in the middle abdomen and blood analysis a middle grade systemic inflammatory reaction. Laparotomy revealed a peritoneal larval cestodosis (PLC). The diagnosis of an infection with tetrathyridia of Mesocestoides spp. was confirmed by parasitological examination and molecularbiological analysis. Reduction of the intra-abdominal parasitic load as well as a high dose administration of fenbendazole over 3 months led to a successful treatment which could be documented sonographically and by decreased concentrations of C-reactive protein (CRP). Seven months after discontinuation of fenbendazole administration, PLC recurred, pre-empted by an elevation of serum CRP values. According to the literature a life-long fenbendazole treatment was initiated. In cases of unclear chronic granulomatous inflammations in the abdominal cavity in dogs, PLC should be considered. CRP concentration and sonographic examinations are suitable to control for treatment success and a possibly occurring relapse.

  17. Pumilio genes from the Platyhelminthes.

    PubMed

    Koziol, Uriel; Marín, Monica; Castillo, Estela

    2008-01-01

    Pumilio proteins are proposed to have a conserved primordial function in the maintenance of proliferation in stem cells through post-transcriptional regulation. In this work, a search for pumilio homology domain (PUM-HD) sequences of pumilio genes from several Platyhelminthes species was performed, including representatives form Cestoda, Trematoda and Tricladida. Only one PUM-HD sequence was found in each triclad species; however, two PUM-HD homologues were found in all the parasitic species. These sequences formed two clearly separated clades: PlatyPum1, with sequences from all species, and PlatyPum2, composed exclusively of neodermatan sequences. Therefore, at least one duplication of the pumilio gene must have occurred before the divergence of cestodes and trematodes. Further duplications of PUM-HD were found in Fasciola hepatica, but these consist of retropseudogenes. This is the first comparative analysis of PUM-HD sequences in the Platyhelminthes and, more generally, in any lophotrochozoan phylum.

  18. Inhibition of Tapeworm Thioredoxin and Glutathione Pathways by an Oxadiazole N-Oxide Leads to Reduced Mesocestoides vogae Infection Burden in Mice.

    PubMed

    Pasquet, Vivian; Bisio, Hugo; López, Gloria V; Romanelli-Cedrez, Laura; Bonilla, Mariana; Saldaña, Jenny; Salinas, Gustavo

    2015-06-26

    Parasitic flatworms cause serious infectious diseases that affect humans and livestock in vast regions of the world, yet there are few effective drugs to treat them. Thioredoxin glutathione reductase (TGR) is an essential enzyme for redox homeostasis in flatworm parasites and a promising pharmacological target. We purified to homogeneity and characterized the TGR from the tapeworm Mesocestoides vogae (syn. M. corti). This purification revealed absence of conventional TR and GR. The glutathione reductase activity of the purified TGR exhibits a hysteretic behavior typical of flatworm TGRs. Consistently, M. vogae genome analysis revealed the presence of a selenocysteine-containing TGR and absence of conventional TR and GR. M. vogae thioredoxin and glutathione reductase activities were inhibited by 3,4-bis(phenylsulfonyl)-1,2,5-oxadiazole N2-oxide (VL16E), an oxadiazole N-oxide previously identified as an inhibitor of fluke and tapeworm TGRs. Finally, we show that mice experimentally infected with M. vogae tetrathyridia and treated with either praziquantel, the reference drug for flatworm infections, or VL16E exhibited a 28% reduction of intraperitoneal larvae numbers compared to vehicle treated mice. Our results show that oxadiazole N-oxide is a promising chemotype in vivo and highlights the convenience of M. vogae as a model for rapid assessment of tapeworm infections in vivo.

  19. Systematics of Mesocestoides (Cestoda: Mesocestoididae): evaluation of molecular and morphological variation among isolates.

    PubMed

    Padgett, Kerry A; Nadler, Steven A; Munson, Linda; Sacks, Ben; Boyce, Walter M

    2005-12-01

    A hypothesis-based framework was used to test if 3 genetic strains of Mesocestoides (clades A, B, and C) are distinct evolutionary lineages, thereby supporting their delimitation as species. For comparative purposes, 3 established cestode species, Taenia pisiformis, Taenia serialis, and Taenia crassiceps were assessed using the same methods. Sequence data from mitochondrial rDNA (12S) and the second internal transcribed spacer of nuclear rDNA (ITS-2) revealed derived (autapomorphic) characters for lineages representing clade A (n = 6 autapomorphies), clade B (n = 4), and clade C (n = 9) as well as T. pisiformis (n = 15) and T. serialis (n = 12). Furthermore, multivariate analysis of morphological data revealed significant differences among the 3 genetic strains of Mesocestoides and between T. pisiformis and T. serialis. The level of phenotypic variation within evolutionary lineages of Mesocestoides and Taenia spp. tapeworms was similar. Results from this study support recognizing Mesocestoides clades A, B, and C as separate species, and provide evidence that clade B and Mesocestoides vogae are conspecific.

  20. [Science and life--the history of Marquis Alfonso Corti].

    PubMed

    Betlejewski, Stanisław

    2008-01-01

    Alfonso Corti was born at Gambarana, near Pavia in 1822. A famous friend of Corti's father, Antonio Scarpa, may have kindled his boyhood interest in anatomy and medicine. As a medical student he enrolled first at the University of Pavia. Corti's favorite study there was microanatomy with Bartolomeo Panizza and Mario Rusconi. In 1845, against paternal wishes, Corti moved to Vienna to complete his medical studies and to work in the anatomical institute of Joseph Hirtl. There he received the degree in medicine in 1847 under the supervision of professor Hyrtl, with a thesis on the bloodstream system of a reptile. He was then appointed by Hyrtl to be his Second Prosector. With the outbreak of the 1848 Revolution he left Vienna, and after brief military service in Italy made visits to eminent scientist in Bern, London and Paris. By the beginning of 1850 Corti had received the invitation of the anatomist Albert Kölliker and had moved to Würzburg, where he made friends with Virchow. At the Kölliker Laboratory he began to work on the mammalian auditory system. A short time Corti spent in Utrecht, where he visited Professors Schroeder van der Kolk and Pieter Harting. In Utrecht Corti learned to use methods to preserve several preparations of the cochlea. From Utrecht he returned to Würzburg to complete his study of at least 200 cochlea's' of man and different animals. His famous paper: "Recherches sur l'organe de l'ouïe des mammiferes" appeared in 1851 in Kölliker's journal "Zeitschrift für wissenschaftliche Zoologie". In the same year, after death of his father, he inherited father's title Marchese de San Stefano Belbo and estate and moved back to Italy. In 1855 Corti married the daughter from a neighboring estate, Maria Bettinzoli. His young wife presented him with a daughter Bianca, and a son Gaspare, but in 1861 she died, leaving him with the responsibility of rearing the children. Unfortunately he was gradually developing arthritis deformans. Corti's last 15

  1. Imaging Organ of Corti Vibration Using Fourier-Domain OCT

    NASA Astrophysics Data System (ADS)

    Choudhury, Niloy; Chen, Fangyi; Fridberger, Anders; Zha, Dingjun; Jacques, Steven L.; Wang, Ruikang K.; Nuttall, Alfred L.

    2011-11-01

    Measuring the sound stimulated vibration from various structures in the organ of Corti is important in understanding how the small vibrations are amplified and detected. In this study we examine the feasibility of using phase-sensitive Fourier domain optical coherence tomography (PSFD-OCT) to measure vibration of the cellular structures of the organ of Corti. PSFD-OCT is a low coherence interferrometry system where the interferrogram is detected as a function of wavelength. The phase of the Fourier transformation of the detected spectra contains path deference (between the sample arm and the reference arm) information of the interferometer. In PSFD-OCT this phase is measured as a function of time and thus any time dependent change in the path difference between the sample arm and the reference arm can be detected. In the experiment, we used an in vitro preparation of the guinea pig cochlea and made a surgical opening at the apical end to access the organ of Corti. By applying tones with different frequencies via the intact middle ear, we recorded the structural vibration inside the organ of Corti. Vibration amplitude and phase of different substructures were mapped on a cross-section view of the organ of Corti. Although the measurements were made at the apical turn of the cochlea, it will be possible to make vibration measurement from various turns of the cochlea. The noise floor of the system was 0.3 nm, calibrated using a piezo stack as a calibrator.

  2. Clinical, cytological and molecular evidence of Mesocestoides sp. infection in a dog from Italy.

    PubMed

    Bonfanti, U; Bertazzolo, W; Pagliaro, L; Demarco, B; Venco, L; Casiraghi, M; Bandi, C

    2004-12-01

    A 12-year-old, 13 kg, mixed-breed male dog was referred for anorexia and depression. The dog showed discomfort on abdominal palpation. Abdominal ultrasound examination revealed multiple, small, round anechoic cystic structures. Cystic fluid obtained with fine needle aspiration contained several 2-4 mm white motile flecks. Microscopic examination of the fluid revealed numerous irregularly shaped organisms measuring several hundred microns to 3 mm, the morphology of which was suggestive of intact and fragmented acephalic metacestodes of the genus Mesocestoides sp. Molecular analysis confirmed that the peritoneal infection was caused by Mesocestoides sp.

  3. Finite-element model of the active organ of Corti

    PubMed Central

    Elliott, Stephen J.; Baumgart, Johannes

    2016-01-01

    The cochlear amplifier that provides our hearing with its extraordinary sensitivity and selectivity is thought to be the result of an active biomechanical process within the sensory auditory organ, the organ of Corti. Although imaging techniques are developing rapidly, it is not currently possible, in a fully active cochlea, to obtain detailed measurements of the motion of individual elements within a cross section of the organ of Corti. This motion is predicted using a two-dimensional finite-element model. The various solid components are modelled using elastic elements, the outer hair cells (OHCs) as piezoelectric elements and the perilymph and endolymph as viscous and nearly incompressible fluid elements. The model is validated by comparison with existing measurements of the motions within the passive organ of Corti, calculated when it is driven either acoustically, by the fluid pressure or electrically, by excitation of the OHCs. The transverse basilar membrane (BM) motion and the shearing motion between the tectorial membrane and the reticular lamina are calculated for these two excitation modes. The fully active response of the BM to acoustic excitation is predicted using a linear superposition of the calculated responses and an assumed frequency response for the OHC feedback. PMID:26888950

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

    PubMed

    Hrčkova, Gabriela; Miterpáková, Martina; O'Connor, Anne; Šnábel, Viliam; Olson, Peter D

    2011-04-01

    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 41.9% of foxes were found to harbour Mesocestoides infections. Among the samples we confirmed the widespread and common occurrence of M. litteratus (Batsch, 1786), and report the presence, for the first time, of M. lineatus (Goeze, 1782) in the Slovak Republic, where it has a more restricted geographical range and low prevalence (7%). Using a combination of 12S rDNA, CO1 and ND1 mitochondrial gene sequences together with analysis of 13 morphometric characters, we show that the two species are genetically distinct and can be differentiated by discrete breaks in the ranges of the male and female reproductive characters, but not by the more commonly examined characters of the scolex and strobila. Estimates of interspecific divergence within Mesocestoides ranged from 9 to 18%, whereas intraspecific variation was less than 2%, and phylogenetic analyses of the data showed that despite overlapping geographical ranges, the two commonly reported European species are not closely related, with M. litteratus more closely allied to North American isolates of Mesocestoides than to M. lineatus. We confirm that morphological analysis of reproductive organs can be used to reliably discriminate between these often sympatric species obtained from red foxes.

  5. Non-muscle contractile proteins in the organ of corti

    SciTech Connect

    Thalmann, I.; Giometti, C.S.; Thalmann, R. )

    1985-01-01

    Evidence indicates that an active contractile process exists in the outer hair cells of the mammalian cochlea. Proteins ordinarily associated with muscle contraction have been identified in the outer hair cells by immunohistologic techniques. On this basis a muscle-like mechanism of contraction/relaxation has been postulated by several investigators. The possibility must be considered, however, that the contractile proteins identified thus far in inner ear structures may be nonmuscle rather than muscle forms. In skeletal muscle, actin and myosin are responsible for the physical movement of the muscle fibers, and tropomyosin and troponin are involved in regulating this movement; these four proteins, as well as a variety of proteins involved with the normal cell maintenance functions are all of a muscle-specific type. Non-muscle-like motion also depends upon the interaction of actin with myosin; however, not only are these proteins structurally different from those specific to skeletal muscle but their proportions are also different. We have used two-dimensional polyacrylamide gel electrophoresis to study the proteins in freeze dried preparations of whole organ of Corti from the guinea pig. The identified proteins include non-muscle actin, three forms of non-muscle tropomyosin, alpha- and beta-tubulin, alpha-actinin, and lactate dehydrogenase (LDH B). Myosin heavy and light chains were not detected in the organ of Corti preparation, but the levels of those proteins might be too low to be detected with the protein load used of those proteins might be too low to be detected with the protein load used for this analysis. Although troponin could not be detected, calmodulin was present. All of these findings tend to indicate that the contraction/relaxation processes that have been associated with the organ of Corti by others are of the non-muscle variety.

  6. Lipid binding proteins from parasitic platyhelminthes.

    PubMed

    Alvite, Gabriela; Esteves, Adriana

    2012-01-01

    TWO MAIN FAMILIES OF LIPID BINDING PROTEINS HAVE BEEN IDENTIFIED IN PARASITIC PLATYHELMINTHES: hydrophobic ligand binding proteins (HLBPs) and fatty acid binding proteins (FABPs). Members of the former family of proteins are specific to the Cestoda class, while FABPs are conserved across a wide range of animal species. Because Platyhelminthes are unable to synthesize their own lipids, these lipid-binding proteins are important molecules in these organisms. HLBPs are a high molecular mass complex of proteins and lipids. They are composed of subunits of low molecular mass proteins and a wide array of lipid molecules ranging from CoA esters to cholesterol. These proteins are excretory-secretory molecules and are key serological tools for diagnosis of diseases caused by cestodes. FABPs are mainly intracellular proteins of low molecular weight. They are also vaccine candidates. Despite that the knowledge of their function is scarce, the differences in their molecular organization, ligand preferences, intra/extracellular localization, evolution, and phylogenetic distribution, suggest that platyhelminths HLBPs and FABPs should play different functions. FABPs might be involved in the removal of fatty acids from the inner surface of the cell membrane and in their subsequent targeting to specific cellular destinations. In contrast, HLBPs might be involved in fatty acid uptake from the host environment.

  7. Epidermal growth factor upregulates production of supernumerary hair cells in neonatal rat organ of corti explants.

    PubMed

    Lefebvre, P P; Malgrange, B; Thiry, M; Van De Water, T R; Moonen, G

    2000-03-01

    The organ of Corti is highly ordered, with a single row of inner hair cells and three rows of outer hair cells. The number of hair cells produced was thought to be limited by the time of their terminal mitosis (i.e. E14 in the mouse). However, exogenous application of retinoic acid has been shown to stimulate the formation of supernumerary hair cells in organ of Corti explants from E13 to E16 mouse embryos. Using late embryonic and neonatal rat organ of Corti explants, we investigated the potential for production of supernumerary hair cells in more mature auditory sensory epithelia. When newborn rat organ of Corti explants were cultured under control conditions, an area of supernumerary hair cells was observed in a segment of organ of Corti that was at the junction between the basal and middle turns. In these areas of supernumerary hair cells the number of hair cells increased per unit of length, but remained constant per surface unit, further demonstrating the supernumerary character of this phenomenon. Organ of Corti explants treated with epidermal growth factor (EGF) showed a 50% increase in the length of the organ of Corti segment containing supernumerary hair cells. Upregulation of supernumerary hair cell formation by EGF was found to start and be maximal at birth (P0) and to disappear by 2 days after birth (P2). Treatment of EGF stimulated P0 explants with an antimitotic drug, cytosine arabinoside (ARAc), demonstrated that the production of supernumerary hair cells occurred independently of cell division.

  8. Comparative analysis of cystatin superfamily in platyhelminths.

    PubMed

    Guo, Aijiang

    2015-01-01

    The cystatin superfamily is comprised of cysteine proteinase inhibitors and encompasses at least 3 subfamilies: stefins, cystatins and kininogens. In this study, the platyhelminth cystatin superfamily was identified and grouped into stefin and cystatin subfamilies. The conserved domain of stefins (G, QxVxG) was observed in all members of platyhelminth stefins. The three characteristics of cystatins, the cystatin-like domain (G, QxVxG, PW), a signal peptide, and one or two conserved disulfide bonds, were observed in platyhelminths, with the exception of cestodes, which lacked the conserved disulfide bond. However, it is noteworthy that cestode cystatins had two tandem repeated domains, although the second tandem repeated domain did not contain a cystatin-like domain, which has not been previously reported. Tertiary structure analysis of Taenia solium cystatin, one of the cestode cystatins, demonstrated that the N-terminus of T. solium cystatin formed a five turn α-helix, a five stranded β-pleated sheet and a hydrophobic edge, similar to the structure of chicken cystatin. Although no conserved disulfide bond was found in T. solium cystatin, the models of T. solium cystatin and chicken cystatin corresponded at the site of the first disulfide bridge of the chicken cystatin. However, the two models were not similar regarding the location of the second disulfide bridge of chicken cystatin. These results showed that T. solium cystatin and chicken cystatin had similarities and differences, suggesting that the biochemistry of T. solium cystatin could be similar to chicken cystatin in its inhibitory function and that it may have further functional roles. The same results were obtained for other cestode cystatins. Phylogenetic analysis showed that cestode cystatins constituted an independent clade and implied that cestode cystatins should be considered to have formed a new clade during evolution.

  9. Linked thioredoxin-glutathione systems in platyhelminths.

    PubMed

    Salinas, Gustavo; Selkirk, Murray E; Chalar, Cora; Maizels, Rick M; Fernández, Cecilia

    2004-07-01

    The thioredoxin and glutathione systems play a central role in thiol-disulfide redox homeostasis in many organisms by providing electrons to essential enzymes, and defence against oxidative stress. These systems have recently been characterized in platyhelminth parasites, and the emerging biochemical scenario is the existence of linked processes with the enzyme thioredoxin glutathione reductase supplying reducing equivalents to both pathways. In contrast to their hosts, conventional thioredoxin reductase and glutathione reductase enzymes appear to be absent. Analysis of published data and expressed-sequence tag databases indicates the presence of linked thioredoxin-glutathione systems in the cytosolic and mitochondrial compartments of these parasites.

  10. Environmental determinants of the spatial distribution of Mesocestoides spp. and sensitivity of flotation method for the diagnosis of mesocestoidosis.

    PubMed

    Széll, Z; Tolnai, Z; Sréter, T

    2015-09-15

    Mesocestoides spp. are zoonotic cestodes of wild and domesticated carnivores. Although the adult stages are relatively harmless intestinal parasites, the metacestode stages (tetrathyridia) can be responsible for life-threatening peritonitis and pleuritis in several species including dogs, cats, non-human primates and probably man. The aim of the present study was to reveal the spatial distribution pattern of Mesocestoides spp. in the most important final hosts, red foxes (Vulpes vulpes), to analyse the relationship of these patterns with landscape and climate by geographical information systems and to evaluate faecal flotation method for the detection of infection in the final host. Fox carcasses, representing 0.5% of the total fox population were randomly selected out of all the foxes of Hungary. The intestinal tract was examined by sedimentation and counting technique. The sensitivity of the flotation method was evaluated by the testing of the faecal samples of 180 foxes infected with Mesocestoides spp. The prevalence of infection was high in foxes (45.8%; 95% CI=41.0-50.6%), and the parasite was detected in all areas of Hungary. The high prevalence of the parasite in foxes suggests that the infection might also be common in outdoor dogs and cats. Mesocestoides infection could not be detected in any of the foxes by flotation method indicating that the sensitivity of the method is less than 0.6%. Therefore, almost all canine and feline infections remain undetected in the veterinary practice. Based on the statistical analysis, the altitude was the only determinant of the spatial distribution of Mesocestoides spp. indicating that infections in carnivores including dogs and cats can be expected mainly in midland regions (150-750 m above sea level). It might be attributed to the altitude-dependent species richness and abundance of the intermediate and final hosts of the parasite.

  11. Hox genes from the Polystomatidae (Platyhelminthes, Monogenea).

    PubMed

    Badets, Mathieu; Verneau, Olivier

    2009-11-01

    Hox genes form a multigenic family that play a fundamental role during the early stages of development. They are organised in a single cluster and share a 60 amino acid conserved sequence that corresponds to the DNA binding domain, i.e. the homeodomain. Sequence conservation in this region has allowed investigators to explore Hox diversity in the metazoan lineages. Within parasitic flatworms only homeobox sequences of parasite species from the Cestoda and Digenea have been reported. In the present study we surveyed species of the Polyopisthocotylea (Monogenea) in order to clarify Hox identification and diversification processes in the neodermatan lineage. From cloning of degenerative PCR products of the central region of the homeobox, we report one ParaHox and 25 new Hox sequences from 10 species of the Polystomatidae and one species of the Diclidophoridae, which extend Hox gene diversity from 46 to 72 within Neodermata. Hox sequences from the Polyopisthocotylea were annotated and classified from sequence alignments and Bayesian inferences of 178 Hox, ParaHox and related gene families recovered from all available parasitic platyhelminths and other bilaterian taxa. Our results are discussed in the light of the recent Hox evolutionary schemes. They may provide new perspectives to study the transition from turbellarians to parasitic flatworms with complex life-cycles and outline the first steps for evolutionary developmental biological approaches within platyhelminth parasites.

  12. Cytogenetics and chromosomes of tapeworms (Platyhelminthes, Cestoda).

    PubMed

    Spakulová, Marta; Orosová, Martina; Mackiewicz, John S

    2011-01-01

    Tapeworms (Cestoda, Platyhelminthes) are a highly diversified group of parasites that can have significant veterinary importance as well as medical impact as disease agents of human alveococcosis, hydatidosis, taeniosis/cysticercosis/neurocysticercosis, hymenolepidosis or diphyllobothriasis. Because of their great diversity, there has been keen interest in their phylogenetic relationships to other obligate parasitic platyhelminthes, as well as within the group itself. Recent phylogenetic analyses of cestodes, however, have focused on morphological, molecular, life cycle, embryology and host-specificity features and conspicuously omitted inclusion of karyological data. Here we review the literature from 1907 to 2010 and the current status of knowledge of the chromosomes and cytogenetics within all of the cestode orders and place it within an evolutionary perspective. Karyological data are discussed and tabulated for 115 species from nine eucestode orders with ideograms of 46 species, and a comparison of cytogenetic patterns between acetabulate and bothriate cestode lineages is made. Attention is drawn to gaps in our knowledge for seven remaining orders and cestodarian groups Gyrocotylidea and Amphilinidea. Among the cytogenetic aspects covered are: chromosome number, triploidy, classical karyotype cytogenetics (banding patterns, karyotype asymmetry, secondary constrictions), as well as advanced karyotype techniques allowing location of genes on chromosomes by fluorescence in situ hybridization. We demonstrate that further progress in cestode karyosystematics rests with new molecular approaches and the application of advanced cytogenetic markers facilitating intimate karyotype analysis.

  13. Organ of Corti Micromechanics with Local Electrical Stimulation

    NASA Astrophysics Data System (ADS)

    Chen, Fangyi; Zheng, Jiefu; Choudhury, Niloy; Jaques, Steve; Nuttall, Alfred L.

    2009-02-01

    Optical low coherence interferometry is able to both image and measure the vibration of the cellular and non-cellular structures of the organ of Corti in vivo. In this study we applied an electric current to the basal turn from a pair of electrodes, one in scala tympani and the other in scala vestibuli, at the location corresponding to ~17 kHz when interferometry measurements were made. The coherence gate of the interferometer was positioned 1) at the basilar membrane (BM) near the radial location of the outer hair cells (OHCs) (approximately 1/2 the width of the BM) and 2) at the reticular lamina (RL) where the OHCs are located. We confirmed that electrical stimulation with a frequency sweep (12 kHz -25 kHz) caused a mechanical BM displacement with a peak and a traveling wave-like phase delay as we reported previously using laser Doppler velocimetry and reflective beads on the BM. Reflective beads were not used in the current study. The vibration of the RL had little or no phase delay that would characterize a traveling wave. These data suggest a very high compliance system for the electrically activated cellular structure of the organ.

  14. Primary culture and plasmid electroporation of the murine organ of Corti.

    PubMed

    Parker, Mark; Brugeaud, Aurore; Edge, Albert S B

    2010-02-04

    In all mammals, the sensory epithelium for audition is located along the spiraling organ of Corti that resides within the conch shaped cochlea of the inner ear (fig 1). Hair cells in the developing cochlea, which are the mechanosensory cells of the auditory system, are aligned in one row of inner hair cells and three (in the base and mid-turns) to four (in the apical turn) rows of outer hair cells that span the length of the organ of Corti. Hair cells transduce sound-induced mechanical vibrations of the basilar membrane into neural impulses that the brain can interpret. Most cases of sensorineural hearing loss are caused by death or dysfunction of cochlear hair cells. An increasingly essential tool in auditory research is the isolation and in vitro culture of the organ explant. Once isolated, the explants may be utilized in several ways to provide information regarding normative, anomalous, or therapeutic physiology. Gene expression, stereocilia motility, cell and molecular biology, as well as biological approaches for hair cell regeneration are examples of experimental applications of organ of Corti explants. This protocol describes a method for the isolation and culture of the organ of Corti from neonatal mice. The accompanying video includes stepwise directions for the isolation of the temporal bone from mouse pups, and subsequent isolation of the cochlea, spiral ligament, and organ of Corti. Once isolated, the sensory epithelium can be plated and cultured in vitro in its entirety, or as a further dissected micro-isolate that lacks the spiral limbus and spiral ganglion neurons. Using this method, primary explants can be maintained for 7-10 days. As an example of the utility of this procedure, organ of Corti explants will be electroporated with an exogenous DsRed reporter gene. This method provides an improvement over other published methods because it provides reproducible, unambiguous, and stepwise directions for the isolation, microdissection, and primary

  15. Consequences of Location-Dependent Organ of Corti Micro-Mechanics

    PubMed Central

    Liu, Yanju; Gracewski, Sheryl M.; Nam, Jong-Hoon

    2015-01-01

    The cochlea performs frequency analysis and amplification of sounds. The graded stiffness of the basilar membrane along the cochlear length underlies the frequency-location relationship of the mammalian cochlea. The somatic motility of outer hair cell is central for cochlear amplification. Despite two to three orders of magnitude change in the basilar membrane stiffness, the force capacity of the outer hair cell’s somatic motility, is nearly invariant over the cochlear length. It is puzzling how actuators with a constant force capacity can operate under such a wide stiffness range. We hypothesize that the organ of Corti sets the mechanical conditions so that the outer hair cell’s somatic motility effectively interacts with the media of traveling waves—the basilar membrane and the tectorial membrane. To test this hypothesis, a computational model of the gerbil cochlea was developed that incorporates organ of Corti structural mechanics, cochlear fluid dynamics, and hair cell electro-physiology. The model simulations showed that the micro-mechanical responses of the organ of Corti are different along the cochlear length. For example, the top surface of the organ of Corti vibrated more than the bottom surface at the basal (high frequency) location, but the amplitude ratio was reversed at the apical (low frequency) location. Unlike the basilar membrane stiffness varying by a factor of 1700 along the cochlear length, the stiffness of the organ of Corti complex felt by the outer hair cell remained between 1.5 and 0.4 times the outer hair cell stiffness. The Y-shaped structure in the organ of Corti formed by outer hair cell, Deiters cell and its phalange was the primary determinant of the elastic reactance imposed on the outer hair cells. The stiffness and geometry of the Deiters cell and its phalange affected cochlear amplification differently depending on the location. PMID:26317521

  16. Morphological characteristics of Mesocestoides canislagopodis (Krabbe 1865) tetrathyridia found in rock ptarmigan (Lagopus muta) in Iceland.

    PubMed

    Skirnisson, Karl; Sigurðardóttir, Ólöf G; Nielsen, Ólafur K

    2016-08-01

    Necropsies of 1010 rock ptarmigans (Lagopus muta) sampled in autumn 2006-2015 in northeast Iceland revealed Mesocestoides canislagopodis tetrathyridia infections in six birds (0.6 %), two juvenile birds (3 month old), and four adult birds (15 months or older). Four birds had tetrathyridia in the body cavity, one bird in the liver, and one bird both in the body cavity and the liver. There were more tetrathyridia in the body cavity of the two juveniles (c. 50 in each) than in three adults (10-40), possibly indicating a host-age-related tetrathyridia mortality. Approximately, half of tetrathyridia in the body cavity were free or loosely attached to the serosa, the other half were encapsulated in a thin, loose connective tissue stroma, frequently attached to the lungs and the liver. Tetrathyridia in the liver parenchyma incited variably intense inflammation. Tetrathyridia from the juvenile hosts were whitish, heart-shaped, and flattened, with unsegmented bodies with a slightly pointed posterior end. In the adult hosts, tetrathyridia were sometimes almost rectangular-shaped, slightly wider compared to those in the juveniles, but more than twice as long as the younger-aged tetrathyridia. Tetrathyridia infections are most likely acquired during the brief insectivorous feeding phase of ptarmigan chicks, and the tetrathyridia persist throughout the lifespan of the birds.

  17. Tetrathyridia of Mesocestoides lineatus in Chinese snakes and their adults recovered from experimental animals.

    PubMed

    Cho, Shin-Hyeong; Kim, Tong-Soo; Kong, Yoon; Na, Byoung-Kuk; Sohn, Woon-Mok

    2013-10-01

    Morphological characteristics of Mesocestoides lineatus tetrathyridia collected from Chinese snakes and their adults recovered from experimental animals were studied. The tetrathyridia were detected mainly in the mesentery of 2 snake species, Agkistrodon saxatilis (25%) and Elaphe schrenckii (20%). They were 1.73 by 1.02 mm in average size and had an invaginated scolex with 4 suckers. Adult tapeworms were recovered from 2 hamsters and 1 dog, which were orally infected with 5-10 larvae each. Adults from hamsters were about 32 cm long and those from a dog were about 58 cm long. The scolex was 0.56 mm in average width with 4 suckers of 0.17 by 0.15 mm in average size. Mature proglottids measured 0.29 by 0.91 mm (av.). Ovaries and vitellaria bilobed and located in the posterior portion of proglottids. The cirrus sac was oval-shaped and located median. Testes were follicular, distributed in both lateral fields of proglottids, and 41-52 in number per proglottid. Gravid proglottids were 1.84 by 1.39 mm (av.) with a characteristic paruterine organ. Eggs were 35 by 27 µm in average size with a hexacanth embryo. These morphological characteristics of adult worms were identical with those of M. lineatus reported previously. Therefore, it has been confirmed that the tetrathyridia detected in 2 species of Chinese snakes are the metacestodes of M. lineatus, and 2 snake species, A. saxatilis and E. schrenckii, play the role of intermediate hosts.

  18. Outer Hair Cells Provide Active Tuning in the Organ of Corti.

    PubMed

    Ulfendahl, Mats; Flock Å, Åke

    1998-06-01

    The detection of sound by the mammalian hearing organ, the organ of Corti, is far from a passive process with the sensory cells acting as mere receptors. The high sensitivity and sharp tuning of the auditory apparatus are very much dependant on the active mechanical behavior of the outer hair cells, acting as effector cells.

  19. Life-history studies on two molecular strains of mesocestoides (Cestoda: Mesocestoididae): identification of sylvatic hosts and infectivity of immature life stages.

    PubMed

    Padgett, Kerry A; Boyce, Walter M

    2004-02-01

    Life-cycle studies were conducted on 2 molecular strains of Mesocestoides tapeworms that represent different evolutionary lineages (clades A and B). Wild carnivores, reptiles, and rodents were examined for tapeworm infections at 2 enzootic sites: (1) San Miguel Island (SMI), a small island off the coast of southern California and (2) Hopland Research and Extension Center (HREC), a field station in northern California. Results indicate that deer mice (Peromyscus maniculatus) and coyotes (Canis latrans) may play an important role in the life cycles of Mesocestoides (clades A and B) in California. Over half the coyotes at HREC and at least a third of the population of island fox (Urocyon littoralis) at SMI were found to harbor clade A adult Mesocestoides spp. One of every 4 Mesocestoides-infected coyotes had tapeworms representing both clades A and B. Experimental inoculations revealed that proglottids (clades A and B) were not directly infectious to rodents, reptiles, or dogs. On the other hand, mice, lizards, and hamsters fed tetrathyridia of Mesocestoides spp. (clades A or B) developed peritoneal tetrathyridial infections. A dog that was fed tetrathyridia (clade B) developed an adult tapeworm infection. Acephalic metacestodes given orally to western fence lizards, laboratory mice, or domestic dogs did not result in metacestode or adult tapeworm infections. Whereas most clade A acephalic metacestodes from dogs were asexually proliferative, clade A tetrathyridia isolated from wild deer mice did not show evidence of asexual replication. Our study supports the hypothesis that a second, as of yet unidentified, intermediate host is necessary to complete the life cycles of Mesocestoides spp., and that acephalic metacestodes represent an aberrant form, incapable of further development.

  20. Tetrathyridia of Mesocestoides lineatus in Chinese Snakes and Their Adults Recovered from Experimental Animals

    PubMed Central

    Cho, Shin-Hyeong; Kim, Tong-Soo; Kong, Yoon; Na, Byoung-Kuk

    2013-01-01

    Morphological characteristics of Mesocestoides lineatus tetrathyridia collected from Chinese snakes and their adults recovered from experimental animals were studied. The tetrathyridia were detected mainly in the mesentery of 2 snake species, Agkistrodon saxatilis (25%) and Elaphe schrenckii (20%). They were 1.73 by 1.02 mm in average size and had an invaginated scolex with 4 suckers. Adult tapeworms were recovered from 2 hamsters and 1 dog, which were orally infected with 5-10 larvae each. Adults from hamsters were about 32 cm long and those from a dog were about 58 cm long. The scolex was 0.56 mm in average width with 4 suckers of 0.17 by 0.15 mm in average size. Mature proglottids measured 0.29 by 0.91 mm (av.). Ovaries and vitellaria bilobed and located in the posterior portion of proglottids. The cirrus sac was oval-shaped and located median. Testes were follicular, distributed in both lateral fields of proglottids, and 41-52 in number per proglottid. Gravid proglottids were 1.84 by 1.39 mm (av.) with a characteristic paruterine organ. Eggs were 35 by 27 µm in average size with a hexacanth embryo. These morphological characteristics of adult worms were identical with those of M. lineatus reported previously. Therefore, it has been confirmed that the tetrathyridia detected in 2 species of Chinese snakes are the metacestodes of M. lineatus, and 2 snake species, A. saxatilis and E. schrenckii, play the role of intermediate hosts. PMID:24327778

  1. Proliferative peritoneal and pleural cestodiasis in a cat caused by metacestodes of Mesocestoides sp. Anatomohistopathological findings and genetic identification.

    PubMed

    Eleni, C; Scaramozzino, P; Busi, M; Ingrosso, S; D'Amelio, S; De Liberato, C

    2007-03-01

    A 10-year-old female cat was brought to Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana for post-mortem examination. The animal used to live, together with 26 other cats, in the big terrace of an apartment at the 8th floor in Rome; and was always fed with industrial pet food. Anamnesis referred balance troubles, vomit and convulsions, during a couple of days, followed by sudden death. At necropsy, the cat presented mucoid rhinitis, purulent tracheitis, small areas of pneumonia, dark spots in the liver, catarrhal-hemorrhagic gastritis, fibrinous enteritis and meningeal hyperemia. Thoracic and abdominal cavities were completely invaded by hundreds of larval stages of cestodes. The same parasites were also included in nodules in pancreatic, lung and kidney parenchyma. Microscopic examination of parasites allowed their identification as larval stages (metacestodes) of cestodes of the genus Mesocestoides. The molecular genotyping of the metacestodes indicates a close relationship with members of the genus Mesocestoides, although a significant variation was found with respect to the available sequences of other species of the genus.

  2. Harmonic Response of the Organ of Corti: Results for Wave Dispersion

    NASA Astrophysics Data System (ADS)

    Foucaud, Simon; Michon, Guilhem; Morlier, Joseph; Gourinat, Yves

    2011-11-01

    Inner ear is a remarkable multiphysical system and its modelling is a great challenge. The approach used in this paper aims to reproduce physic with a realistic description of the radial cross section of the cochlea. A 2D-section of the organ of Corti is fully described. Wavenumbers and corresponding modes of propagation are calculated taking into account passive structural responses. The study is extended to six cross sections of the organ of Corti and a large frequency bandwidth from 100 Hz to 3 kHz. Dispersion curves reveal the influence of fluid structure interactions with a dispersive behavior at high frequencies. Longitudinal mechanical coupling provides new interacting modes of propagation.

  3. Re-examination of spermatogenesis of Multicotyle purvisi (Platyhelminthes, Aspidogastrea).

    PubMed

    Watson, N A; Rohde, K

    1995-05-01

    Examination of spermatogenesis in Multicotyle purvisi revealed that the process follows the classical pattern previously described for many parasitic platyhelminths, especially other Aspidogastrea and Digenea. Free flagella (with an intercentriolar body between the basal bodies and with striated flagellar rootlets) and a median cytoplasmic process grow from a zone of differentiation. The flagella then fuse with the process in a proximo-distal direction and nucleus and mitochondrion grow out into the elongating spermatid. Spermatids are pinched off at the base, and rootlets and intercentriolar body remain behind in the residual cytoplasm. It is suggested that the aberrant processes described in an earlier report constitute a pathological condition or a response to stress. Changes in the intercentriolar body during spermiogenesis are documented and for the first time in a platyhelminth it is demonstrated that rootlets and intercentriolar bodies are discarded and left behind in the residual cytoplasm.

  4. The complete mitochondrial genome of Dugesia japonica (Platyhelminthes; order Tricladida).

    PubMed

    Sakai, Masato; Sakaizumi, Mitsuru

    2012-10-01

    We used two sequencing methods, namely long polymerase chain reaction (PCR) and primer walking, to determine the complete mitochondrial DNA (mtDNA) sequence of Dugesia japonica and most of the mtDNA sequence of Dugesia ryukyuensis. The genome of D. japonica contained 36 genes including 12 of the 13 protein-coding genes characteristic of metazoan mitochondrial genomes, two ribosomal RNA genes, and 22 transfer RNA genes. The genome of D. ryukyuensis contained 33 genes, including 12 protein-coding genes, two ribosomal RNA genes, and 19 transfer RNA genes. The gene order of the mitochondrial genome from the Dugesia species showed no clear homology with either the Neodermata or other free-living Rhabditophora. This indicates that the platyhelminths exhibit great variability in mitochondrial gene order. This is the first complete sequence analysis of the mitochondrial genome of a free-living member of Rhabditophora, which will facilitate further studies on the population genetics and genomic evolution of the Platyhelminthes.

  5. Characterization of the mouse organ of Corti cytoarchitecture using a stick representation

    NASA Astrophysics Data System (ADS)

    Soons, Joris A.; Ricci, Anthony J.; Steele, Charles R.; Puria, Sunil

    2015-02-01

    The supporting cells and hair cells (HCs) in the organ of Corti (OoC) are highly organized. The precise 3D micro-structure is hypothesized to play a critical role in cochlear function. Recently, we combined two techniques to obtain the organ of Corti cytoarchitecture. Two-photon imaging allowed us to perform in situ imaging without subjecting the tissue to other potential distortions, while genetically engineered mTmG mice have a fluorophore embedded in the cell membranes. In this contribution we discuss the parameterization step necessary to compare structures obtained with this technique at different locations and in different specimens. First, the z-axis is chosen perpendicular to the basilar membrane. Subsequently, base and apex of cells are indicated by landmarks. As such, the cells are approximated as a stick representation. This representation is used to calculate the 3D lengths and angles of all imaged cells. Since the OoC is not straight but spiral-shaped, the radial (y) and longitudinal (x) directions differ at each location. Therefore, circular arcs are fitted through the 3 rows of outer HCs to define the local radial (y) and longitudinal (x) direction. Novel in this approach is the 3D data of the cell position in the organ of Corti. Cell diameters and tissue areas cannot be quantified with this stick representation and need to be measured separately.

  6. Thioredoxin Glutathione Reductase-Dependent Redox Networks in Platyhelminth Parasites

    PubMed Central

    Bonilla, Mariana; Gladyshev, Vadim N.

    2013-01-01

    Abstract Significance: Platyhelminth parasites cause chronic infections that are a major cause of disability, mortality, and economic losses in developing countries. Maintaining redox homeostasis is a major adaptive problem faced by parasites and its disruption can shift the biochemical balance toward the host. Platyhelminth parasites possess a streamlined thiol-based redox system in which a single enzyme, thioredoxin glutathione reductase (TGR), a fusion of a glutaredoxin (Grx) domain to canonical thioredoxin reductase (TR) domains, supplies electrons to oxidized glutathione (GSSG) and thioredoxin (Trx). TGR has been validated as a drug target for schistosomiasis. Recent Advances: In addition to glutathione (GSH) and Trx reduction, TGR supports GSH-independent deglutathionylation conferring an additional advantage to the TGR redox array. Biochemical and structural studies have shown that the TR activity does not require the Grx domain, while the glutathione reductase and deglutathionylase activities depend on the Grx domain, which receives electrons from the TR domains. The search for TGR inhibitors has identified promising drug leads, notably oxadiazole N-oxides. Critical Issues: A conspicuous feature of platyhelminth TGRs is that their Grx-dependent activities are temporarily inhibited at high GSSG concentrations. The mechanism underlying the phenomenon and its biological relevance are not completely understood. Future Directions: The functional diversity of Trxs and Grxs encoded in platyhelminth genomes remains to be further assessed to thoroughly understand the TGR-dependent redox network. Optimization of TGR inhibitors and identification of compounds targeting other parasite redox enzymes are good options to clinically develop relevant drugs for these neglected, but important diseases. Antioxid. Redox Signal. 19, 735–745. PMID:22909029

  7. Acoel flatworms are not platyhelminthes: evidence from phylogenomics.

    PubMed

    Philippe, Hervé; Brinkmann, Henner; Martinez, Pedro; Riutort, Marta; Baguñà, Jaume

    2007-08-08

    Acoel flatworms are small marine worms traditionally considered to belong to the phylum Platyhelminthes. However, molecular phylogenetic analyses suggest that acoels are not members of Platyhelminthes, but are rather extant members of the earliest diverging Bilateria. This result has been called into question, under suspicions of a long branch attraction (LBA) artefact. Here we re-examine this problem through a phylogenomic approach using 68 different protein-coding genes from the acoel Convoluta pulchra and 51 metazoan species belonging to 15 different phyla. We employ a mixture model, named CAT, previously found to overcome LBA artefacts where classical models fail. Our results unequivocally show that acoels are not part of the classically defined Platyhelminthes, making the latter polyphyletic. Moreover, they indicate a deuterostome affinity for acoels, potentially as a sister group to all deuterostomes, to Xenoturbellida, to Ambulacraria, or even to chordates. However, the weak support found for most deuterostome nodes, together with the very fast evolutionary rate of the acoel Convoluta pulchra, call for more data from slowly evolving acoels (or from its sister-group, the Nemertodermatida) to solve this challenging phylogenetic problem.

  8. Mitochondrial genome data support the basal position of acoelomorpha and the polyphyly of the platyhelminthes

    SciTech Connect

    Ruiz-Trillo, Inaki; Riutort, Marta; Fourcade, H. Matthew; Baguna, Jaume; Boore, Jeffrey L.

    2004-05-01

    We determined 9.7, 5.2, and 6.8 kb, respectively, of the mitochondrial genomes of the acoel Paratomella rubra, the nemertodermatid Nemertoderma westbladi and the free-living rhabditophoran platyhelminth Microstomum lineare. The identified gene arrangements are unique among metazoans, including each other, sharing no more than one or two single gene boundaries with a few distantly related taxa. Phylogenetic analysis of the amino acid sequences inferred from the sequenced genes confirms that the acoelomorph flatworms (acoels + nemertodermatids) do not belong to the Platyhelminthes, but are, instead, the most basal extant bilaterian group. Therefore, the Platyhelminthes, as traditionally constituted, is a polyphyletic phylum.

  9. Acoel flatworms: earliest extant bilaterian Metazoans, not members of Platyhelminthes.

    PubMed

    Ruiz-Trillo, I; Riutort, M; Littlewood, D T; Herniou, E A; Baguña, J

    1999-03-19

    Because of their simple organization the Acoela have been considered to be either primitive bilaterians or descendants of coelomates through secondary loss of derived features. Sequence data of 18S ribosomal DNA genes from non-fast evolving species of acoels and other metazoans reveal that this group does not belong to the Platyhelminthes but represents the extant members of the earliest divergent Bilateria, an interpretation that is supported by recent studies on the embryonic cleavage pattern and nervous system of acoels. This study has implications for understanding the evolution of major body plans, and for perceptions of the Cambrian evolutionary explosion.

  10. Evolution and Development of the Tetrapod Auditory System: an Organ of Corti-Centric Perspective

    PubMed Central

    Fritzsch, Bernd; Pan, Ning; Jahan, Israt; Duncan, Jeremy S.; Kopecky, Benjamin J.; Elliott, Karen L.; Kersigo, Jennifer; Yang, Tian

    2013-01-01

    The tetrapod auditory system transmits sound through the outer and middle ear to the organ of Corti or other sound pressure receivers of the inner ear where specialized hair cells translate vibrations of the basilar membrane into electrical potential changes that are conducted by the spiral ganglion neurons to the auditory nuclei. In other systems, notably the vertebrate limb, a detailed connection between the evolutionary variations in adaptive morphology and the underlying alterations in the genetic basis of development has been partially elucidated. In this review, we attempt to correlate evolutionary and partially characterized molecular data into a cohesive perspective of the evolution of the mammalian organ of Corti out of the tetrapod basilar papilla. We propose a stepwise, molecularly partially characterized transformation of the ancestral, vestibular developmental program of the vertebrate ear. This review provides a framework to decipher both discrete steps in development and the evolution of unique functional adaptations of the auditory system. The combined analysis of evolution and development establishes a powerful cross-correlation where conclusions derived from either approach become more meaningful in a larger context not possible through exclusively evolution or development centered perspectives. PMID:23331918

  11. Displacements of the organ of Corti by gel injections into the cochlear apex

    PubMed Central

    Salt, Alec N.; Brown, Daniel J.; Hartsock, Jared J.; Plontke, Stefan K.

    2009-01-01

    In order to transduce sounds efficiently, the stereocilia of hair cells in the organ of Corti must be positioned optimally. Mechanical displacements, such as pressure differentials across the organ caused by endolymphatic hydrops, may impair sensitivity. Studying this phenomenon has been limited by the technical difficulty of inducing sustained displacements of stereocilia in vivo. We have found that small injections (0.5 to 2 μL) of Healon gel into the cochlear apex of guinea pigs produced sustained changes of endocochlear potential (EP), summating potential (SP) and transducer operating point (OP) in a manner consistent with a mechanically-induced position change of the organ of Corti in the basal turn. Induced changes immediately recovered when injection ceased. In addition, effects of low-frequency bias tones on EP, SP and OP were enhanced during the injection of gel and remained hypersensitive after injection ceased. This is thought to result from the viscous gel mechanically limiting pressure shunting through the helicotrema. Cochlear microphonics measured as frequency was varied showed enhancement below 100 Hz but most notably in the sub-auditory range. Sensitivity to low-frequency biasing was also enhanced in animals with surgically-induced endolymphatic hydrops, suggesting that obstruction of the perilymphatic space by hydrops could contribute to the pathophysiology of this condition. PMID:19217935

  12. Three-Dimensional Imaging of the Mouse Organ of Corti Cytoarchitecture for Mechanical Modeling

    NASA Astrophysics Data System (ADS)

    Puria, Sunil; Hartman, Byron; Kim, Jichul; Oghalai, John S.; Ricci, Anthony J.; Liberman, M. Charles

    2011-11-01

    Cochlear models typically use continuous anatomical descriptions and homogenized parameters based on two-dimensional images for describing the organ of Corti. To produce refined models based more closely on the actual cochlear cytoarchitecture, three-dimensional morphometric parameters of key mechanical structures are required. Towards this goal, we developed and compared three different imaging methods: (1) A fixed cochlear whole-mount preparation using the fluorescent dye Cellmask®, which is a molecule taken up by cell membranes and clearly delineates Deiters' cells, outer hair cells, and the phalangeal process, imaged using confocal microscopy; (2) An in situ fixed preparation with hair cells labeled using anti-prestin and supporting structures labeled using phalloidin, imaged using two-photon microscopy; and (3) A membrane-tomato (mT) mouse with fluorescent proteins expressed in all cell membranes, which enables two-photon imaging of an in situ live preparation with excellent visualization of the organ of Corti. Morphometric parameters including lengths, diameters, and angles, were extracted from 3D cellular surface reconstructions of the resulting images. Preliminary results indicate that the length of the phalangeal processes decreases from the first (inner most) to third (outer most) row of outer hair cells, and that their length also likely varies from base to apex and across species.

  13. Impedance analysis of the organ of corti with magnetically actuated probes.

    PubMed

    Scherer, Marc P; Gummer, Anthony W

    2004-08-01

    An innovative method is presented to measure the mechanical driving point impedance of biological structures up to at least 40 kHz. The technique employs an atomic force cantilever with a ferromagnetic coating and an external magnetic field to apply a calibrated force to the cantilever. Measurement of the resulting cantilever velocity using a laser Doppler vibrometer yields the impedance. A key feature of the method is that it permits measurements for biological tissue in physiological solutions. The method was applied to measure the point impedance of the organ of Corti in situ, to elucidate the biophysical basis of cochlear amplification. The basilar membrane was mechanically clamped at its tympanic surface and the measurements conducted at different radial positions on the reticular lamina. The tectorial membrane was removed. The impedance was described by a generalized Voigt-Kelvin viscoelastic model, in which the stiffness was real-valued and independent of frequency, but the viscosity was complex-valued with positive real part, which was dependent on frequency and negative imaginary part, which was independent of frequency. There was no evidence for an inertial component. The magnitude of the impedance was greatest at the tunnel of Corti, and decreased monotonically in each of the radial directions. In the absence of inertia, the mechanical load on the outer hair cells causes their electromotile displacement responses to be reduced by only 10-fold over the entire range of auditory frequencies.

  14. Can Outer Hair Cells Actively Pump Fluid into the Tunnel of Corti?

    NASA Astrophysics Data System (ADS)

    Zagadou, Brissi Franck; Mountain, David C.

    2011-11-01

    Non-classical models of the cochlear traveling wave have been introduced in attempt to capture the unique features of the cochlear amplifier (CA). These models include multiple modes of longitudinal coupling. In one approach, it is hypothesized that two wave modes can add their energies to create amplification such as that desired in the CA. The tunnel of Corti (ToC) was later used to represent the second wave mode for the proposed traveling wave amplifier model, and was incorporated in a multi-compartment cochlea model. The results led to the hypothesis that the CA functions as a fluid pump. However, this hypothesis must be consistent with the anatomical structure of the organ of Corti (OC). The fluid must pass between the outer pillar cells before reaching the ToC, and the ToC fluid and the underlying basilar membrane must constitute an appropriate waveguide. We have analyzed an anatomically based 3D finite element model of the ToC of the gerbil. Our results demonstrate that the OC structure is consistent with the hypothesis.

  15. Comparative analysis of known miRNAs across platyhelminths.

    PubMed

    Jin, Xiaoliang; Lu, Lixia; Su, Hailong; Lou, Zhongzi; Wang, Fang; Zheng, Yadong; Xu, Guo-Tong

    2013-08-01

    MicroRNAs (miRNAs) are a subtype of small regulatory RNAs that are involved in numerous biological processes through small RNA-induced silencing networks. In an attempt to explore the phylogeny of miRNAs across five platyhelminths, we integrated annotated miRNAs and their full genomes. We identified conserved miRNA clusters and, in particular, miR-71/2 was conserved from planarian to parasitic flatworms and was expanded in free-living Schmidtea mediterranea. Analysis of 22 miRNA loci provided compelling evidence that most known miRNAs are conserved across platyhelminths. Meanwhile, we also observed alterations of known protein-coding genes flanking miRNA(s), such as transcriptional direction conversion and locus relocation, in around ~ 41% of 22 known miRNA loci. Compared with Echinococcus multilocularis, the majority of these events occurred in evolution-distant Hymenolepis microstoma, Schistosoma japonicum or/and S. mediterranea. These results imply rearrangement events occurred near the known miRNA loci.

  16. Phylogenetic analysis of the Argonaute protein family in platyhelminths.

    PubMed

    Zheng, Yadong

    2013-03-01

    Argonaute proteins (AGOs) are mediators of gene silencing via recruitment of small regulatory RNAs to induce translational regression or degradation of targeted molecules. Platyhelminths have been reported to express microRNAs but the diversity of AGOs in the phylum has not been explored. Phylogenetic relationships of members of this protein family were studied using data from six platyhelminth genomes. Phylogenetic analysis showed that all cestode and trematode AGOs, along with some triclad planarian AGOs, were grouped into the Ago subfamily and its novel sister clade, here referred to as Cluster 1. These were very distant from Piwi and Class 3 subfamilies. By contrast, a number of planarian Piwi-like AGOs formed a novel sister clade to the Piwi subfamily. Extensive sequence searching revealed the presence of an additional locus for AGO2 in the cestode Echinococcus granulosus and exon expansion in this species and E. multilocularis. The current study suggests the absence of the Piwi subfamily and Class 3 AGOs in cestodes and trematodes and the Piwi-like AGO expansion in a free-living triclad planarian and the occurrence of exon expansion prior to or during the evolution of the most-recent common ancestor of the Echinococcus species studied.

  17. Influence of parasitism on trace element contents in tissues of red fox (Vulpes vulpes) and its parasites Mesocestoides spp. (Cestoda) and Toxascaris leonina (Nematoda).

    PubMed

    Jankovská, Ivana; Miholová, Daniela; Bejcek, Vladimír; Vadlejch, Jaroslav; Sulc, Miloslav; Száková, Jirina; Langrová, Iva

    2010-02-01

    Bioaccumulation of cadmium, chromium, copper, manganese, nickel, lead, and zinc in 56 foxes (Vulpes vulpes) and their parasites Mesocestoides spp. (Cestoda) and Toxascaris leonina (Nematoda) was studied. The levels of heavy metals were determined in the livers and kidneys of the animals depending on parasitism in the following ranges: Pb, 0.029-3.556; Cd, 0.055-9.967; Cr, 0.001-0.304; Cu, 4.15-41.15; Mn, 1.81-19.94; Ni: 0.037-0.831; Zn, 52.0-212.9 microg/g dry weight (dw). Cd in parasites (0.038-3.678 microg/g dw) were comparable with those in the livers of the host and lower than in the kidneys (0.095-6.032 microg/g dw). Contents of Pb, Cr, Cu, Mn, Ni, and Zn in cestodes were predominantly higher than those in the kidney and liver of the host. Median lead levels in Mesocestoides spp. (45.6 microg/g dw) were 52-fold higher than in the kidney and liver of the red fox (Vulpes vulpes) infected by both parasites and median Pb values in T. leonina (8.98 microg/g dw) were 8-fold higher than in the tissues of the parasitized red fox. Bioaccumulation factors of copper, zinc, nickel, and manganese are lower than those of lead and mostly range from 1.9 to 24 for Mesocestoides spp. and from 1.5 to 6 for nematode T. leonina depending on the tissue of host and element. A significant decrease in the content of Pb was found in the kidney of animals infected by T. leonina (0.260 microg/g dw) as well as those infected by Mesocestoides spp. (0.457 microg/g dw) in comparison with the lead content (0.878 microg/g dw) in the kidneys of the nonparasitized red fox. Regardless of a bioaccumulation of copper and manganese in the parasites, a significant increase of the concentrations of Mn and Cu was observed in the host's livers infected predominantly by Mesocestoides spp.

  18. Shape deformation of the organ of Corti associated with length changes of outer hair cell

    NASA Technical Reports Server (NTRS)

    Zimmermann, U.; Fermin, C.

    1996-01-01

    Cochlear outer hair cells (OHC) are commonly assumed to function as mechanical effectors as well as sensory receptors in the organ of Corti (OC) of the inner ear. OHC in vitro and in organ explants exhibit mechanical responses to electrical, chemical or mechanical stimulation which may represent an aspect of their effector process that is expected in vivo. A detailed description, however, of an OHC effector operation in situ is still missing. Specifically, little is known as to how OHC movements influence the geometry of the OC in situ. Previous work has demonstrated that the motility of isolated OHCs in response to electrical stimulation and to K(+)-gluconate is probably under voltage control and causes depolarisation (shortening) and hyperpolarization (elongation). This work was undertaken to investigate if the movements that were observed in isolated OHC, and which are induced by ionic stimulation, could change the geometry of the OC. A synchronized depolarization of OHC was induced in guinea pig cochleae by exposing the entire OC to artificial endolymph (K+). Subsequent morphometry of mid-modiolar sections from these cochleae revealed that the distance between the basilar membrane (BM) and the reticular lamina (RL) had decreased considerably. Furthermore, in the three upper turns OHC had significantly shortened in all rows. The results suggest that OHC can change their length in the organ of Corti (OC) thus deforming the geometry of the OC. The experiments reveal a tonic force generation within the OC that may change the position of RL and/or BM, contribute to damping, modulate the BM-RL-distance and control the operating points of RL and sensory hair bundles. Thus, the results suggest active self-adjustments of cochlear mechanics by slow OHC length changes. Such mechanical adjustments have recently been postulated to correspond to timing elements of animal communication, speech or music.

  19. Localization of organ of Corti protein II in the adult and developing gerbil cochlea.

    PubMed

    Yoho, E R; Thomopoulos, G N; Thalmann, I; Thalmann, R; Schulte, B A

    1997-02-01

    The distribution of organ of Corti protein II (OCP-II) was assessed in the developing and mature gerbil cochlea by light and electron microscopic immunohistochemistry. In the adult cochlea, OCP-II was expressed only in certain epithelial cells which included all supporting cells of the organ of Corti, inner and outer sulcus cells and interdental cells. Inner and outer hair cells lacked immunoreactivity. The highest gold particle labeling density was seen overlying intracellular regions devoid of organelles. In the developing inner ear, OCP-II was first detected at 2 days after birth (DAB) with the strongest staining in immature Deiters, inner phalangeal and pillar cells. Immunostaining intensity increased gradually in cells lying laterally and medially to the more centrally located supporting cells and reached adult levels in all reactive cell types around 18 DAB. The results demonstrated conclusively that OCP-II is a cytosolic protein and fail to support its role as a transcription factor postulated on the basis of its homology with p15 or a role in the control of the cycle as suggested by its near-identity with p19Skp1, a cyclin A/CDK2-associated protein. The continued high level of expression in the mature cochlea argues against OCP-II's involvement in regulating the development and differentiation of epithelial cells. The protein's unique distribution and its gradual increase in expression prior to and during the onset and maturation of hearing, however, support its potential function in the recycling of K+ effluxed from hair cells and neurons back to endolymph.

  20. In vivo measurement of amplifying motion within the organ of Corti under sound stimulation using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Choudhury, Niloy; Chen, Fangyi; Zha, Dingjun; Fridberger, Anders; Zheng, Jiefu; Jacques, Steven L.; Wang, Ruikang K.; Nuttall, Alfred L.

    2012-01-01

    Hearing in mammals, depend on an amplifying motion which hypothetically uses force from outer hair cells (OHC) motility to enhance sound induced vibration of the organ of Corti of cochlea. In this hypothesis the differential motion among key structures in this organ and the timing of the OHC force generation is essential for cochlear amplification to occur. Using a time domain optical coherence tomography system which allows us to make vibration measurements we were able to measure differential motion of two functionally important surfaces, namely, basilar membrane and reticular lamina. The reticular lamina vibrates at higher amplitude than the basilar membrane and has significant phase lead over basilar membrane vibration. The differential motion, that is, different amplitude and phase of vibration, become less as the energy of the sound stimulus is increased and the amplification processes in the organ of Corti are quenched.

  1. Optical Coherence Tomography to Measure Sound-Induced Motions Within the Mouse Organ of Corti In Vivo.

    PubMed

    Jawadi, Zina; Applegate, Brian E; Oghalai, John S

    2016-01-01

    The measurement of mechanical vibrations within the living cochlea is critical to understanding the first nonlinear steps in auditory processing, hair cell stimulation, and cochlear amplification. However, it has proven to be a challenging endeavor. This chapter describes how optical coherence tomography (OCT) can be used to measure vibrations within the tissues of the organ of Corti. These experimental measurements can be performed within the unopened cochlea of living mice routinely and reliably.

  2. Fine-tuning of Notch signaling sets the boundary of the organ of Corti and establishes sensory cell fates

    PubMed Central

    Basch, Martin L; Brown, Rogers M; Jen, Hsin-I; Semerci, Fatih; Depreux, Frederic; Edlund, Renée K; Zhang, Hongyuan; Norton, Christine R; Gridley, Thomas; Cole, Susan E; Doetzlhofer, Angelika; Maletic-Savatic, Mirjana; Segil, Neil; Groves, Andrew K

    2016-01-01

    The signals that induce the organ of Corti and define its boundaries in the cochlea are poorly understood. We show that two Notch modifiers, Lfng and Mfng, are transiently expressed precisely at the neural boundary of the organ of Corti. Cre-Lox fate mapping shows this region gives rise to inner hair cells and their associated inner phalangeal cells. Mutation of Lfng and Mfng disrupts this boundary, producing unexpected duplications of inner hair cells and inner phalangeal cells. This phenotype is mimicked by other mouse mutants or pharmacological treatments that lower but not abolish Notch signaling. However, strong disruption of Notch signaling causes a very different result, generating many ectopic hair cells at the expense of inner phalangeal cells. Our results show that Notch signaling is finely calibrated in the cochlea to produce precisely tuned levels of signaling that first set the boundary of the organ of Corti and later regulate hair cell development. DOI: http://dx.doi.org/10.7554/eLife.19921.001 PMID:27966429

  3. In vivo measurement of differential motion inside the organ of Corti using a low coherence interferometer system

    NASA Astrophysics Data System (ADS)

    Chen, Fangyi; Zha, Dingjun; Fridberger, Anders; Zheng, Jiefu; Choudhury, Niloy; Jacques, Steven L.; Wang, Ruikang K.; Nuttall, Alfred L.

    2012-02-01

    The differential motion of the organ of Corti has been expected as a result of the outer hair cell force, believed to be necessary for the cochlear amplifier. In vitro experiments have been performed to demonstrate this motion but the in vivo data was unavailable due to the technical difficulties. Using a specially-designed time-domain optical coherence tomography system, we performed in vivo imaging and vibration measurement at the sensitive base of the guinea pig cochlea. This technique, for the first time, provides in vivo information about the internal vibration of the organ of Corti. At low sound level, when the cochlea is more sensitive, top surface of the organ of Corti, the reticular lamina (RL) showed tuning at a higher frequency than of the bottom surface, basilar membrane (BM) and its vibration amplitude is 2-3 times of that of the BM. Corresponding to the frequency difference, the phase of RL vibration is lead to that of the BM. Both the amplitude gain and the phase lead on RL is level dependent. This suggests that they are related to the cochlear amplification. The amplitude gain at the RL is an enhancement of the BM motion for stimulating the stereocillia. The advance in time of RL vibration can prepare proper timing of stereocillia stimulation for the cochlear amplification.

  4. Ultrastructure of the Odontocete organ of Corti: scanning and transmission electron microscopy.

    PubMed

    Morell, Maria; Lenoir, Marc; Shadwick, Robert E; Jauniaux, Thierry; Dabin, Willy; Begeman, Lineke; Ferreira, Marisa; Maestre, Iranzu; Degollada, Eduard; Hernandez-Milian, Gema; Cazevieille, Chantal; Fortuño, José-Manuel; Vogl, Wayne; Puel, Jean-Luc; André, Michel

    2015-02-15

    The morphological study of the Odontocete organ of Corti, together with possible alterations associated with damage from sound exposure, represents a key conservation approach to assess the effects of acoustic pollution on marine ecosystems. By collaborating with stranding networks from several European countries, 150 ears from 13 species of Odontocetes were collected and analyzed by scanning (SEM) and transmission (TEM) electron microscopy. Based on our analyses, we first describe and compare Odontocete cochlear structures and then propose a diagnostic method to identify inner ear alterations in stranded individuals. The two species analyzed by TEM (Phocoena phocoena and Stenella coeruleoalba) showed morphological characteristics in the lower basal turn of high-frequency hearing species. Among other striking features, outer hair cell bodies were extremely small and were strongly attached to Deiters cells. Such morphological characteristics, shared with horseshoe bats, suggest that there has been convergent evolution of sound reception mechanisms among echolocating species. Despite possible autolytic artifacts due to technical and experimental constraints, the SEM analysis allowed us to detect the presence of scarring processes resulting from the disappearance of outer hair cells from the epithelium. In addition, in contrast to the rapid decomposition process of the sensory epithelium after death (especially of the inner hair cells), the tectorial membrane appeared to be more resistant to postmortem autolysis effects. Analysis of the stereocilia imprint pattern at the undersurface of the tectorial membrane may provide a way to detect possible ultrastructural alterations of the hair cell stereocilia by mirroring them on the tectorial membrane.

  5. Phase of neural excitation relative to basilar membrane motion in the organ of Corti: Theoretical considerations

    NASA Astrophysics Data System (ADS)

    Andoh, Masayoshi; Nakajima, Chihiro; Wada, Hiroshi

    2005-09-01

    Although the auditory transduction process is dependent on neural excitation of the auditory nerve in relation to motion of the basilar membrane (BM) in the organ of Corti (OC), specifics of this process are unclear. In this study, therefore, an attempt was made to estimate the phase of the neural excitation relative to the BM motion using a finite-element model of the OC at the basal turn of the gerbil, including the fluid-structure interaction with the lymph fluid. It was found that neural excitation occurs when the BM exhibits a maximum velocity toward the scala vestibuli at 10 Hz and shows a phase delay relative to the BM motion with increasing frequency up to 800 Hz. It then shows a phase advance until the frequency reaches 2 kHz. From 2 kHz, neural excitation again shows a phase delay with increasing frequency. From 800 Hz up to 2 kHz, the phase advances because the dominant force exerted on the hair bundle shifts from a velocity-dependent Couette flow-induced force to a displacement-dependent force induced by the pressure difference. The phase delay that occurs from 2 kHz is caused by the resonance process of the hair bundle of the IHC.

  6. Organ of Corti explants direct tonotopically graded morphology of spiral ganglion neurons in vitro.

    PubMed

    Smith, Felicia L; Davis, Robin L

    2016-08-01

    The spiral ganglion is a compelling model system to examine how morphological form contributes to sensory function. While the ganglion is composed mainly of a single class of type I neurons that make simple one-to-one connections with inner hair cell sensory receptors, it has an elaborate overall morphological design. Specific features, such as soma size and axon outgrowth, are graded along the spiral contour of the cochlea. To begin to understand the interplay between different regulators of neuronal morphology, we cocultured neuron explants with peripheral target tissues removed from distinct cochlear locations. Interestingly, these "hair cell microisolates" were capable of both increasing and decreasing neuronal somata size, without adversely affecting survival. Moreover, axon characteristics elaborated de novo by the primary afferents in culture were systematically regulated by the sensory endorgan. Apparent peripheral nervous system (PNS)-like and central nervous system (CNS)-like axonal profiles were established in our cocultures allowing an analysis of putative PNS/CNS axon length ratios. As predicted from the in vivo organization, PNS-like axon bundles elaborated by apical cocultures were longer than their basal counterparts and this phenotype was methodically altered when neuron explants were cocultured with microisolates from disparate cochlear regions. Thus, location-dependent signals within the organ of Corti may set the "address" of neurons within the spiral ganglion, allowing them to elaborate the appropriate tonotopically associated morphological features in order to carry out their signaling function. J. Comp. Neurol. 524:2182-2207, 2016. © 2015 Wiley Periodicals, Inc.

  7. High-Frequency Vibration of the Organ of Corti in Vitro

    NASA Astrophysics Data System (ADS)

    Scherer, M. P.; Nowotny, M.; Dalhoff, E.; Zenner, H.-P.; Gummer, A. W.

    2003-02-01

    The mechanism by which the electromechanical force generated by the outer hair cells (OHC) produces the exquisite sensitivity, frequency selectivity and dynamic range of the cochlea is unknown. To address this question, we measured the electrically induced radial vibration pattern at different levels within the organ of Corti of the guinea pig. Two in vitro preparations were used: 1) a half turn including modiolar bone and cochlear partition, without tectorial membrane (TM); the basilar membrane (BM) was supported from its tympanal side. 2) A temporal bone preparation, where the bony wall was removed above and below the measurement location to permit introduction of electrodes. In the latter case, the cochlear partition was in its normal mechanical environment, with free swinging BM and with TM. Velocity of BM, reticular lamina (RL), and upper and lower sides of the TM in response to broadband electrical stimulation of the OHCs was measured with a laser Doppler vibrometer. The interferometer was sensitive enough to permit measurement without reflective beads or the like. The frequency range of the stimulation was 480 Hz - 70 kHz. Displacement amplitudes were constant up to 10 kHz, after which they dropped with -14 to -17 dB/oct. Moving across the RL in the radial direction, phase reversals characteristic of pivoting points occurred above the pillar cells and the outer tunnel. No phase reversals were observed on the BM and TM.

  8. Characterizing Wave Propagation in the Organ of Corti with Stroboscopic Imaging

    NASA Astrophysics Data System (ADS)

    Zosuls, Aleks; Rupprecht, Laura C.; Mountain, David C.

    2011-11-01

    Here we present the results from a new high-frequency mechanical stimulation system that was designed to provide more precise local excitation and motion sensing of the organ of Corti (OC/BM complex). It is based on mechanical tissue excitation via a small vibrating probe and measurement using stroboscopic video microscopy. The system is currently capable of measuring sub-micrometer motion at frequencies from DC to 60 kHz. Measurements were performed on excised Mongolian gerbil (Meriones unguiculatus) cochleae. The underside of the BM was mechanically stimulated in the direction normal to the membrane with a 20 μm diameter glass probe. Data was collected at multiple focal planes from the BM to the tectorial membrane in order to capture motion for cellular and extracellular structures. For this study, inner hair cell hair bundles and basilar membrane collagen fiber bundle regions of interest were selected and displacements quantified using a cross-correlation technique. Displacement magnitude and phase was measured as a function of distance from the probe and a function of stimulus frequency. At certain frequencies both magnitudes and phases decreased with distance from the probe in a manner that suggests that both direct longitudinal coupling and wave propagation were contributing to the responses.

  9. Discovery of multiple neuropeptide families in the phylum Platyhelminthes.

    PubMed

    McVeigh, Paul; Mair, Gunnar R; Atkinson, Louise; Ladurner, Peter; Zamanian, Mostafa; Novozhilova, Ekaterina; Marks, Nikki J; Day, Tim A; Maule, Aaron G

    2009-09-01

    Available evidence shows that short amidated neuropeptides are widespread and have important functions within the nervous systems of all flatworms (phylum Platyhelminthes) examined, and could therefore represent a starting point for new lead drug compounds with which to combat parasitic helminth infections. However, only a handful of these peptides have been characterised, the rigorous exploration of the flatworm peptide signalling repertoire having been hindered by the dearth of flatworm genomic data. Through searches of both expressed sequence tags and genomic resources using the basic local alignment search tool (BLAST), we describe 96 neuropeptides on 60 precursors from 10 flatworm species. Most of these (51 predicted peptides on 14 precursors) are novel and are apparently restricted to flatworms; the remainder comprise nine recognised peptide families including FMRFamide-like (FLPs), neuropeptide F (NPF)-like, myomodulin-like, buccalin-like and neuropeptide FF (NPFF)-like peptides; notably, the latter have only previously been reported in vertebrates. Selected peptides were localised immunocytochemically to the Schistosoma mansoni nervous system. We also describe several novel flatworm NPFs with structural features characteristic of the vertebrate neuropeptide Y (NPY) superfamily, previously unreported characteristics which support the common ancestry of flatworm NPFs with the NPY-superfamily. Our dataset provides a springboard for investigation of the functional biology and therapeutic potential of neuropeptides in flatworms, simultaneously launching flatworm neurobiology into the post-genomic era.

  10. Comparative selenoproteome analysis reveals a reduced utilization of selenium in parasitic platyhelminthes.

    PubMed

    Jiang, Liang; Zhu, Hua-Zhang; Xu, Yin-Zhen; Ni, Jia-Zuan; Zhang, Yan; Liu, Qiong

    2013-01-01

    Background. The selenocysteine(Sec)-containing proteins, selenoproteins, are an important group of proteins present in all three kingdoms of life. Although the selenoproteomes of many organisms have been analyzed, systematic studies on selenoproteins in platyhelminthes are still lacking. Moreover, comparison of selenoproteomes between free-living and parasitic animals is rarely studied. Results. In this study, three representative organisms (Schmidtea mediterranea, Schistosoma japonicum and Taenia solium) were selected for comparative analysis of selenoproteomes in Platyhelminthes. Using a SelGenAmic-based selenoprotein prediction algorithm, a total of 37 selenoprotein genes were identified in these organisms. The size of selenoproteomes and selenoprotein families were found to be associated with different lifestyles: free-living organisms have larger selenoproteome whereas parasitic lifestyle corresponds to reduced selenoproteomes. Five selenoproteins, SelT, Sel15, GPx, SPS2 and TR, were found to be present in all examined platyhelminthes as well as almost all sequenced animals, suggesting their essential role in metazoans. Finally, a new splicing form of SelW that lacked the first exon was found to be present in S. japonicum. Conclusions. Our data provide a first glance into the selenoproteomes of organisms in the phylum Platyhelminthes and may help understand function and evolutionary dynamics of selenium utilization in diversified metazoans.

  11. Near field fluid coupling between internal motion of the organ of Corti and the basilar membrane

    SciTech Connect

    Elliott, Stephen J.; Ni, Guangjian

    2015-12-31

    The pressure distribution in each of the fluid chambers of the cochlea can be decomposed into a 1D, or plane wave, component and a near field component, which decays rapidly away from the excitation point. The transverse motion of the basilar membrane, BM, for example, generates both a 1D pressure field, which couples into the slow wave, and a local near field pressure, proportional to the BM acceleration, that generates an added mass on the BM due to the fluid motion. When the organ of Corti, OC, undergoes internal motion, due for example to outer hair cell activity, this motion will not itself generate any 1D pressure if the OC is incompressible and the BM is constrained not to move volumetrically, and so will not directly couple into the slow wave. This motion will, however, generate a near field pressure, proportional to the OC acceleration, which will act on the OC and thus increases its effective mass. The near field pressure due to this OC motion will also act on the BM, generating a force on the BM proportional to the acceleration of the OC, and thus create a “coupling mass” effect. By reciprocity, this coupling mass is the same as that acting on the OC due to the motion of the BM. This near field fluid coupling is initially observed in a finite element model of a slice of the cochlea. These simulations suggest a simple analytical formulation for the fluid coupling, using higher order beam modes across the width of the cochlear partition. It is well known that the added mass due to the near field pressure dominates the overall mass of the BM, and thus significantly affects the micromechanical dynamics. This work not only quantifies the added mass of the OC due its own motion in the fluid, and shows that this is important, but also demonstrates that the coupling mass effect between the BM and OC significantly affects the dynamics of simple micromechanical models.

  12. Effect of LLLT on the level of ATP and ROS from organ of corti cells

    NASA Astrophysics Data System (ADS)

    Rhee, ChungKu; Chang, So-Young; Ahn, Jin-Chul; Suh, Myung-Whan; Jung, Jae Yun

    2014-03-01

    It is well established that ototoxic antibiotics and acoustic trauma can damage cochlear hair cells and cause hearing loss. Previous studies using transcanal LLLT (Low level laser therapy) showed that LLLT can promote recovery of hearing thresholds and cochlear hair cells. However, its mechanism has not been studied. Aim: The aim of this study is to investigate the mechanism of hearing recovery from gentamicin induced ototoxic hearing loss by LLLT. Methods: HEI- OC1 (House ear institute organ of Corti) cells were cultured for 18 hours and ototoxicity was induced by gentamicin (GM) treatment to the cells. Cultured cells were divided into 6 groups, No treatment control, LLLT only, GM 6.6 mM and GM 13.1 mM, GM 6.6 mM+LLLT and GM 13.1 mM+LLLT cells. LD laser 808 nm, 15 mW, was irradiated to the cultured cells for 15 min, at 4 hours after GM treatment to the cells. ATP was assayed using the ATP assay Kit. ROS was measured using confocal microscope after application of H2DCFDA dye. Results: ATP was decreased in GM 13.1 mM cells and increased in LLLT only cells and GM 13.1 mM+LLLT cells compared to control and 13.1 mM cells. ROS was increased in GM 6.6 mM and GM 13.1 mM cells, and decreased in GM 6.6 mM+LLLT and GM 13.1 mM+LLLT cells compared to GM 6.6 and 13.1 mM cells immediately after laser irradiation. Conclusion: This study demonstrated that LLLT on GM treated HEI-OC1 cells increased ATP and decreased ROS that may contribute to the recovery of hearing.

  13. Near field fluid coupling between internal motion of the organ of Corti and the basilar membrane

    NASA Astrophysics Data System (ADS)

    Elliott, Stephen J.; Ni, Guangjian

    2015-12-01

    The pressure distribution in each of the fluid chambers of the cochlea can be decomposed into a 1D, or plane wave, component and a near field component, which decays rapidly away from the excitation point. The transverse motion of the basilar membrane, BM, for example, generates both a 1D pressure field, which couples into the slow wave, and a local near field pressure, proportional to the BM acceleration, that generates an added mass on the BM due to the fluid motion. When the organ of Corti, OC, undergoes internal motion, due for example to outer hair cell activity, this motion will not itself generate any 1D pressure if the OC is incompressible and the BM is constrained not to move volumetrically, and so will not directly couple into the slow wave. This motion will, however, generate a near field pressure, proportional to the OC acceleration, which will act on the OC and thus increases its effective mass. The near field pressure due to this OC motion will also act on the BM, generating a force on the BM proportional to the acceleration of the OC, and thus create a "coupling mass" effect. By reciprocity, this coupling mass is the same as that acting on the OC due to the motion of the BM. This near field fluid coupling is initially observed in a finite element model of a slice of the cochlea. These simulations suggest a simple analytical formulation for the fluid coupling, using higher order beam modes across the width of the cochlear partition. It is well known that the added mass due to the near field pressure dominates the overall mass of the BM, and thus significantly affects the micromechanical dynamics. This work not only quantifies the added mass of the OC due its own motion in the fluid, and shows that this is important, but also demonstrates that the coupling mass effect between the BM and OC significantly affects the dynamics of simple micromechanical models.

  14. Correlating early evolution of parasitic platyhelminths to Gondwana breakup.

    PubMed

    Badets, Mathieu; Whittington, Ian; Lalubin, Fabrice; Allienne, Jean-Francois; Maspimby, Jean-Luc; Bentz, Sophie; Du Preez, Louis H; Barton, Diane; Hasegawa, Hideo; Tandon, Veena; Imkongwapang, Rangpenyuba; Imkongwapang, Rangpenyubai; Ohler, Annemarie; Combes, Claude; Verneau, Olivier

    2011-12-01

    Investigating patterns and processes of parasite diversification over ancient geological periods should involve comparisons of host and parasite phylogenies in a biogeographic context. It has been shown previously that the geographical distribution of host-specific parasites of sarcopterygians was guided, from Palaeozoic to Cainozoic times, mostly by evolution and diversification of their freshwater hosts. Here, we propose phylogenies of neobatrachian frogs and their specific parasites (Platyhelminthes, Monogenea) to investigate coevolutionary processes and historical biogeography of polystomes and further discuss all the possible assumptions that may account for the early evolution of these parasites. Phylogenetic analyses of concatenated rRNA nuclear genes (18S and partial 28S) supplemented by cophylogenetic and biogeographic vicariance analyses reveal four main parasite lineages that can be ascribed to centers of diversity, namely Australia, India, Africa, and South America. In addition, the relationships among these biogeographical monophyletic groups, substantiated by molecular dating, reflect sequential origins during the breakup of Gondwana. The Australian polystome lineage may have been isolated during the first stages of the breakup, whereas the Indian lineage would have arisen after the complete separation of western and eastern Gondwanan components. Next, polystomes would have codiverged with hyloid sensu stricto and ranoid frog lineages before the completion of South American and African plate separation. Ultimately, they would have undergone an extensive diversification in South America when their ancestral host families diversified. Therefore, the presence of polystome parasites in specific anuran host clades and in discrete geographic areas reveals the importance of biogeographic vicariance in diversification processes and supports the occurrence and radiation of amphibians over ancient and recent geological periods.

  15. Whole-Cell Patch-Clamp Recording of Mouse and Rat Inner Hair Cells in the Intact Organ of Corti.

    PubMed

    Goutman, Juan D; Pyott, Sonja J

    2016-01-01

    Whole-cell patch clamping is a widely applied method to record currents across the entire membrane of a cell. This protocol describes application of this method to record currents from the sensory inner hair cells in the intact auditory sensory epithelium, the organ of Corti, isolated from rats or mice. This protocol particularly outlines the basic equipment required, provides instructions for the preparation of solutions and small equipment items, and methodology for recording voltage-activated and evoked synaptic currents from the inner hair cells.

  16. Microstructures in the organ of Corti help outer hair cells form traveling waves along the cochlear coil.

    PubMed

    Nam, Jong-Hoon

    2014-06-03

    According to the generally accepted theory of mammalian cochlear mechanics, the fluid in the cochlear scalae interacts with the elastic cochlear partition to generate transversely oscillating displacement waves that propagate along the cochlear coil. Using a computational model of cochlear segments, a different type of propagating wave is reported, an elastic propagating wave that is independent of the fluid-structure interaction. The characteristics of the propagating wave observed in the model, such as the wavelength, speed, and phase lag, are similar to those observed in the living cochlea. Three conditions are required for the existence of the elastic propagating wave in the cochlear partition without fluid-interaction: 1), the stiffness gradient of the cochlear partition; 2), the elastic longitudinal coupling; and 3), the Y-shaped structure in the organ of Corti formed by the outer hair cell, the Deiters cell, and the Deiters cell phalangeal process. The elastic propagating waves in the cochlear partition disappeared without the push-pull action provided by the outer hair cell and Deiters cell phalangeal process. The results suggest that the mechanical feedback of outer hair cells, facilitated by the organ of Corti microstructure, can control the tuning and amplification by modulating the cochlear traveling wave.

  17. Interrelationships and evolution of the tapeworms (Platyhelminthes: Cestoda).

    PubMed

    Olson, P D; Littlewood, D T; Bray, R A; Mariaux, J

    2001-06-01

    Interrelationships of the tapeworms (Platyhelminthes: Cestoda) were examined by use of small (SSU) and large (LSU) subunit ribosomal DNA sequences and morphological characters. Fifty new complete SSU sequences were added to 21 sequences previously determined, and 71 new LSU (D1-D3) sequences were determined for the complementary set of taxa representing each of the major lineages of cestodes as currently understood. New sequences were determined for three amphilinidean taxa, but were removed from both alignments due to their excessively high degree of divergence from other cestode sequences. A morphological character matrix coded for supraspecific taxa was constructed by the modification of matrices from recently published studies. Maximum-parsimony (MP) analyses were performed on the LSU, SSU, LSU+SSU, and morphological data partitions, and minimum-evolution (ME) analyses utilizing a general time reversible model of nucleotide substitution including estimates of among-site rate heterogeneity were performed on the molecular data partitions. Resulting topologies were rooted at the node separating the Gyrocotylidea from the Eucestoda. The LSU data were found to be more informative than the SSU data and were more consistent with inferences from morphology, although nodal support was generally weak for most basal nodes. One class of transitions was found to be saturated for comparisons between the most distantly related taxa (gyrocotylideans vs cyclophyllideans and tetrabothriideans). Differences in the topologies resulting from MP and ME analyses were not statistically significant. Nonstrobilate orders formed the basal lineages of trees resulting from analysis of LSU data and morphology. Difossate orders were basal to tetrafossate orders, the latter of which formed a strongly supported clade. A clade including the orders Cyclophyllidea, Nippotaeniidea, and Tetrabothriidea was supported by all data partitions and methods of analysis. Paraphyly of the orders

  18. Nuclear genomic signals of the 'microturbellarian' roots of platyhelminth evolutionary innovation.

    PubMed

    Laumer, Christopher E; Hejnol, Andreas; Giribet, Gonzalo

    2015-03-12

    Flatworms number among the most diverse invertebrate phyla and represent the most biomedically significant branch of the major bilaterian clade Spiralia, but to date, deep evolutionary relationships within this group have been studied using only a single locus (the rRNA operon), leaving the origins of many key clades unclear. In this study, using a survey of genomes and transcriptomes representing all free-living flatworm orders, we provide resolution of platyhelminth interrelationships based on hundreds of nuclear protein-coding genes, exploring phylogenetic signal through concatenation as well as recently developed consensus approaches. These analyses robustly support a modern hypothesis of flatworm phylogeny, one which emphasizes the primacy of the often-overlooked 'microturbellarian' groups in understanding the major evolutionary transitions within Platyhelminthes: perhaps most notably, we propose a novel scenario for the interrelationships between free-living and vertebrate-parasitic flatworms, providing new opportunities to shed light on the origins and biological consequences of parasitism in these iconic invertebrates.

  19. Characterization of the complete mitochondrial genomes from Polycladida (Platyhelminthes) using next-generation sequencing.

    PubMed

    Aguado, M Teresa; Grande, Cristina; Gerth, Michael; Bleidorn, Christoph; Noreña, Carolina

    2016-01-10

    The complete mitochondrial genomes of three polycladids, the acotylean Hoploplana elisabelloi and the cotyleans Enchiridium sp. and Prosthiostomum siphunculus have been assembled with high coverage from Illumina sequencing data. The mt genomes contain 36 genes including 12 of the 13 protein-coding genes characteristic for metazoan mitochondrial genomes, two ribosomal RNA genes, and 22 transfer RNA genes. Gene annotation, gene order, genetic code, start and stop codons and codon bias have been identified. In comparison with the well investigated parasitic Neodermata, our analysis reveals a great diversity of gene orders within Polycladida and Platyhelminthes in general. By analyzing representative genomes of the main groups of Platyhelminthes we explored the phylogenetic relationships of this group. The phylogenetic analyses strongly supported the monophyly of Polycladida, and based on a small taxon sampling suggest the monophyly of Acotylea and Cotylea.

  20. Regeneration in Macrostomum lignano (Platyhelminthes): cellular dynamics in the neoblast stem cell system.

    PubMed

    Nimeth, Katharina Theresia; Egger, Bernhard; Rieger, Reinhard; Salvenmoser, Willi; Peter, Roland; Gschwentner, Robert

    2007-03-01

    Neoblasts are potentially totipotent stem cells and the only proliferating cells in adult Platyhelminthes. We have examined the cellular dynamics of neoblasts during the posterior regeneration of Macrostomum lignano. Double-labeling of neoblasts with bromodeoxyuridine and the anti-phospho histone H3 mitosis marker has revealed a complex cellular response in the first 48 h after amputation; this response is different from that known to occur during regeneration in triclad platyhelminths and in starvation/feeding experiments in M. lignano. Mitotic activity is reduced during the first 8 h of regeneration but, at 48 h after amputation, reaches almost twice the value of control animals. The total number of S-phase cells significantly increases after 1 day of regeneration. A subpopulation of fast-cycling neoblasts surprisingly shows the same dynamics during regeneration as those in control animals. Wound healing and regeneration are accompanied by the formation of a distinct blastema. These results present new insights, at the cellular level, into the early regeneration of rhabditophoran Platyhelminthes.

  1. Two-Dimensional Cochlear Micromechanics Measured In Vivo Demonstrate Radial Tuning within the Mouse Organ of Corti

    PubMed Central

    Lee, Hee Yoon; Raphael, Patrick D.; Xia, Anping; Kim, Jinkyung; Grillet, Nicolas; Applegate, Brian E.; Ellerbee Bowden, Audrey K.

    2016-01-01

    The exquisite sensitivity and frequency discrimination of mammalian hearing underlie the ability to understand complex speech in noise. This requires force generation by cochlear outer hair cells (OHCs) to amplify the basilar membrane traveling wave; however, it is unclear how amplification is achieved with sharp frequency tuning. Here we investigated the origin of tuning by measuring sound-induced 2-D vibrations within the mouse organ of Corti in vivo. Our goal was to determine the transfer function relating the radial shear between the structures that deflect the OHC bundle, the tectorial membrane and reticular lamina, to the transverse motion of the basilar membrane. We found that, after normalizing their responses to the vibration of the basilar membrane, the radial vibrations of the tectorial membrane and reticular lamina were tuned. The radial tuning peaked at a higher frequency than transverse basilar membrane tuning in the passive, postmortem condition. The radial tuning was similar in dead mice, indicating that this reflected passive, not active, mechanics. These findings were exaggerated in TectaC1509G/C1509G mice, where the tectorial membrane is detached from OHC stereocilia, arguing that the tuning of radial vibrations within the hair cell epithelium is distinct from tectorial membrane tuning. Together, these results reveal a passive, frequency-dependent contribution to cochlear filtering that is independent of basilar membrane filtering. These data argue that passive mechanics within the organ of Corti sharpen frequency selectivity by defining which OHCs enhance the vibration of the basilar membrane, thereby tuning the gain of cochlear amplification. SIGNIFICANCE STATEMENT Outer hair cells amplify the traveling wave within the mammalian cochlea. The resultant gain and frequency sharpening are necessary for speech discrimination, particularly in the presence of background noise. Here we measured the 2-D motion of the organ of Corti in mice and found

  2. Bmi1 Loss in the Organ of Corti Results in p16ink4a Upregulation and Reduced Cell Proliferation of Otic Progenitors In Vitro

    PubMed Central

    Dos Santos, Aurélie; Avci, Hasan X.; Löwenheim, Hubert; Müller, Marcus

    2016-01-01

    The mature mammalian organ of Corti does not regenerate spontaneously after injury, mainly due to the absence of cell proliferation and the depletion of otic progenitors with age. The polycomb gene B lymphoma Mo-MLV insertion region 1 homolog (Bmi1) promotes proliferation and cell cycle progression in several stem cell populations. The cell cycle inhibitor p16ink4a has been previously identified as a downstream target of Bmi1. In this study, we show that Bmi1 is expressed in the developing inner ear. In the organ of Corti, Bmi1 expression is temporally regulated during embryonic and postnatal development. In contrast, p16ink4a expression is not detectable during the same period. Bmi1-deficient mice were used to investigate the role of Bmi1 in cochlear development and otosphere generation. In the absence of Bmi1, the postnatal organ of Corti displayed normal morphology at least until the end of the first postnatal week, suggesting that Bmi1 is not required for the embryonic or early postnatal development of the organ of Corti. However, Bmi1 loss resulted in the reduced sphere-forming capacity of the organ of Corti, accompanied by the decreased cell proliferation of otic progenitors in otosphere cultures. This reduced proliferative capacity was associated with the upregulation of p16ink4a in vitro. Viral vector-mediated overexpression of p16ink4a in wildtype otosphere cultures significantly reduced the number of generated otospheres in vitro. The findings strongly suggest a role for Bmi1 as a promoter of cell proliferation in otic progenitor cells, potentially through the repression of p16ink4a. PMID:27755610

  3. Platyhelminth Venom Allergen-Like (VAL) proteins: revealing structural diversity, class-specific features and biological associations across the phylum

    PubMed Central

    CHALMERS, IAIN W.; HOFFMANN, KARL F.

    2012-01-01

    SUMMARY During platyhelminth infection, a cocktail of proteins is released by the parasite to aid invasion, initiate feeding, facilitate adaptation and mediate modulation of the host immune response. Included amongst these proteins is the Venom Allergen-Like (VAL) family, part of the larger sperm coating protein/Tpx-1/Ag5/PR-1/Sc7 (SCP/TAPS) superfamily. To explore the significance of this protein family during Platyhelminthes development and host interactions, we systematically summarize all published proteomic, genomic and immunological investigations of the VAL protein family to date. By conducting new genomic and transcriptomic interrogations to identify over 200 VAL proteins (228) from species in all 4 traditional taxonomic classes (Trematoda, Cestoda, Monogenea and Turbellaria), we further expand our knowledge related to platyhelminth VAL diversity across the phylum. Subsequent phylogenetic and tertiary structural analyses reveal several class-specific VAL features, which likely indicate a range of roles mediated by this protein family. Our comprehensive analysis of platyhelminth VALs represents a unifying synopsis for understanding diversity within this protein family and a firm context in which to initiate future functional characterization of these enigmatic members. PMID:22717097

  4. Biology and pathobiology of lipid droplets and their potential role in the protection of the organ of Corti.

    PubMed

    Urrutia, Raul A; Kalinec, Federico

    2015-12-01

    The current review article seeks to extend our understanding on the role of lipid droplets within the organ of Corti. In addition to presenting an overview of the current information about the origin, structure and function of lipid droplets we draw inferences from the collective body of knowledge about this cellular organelle to build a conceptual framework to better understanding their role in auditory function. This conceptual model considers that lipid droplets play a significant role in the synthesis, storage, and release of lipids and proteins for energetic use and/or modulating cell signaling pathways. We describe the role and mechanism by which LD play a role in human diseases, and we also review emerging data from our laboratory revealing the potential role of lipid droplets from Hensen cells in the auditory organ. We suggest that lipid droplets might help to develop rapidly and efficiently the resolution phase of inflammatory responses in the mammalian cochlea, preventing inflammatory damage of the delicate inner ear structures and, consequently, sensorineural hearing loss.

  5. Outer Hair Cell Somatic Electromotility In Vivo and Power Transfer to the Organ of Corti

    PubMed Central

    Ramamoorthy, Sripriya; Nuttall, Alfred L.

    2012-01-01

    The active amplification of sound-induced vibrations in the cochlea, known to be crucial for auditory sensitivity and frequency selectivity, is not well understood. The outer hair cell (OHC) somatic electromotility is a potential mechanism for such amplification. Its effectiveness in vivo is putatively limited by the electrical low-pass filtering of the cell's transmembrane potential. However, the transmembrane potential is an incomplete metric. We propose and estimate two metrics to evaluate the effectiveness of OHC electromotility in vivo. One metric is the OHC electromechanical ratio defined as the amplitude of the ratio of OHC displacement to the change in its transmembrane potential. The in vivo electromechanical ratio is derived from the recently measured in vivo displacements of the reticular lamina and the basilar membrane at the 19 kHz characteristic place in guinea pigs and using a model. The ratio, after accounting for the differences in OHC vibration in situ due to the impedances from the adjacent structures, is in agreement with the literature values of the in vitro electromechanical ratio measured by others. The second and more insightful metric is the OHC somatic power. Our analysis demonstrates that the organ of Corti is nearly optimized to receive maximum somatic power in vivo and that the estimated somatic power could account for the active amplification. PMID:22325260

  6. Staining of Platyhelminthes by herbal dyes: An eco-friendly technique for the taxonomist

    PubMed Central

    Kumar, Niranjan; Mehul, Jadav; Das, Bhupamani; Solanki, J. B.

    2015-01-01

    Aim: An environment compatible technique to stain Platyhelminthes, Fasciola gigantica, Gastrothylax crumenifer, Taenia solium, and Moniezia expansa using aqueous and alcoholic extract of sugar beet (Beta vulgaris), China rose (Hibiscus rosa-sinensis), and red rose (Rosa hybrida) were described to minimized the deleterious effects of the synthetic dyes. Materials and Methods: Aqueous/ethanolic extracts of roses were extracted from the flowers while red beet was extracted from the roots. Results: Stained helminthes acquired a comparable level of pigmentation with the distinction of their internal structure in these natural dyes. The flukes (liver and rumen) internal structure, oral and ventral/posterior sucker, cirrus sac, gravid uterus, testes, ovary, and vitallaria were appeared pink color in aqueous and alcoholic extract of either China or red rose and yellow to brown color in sugar beet stain. The interior of the proglottid of T. solium and M. expansa took yellow to brown color with good contrast in sugar beet stain and of pink to pink-red in China and red rose stain. Conclusion: The extract of roses (red rose followed by China rose) followed by red beet possess the potential to replace the conventional stains in the taxonomic study of Platyhelminthes parasites. PMID:27047037

  7. Nuclear genomic signals of the ‘microturbellarian’ roots of platyhelminth evolutionary innovation

    PubMed Central

    Laumer, Christopher E; Hejnol, Andreas; Giribet, Gonzalo

    2015-01-01

    Flatworms number among the most diverse invertebrate phyla and represent the most biomedically significant branch of the major bilaterian clade Spiralia, but to date, deep evolutionary relationships within this group have been studied using only a single locus (the rRNA operon), leaving the origins of many key clades unclear. In this study, using a survey of genomes and transcriptomes representing all free-living flatworm orders, we provide resolution of platyhelminth interrelationships based on hundreds of nuclear protein-coding genes, exploring phylogenetic signal through concatenation as well as recently developed consensus approaches. These analyses robustly support a modern hypothesis of flatworm phylogeny, one which emphasizes the primacy of the often-overlooked ‘microturbellarian’ groups in understanding the major evolutionary transitions within Platyhelminthes: perhaps most notably, we propose a novel scenario for the interrelationships between free-living and vertebrate-parasitic flatworms, providing new opportunities to shed light on the origins and biological consequences of parasitism in these iconic invertebrates. DOI: http://dx.doi.org/10.7554/eLife.05503.001 PMID:25764302

  8. Biogeography and karyotypes of freshwater planarians (Platyhelminthes, Tricladida, Paludicola) in southern Brazil.

    PubMed

    Knakievicz, Tanise; Lau, Adriana Helena; Prá, Daniel; Erdtmann, Bernardo

    2007-02-01

    In the Tricladida (Platyhelminthes), the incidence of different biotypes identified by several ploidy levels is very common. Planarians collected in the State of Rio Grande do Sul were identified using cytogenetics. Different species distributions were observed with respect to Rio Grande do Sul's geomorphology, which could have been caused by their different microhabitats. Girardia tigrina and G. anderlani consisted of diploid and triploid individuals, whereas G. schubarti showed diploids, triploids, and mixoploids; for all these species, individuals of different ploidies were sympatric. Only for diploid G. anderlani were B chromosomes observed. These B chromosomes seem to have an irregular segregational behavior during mitosis, and possibly also during meiosis. However the processes (e.g., selection, mutation) of maintaining 2n, 3n, and 2n/3n individuals within natural populations of G. schubarti remain to be clarified.

  9. A simple technique for staining of platyhelminths with the lactophnol cotton blue stain.

    PubMed

    Henedi, Adawia A M; El-Azazy, Osama M E

    2013-08-01

    This paper describes a simple technique for staining of flatworms using lactophenol cotton blue (LPCB). The staining was tested on 2 trematode species: Heterophyes heterophyes and Mesostephanus appendiculatus, and one cestode: Diplopylidium acanthotetra, which were collected from the intestine of stray cats in Kuwait. The specimens were mounted in a small amount of the LPCB stain on a clean slide for 2-3 minutes before covering with a cover slip. The technique rapidly and clearly differentiated the internal structures of the helminthes. Its speed and simplicity are advantages over other staining methods. It is easily used in wide-scale surveys where a large number of platyhelminths have to be identified and it is suitable for field studies.

  10. Telomere analysis of platyhelminths and acanthocephalans by FISH and Southern hybridization.

    PubMed

    Bombarová, Marta; Vítková, Magda; Spakulová, Marta; Koubková, Bozena

    2009-11-01

    We examined the composition of telomeres in chromosomes of parasitic worms, representatives of the flatworm groups Monogenea and Cestoda (Platyhelminthes), and thorny-headed worms (Syndermata: Acanthocephala) by fluorescence in situ hybridization (FISH) with different telomeric repeat probes. Our results show that the (TTAGGG)n sequence, supposed to be the ancestral telomeric repeat motif of Metazoa, is conserved in Monogenea (Paradiplozoon homoion) and Cestoda (Caryophyllaeus laticeps, Caryophyllaeides fennica, and Nippotaenia mogurndae) but not in Acanthocephala (Pomphorhynchus laevis and Pomphorhynchus tereticollis). In the Pomphorhynchus species, no hybridization signals were obtained with the "nematode" (TTAGGC)n, "arthropod" (TTAGG)n, and bdelloid (TGTGGG)n telomeric probes using FISH with their chromosomes and Southern hybridization with P. laevis DNA. Therefore, we suggest that parasitic Acanthocephala have evolved yet unknown telomeric repeat motifs or different mechanisms of telomere maintenance.

  11. [The influence of Janicki cercomer theory on the development of platyhelminthes systematics and evolution investigations].

    PubMed

    Pojmańska, Teresa

    2005-01-01

    The aim of this article was to present the development of ideas about the provenience of parasitic helminths and the phylogenetical relationships within this taxon, since the publication of the "cercomer theory" just to nowadays. The following essentials of the Janicki theory are outlined: main differences between free-living Turbellaria and parasitic platyhelminths (ciliated epithelium in Turbellaria versus unciliated surface in the others); universality of the cercomer presence in Monogenea, Digenea and Cestoda; evolutionary changes in the morphology and function of the cercomer; homology of the caudal appendices of all parasitic helminths; the subsequent evolution of parasitic platyhelminthes from the ancestor to Monogena, Digenea and Cestoda; proposition to establish a new common taxon--Cercomerophora--for these three groups. In this background the evolution of evolutionary ideas is reviewed, divided into two periods: up to the eighties of the XX century, and up to date. The first period can be characterised by the criticism of some points of the "cercomer theory" and formulation of some new hypotheses; these are those of Fuhrmann, Bychovsky, Llewellyn, Price and Malmberg, which: questioned the homology of the cercarial tail with the caudal appendices of Monogenea and Cestoda; rejected Digenea from the common group; established the common taxon--Cercomeromorpha--comprising only Monogenea and Cestoda; opposed the idea of radial evolution of three main groups of Platyhelmithes (Turbellaria, Digenea and Cercomeromorpha) to the idea of subsequent evolution presented by Janicki. The differences between these last hypotheses are also underlined, arising mainly from the different ideas on the importance of particular features as the evolutionary indicators of affinities between and within the taxons. As to the hypotheses dealing with the evolution of particular groups of parasitic platyhelminths formulated at the same period, the publications of Freeman and Jarecka

  12. Chromosome polymorphism and complements in populations of Girardia species (Platyhelminthes, Tricladida, Paludicola) from southern Brazil.

    PubMed

    Benya, E; Leal-Zanchet, A M; Santos, W H; Hauser, J; Erdtmann, B

    2007-12-01

    The karyotypes of four species of freshwater triclads of the genus Girardia (Platyhelminthes), i.e. G. schubarti, G. tigrina, G. anderlani, and G. biapertura, from populations of different localities of the Rio Grande do Sul State, in southern Brazil, were analyzed. The karyotype of G. biapertura is presented for the first time. Three basic complements of 4, 8, and 9 chromosomes were found. Diploids, triploids, or mixoploids (2n/3n) specimens were frequently detected in these populations. The basic chromosomal complement of n=9 was verified in two different species (G. biapertura and G. anderlani), presenting a large acrocentric chromosome which is rare in the family Dugesiidae. An intra and interspecific chromosomal variability was also detected and its evolutionary implications are discussed.

  13. New species of Gieysztoria (Platyhelminthes, Rhabdocoela) from Peruvian Amazon floodplain with description of their stylet ultrastructure.

    PubMed

    Damborenea, Cristina; Brusa, Francisco; Noreña, Carolina

    2005-12-01

    The free-living Platyhelminthes of the Amazon basin are poorly known. Presently only four turbellarian species have been mentioned from the Amazon river, a fact that confirms the lack of information on this kind of faunas in this huge basin. Three new species of Gieysztoria from Amazonian floodplain in Peru are described herein: G. chiqchi n. sp., G. kasasapa n. sp. and G. sasa n. sp. The samples were taken in the Pacaya-Samiria National Reserve (Peru) during September 2002. Besides the usual description of the stylet based on whole mounted specimens, we provide a complementary description using SEM, which allowed differentiation of the new species within the currently yet imperfect picture of the Amazonian turbellarian fauna. Although further research is desired, current findings are suggestive of high diversity of free-living Turbellaria in the surveyed region.

  14. The taxonomic status of Dugesia biblica from Israel and Turkey (Platyhelminthes, Tricladida, Dugesiidae)

    PubMed Central

    Solà, Eduard; Sluys, Ronald; Segev, Ori; Blaustein, Leon; Riutort, Marta

    2015-01-01

    Abstract The taxonomic status of Dugesia biblica (Platyhelminthes, Tricladida, Dugesiidae) from Israel and Turkey is problematic due to its morphological similarity with Dugesia sicula since these nominal species present overlapping characters. In this study we analyzed histological preparations of specimens of these two nominal species and also compared mitochondrial COI gene sequences from Israeli populations to the already known haplotype composition of Dugesia sicula. We concluded that these animals belong to the same species and therefore we consider Dugesia biblica to be a junior synonym of Dugesia sicula. This implies that the distribution range of Dugesia sicula is even wider than previously thought, and that the species is present all around the Mediterranean Basin and on many of its islands. PMID:26085791

  15. Phylogenetic distribution of microRNAs supports the basal position of acoel flatworms and the polyphyly of Platyhelminthes.

    PubMed

    Sempere, Lorenzo F; Martinez, Pedro; Cole, Charles; Baguñà, Jaume; Peterson, Kevin J

    2007-01-01

    Phylogenetic analyses based on gene sequences suggest that acoel flatworms are not members of the phylum Platyhelminthes, but instead are the most basal branch of triploblastic bilaterians. Nonetheless, this result has been called into question. An alternative test is to use qualitative molecular markers that should, in principle, exclude the possibility of convergent (homoplastic) evolution in unrelated groups. microRNAs (miRNAs), noncoding regulatory RNA molecules that are under intense stabilizing selection, are a newly discovered set of phylogenetic markers that can resolve such taxonomic disputes. The acoel Childia sp. has recently been shown to possess a subset of the conserved core of miRNAs found across deuterostomes and protostomes, whereas a polyclad flatworm-in addition to this core subset-possesses miRNAs restricted to just protostomes. Here, we examine another acoel, Symsagittifera roscoffensis, and three other platyhelminths. Our results show that the distribution of miRNAs in S. roscoffensis parallels that of Childia. In addition, two of 13 new miRNAs cloned from a triclad flatworm are also found in other lophotrochozoan protostomes, but not in ecdysozoans, deuterostomes, or in basal metazoans including acoels. The limited set of miRNAs found in acoels, intermediate between the even more reduced set in cnidarians and the larger and expanding set in the rest of bilaterians, is compelling evidence for the basal position of acoel flatworms and the polyphyly of Platyhelminthes.

  16. Two dimensional vibrations of the guinea pig apex organ of Corti measured in vivo using phase sensitive Fourier domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, Sripriya; Zhang, Yuan; Petrie, Tracy; Fridberger, Anders; Ren, Tianying; Wang, Ruikang; Jacques, Steven L.; Nuttall, Alfred L.

    2015-02-01

    In this study, we measure the in vivo apical-turn vibrations of the guinea pig organ of Corti in both axial and radial directions using phase-sensitive Fourier domain optical coherence tomography. The apical turn in guinea pig cochlea has best frequencies around 100 - 500 Hz which are relevant for human speech. Prior measurements of vibrations in the guinea pig apex involved opening the otic capsule, which has been questioned on the basis of the resulting changes to cochlear hydrodynamics. Here this limitation is overcome by measuring the vibrations through bone without opening the otic capsule. Furthermore, we have significantly reduced the surgery needed to access the guinea pig apex in the axial direction by introducing a miniature mirror inside the bulla. The method and preliminary data are discussed in this article.

  17. Molecular phylogeny of land and freshwater planarians (Tricladida, Platyhelminthes): from freshwater to land and back.

    PubMed

    Alvarez-Presas, Marta; Baguñà, Jaume; Riutort, Marta

    2008-05-01

    The suborder Tricladida (phylum Platyhelminthes) comprises the well-known free-living flatworms, taxonomically grouped into three infraorders according to their ecology: Maricola (marine planarians), Paludicola (freshwater planarians), and Terricola (land planarians). Molecular analyses have demonstrated that the Paludicola are paraphyletic, the Terricola being the sister group of one of the three paludicolan families, the Dugesiidae. However, neither 18S rDNA nor COI based trees have been able to resolve the relationships among species of Terricola and Dugesiidae, particularly the monophyly of Terricola. Here, we present new molecular data including sequences of nuclear genes (18S rDNA, 28S rDNA) and a mitochondrial gene (COI) of a wider sample of dugesiid and terricolan species. The new sequences have been analyzed, together with those previously obtained, in independent and concatenated analyses using maximum likelihood and bayesian methods. The results show that, although some parts of the trees remain poorly resolved, they support a monophyletic origin for Terricola followed by a likely return of some species to freshwater habitats. Relationships within the monophyletic group of Dugesiidae are clearly resolved, and relationships among some terricolan subfamilies are also clearly established and point to the need for a thorough revision of Terricola taxonomy.

  18. [Peculiarities of ultrastructure of excretory system in Bothrioplana semperi (Platyhelminthes, Turbellaria)].

    PubMed

    Kornakova, E E

    2010-01-01

    Ultrastructural study of morphology of cirtocytes and excretory channels was performed in the free living turbellaria Bothrioplana semperi (Turbellaria, Seriata). It has been shown that cirtocytes of this species are formed by two cells--the terminal and the proximal cells of the channel. The fan is composed of two rod rows. The external row goes out from the terminal cell, the internal one is a derivate of the channel proximal cell. Inside each rod of the external row there runs a bundle of microfilaments; it originates in the cytoplasm of the channel proximal cell distal to bases of the external rods. On the internal rod membranes there are noted small electrondense granules disposed separately or fused in the solid layer continuing into a dense "membrane" connecting rods of the external and internal rows. Rare internal leptotrichiae go out from the cirtocyte cavity bottom. External leptotrichiae are absent. The septate desmosome at the level of the terminal cell is absent, but is present in the channel proximal cell at the level of terminal of cilia. The apical surface of the channel cell carries rare short microvilli. The basement membrane of cells of excretory channels forms deep invaginations almost reaching the apical membrane. Epithelium of excretory channels is deprived of cilia. Ultrastructure of cirtocytes and excretory channels of B. semperi is similar to those in representatives of the suborder Proseriata (Seriata). The significance of ultrastructure of the Proseriata cirtocytes, especially of the order of formation of versh, for construction of phylogeny of Platyhelminthes is discussed.

  19. The power of regeneration and the stem-cell kingdom: freshwater planarians (Platyhelminthes).

    PubMed

    Saló, Emili

    2006-05-01

    The great powers of regeneration shown by freshwater planarians, capable of regenerating a complete organism from any tiny body fragment, have attracted the interest of scientists throughout history. In 1814, Dalyell concluded that planarians could "almost be called immortal under the edge of the knife". Equally impressive is the developmental plasticity of these platyhelminthes, including continuous growth and fission (asexual reproduction) in well-fed organisms, and shrinkage (degrowth) during prolonged starvation. The source of their morphological plasticity and regenerative capability is a stable population of totipotent stem cells--"neoblasts"; this is the only cell type in the adult that has mitotic activity and differentiates into all cell types. This cellular feature is unique to planarians in the Bilateria clade. Over the last fifteen years, molecular studies have begun to reveal the role of developmental genes in regeneration, although it would be premature to propose a molecular model for planarian regeneration. Genomic and proteomic data are essential in answering some of the fundamental questions concerning this remarkable morphological plasticity. Such information should also pave the way to understanding the genetic pathways associated with metazoan somatic stem-cell regulation and pattern formation.

  20. Diseases of cultured marine fishes caused by Platyhelminthes (Monogenea, Digenea, Cestoda).

    PubMed

    Ogawa, K

    2015-01-01

    Mariculture is a rapidly developing industrial sector. Generally, fish are maintained in net cages with high density. Cage culture systems allow uncontrolled flow of sea water containing potentially infectious stages of fish parasites. In such culture conditions, prevention of such parasitic infections is difficult for parasites with life cycles that complete within culture sites, among which monogeneans and blood flukes are the most important platyhelminthes. Intense monogenean infections induce respiratory and osmo-regulatory dysfunctions. A variety of control measures have been developed, including freshwater bath treatment and chemotherapy. The potential to control monogenean infections through selective breeding, modified culture techniques to avoid infection, and general fish health management are discussed. It should be noted that mariculture conditions have provided some host-specific monogeneans with a chance to expand their host ranges. Blood flukes sometimes induce mass mortality among farmed fish. In-feed administration of praziquantel is the best solution to treat infected fish. Some cases are described that show how international trade in marine fish has resulted in the spread of hitherto unknown parasites into indigenous farmed and wild fish.

  1. Ultrastructure of spermatogenesis and mature spermatozoon of the freshwater planarian Schmidtea mediterranea (Platyhelminthes, Paludicola).

    PubMed

    Harrath, Abdul Halim; Alwasel, Saleh; Zghal, Fathia; Tekaya, Saïda

    2012-02-01

    The aim of this study was to characterize for the first time spermatogenesis and spermiogenesis in the freshwater planarian Schmidtea mediterranea using both light and electron microscopy. Starting from the border towards the testis lumen we found types I and II spermatogonia, clusters of primary and secondary spermatocytes, spermatids and free spermatozoa. Light microscope observations show that type I spermatogonia have a large and pale nucleus whereas type II spermatogonia are significantly smaller than the one of type I, and show a darker and central bulky nucleus. At the ultrastructure level, both type I and type II spermatogonia are characterized by a wide nucleus with scanty cytoplasm containing free ribosomes, mitochondria and a dense chromatoid body whereas endoplasmic reticulum and Golgi complex were not observed. The cytoplasm of primary and secondary spermatocytes displays numerous free ribosomes and many endoplasmic reticulum cisternae and Golgi complexes, suggesting that the development of these organelles during spermatogenesis might contribute to the synthesis of hormones and proteins such as testosterone, transcription factors and tubulin. Mature spermatozoa structure closely resembles those of other freshwater triclads with a nucleus, a single fused mitochondrion, a row of cortical microtubules and a pair of flagella conforming to the 9+'1' microtubule pattern described for other Platyhelminthes.

  2. Comparative study of adaptive radiations with an example using parasitic flatworms (Platyhelminthes): Cercomeria

    SciTech Connect

    Brooks, D.R.; McLennan, D.A. )

    1993-11-01

    Studies of adaptive radiations require robust phylogenies, estimates of species numbers for monophyletic groups within clades, assessments of the adaptive value of putative key innovations, and estimates of the frequency of speciation modes. Four criteria are necessary to identify an adaptive radiation within the parasitic platyhelminths: (1) a group contains significantly more species than its sister group, (2) species richness is apomorphic, (3) apomorphic traits enhance the potential for adaptively driven modes of speciation (sympatric speciation and speciation by peripheral isolation via host switching), and (4) the frequency of adaptively driven speciation modes is high within the group when compared with data from free-living groups. Only the species-rich Monogenea fulfill all four criteria. The Digenea and Eucestoda also are more species rich than their sister groups, their species richness is derived, and they possess unique characters that increase the potential for host switching to occur. However, because there is not enough information to determine whether the frequency of adaptive modes of speciation is high for those groups, we cannot yet assert that their radiations have been adaptive. 102 refs., 3 figs., 1 tab.

  3. Myogenesis in two polyclad platyhelminths with indirect development, Pseudoceros canadensis and Stylostomum sanjuania.

    PubMed

    Semmler, Henrike; Wanninger, Andreas

    2010-01-01

    Myogenesis of two representatives of Platyhelminthes, Stylostomum sanjuania and Pseudoceros canadensis, was followed from egg deposition until well-differentiated free-swimming larval stages, using F-actin staining and confocal laserscanning microscopy. Zonulae adhaerentes are the only structures to stain before 50% of development between egg deposition and hatching in S. sanjuania, and before 67% of development in P. canadenis. Subsequently, irregular fibers appear in the embryo, followed by a helicoid muscle close to the apical pole. Three longitudinal muscle pairs form, of which the dorsal pair remains more pronounced than the others. Gradually, new muscles form by branching or from double-stranded muscle zones adjacent to existing muscles. This results in an elaborate muscular bodywall that consists of a single helicoid muscle as well as multiple circular and longitudinal muscles. Diverse retractor muscles insert at the sphincter muscles around the stomodeum. The overall arrangement and formation mode of the larval musculature appears very similar in both species, although only P. canadensis has a primary circular muscle posterior to the helicoid muscle. Muscle formation in the apical region of the embryo precedes that at the abapical pole and the primary longitudinal muscles form slightly later than the primary circular muscles. Myogenesis and larval myoanatomy appears highly conserved among polyclad flatworms, but differs significantly from that of other trochozoan clades. Our data suggest that the larval muscular ground pattern of polyclad larvae comprises a bodywall consisting of a helicoid muscle, circular and longitudinal muscles, several retractor muscles, and sphincter muscles around the stomodeum.

  4. Elucidating the phylogenetic position of Gnathostomulida and first mitochondrial genomes of Gnathostomulida, Gastrotricha and Polycladida (Platyhelminthes).

    PubMed

    Golombek, Anja; Tobergte, Sarah; Struck, Torsten H

    2015-05-01

    Gnathostomulida is a taxon of small marine worms, which exclusively inhabit the interstitium. The evolution of Gnathostomulida has been discussed for decades. Originally regarded as primitive animals with affinities to flatworms, the phylogenetic position of Gnathostomulida has been debated. Given the lack of an anus a close relationship to Platyhelminthes has been maintained (i.e., Plathelminthomorpha hypothesis). Alternative hypotheses proposed Gnathostomulida as being close to Gastrotricha due to the presence of a monociliary epidermis (i.e., Monokonta/Neotrichozoa hypothesis) or to Syndermata based on the complicated jaw apparatus (i.e., Gnathifera hypothesis). Molecular analyses using only few genes were inconclusive. Recent phylogenomic studies brought some progress by placing Gnathostomulida as sister to Syndermata, but support for this relationship was low and depended on the analytical strategy. Herein we present the first data of complete or nearly complete mitochondrial genomes for two gnathostomulids (Gnathostomula paradoxa &G. armata), one gastrotrich (Lepidodermella squamata) and one polyclad flatworm (Stylochoplana maculata) to address the uncertain phylogenetic affinity of Gnathostomulida. Our analyses found Gnathostomulida as sister to Syndermata (Gnathifera hypothesis). Thorough sensitivity analyses addressing taxon instability, branch length heterogeneity (also known as long branch attraction) and base composition heterogeneity showed that the position of Gnathostomulida is consistent across the different analyses and, hence, independent of potential misleading biases. Moreover, by ameliorating these different biases nodal support values could be increased to maximum values. Thus, our data support the hypothesis that the different jaw apparatuses of Syndermata and Gnathostomulida are indeed homologous structures as proposed by the Gnathifera hypothesis.

  5. Problematic barcoding in flatworms: A case-study on monogeneans and rhabdocoels (Platyhelminthes)

    PubMed Central

    Vanhove, Maarten P. M.; Tessens, Bart; Schoelinck, Charlotte; Jondelius, Ulf; Littlewood, D. Tim J.; Artois, Tom; Huyse, Tine

    2013-01-01

    Abstract Some taxonomic groups are less amenable to mitochondrial DNA barcoding than others. Due to the paucity of molecular information of understudied groups and the huge molecular diversity within flatworms, primer design has been hampered. Indeed, all attempts to develop universal flatworm-specific COI markers have failed so far. We demonstrate how high molecular variability and contamination problems limit the possibilities for barcoding using standard COI-based protocols in flatworms. As a consequence, molecular identification methods often rely on other widely applicable markers. In the case of Monogenea, a very diverse group of platyhelminth parasites, and Rhabdocoela, representing one-fourth of all free-living flatworm taxa, this has led to a relatively high availability of nuclear ITS and 18S/28S rDNA sequences on GenBank. In a comparison of the effectiveness in species assignment we conclude that mitochondrial and nuclear ribosomal markers perform equally well. In case intraspecific information is needed, rDNA sequences can guide the selection of the appropriate (i.e. taxon-specific) COI primers if available. PMID:24453567

  6. A new species of Supramontana Carbayo & Leal-Zanchet (Platyhelminthes, Continenticola, Geoplanidae) from the Interior Atlantic Forest.

    PubMed

    Negrete, Lisandro; Leal-Zanchet, Ana Maria; Brusa, Francisco

    2014-01-06

    Supramontana argentina sp. nov. (Platyhelminthes, Continenticola, Geoplanidae) from north-eastern Argentina is herein described. The new species differs from Supramontana irritata Carbayo & Leal-Zanchet, 2003 from Brazil, the only species of this genus so far described, by external and internal morphological characters. Supramontana argentina sp. nov. is characterized by having a colour pattern with a yellowish median band, thin para-median black stripes, and two dark grey lateral bands on the dorsal surface. The most outstanding features of the internal morphology are a ventral cephalic retractor muscle almost circular in cross section, prostatic vesicle extrabulbar, tubular and very long, and penis papilla conical and blunt with a sinuous ejaculatory duct.

  7. Closing the mitochondrial circle on paraphyly of the Monogenea (Platyhelminthes) infers evolution in the diet of parasitic flatworms.

    PubMed

    Perkins, Elizabeth M; Donnellan, Steve C; Bertozzi, Terry; Whittington, Ian D

    2010-09-01

    Relationships between the three classes of Neodermata (parasitic Platyhelminthes) are much debated and restrict our understanding of the evolution of parasitism and contingent adaptations. The historic view of a sister relationship between Cestoda and Monogenea (Cercomeromorphae; larvae bearing posterior hooks) has been dismissed and the weight of evidence against monogenean monophyly has mounted. We present the nucleotide sequence of the complete mitochondrial (mt) genome of Benedenia seriolae (Monogenea: Monopisthocotylea: Capsalidae), the first complete non-gyrodactylid monopisthocotylean mt genome to be reported. We also include nucleotide sequence data for some mt protein coding genes for a second capsalid, Neobenedenia sp. Analyses of the new mt genomes with all available platyhelminth mt genomes provide new phylogenetic hypotheses, which strongly influence perspectives on the evolution of diet in the Neodermata. Our analyses do not support monogenean monophyly but confirm that the Digenea and Cestoda are each monophyletic and sister groups. Epithelial feeding monopisthocotyleans on fish hosts are basal in the Neodermata and represent the first shift to parasitism from free-living ancestors. The next evolutionary step in parasitism was a dietary change from epithelium to blood. The common ancestor of Digenea+Cestoda was monogenean-like and most likely sanguinivorous. From this ancestral condition, adult digeneans and cestodes independently evolved dietary specialisations to suit their diverse microhabitats in their final vertebrate hosts. These improved perspectives on relationships fundamentally enhance our understanding of the evolution of parasitism in the Neodermata and in particular, the evolution of diet.

  8. Septins of Platyhelminths: identification, phylogeny, expression and localization among developmental stages of Schistosoma mansoni.

    PubMed

    Zeraik, Ana E; Rinaldi, Gabriel; Mann, Victoria H; Popratiloff, Anastas; Araujo, Ana P U; Demarco, Ricardo; Brindley, Paul J

    2013-01-01

    Septins are a family of eukaryotic GTP binding proteins conserved from yeasts to humans. Originally identified in mutants of budding yeast, septins participate in diverse cellular functions including cytokinesis, organization of actin networks, cell polarity, vesicle trafficking and many others. Septins assemble into heteroligomers to form filaments and rings. Here, four septins of Schistosoma mansoni are described, which appear to be conserved within the phylum Platyhelminthes. These orthologues were related to the SEPT5, SEPT10 and SEPT7 septins of humans, and hence we have termed the schistosome septins SmSEPT5, SmSEPT10, SmSEPT7.1 and SmSEPT7.2. Septin transcripts were detected throughout the developmental cycle of the schistosome and a similar expression profile was observed for septins in the stages examined, consistent with concerted production of these proteins to form heterocomplexes. Immunolocalization analyses undertaken with antibodies specific for SmSEPT5 and SmSEPT10 revealed a broad tissue distribution of septins in the schistosomulum and colocalization of septin and actin in the longitudinal and circular muscles of the sporocyst. Ciliated epidermal plates of the miracidium were rich in septins. Expression levels for these septins were elevated in germ cells in the miracidium and sporocyst. Intriguingly, septins colocalize with the protonephridial system of the cercaria, which extends laterally along the length of this larval stage. Together, the findings revealed that schistosomes expressed several septins which likely form filaments within the cells, as in other eukaryotes. Identification and localization demonstrating a broad distribution of septins across organs and tissues of schistosome contributes towards the understanding of septins in schistosomes and other flatworms.

  9. Phylogenetic relationships and systematic position of the families Cortrematidae and Phaneropsolidae (Platyhelminthes: Digenea).

    PubMed

    Kanarek, Gerard; Zaleśny, Grzegorz; Sitko, Jiljí; Tkach, Vasyl V

    2014-12-01

    The systematic position and phylogenetic relationships of the family Cortrematidae Yamaguti, 1958 have always been controversial. In the present study, the phylogenetic relationships of this family and its constituent genera and families within the superfamily Microphalloidea were evaluated using previously published and newly obtained sequences of 28S rDNA of Cortrema magnicaudata (Bykhovskaya-Pavlovskaya, 1950) (Cortrematidae), Phaneropsolus praomydis Baer, 1971 and Microtrema barusi Sitko, 2013 (Phaneropsolidae). Results clearly demonstrate that the genus Cortrema Tang, 1951 is closest to Gyrabascus Macy 1935, both genera forming one of the clades within the family Pleurogenidae in the superfamily Microphalloidea and sharing several important morphological features. Thus, the family Cortrematidae should be considered among synonyms of the Pleurogenidae. Based on the analysis of morphology, C. corti Tang, 1951, C. testilobata (Bykhovskaya-Pavlovskaya, 1953) and C. niloticus Ashour, Ahmed et Lewis, 1994 are considered junior synonyms of C. magnicaudata. The phylogenetic position of P. praomydis as a family-level branch not showing close relationships with other families of the Microphalloidea, supports the status of the Phaneropsolidae as an independent family. The genus Parabascus Looss, 1907 previously considered within the Phaneropsolidae clearly belongs to the Pleurogenidae. In addition, the molecular phylogeny has demonstrated that the recently described phaneropsolid Microtrema barusi belongs to the microphallid genus Microphallus Ward, 1901. Therefore, Microtrema Sitko, 2013 is considered a junior synonym of Microphallus. Our analysis has also confirmed the status of Collyriclidae as a family within the Microphalloidea. Not yet sequenced representatives of other families within the Microphalloidea (e.g. Anenterotrematidae, Eumegacetidae, Renschtrematidae, Stomylotrematidae, etc.) need to be included in future molecular phylogenetic studies to better unravel

  10. Effects of pulsed Er:YSGG and Ho:YAG laser on the organ of Corti of the guinea pig cochlea: a scanning electron microscopic study

    NASA Astrophysics Data System (ADS)

    Jamali, Yasmin; Jovanovic, Sergije; Schoenfeld, Uwe; Anft, D.; Ertl, Thomas P.; Scherer, Hans H.; Berghaus, A.; Mueller, Gerhard J.

    1998-01-01

    Laser stapedotomy has now become an established method in the surgical treatment of otosclerosis. Recent experimental studies have demonstrated that, apart from the continuous wave lasers, several pulsed laser systems are also suitable for stapes management. Experiments were performed in guinea pigs to clarify which, if any, of the pulsed lasers used can damage the inner ear on application of the laser parameters required for the stapedotomy. The basal convolution of the guinea-pig cochlea was chosen as the application site. Acoustic evoked potentials (compound action potentials) yielded information on inner-ear function. With the Er:YSGG laser (energy: 85 J/pulse, energy density: 36 J/cm2, total energy: 0.425 J), five applications to the cochlea are necessary for a foot plate perforation of 500 - 600 micrometers . With the Ho:YAG laser, an adequately large perforation can be achieved with at least 10 applications of an energy of 210 mJ per pulse (energy density: 90 J/cm2, total energy: 2.1 J). The aim of this study was: (1) to clarify whether the Er:YSGG and Ho:YAG laser could cause morphological changes in the organ of Corti of the guinea pig on application of the laser parameters required for stapedotomy, and (2) to verify our experimental electrophysiological results and correlate them with the morphological changes detected in the organ of Corti in the guinea pig cochlea by scanning-electron-microscopic examination. It shows that the effective laser parameters (5 X 85 mJ) of the Er:YSGG-laser cause no changes of the guinea pig cochlea. Even with the application of 25 pulses with the same energy the guinea pig cochlea shows normal appearance. The effective laser parameters of the Ho:YAG laser (10 X 210 mJ) show changes in the outer hair cells in the form of stereocilie fusion and giant hair cell formation while the inner hair cells and supporting cells are showing normal appearance. Our results clearly demonstrate a high application safety for the Er:YSGG laser

  11. Phase-sensitive optical coherence tomography imaging of the tissue motion within the organ of Corti at a subnanometer scale: a preliminary study

    NASA Astrophysics Data System (ADS)

    Wang, Ruikang K.; Nuttall, Alfred L.

    2010-09-01

    Hearing loss can mean severe impairment to the quality of life. However, the biomechanical mechanisms of how the hearing organ, i.e., the organ of Corti (OC), responds to sound are still elusive, largely because there is currently no means available to image the 3-D motion characteristics of the OC. We present a novel use of the phase-sensitive spectral domain optical coherence tomography (PSOCT) to characterize the motion of cellular compartments within the OC at a subnanometer scale. The PSOCT system operates at 1310 nm with a spatial resolution of ~16 μm and an imaging speed of 47,000 A-lines/s. The phase changes of the spectral interferograms induced by the localized tissue motion are used to quantify the vibration magnitude. Fourier transform analysis of the phase changes improves the system sensitivity to sense minute vibrations smaller than 1 nm. We demonstrate that the PSOCT system is feasible to image the meaningful vibration of cellular compartments within the OC with an unprecedented sensitivity down to ~0.5 A˚.

  12. Geldanamycin induces production of heat shock protein 70 and partially attenuates ototoxicity caused by gentamicin in the organ of Corti explants

    PubMed Central

    2009-01-01

    Background Heat shock protein 70 (HSP70) protects inner ear cells from damage and death induced by e.g. heat or toxins. Benzoquinone ansamycin antibiotic geldanamycin (GA) was demonstrated to induce the expression of HSP70 in various animal cell types. The aim of our study was to investigate whether GA induces HSP70 in the organ of Corti (OC), which contains the auditory sensory cells, and whether GA can protect these cells from toxicity caused by a common aminoglycoside antibiotic gentamicin. Methods To address these questions, we used the OC explants isolated from p3-p5 rats. As a read-out, we used RT-PCR, ELISA and immunofluorescence. Results We found that GA at the concentration of 2 μM efficiently induced HSP70 expression on mRNA and protein level in the OC explants. Confocal microscopy revealed that HSP70 induced by GA is expressed by hair cells and interdental cells of spiral limbus. Preincubation of explants with 2 μM GA prior to adding gentamicin (500 μM) significantly reduced the loss of outer but not inner hair cells, suggesting different mechanisms of otoprotection needed for these two cell types. Conclusion GA induced HSP70 in the auditory sensory cells and partially protected them from toxicity of gentamicin. Understanding the molecular mechanisms of GA otoprotection may provide insights for preventative therapy of the hearing loss caused by aminoglycoside antibiotics. PMID:19723345

  13. Venus kinase receptors control reproduction in the platyhelminth parasite Schistosoma mansoni.

    PubMed

    Vanderstraete, Mathieu; Gouignard, Nadège; Cailliau, Katia; Morel, Marion; Hahnel, Steffen; Leutner, Silke; Beckmann, Svenja; Grevelding, Christoph G; Dissous, Colette

    2014-05-01

    The Venus kinase receptor (VKR) is a single transmembrane molecule composed of an intracellular tyrosine kinase domain close to that of insulin receptor and an extracellular Venus Flytrap (VFT) structure similar to the ligand binding domain of many class C G protein coupled receptors. This receptor tyrosine kinase (RTK) was first discovered in the platyhelminth parasite Schistosoma mansoni, then in a large variety of invertebrates. A single vkr gene is found in most genomes, except in S. mansoni in which two genes Smvkr1 and Smvkr2 exist. VKRs form a unique family of RTKs present only in invertebrates and their biological functions are still to be discovered. In this work, we show that SmVKRs are expressed in the reproductive organs of S. mansoni, particularly in the ovaries of female worms. By transcriptional analyses evidence was obtained that both SmVKRs fulfill different roles during oocyte maturation. Suppression of Smvkr expression by RNA interference induced spectacular morphological changes in female worms with a strong disorganization of the ovary, which was dominated by the presence of primary oocytes, and a defect of egg formation. Following expression in Xenopus oocytes, SmVKR1 and SmVKR2 receptors were shown to be activated by distinct ligands which are L-Arginine and calcium ions, respectively. Signalling analysis in Xenopus oocytes revealed the capacity of SmVKRs to activate the PI3K/Akt/p70S6K and Erk MAPK pathways involved in cellular growth and proliferation. Additionally, SmVKR1 induced phosphorylation of JNK (c-Jun N-terminal kinase). Activation of JNK by SmVKR1 was supported by the results of yeast two-hybrid experiments identifying several components of the JNK pathway as specific interacting partners of SmVKR1. In conclusion, these results demonstrate the functions of SmVKR in gametogenesis, and particularly in oogenesis and egg formation. By eliciting signalling pathways potentially involved in oocyte proliferation, growth and migration

  14. Venus Kinase Receptors Control Reproduction in the Platyhelminth Parasite Schistosoma mansoni

    PubMed Central

    Cailliau, Katia; Morel, Marion; Hahnel, Steffen; Leutner, Silke; Beckmann, Svenja; Grevelding, Christoph G.; Dissous, Colette

    2014-01-01

    The Venus Kinase Receptor (VKR) is a single transmembrane molecule composed of an intracellular tyrosine kinase domain close to that of insulin receptor and an extracellular Venus Flytrap (VFT) structure similar to the ligand binding domain of many class C G Protein Coupled Receptors. This receptor tyrosine kinase (RTK) was first discovered in the platyhelminth parasite Schistosoma mansoni, then in a large variety of invertebrates. A single vkr gene is found in most genomes, except in S. mansoni in which two genes Smvkr1 and Smvkr2 exist. VKRs form a unique family of RTKs present only in invertebrates and their biological functions are still to be discovered. In this work, we show that SmVKRs are expressed in the reproductive organs of S. mansoni, particularly in the ovaries of female worms. By transcriptional analyses evidence was obtained that both SmVKRs fulfill different roles during oocyte maturation. Suppression of Smvkr expression by RNA interference induced spectacular morphological changes in female worms with a strong disorganization of the ovary, which was dominated by the presence of primary oocytes, and a defect of egg formation. Following expression in Xenopus oocytes, SmVKR1 and SmVKR2 receptors were shown to be activated by distinct ligands which are L-Arginine and calcium ions, respectively. Signalling analysis in Xenopus oocytes revealed the capacity of SmVKRs to activate the PI3K/Akt/p70S6K and Erk MAPK pathways involved in cellular growth and proliferation. Additionally, SmVKR1 induced phosphorylation of JNK (c-Jun N-terminal kinase). Activation of JNK by SmVKR1 was supported by the results of yeast two-hybrid experiments identifying several components of the JNK pathway as specific interacting partners of SmVKR1. In conclusion, these results demonstrate the functions of SmVKR in gametogenesis, and particularly in oogenesis and egg formation. By eliciting signalling pathways potentially involved in oocyte proliferation, growth and migration

  15. Complete sequence of the mitochondrial genome of the tapeworm Hymenolepis diminuta: gene arrangements indicate that Platyhelminths are Eutrochozoans.

    PubMed

    von Nickisch-Rosenegk, M; Brown, W M; Boore, J L

    2001-05-01

    Using "long-PCR," we amplified in overlapping fragments the complete mitochondrial genome of the tapeworm Hymenolepis diminuta (Platyhelminthes: Cestoda) and determined its 13,900-nt sequence. The gene content is the same as that typically found for animal mitochondrial DNA (mtDNA) except that atp8 appears to be lacking, a condition found previously for several other animals. Despite the small size of this mtDNA, there are two large noncoding regions, one of which contains 13 repeats of a 31-nt sequence and a potential stem-loop structure of 25 bp with an 11-member loop. Large potential secondary structures were identified also for the noncoding regions of two other cestode mtDNAS: Comparison of the mitochondrial gene arrangement of H. diminuta with those previously published supports a phylogenetic position of flatworms as members of the Eutrochozoa, rather than placing them basal to either a clade of protostomes or a clade of coelomates.

  16. New Acotylea (Polycladida, Platyhelminthes) from the east coast of the North Atlantic Ocean with special mention of the Iberian littoral.

    PubMed

    Noreña, Carolina; Rodríguez, Jorge; Pérez, Jacinto; Almon, Bruno

    2015-11-03

    Polyclad species diversity, although generally well known for European North Atlantic waters, is nearly unknown for the Iberian Peninsula. The "Ría de Arousa", located on the Atlantic coast of Galicia (Spain), is a place where many positive biological factors for species biodiversity converge. Therefore, it is an ideal location to study polyclad diversity. This research, which describes new records and new species, contributes to the knowledge of the distribution of Polycladida (Platyhelminthes), particularly of the suborder Acotylea, in the Atlantic waters of the Iberian Peninsula. The new records include the re-descriptions of Cryptocelis compacta Lang, 1884, Stylochus neapolitanus (Delle Chiaje, 1841-1844) and Discocelis tigrina (Blanchard, 1847), while the two newly described species are Hoploplana elisabelloi n. sp. and Armatoplana celta n. sp.

  17. Transplantation and survival of mouse inner ear progenitor/stem cells in the organ of Corti after cochleostomy of hearing-impaired guinea pigs: preliminary results

    PubMed Central

    Barboza, L.C.M.; Lezirovitz, K.; Zanatta, D.B.; Strauss, B.E.; Mingroni-Netto, R.C.; Oiticica, J.; Haddad, L.A.; Bento, R.F.

    2016-01-01

    In mammals, damage to sensory receptor cells (hair cells) of the inner ear results in permanent sensorineural hearing loss. Here, we investigated whether postnatal mouse inner ear progenitor/stem cells (mIESCs) are viable after transplantation into the basal turns of neomycin-injured guinea pig cochleas. We also examined the effects of mIESC transplantation on auditory functions. Eight adult female Cavia porcellus guinea pigs (250-350g) were deafened by intratympanic neomycin delivery. After 7 days, the animals were randomly divided in two groups. The study group (n=4) received transplantation of LacZ-positive mIESCs in culture medium into the scala tympani. The control group (n=4) received culture medium only. At 2 weeks after transplantation, functional analyses were performed by auditory brainstem response measurement, and the animals were sacrificed. The presence of mIESCs was evaluated by immunohistochemistry of sections of the cochlea from the study group. Non-parametric tests were used for statistical analysis of the data. Intratympanic neomycin delivery damaged hair cells and increased auditory thresholds prior to cell transplantation. There were no significant differences between auditory brainstem thresholds before and after transplantation in individual guinea pigs. Some mIESCs were observed in all scalae of the basal turns of the injured cochleas, and a proportion of these cells expressed the hair cell marker myosin VIIa. Some transplanted mIESCs engrafted in the cochlear basilar membrane. Our study demonstrates that transplanted cells survived and engrafted in the organ of Corti after cochleostomy. PMID:27007652

  18. No Evidence for a Culturable Bacterial Tetrodotoxin Producer in Pleurobranchaea maculata (Gastropoda: Pleurobranchidae) and Stylochoplana sp. (Platyhelminthes: Polycladida)

    PubMed Central

    Salvitti, Lauren R.; Wood, Susanna A.; McNabb, Paul; Cary, Stephen Craig

    2015-01-01

    Tetrodotoxin (TTX) is a potent neurotoxin found in the tissues of many taxonomically diverse organisms. Its origin has been the topic of much debate, with suggestions including endogenous production, acquisition through diet, and symbiotic bacterial synthesis. Bacterial production of TTX has been reported in isolates from marine biota, but at lower than expected concentrations. In this study, 102 strains were isolated from Pleurobranchaea maculata (Opisthobranchia) and Stylochoplana sp. (Platyhelminthes). Tetrodotoxin production was tested utilizing a recently developed sensitive method to detect the C9 base of TTX via liquid chromatography—mass spectrometry. Bacterial strains were characterized by sequencing a region of the 16S ribosomal RNA gene. To account for the possibility that TTX is produced by a consortium of bacteria, a series of experiments using marine broth spiked with various P. maculata tissues were undertaken. Sixteen unique strains from P. maculata and one from Stylochoplana sp. were isolated, representing eight different genera; Pseudomonadales, Actinomycetales, Oceanospirillales, Thiotrichales, Rhodobacterales, Sphingomonadales, Bacillales, and Vibrionales. Molecular fingerprinting of bacterial communities from broth experiments showed little change over the first four days. No C9 base or TTX was detected in isolates or broth experiments (past day 0), suggesting a culturable microbial source of TTX in P. maculata and Stylochoplana sp. is unlikely. PMID:25635464

  19. A new genus and species for the first recorded cave-dwelling Cavernicola (Platyhelminthes) from South America

    PubMed Central

    Leal-Zanchet, Ana Maria; de Souza, Stella Teles; Ferreira, Rodrigo Lopes

    2014-01-01

    Abstract Species diversity of Brazilian cave fauna has been seriously underestimated. A karst area located in Felipe Guerra, northeastern Brazil, which is a hotspot of subterranean diversity in Brazil, has revealed more than 20 troglobitic species, most of them still undescribed. Based on recent samplings in this karst area, we document the occurrence of the suborder Cavernicola (Platyhelminthes) in South American hypogean environments for the first time and describe a new genus and species for this suborder. Hausera Leal-Zanchet & Souza, gen. n. has features concordant with those defined for the family Dimarcusidae. The new genus is characterized by two unique features, viz. an intestine extending dorsally to the brain and ovovitelline ducts located dorsally to the nerve cords, which is complemented by a combination of other characters. The type-specimens of Hausera hauseri Leal-Zanchet & Souza, sp. n. are typical stygobionts, unpigmented and eyeless, and they may constitute an oceanic relict as is the case of other stygobiotic invertebrates found in this karst area in northeastern Brazil. PMID:25349486

  20. Taxonomy of Cotylea (Platyhelminthes: Polycladida) from Cabo Frio, southeastern Brazil, with the description of a new species.

    PubMed

    Bahia, Juliana; Padula, Vinicius; Lavrado, Helena Passeri; Quiroga, Sigmer

    2014-10-20

    Polyclads are free-living Platyhelminthes with a simple, dorsoventrally flattened body and a much ramified intestine. In Brazil, 66 species are reported; only three from Rio de Janeiro State (RJ). The main objective of this study is to describe and illustrate coloration pattern, external morphology, reproductive system morphology and, when possible, biological and ecological aspects of species of the suborder Cotylea found in Cabo Frio, RJ. Of the 13 cotylean polyclad species found, Pseudobiceros pardalis, Cycloporus variegatus and Eurylepta aurantiaca are new records from the Brazilian coast and one species is new to science, Pseudoceros juani sp. nov. Feeding observations were made of four species. It is the first time that Lurymare utarum, Cycloporus gabriellae, C. variegatus and E. aurantiaca are illustrated with digital photographs of live specimens and histological preparations. This study increases to 70 the number of Brazilian Polycladida and to 14 the number of species known from Rio de Janeiro State. However, the knowledge about Polycladida in Brazil still has gaps, with great parts of the coast remaining unsampled. 

  1. No evidence for a culturable bacterial tetrodotoxin producer in Pleurobranchaea maculata (Gastropoda: Pleurobranchidae) and Stylochoplana sp. (Platyhelminthes: Polycladida).

    PubMed

    Salvitti, Lauren R; Wood, Susanna A; McNabb, Paul; Cary, Stephen Craig

    2015-01-28

    Tetrodotoxin (TTX) is a potent neurotoxin found in the tissues of many taxonomically diverse organisms. Its origin has been the topic of much debate, with suggestions including endogenous production, acquisition through diet, and symbiotic bacterial synthesis. Bacterial production of TTX has been reported in isolates from marine biota, but at lower than expected concentrations. In this study, 102 strains were isolated from Pleurobranchaea maculata (Opisthobranchia) and Stylochoplana sp. (Platyhelminthes). Tetrodotoxin production was tested utilizing a recently developed sensitive method to detect the C9 base of TTX via liquid chromatography-mass spectrometry. Bacterial strains were characterized by sequencing a region of the 16S ribosomal RNA gene. To account for the possibility that TTX is produced by a consortium of bacteria, a series of experiments using marine broth spiked with various P. maculata tissues were undertaken. Sixteen unique strains from P. maculata and one from Stylochoplana sp. were isolated, representing eight different genera; Pseudomonadales, Actinomycetales, Oceanospirillales, Thiotrichales, Rhodobacterales, Sphingomonadales, Bacillales, and Vibrionales. Molecular fingerprinting of bacterial communities from broth experiments showed little change over the first four days. No C9 base or TTX was detected in isolates or broth experiments (past day 0), suggesting a culturable microbial source of TTX in P. maculata and Stylochoplana sp. is unlikely.

  2. State of knowledge of the Acotylea (Polycladida, Platyhelminthes) from the Mediterranean coasts of Spain: new records and new species.

    PubMed

    Marquina, Daniel; Osca, David; Rodríguez, Jorge; Fernández-Despiau, Estrella; Noreña, Carolina

    2014-03-20

    Along the Mediterranean coast of the Iberian Peninsula, great species diversity is thought to exist, but our knowledge of Iberian polyclads is, in fact, very limited. This study contributes to the Polycladida (Platyhelminthes) of the Iberian Peninsula, in particular those of the Mediterranean coast. Nine species, mainly new species or new records, are described. Imogine stellae sp. nov. from Mar Menor (Murcia, Spain) is described, while I. mediterranea Galleni, 1976 is recorded for the first time in Spain. The genus Planocera Blainville, 1828 within the Mediterranean basin is reviewed: Planocera graffi Lang, 1879 is redescribed, and its synonymisation with Planocera pellucida (Mertens, 1833) considered. Also, the genus Notoplanella Bock, 1931 is represented by two species in Spain, N. inarmata Bock, 1931 type species, from Formentera Island and N. estelae sp. nov., from Mar Menor. Trigonoporus cephalophtalmus Lang, 1884 is rediscovered after the description of Lang (1884). Stylochus neapolitanus (Delle Chiaje, 1841-1844) Lang, 1884 is recorded and S. pilidium (Goette, 1881) is also redescribed, and Leptoplana mediterranea (Bock, 1913) is newly recorded for the Iberian Peninsula.

  3. Suppression of the tapeworm order Pseudophyllidea (Platyhelminthes: Eucestoda) and the proposal of two new orders, Bothriocephalidea and Diphyllobothriidea.

    PubMed

    Kuchta, R; Scholz, T; Brabec, J; Bray, R A

    2008-01-01

    Pseudophyllidea van Beneden in Carus, 1863, a well recognised order of tapeworms (Platyhelminthes: Eucestoda), is suppressed because it is composed of two phylogenetically unrelated groups, for which the new names Bothriocephalidea and Diphyllobothriidea are proposed. The new orders differ from each other in the following characters: (i) position of the genital pore: on the dorsal, dorso-lateral or lateral aspects and posterior to the ventral uterine pore in the Bothriocephalidea versus on the ventral aspect of segments and anterior to the uterine pore in the Diphyllobothriidea; (ii) the presence of a muscular external seminal vesicle in the Diphyllobothriidea, which is absent in the Bothriocephalidea; (iii) the presence of a uterine sac in the Bothriocephalidea, which is absent in the Diphyllobothriidea; and (iv) the spectrum of definitive hosts: mainly teleost fishes, never homoiothermic vertebrates in the Bothriocephalidea, versus tetrapods, most frequently mammals, in the Diphyllobothriidea, with species of Diphyllobothrium, Spirometra and Diplogonoporus parasitic in humans. The Diphyllobothriidea, which includes 17 genera in four families (Digramma is synonymised with Ligula), is associated with cestode groups that have a range of plesiomorphic characters (Haplobothriidea and Caryophyllidea), whereas the Bothriocephalidea, consisting of 41 genera grouped in four families, is the sister-group to the 'acetabulate' or 'tetrafossate' cestodes, which are generally regarded as having derived characters.

  4. Evolutionary history of the Tricladida and the Platyhelminthes: an up-to-date phylogenetic and systematic account.

    PubMed

    Riutort, Marta; Álvarez-Presas, Marta; Lázaro, Eva; Solà, Eduard; Paps, Jordi

    2012-01-01

    Within the free-living platyhelminths, the triclads, or planarians, are the best-known group, largely as a result of long-standing and intensive research on regeneration, pattern formation and Hox gene expression. However, the group's evolutionary history has been long debated, with controversies ranging from their phyletic structure and position within the Metazoa to the relationships among species within the Tricladida. Over the the last decade, with the advent of molecular phylogenies, some of these issues have begun to be resolved. Here, we present an up-to-date summary of the main phylogenetic changes and novelties with some comments on their evolutionary implications. The phylum has been split into two groups, and the position of the main group (the Rhabdithophora and the Catenulida), close to the Annelida and the Mollusca within the Lophotrochozoa, is now clear. Their internal relationships, although not totally resolved, have been clarified. Tricladida systematics has also experienced a revolution since the implementation of molecular data. The terrestrial planarians have been demonstrated to have emerged from one of the freshwater families, giving a different view of their evolution and greatly altering their classification. The use of molecular data is also facilitating the identification of Tricladida species by DNA barcoding, allowing better knowledge of their distribution and genetic diversity. Finally, molecular phylogenetic and phylogeographical analyses, taking advantage of recent data, are beginning to give a clear picture of the recent history of the Dugesia and Schmidtea species in the Mediterranean.

  5. Evolution of ITS1 rDNA in the Digenea (Platyhelminthes: trematoda): 3' end sequence conservation and its phylogenetic utility.

    PubMed

    vd Schulenburg, J H; Englisch, U; Wägele, J W

    1999-01-01

    A comparison of ribosomal internal transcribed spacer 1 (ITS1) elements of digenetic trematodes (Platyhelminthes) including unidentified digeneans isolated from Cyathura carinata (Crustacea: Isopoda) revealed DNA sequence similarities at more than half of the spacer at its 3' end. Primary sequence similarity was shown to be associated with secondary structure conservation, which suggested that similarity is due to identity by descent and not chance. Using an analysis of apomorphies, the sequence data were shown to produce a distinct phylogenetic signal. This was confirmed by the consistency of results of different tree reconstruction methods such as distance approaches, maximum parsimony, and maximum likelihood. Morphological evidence additionally supported the phylogenetic tree based on ITS1 data and the inferred phylogenetic position of the unidentified digeneans of C. carinata met the expectations from known trematode life-cycle patterns. Although ribosomal ITS1 elements are generally believed to be too variable for phylogenetic analysis above the species or genus level, the overall consistency of the results of this study strongly suggests that this is not the case in digenetic trematodes. Here, 3' end ITS1 sequence data seem to provide a valuable tool for elucidating phylogenetic relationships of a broad range of phylogenetically distinct taxa.

  6. Complete Sequence of the mitochondrial genome of the tapeworm Hymenolepis diminuta: Gene arrangements indicate that platyhelminths are eutrochozoans

    SciTech Connect

    von Nickisch-Rosenegk, Markus; Brown, Wesley M.; Boore, Jeffrey L.

    2001-01-01

    Using ''long-PCR'' we have amplified in overlapping fragments the complete mitochondrial genome of the tapeworm Hymenolepis diminuta (Platyhelminthes: Cestoda) and determined its 13,900 nucleotide sequence. The gene content is the same as that typically found for animal mitochondrial DNA (mtDNA) except that atp8 appears to be lacking, a condition found previously for several other animals. Despite the small size of this mtDNA, there are two large non-coding regions, one of which contains 13 repeats of a 31 nucleotide sequence and a potential stem-loop structure of 25 base pairs with an 11-member loop. Large potential secondary structures are identified also for the non-coding regions of two other cestode mtDNAs. Comparison of the mitochondrial gene arrangement of H. diminuta with those previously published supports a phylogenetic position of flatworms as members of the Eutrochozoa, rather than being basal to either a clade of protostomes or a clade of coelomates.

  7. [New occurrences of metacercariae of Austrodiplostomum compactum (Lutz, 1928) (Platyhelminthes: Digenea) eye flukes of fish from the Paraná Basin].

    PubMed

    Yamada, Fábio Hideki; Moreira, Luis Henrique De A; Ceschini, Tiago L; Takemoto, Ricardo Massato; Pavanelli, Gilberto Cezar

    2008-01-01

    Austrodiplostomum compactum (Platyhelminthes, Digenea) eye flukes of several species of fishes. The presence of this parasite, in extreme cases, can cause swelling of the eyelids, displacement of the retina, opacity of the crystalline lens and blindness or even death. The present study it registers new occurrences of this metacercariae infecting the eyes of four new hosts of fish, Serrasalmus maculatus collected in the Rosana reservoir in the Paranapanema river and Hypostomus regani, Schizodon borellii and Auchenipterus osteomystax collected in the the Upper Paraná River floodplain.

  8. News Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

    NASA Astrophysics Data System (ADS)

    2011-01-01

    Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

  9. Diversity, specificity and speciation in larval Diplostomidae (Platyhelminthes: Digenea) in the eyes of freshwater fish, as revealed by DNA barcodes.

    PubMed

    Locke, Sean A; Al-Nasiri, Fatima S; Caffara, Monica; Drago, Fabiana; Kalbe, Martin; Lapierre, Angela Rose; McLaughlin, J Daniel; Nie, Pin; Overstreet, Robin M; Souza, Geza T R; Takemoto, Ricardo M; Marcogliese, David J

    2015-11-01

    Larvae (metacercariae) in some species of Diplostomidae (Platyhelminthes: Digenea) inhabit fish eyes and are difficult to identify to species based on morphology. DNA barcoding has clarified the diversity and life cycles of diplostomids in North America, Europe and Africa, but has seldom been used in parasites sampled in large numbers or at large spatial scales. Here, distance-based analysis of cytochrome c oxidase 1 barcodes and, in some specimens, internal transcribed spacer (ITS-1, 5.8S, ITS-2) sequences was performed for over 2000 diplostomids from Africa, the Middle East, Europe, Asia and the Americas. Fifty-two species of Diplostomum, Tylodelphys and Austrodiplostomum (Digenea: Diplostomidae) were distinguished. The 52 species comprise 12 identified species, six species in two species complexes and 34 putative species, and 33/52 had been delineated in previous studies. Most (23/40) of the unidentified, putative species distinguished by cytochrome c oxidase 1 distances were supported by at least one additional line of evidence. As the intensity of sampling of the 52 species increased, variation in cytochrome c oxidase 1 decreased between and increased within species, while the spatial scale at which species were sampled had no effect. Nonetheless, variation between species always exceeded variation within species. New life-cycle linkages, geographic and host records, and genetic data were recorded in several species, including Tylodelphys jenynsiae, Tylodelphys immer and Diplostomum ardeae. Species of Diplostomum inhabiting the lens are less host-specific and less numerous than those infecting other tissues, suggesting that reduced immune activity in the lens has influenced rates of speciation.

  10. Molecular characterization of Gastrothylax crumenifer (Platyhelminthes: Gastrothylacidae) from goats in the western part of India by LSU of nuclear ribosomal DNA.

    PubMed

    Kumar, Ashwani; Chaudhary, Anshu; Verma, Chandni; Singh, Hridaya Shanker

    2014-12-01

    The rumen parasite, Gastrothylax crumenifer (Platyhelminthes: Gastrothylacidae), is a highly pathogenic trematode parasite of goat (Capra hircus). It sucks blood that causes acute disease like anemia, and severe economic losses occur due to morbidity and mortality of the ruminant infected by these worms. The study of these rumen paramphistomes, their infection, and public health importance remains unclear in India especially in the western part of state Uttar Pradesh (U.P.), Meerut, India, where the goat meat consumption is very high. This paper provides the molecular characterization of G. crumenifer recovered from the rumen of Capra hircus from Meerut, U.P., India by the partial sequence of 28S rDNA. Nucleotide sequence similarity searching on BLAST of 28S rDNA from parasites showed the highest identity with those of G. crumenifer from the same host Capra hircus. This is the first report of molecular identification of G. crumenifer from this part of India.

  11. Molecular Characterization of Gastrothylax crumenifer (Platyhelminthes: Gastrothylacidae) from Goats in the Western Part of India by LSU of Nuclear Ribosomal DNA

    PubMed Central

    Kumar, Ashwani; Verma, Chandni; Singh, Hridaya Shanker

    2014-01-01

    The rumen parasite, Gastrothylax crumenifer (Platyhelminthes: Gastrothylacidae), is a highly pathogenic trematode parasite of goat (Capra hircus). It sucks blood that causes acute disease like anemia, and severe economic losses occur due to morbidity and mortality of the ruminant infected by these worms. The study of these rumen paramphistomes, their infection, and public health importance remains unclear in India especially in the western part of state Uttar Pradesh (U.P.), Meerut, India, where the goat meat consumption is very high. This paper provides the molecular characterization of G. crumenifer recovered from the rumen of Capra hircus from Meerut, U.P., India by the partial sequence of 28S rDNA. Nucleotide sequence similarity searching on BLAST of 28S rDNA from parasites showed the highest identity with those of G. crumenifer from the same host Capra hircus. This is the first report of molecular identification of G. crumenifer from this part of India. PMID:25548426

  12. Transfection of Platyhelminthes

    PubMed Central

    Moguel, Bárbara; Bobes, Raúl J.; Carrero, Julio C.; Laclette, Juan P.

    2015-01-01

    Flatworms are one of the most diverse groups within Lophotrochozoa with more than 20,000 known species, distributed worldwide in different ecosystems, from the free-living organisms in the seas and lakes to highly specialized parasites living in a variety of hosts, including humans. Several infections caused by flatworms are considered major neglected diseases affecting countries in the Americas, Asia, and Africa. For several decades, a particular interest on free-living flatworms was due to their ability to regenerate considerable portions of the body, implying the presence of germ cells that could be important for medicine. The relevance of reverse genetics for this group is clear; understanding the phenotypic characteristics of specific genes will shed light on developmental traits of free-living and parasite worms. The genetic manipulation of flatworms will allow learning more about the mechanisms for tissue regeneration, designing new and more effective anthelmintic drugs, and explaining the host-parasite molecular crosstalk so far partially inaccessible for experimentation. In this review, availability of transfection techniques is analyzed across flatworms, from the initial transient achievements to the stable manipulations now developed for free-living and parasite species. PMID:26090388

  13. Transfection of Platyhelminthes.

    PubMed

    Moguel, Bárbara; Bobes, Raúl J; Carrero, Julio C; Laclette, Juan P

    2015-01-01

    Flatworms are one of the most diverse groups within Lophotrochozoa with more than 20,000 known species, distributed worldwide in different ecosystems, from the free-living organisms in the seas and lakes to highly specialized parasites living in a variety of hosts, including humans. Several infections caused by flatworms are considered major neglected diseases affecting countries in the Americas, Asia, and Africa. For several decades, a particular interest on free-living flatworms was due to their ability to regenerate considerable portions of the body, implying the presence of germ cells that could be important for medicine. The relevance of reverse genetics for this group is clear; understanding the phenotypic characteristics of specific genes will shed light on developmental traits of free-living and parasite worms. The genetic manipulation of flatworms will allow learning more about the mechanisms for tissue regeneration, designing new and more effective anthelmintic drugs, and explaining the host-parasite molecular crosstalk so far partially inaccessible for experimentation. In this review, availability of transfection techniques is analyzed across flatworms, from the initial transient achievements to the stable manipulations now developed for free-living and parasite species.

  14. Heterogeneity of ouabain binding sites in Schistosoma mansoni. First evidence for the presence of two (Na+ + K+)-ATPase isoforms in platyhelminths.

    PubMed

    Pardon, R S; Noël, F

    1994-01-20

    Binding experiments with [3H]ouabain were performed to investigate the presence of (Na+ + K+)-ATPase (EC3.6.1.3) isoforms in adult male Schistosoma mansoni, the trematode responsible for human schistosomiasis. Non-linear regression analysis of equilibrium experiments performed with homogenates in a Mg-Pi medium indicated the presence of about 10% (Bmax = 223 +/- 67 fmol/mg protein) high-affinity sites (KD = 0.285 +/- 0.045 microM) and 90% (Bmax = 2117 +/- 348 fmol/mg protein) sites with a 20-fold lower affinity (KD = 4.9 +/- 1.28 microM). This was confirmed by their-exponential decay of [3H]ouabain dissociation. Furthermore, determination of association and dissociation rate constants indicated that the two classes of binding sites differed by their dissociation rate constants for ouabain (k-1 = 0.0185 +/- 0.0019 min-1 and 0.0997 +/- 0.0528 min-1 for high- and low-affinity sites, respectively). Surprisingly, the association rate constant measured for ouabain binding to S. mansoni homogenate (0.038 microM-1.min-1) was lower (25- to 80-fold) than the one usually observed for mammalian enzymes. This is the first direct evidence for the existence of (Na+ + K+)-ATPase isoforms in platyhelminths, invertebrates of great importance from the phylogenetic point of view.

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

    PubMed

    Brabec, Jan; Scholz, Tomáš; Králová-Hromadová, Ivica; Bazsalovicsová, Eva; Olson, Peter D

    2012-01-01

    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. Moreover, we detected multiple trnK+nad3+trnS+trnW+cox1 haplotypes within individuals, indicating a history of gene exchange between the mitochondrial and nuclear genomes. The presence of such nuclear paralogs (i.e. numts), to our knowledge described here in cestodes for the first time, together with the results of phylogenetic, saturation and split-decomposition analyses all suggest that finding informative markers for estimating caryophyllidean evolution is unusually problematic in comparison to other major lineages of tapeworms.

  16. Immunogold-labeled S-phase neoblasts, total neoblast number, their distribution, and evidence for arrested neoblasts in Macrostomum lignano (Platyhelminthes, Rhabditophora).

    PubMed

    Bode, A; Salvenmoser, W; Nimeth, K; Mahlknecht, M; Adamski, Z; Rieger, R M; Peter, R; Ladurner, P

    2006-09-01

    Neoblasts in Platyhelminthes are the only cells to proliferate and differentiate into all cell types. In Macrostomum lignano, the incorporation of 5'-bromo-2'-deoxyuridine (BrdU) in neoblasts confirmed the distribution of S-phase cells in two lateral bands. BrdU labeling for light and for transmission electron microscopy (TEM) identified three populations of proliferating cells: somatic neoblasts located between the epidermis and gastrodermis (mesodermal neoblasts), neoblasts located within the gastrodermis (gastrodermal neoblasts), and gonadal S-phase cells. In adults, three stages of mesodermal neoblasts (2, 2-3, and 3) defined by their ultrastructure were found. Stage 1 neoblasts where only seen in hatchlings. These stages either were phases within the S-phase of one neoblast pool or were subsequent stages of differentiating neoblasts, each with its own cell cycle. Regular TEM and immunogold labeling provided the basis for calculating the total number of neoblasts and the ratio of labeled to non-labeled neoblasts. Somatic neoblasts represented 6.5% of the total number of cells. Of these, 27% were labeled in S-phase. Of this fraction, 33% were in stage 2, 46% in stage 2-3, and 21% in stage 3. Immunogold labeling substantiated results concerning the differentiation of neoblasts into somatic cells. Non-labeled stage 2 neoblasts were present, even after a 2-week BrdU exposure. Double labeling of mitoses and FMRF-amide revealed a close spatial relationship of mesodermal neoblasts with the nervous system. Immunogold-labeled sections showed that nearly 70% of S-phase cells were in direct contact or within 5 microm from nerve cords.

  17. A common origin of complex life cycles in parasitic flatworms: evidence from the complete mitochondrial genome of Microcotyle sebastis (Monogenea: Platyhelminthes)

    PubMed Central

    Park, Joong-Ki; Kim, Kyu-Heon; Kang, Seokha; Kim, Won; Eom, Keeseon S; Littlewood, DTJ

    2007-01-01

    Background The parasitic Platyhelminthes (Neodermata) contains three parasitic groups of flatworms, each having a unique morphology, and life style: Monogenea (primarily ectoparasitic), Trematoda (endoparasitic flukes), and Cestoda (endoparasitic tapeworms). The evolutionary origin of complex life cyles (multiple obligate hosts, as found in Trematoda and Cestoda) and of endo-/ecto-parasitism in these groups is still under debate and these questions can be resolved, only if the phylogenetic position of the Monogenea within the Neodermata clade is correctly estimated. Results To test the interrelationships of the major parasitic flatworm groups, we estimated the phylogeny of the Neodermata using complete available mitochondrial genome sequences and a newly characterized sequence of a polyopisthocotylean monogenean Microcotyle sebastis. Comparisons of inferred amino acid sequences and gene arrangement patterns with other published flatworm mtDNAs indicate Monogenea are sister group to a clade of Trematoda+Cestoda. Conclusion Results confirm that vertebrates were the first host for stem group neodermatans and that the addition of a second, invertebrate, host was a single event occurring in the Trematoda+Cestoda lineage. In other words, the move from direct life cycles with one host to complex life cycles with multiple hosts was a single evolutionary event. In association with the evolution of life cycle patterns, our result supports the hypothesis that the most recent common ancestor of the Neodermata giving rise to the Monogenea adopted vertebrate ectoparasitism as its initial life cycle pattern and that the intermediate hosts of the Trematoda (molluscs) and Cestoda (crustaceans) were subsequently added into the endoparasitic life cycles of the Trematoda+Cestoda clade after the common ancestor of these branched off from the monogenean lineage. Complex life cycles, involving one or more intermediate hosts, arose through the addition of intermediate hosts and not the

  18. Gyrodactylus salinae n. sp. (Platyhelminthes: Monogenea) infecting the south European toothcarp Aphanius fasciatus (Valenciennes) (Teleostei, Cyprinodontidae) from a hypersaline environment in Italy

    PubMed Central

    2011-01-01

    Background Historically, non-native species of Gambusia (Poeciliidae) have been used to control larval stages of the Asian tiger mosquito, Stegomyia albopicta Reinert, Harbach et Kitching, 2004 throughout Italy. The potential utility of indigenous populations of Aphanius fasciatus (Valenciennes) (Teleostei: Cyprinodontidae) as an appropriate alternative biological control is currently being explored. A sub-sample of ten fish collected from Cervia Saline, Italy (salinity 65 ppt; 30°C) to assess their reproductive capability in captivity, harboured a moderate infection of Gyrodactylus von Nordmann, 1832 (Platyhelminthes, Monogenea). A subsequent morphological and molecular study identified this as being a new species. Results Gyrodactylus salinae n. sp. is described from the skin, fins and gills of A. fasciatus. Light and scanning electron microscopical (SEM) examination of the opisthaptoral armature and their comparison with all other recorded species suggested morphological similarities to Gyrodactylus rugiensoides Huyse et Volckaert, 2002 from Pomatoschistus minutus (Pallas). Features of the ventral bar, however, permit its discrimination from G. rugiensoides. Sequencing of the nuclear ribosomal DNA internal transcribed spacers 1 and 2 and the 5.8S rRNA gene and a comparison with all species listed in GenBank confirmed they are unique and represent a new species (most similar to Gyrodactylus anguillae Ergens, 1960, 8.3% pair-wise distance based on 5.8S+ITS2). This represents the first species of Gyrodactylus to be described from Aphanius and, to date, has the longest ITS1 (774 bp) sequenced from any Gyrodactylus. Additional sampling of Cervia Saline throughout the year, found G. salinae n. sp. to persist in conditions ranging from 35 ppt and 5°C in December to 65 ppt and 30°C in July, while in captivity a low level of infection was present, even in freshwater conditions (0 ppt). Conclusions The ability of G. salinae n. sp. to tolerate a wide range of salinities

  19. Evolutionary processes involved in the diversification of chelonian and mammal polystomatid parasites (Platyhelminthes, Monogenea, Polystomatidae) revealed by palaeoecology of their hosts.

    PubMed

    Héritier, Laurent; Badets, Mathieu; Du Preez, Louis H; Aisien, Martins S O; Lixian, Fan; Combes, Claude; Verneau, Olivier

    2015-11-01

    Polystomatid flatworms (Platyhelminthes) are monogenean parasites that infect exclusively aquatic or semi-aquatic sarcopterygians such as the Australian lungfish, amphibians, freshwater turtles and the African common hippopotamus. Previous studies on the phylogenetic relationships of these parasites, excluding Oculotrema hippopotami infecting common hippos, showed a global coevolution between hosts and their parasites at a macroevolutionary scale. These studies also demonstrated a strong correlation between the diversification of early neobatrachian polystomes and Gondwana breakup in the Mesozoic period. However the origin of chelonian polystomes is still in question as a switch from presumably primitive aquatic amniotes to turtles at the time of their first appearance, or soon after during their radiation, was assumed. In order to resolve this sticking point, we extended the phylogeny of polystomes with broader parasite sampling, i.e. 55 polystome species including Nanopolystoma tinsleyi a polystome infecting caecilians and O. hippopotami, and larger set of sequence data covering two nuclear and two mitochondrial genes coding for the ribosomal RNA 18S and 28S, the Cytochrome c Oxidase I and the ribosomal RNA 12S, respectively. The secondary structure of nuclear rRNAs genes (stems and loops) was taken into account for sequence alignments and Bayesian analyses were performed based on the appropriate models of evolution selected independently for the four designed partitions. Molecular calibrations were also conducted for dating the main speciation events in the polystome tree. The phylogenetic position of chelonian parasites that are phylogenetically closer to N. tinsleyi than all other amphibian polystomes and molecular time estimates suggest that these parasites originated following a switch from caecilians, at a geological period when primitive turtles may already have adapted to an aquatic life style, i.e. at about 178Million years ago, or a little later when

  20. Release of O2- and LTC4 by murine eosinophils: role of intra- and extracellular calcium.

    PubMed Central

    de Andres, B; del Pozo, V; Martin, E; Palomino, P; Lahoz, C

    1990-01-01

    Using an experimental model of mouse peritoneal eosinophilia, we investigated the role of Ca2+ in the in vitro activation of these cells challenged with specific Mesocestoides corti antigen. We have detected LTC4, a metabolite derived from arachidonic acid by way of 5'lipo-oxygenase and superoxide anion from the oxidative burst, as inflammatory mediators produced by activated eosinophils. Preincubation with hyperimmune mice serum increases the amount of LTC4 and superoxide anion in response to the antigenic extract. Release of O2- is inhibited by Verapamil (a voltage-gated calcium channel) and Quin 2 (an intracellular trapped chelator of calcium). Also, LTC4 produced by preincubated eosinophils challenged with M. corti is dramatically inhibited by Quin 2. Our results suggest an intact mechanism for calcium control for the release of these inflammatory mediators by eosinophils, after specific antigenic stimulation. PMID:1689695

  1. Comparative spermatology of selected polyclad flatworms (platyhelminthes).

    PubMed

    Liana, Marcin K; Litvaitis, Marian K

    2007-10-01

    Sperm ultrastructure of four acotylean (Idioplana atlantica, Armatoplana leptalea, Styloplanocera fasciata, Melloplana ferruginea) and three cotylean polyclads (Pseudoceros bicolor, Phrikoceros mopsus, Enchiridium evelinae) was investigated. All spermatozoa are biflagellate, exhibiting a 9+"1" axoneme pattern. All acotylean axonemes originate and extend within the sperm shaft, and once exiting the shaft, remain attached to it. The flagella of all cotylean spermatozoa exit the shaft immediately and remain free. Structures shared by all species include: an elongated nucleus, in acotyleans located only in the posterior part of the shaft, whereas in cotyleans it extends along the entire sperm body; mitochondria along with small and large dense bodies arranged in a specific pattern; and a ring of microtubules that extends along the entire sperm shaft just beneath the cell membrane. A unique spermatozoon has been found in E. evelinae, where round vesicle-like structures fill the anterior part of the nucleus, and a different type of large dense bodies is present. The spermatozoa of all studied species exhibit numerous characters (axoneme/flagella position, distribution and position of large and small dense bodies, of mitochondria, presence of nuclear vesicles) that may be of phylogenetic value at the family and higher taxonomic levels.

  2. Origin of the epidermis in parasitic platyhelminths.

    PubMed

    Tyler, S; Tyler, M S

    1997-06-01

    The epidermis of members of the major parasitic taxon Neodermata is distinctive among flatworms, being a syncytial, insunk, non-ciliated epidermis that develops through a wholesale replacement of larval epidermis at metamorphosis when the larva attacks a host. How it arose in evolution from what must have been a turbellarian-like ancestor is not immediately evident. While many turbellarian flatworms have also adopted a symbiotic way of life, the literature on ultrastructure of epidermis in these symbionts shows quite a variety of morphologies, many not so different from that of their free-living relatives. Various turbellarians do have syncytial or insunk epidermises or reduction of epidermal ciliation as is characteristic of the Neodermata, but co-occurrence in a single turbellarian of all features common to neodermatans has not been reported. Urastoma cyprinae, for example, which is ectosymbiotic on bivalves, has a ciliated cellular epidermis that is little different from what is known of epidermises of its free-living relatives. The endoparasitic Anoplodium hymanae, from the coelom of sea cucumbers, also bears a ciliated cellular epidermis, as is typical of many other rhabdocoels, but it shows marked phagocytic activity as well as incorporation of endosymbiotic bacteria. The closest similarity to neodermatan epidermis is that of the turbellarian Genostoma kozloffi, an ectosymbiont of the crustacean Nebalia: covering the bulk of the body is a non-ciliated syncytium with multiple branching connections to insunk nucleated portions, much as in epidermis of adult neodermatans and, on its ventral surface, is a field of ciliated cellular insunk epidermis resembling the epidermis of some larval neodermatans. Developmental clues to the origin of the neodermatan epidermis can be seen in turbellarian embryos. Before hatching, embryos of proseriate and triclad embryos go through 3 generations of epidermis, each replacing the next; 2 generations of epidermis are reported in the literature on rhabdocoel embryos. This process of replacement parallels the epidermal replacement that larval neodermatans undergo at metamorphosis. Ultrastructural study of developing acoel, polyclad and macrostomid embryos shows that they, too, have epidermal replacement and growth through immigration of deeper-lying cells, comparable to the processes seen in higher flatworms. Succession of distinct generations of epidermis in such animals as the proseriates, triclads and rhabdocoels is probably an adaptation to development of ectolecithal eggs, providing the means for the embryo to use yolk that resides in vitellocytes, outside its blastomeres. We propose that the Neodermata has taken advantage of this developmental mechanism, producing successive generations of epidermal cells even in its larval stages, to counter the defenses of hosts.

  3. STAT6−/− mice exhibit decreased cells with alternatively activated macrophage phenotypes and enhanced disease severity in murine neurocysticercosis

    PubMed Central

    Mishra, Bibhuti B.; Gundra, Uma Mahesh; Teale, Judy M.

    2010-01-01

    In this study, using a murine model for neurocysticercosis, macrophage phenotypes and their functions were examined. Mesocestoides corti infection in the central nervous system (CNS) induced expression of markers associated with alternatively activated macrophages (AAMs) and a scarcity of iNOS, a classically activated macrophage marker. The infection in STAT6−/− mice resulted in significantly reduced accumulation of AAMs as well as enhanced susceptibility to infection coinciding with increased parasite burden and greater neuropathology. These results demonstrate that macrophages in the helminth infected CNS are largely of AAM phenotypes, particularly as the infection progresses, and that STAT6 dependent responses, possibly involving AAMs, are essential for controlling neurocysticercosis. PMID:21051093

  4. Helminth species diversity and biology in the bobcat, Lynx rufus (Schreber), from Nebraska.

    PubMed

    Tiekotter, K L

    1985-04-01

    Cestodes of 4 species and nematodes of 9 species were collected from 75 bobcats, Lynx rufus (Schreber), in Nebraska from 1977 to 1979. Of these 75, 11 were trapped from 6 border counties in 3 border states: South Dakota, 7 carcasses/3 counties; Kansas, 3/2; and Wyoming, 1/1. Helminths recovered included: Mesocestoides corti Hoeppli, 1925 (15% prevalence), Taenia rileyi Loewen, 1929 (67%), Taenia pisiformis (Bloch, 1780) Gmelin, 1790 (27%), Taenia macrocystis (Diesing, 1850) Lühe, 1910 (19%), Physaloptera praeputialis von Linstow, 1889 (55%), Physaloptera rara Hall and Wigdor, 1918 (32%), Toxascaris leonina (von Linstow, 1902) Leiper, 1907 (31%), Toxocara cati (Schrank, 1780) (39%), Ancylostoma tubaeforme (Zeder, 1800) von Linstow, 1885 (5%), Pterygodermatites (Multipectines) cahirensis (Jägerskiöld, 1909) Quentin, 1969 (1%), Vogeloides felis (Vogel, 1928) Davtian, 1933 (7%), Cylicospirura felineus (Chandler, 1925) Sandground, 1932 (12%), and Capillaria aerophila (Creplin, 1839) (4%). One bobcat was not infected; 74 had 1 to 7 species (means = 3). Simpson's index for helminth species was moderately low (0.12), indicating a relatively diverse helminth fauna. Mean levels of infection between prominent species pairs and within each species were compared with bobcat sex and age differences using Student's t-test. Mean intensity of Physaloptera praeputialis was significantly (P less than 0.01) greater than that of Toxocara cati; mean intensity of Mesocestoides corti was significantly (P less than 0.01) greater than that of all other prominent species. No significant intensity differences were indicated among bobcat sex and age categories. G-tests computed for prevalence of prominent species with bobcat age indicated no significance.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Organ of Corti and Stria Vascularis: Is there an Interdependence for Survival?

    PubMed Central

    Liu, Huizhan; Li, Yi; Chen, Lei; Zhang, Qian; Pan, Ning; Nichols, David H.; Zhang, Weiping J.; Fritzsch, Bernd

    2016-01-01

    Cochlear hair cells and the stria vascularis are critical for normal hearing. Hair cells transduce mechanical stimuli into electrical signals, whereas the stria is responsible for generating the endocochlear potential (EP), which is the driving force for hair cell mechanotransduction. We questioned whether hair cells and the stria interdepend for survival by using two mouse models. Atoh1 conditional knockout mice, which lose all hair cells within four weeks after birth, were used to determine whether the absence of hair cells would affect function and survival of stria. We showed that stria morphology and EP remained normal for long time despite a complete loss of all hair cells. We then used a mouse model that has an abnormal stria morphology and function due to mutation of the Mitf gene to determine whether hair cells are able to survive and transduce sound signals without a normal electrochemical environment in the endolymph. A strial defect, reflected by missing intermediate cells in the stria and by reduction of EP, led to systematic outer hair cell death from the base to the apex after postnatal day 18. However, an 18-mV EP was sufficient for outer hair cell survival. Surprisingly, inner hair cell survival was less vulnerable to reduction of the EP. Our studies show that normal function of the stria is essential for adult outer hair cell survival, while the survival and normal function of the stria vascularis do not depend on functional hair cells. PMID:28030585

  6. Evolution and Functional Morphology of the Proboscis in Kalyptorhynchia (Platyhelminthes)

    PubMed Central

    Smith, Julian P. S.; Litvaitis, Marian K.; Gobert, Stefan; Uyeno, Theodore; Artois, Tom

    2015-01-01

    Predatory flatworms belonging to the taxon Kalyptorhynchia are characterized by an anterior muscular proboscis that they use to seize prey. In many cases, the proboscis is armed with hooks, derived either from the extracellular matrix that surrounds the muscles or from intracellular deposits in the epithelium covering the proboscis. Glands associated with the proboscis reportedly are venomous; however, there are few direct tests of this hypothesis. This article reviews the structure and current knowledge of the function of the proboscis in the Kalyptorhynchia, points to areas in which the current understanding of phylogenetic relationships within this taxon is incongruent with our hypothesis of how the proboscis evolved, and addresses areas in need of further research, especially as regards functional morphology and biomechanics. PMID:26002347

  7. Checklist of tapeworms (Platyhelminthes, Cestoda) of vertebrates in Finland

    PubMed Central

    Haukisalmi, Voitto

    2015-01-01

    Abstract A checklist of tapeworms (Cestoda) of vertebrates (fishes, birds and mammals) in Finland is presented, based on published observations, specimens deposited in the collections of the Finnish Museum of Natural History (Helsinki) and the Zoological Museum of the University of Turku, and additional specimens identified by the present author. The checklist includes 170 tapeworm species from 151 host species, comprising 447 parasite species/host species combinations. Thirty of the tapeworm species and 96 of the parasite/host species combinations have not been previously reported from Finland. The total number of tapeworm species in Finland (170 spp.) is significantly lower than the corresponding figure for the Iberian Peninsula (257 spp.), Slovakia (225 spp.) and Poland (279 spp.). The difference between Finland and the other three regions is particularly pronounced for anseriform, podicipediform, charadriiform and passeriform birds, reflecting inadequate and/or biased sampling of these birds in Finland. It is predicted that there are actually ca. 270 species of tapeworms in Finland, assuming that true number of bird tapeworms in Finland corresponds to that in other European countries with more comprehensive knowledge of the local tapeworm fauna. The other main pattern emerging from the present data is the seemingly unexplained absence in (northern) Fennoscandia of several mammalian tapeworms that otherwise have extensive distributions in the Holarctic region or in Eurasia, including the northern regions. Previously unknown type specimens, that is, the holotype of Bothrimonus nylandicus Schneider, 1902 (a junior synonym of Diplocotyle olrikii Krabbe, 1874) (MZH 127096) and the syntypes of Caryophyllaeides fennica (Schneider, 1902) (MZH 127097) were located in the collections of the Finnish Museum of Natural History. PMID:26668540

  8. Killing of Gyrodactylus salaris (Platyhelminthes, Monogenea) mediated by host complement.

    PubMed

    Harris, P D; Soleng, A; Bakke, T A

    1998-08-01

    Gyrodactylus salaris, an important pathogen of Atlantic salmon Salmo salar, has been shown to be highly sensitive to factors in host serum and mucus, being killed rapidly (50% within 1 h) by serum at a dilution of 1:200. The time needed for killing was inversely proportional to serum concentration. Similar effects were noted using host mucus, which contained approximately 1/20th of the anti-Gyrodactylus activity of serum. Serum activity was abolished completely by heating at 45 degrees C for 30 min, and by addition of EDTA, but not by EGTA + 1 mM magnesium ions. Activity was not dependent on whether the serum was from infected or naive fishes, nor was it species specific. Attempts to pre-coat parasites in salmon anti-Gyrodactylus antibodies also failed to enhance the activity of fresh serum. These observations suggest that killing is due to the complement system of the host, acting via the alternate pathway. G. salaris appears to be exceptionally sensitive to complement, being killed at concentrations which could be experienced in vivo. The role of complement in the protection of fishes against gyrodactylid infection therefore deserves further investigation.

  9. Muscular pattern in three species of Macrostomum (platyhelminthes, macrostomorpha).

    PubMed

    Adami, Mariana L; Brusa, Francisco; Ronderos, Jorge R; Damborenea, Cristina

    2017-02-01

    Previous studies demonstrated complex architecture of the muscular system of Macrostomum species, especially in the rostrum area and the pharynx. However, little is known about the differences in muscular pattern between species of the genus. This study examines and compares the muscular systems of specimens belonging to three freshwater Macrostomum species (M. quiritium, M. tuba and M. velastylum), labeled with phalloidin-rhodamine and studied by confocal microscopy. Our results agree with the previous descriptions, confirming that the muscular patterns for the body wall, rostrum area, pharynx and caudal region differ among species. The muscles of the body wall follow the typical architecture, but the number of fibers in the species analyzed varies between dorsal and ventral surfaces, ranging from 80 to 100 fibers, this record being higher than previous observations. The arrangement of the fibers in the rostrum is complex, especially in the brain area. Macrostomum tuba and M. quiritium have a set of two muscles crossing at brain level and forming an "X," which is not evident in M. velastylum. We identified five different sets of fibers associated to the pharynx and mouth at ventral, medium and deep levels. These different sets are present in all three species studied. The caudal plate in M. tuba has an additional layer of diagonal fibers in the body wall, which is not evident in the other two species. The muscles of the reproductive system are independent of the body wall musculature in the species analyzed, but connected to the intestinal wall by specific fibers that may serve as an anchor. J. Morphol. 278:264-282, 2017. © 2016 Wiley Periodicals,Inc.

  10. Evolution and Functional Morphology of the Proboscis in Kalyptorhynchia (Platyhelminthes).

    PubMed

    Smith, Julian P S; Litvaitis, Marian K; Gobert, Stefan; Uyeno, Theodore; Artois, Tom

    2015-08-01

    Predatory flatworms belonging to the taxon Kalyptorhynchia are characterized by an anterior muscular proboscis that they use to seize prey. In many cases, the proboscis is armed with hooks, derived either from the extracellular matrix that surrounds the muscles or from intracellular deposits in the epithelium covering the proboscis. Glands associated with the proboscis reportedly are venomous; however, there are few direct tests of this hypothesis. This article reviews the structure and current knowledge of the function of the proboscis in the Kalyptorhynchia, points to areas in which the current understanding of phylogenetic relationships within this taxon is incongruent with our hypothesis of how the proboscis evolved, and addresses areas in need of further research, especially as regards functional morphology and biomechanics.

  11. A checklist of the aspidogastrea (platyhelminthes: trematoda) of the world.

    PubMed

    Alves, Philippe V; Vieira, Fabiano M; Santos, Cláudia P; Scholz, Tomáš; Luque, José L

    2015-02-12

    A checklist of records of aspidogastrean trematodes (Aspidogastrea) is provided on the basis of a comprehensive survey of the literature since 1826, when the first aspidogastrean species was reported, until December 2014. We list 61 species representing 13 genera within 4 families and 2 orders of aspidogastreans associated with 298 species of invertebrate and vertebrate hosts. The majority of records include bivalves (44% of the total number of host-parasite associations), whereas records from bony fishes represent 32% of host-parasite associations. The aspidogastreans have worldwide distribution, with the highest number of records in the Neartic Region for freshwater hosts and the North Atlantic Ocean for marine ones. The checklist includes a parasite-host list with data on host habitat, site of infection and distribution area of parasites, and a host-parasite list. A limited number of molecular studies on aspidogastreans does not allow us to unravel phylogenetic relationships within the Aspidogastrea.

  12. Embryonic development of Girardia tigrina (Girard, 1850) (Platyhelminthes, Tricladida, Paludicola).

    PubMed

    Vara, D C; Leal-Zanchet, A M; Lizardo-Daudt, H m

    2008-11-01

    The embryonic development of freshwater triclads is mainly known from studies of species of Dendrocoelum, Planaria, Polycelis, and, more recently, Schmidtea. The present study characterizes the development of Girardia tigrina (Girard, 1850) by means of optical microcopy using glycol methacrylate semi-thin sections. 94 cocoons were collected in the period from laying to hatching, with intervals of up to twenty-four hours. The sequence of morphological changes occurring in the embryo permitted the identification of nine embryonic stages. At the time of cocoon laying, numerous embryos were dispersed among many yolk cells, with a rigid capsule covering the entire cocoon. In the first stage (approx. up to 6 hours after cocoon laying), yolk cells and embryonic cells showed random distribution. Stage II (between 12 and 24 hours after cocoon laying) is characterized by aggregates of blastomeres, which later aggregate forming an enteroblastula. Approximately 2 days after cocoon laying (stage III), formation of the embryonic epidermis and embryonic digestive system took place, the latter degenerating during the subsequent stage. Stage V (until the fourth day) is characterized by the formation of the definitive epidermis. Between 4 and 6 days after laying, organogenesis of the definitive inner organs starts (stage VI). Approximately 14 days after laying (stage IX), formation of the nervous system is completed. At this stage, the embryo shows similar characteristics to those of newly hatched juveniles. The hatching of Girardia tigrina occurs in the period between twelve to twenty-two days after cocoon laying.

  13. Marine macrostomorpha (platyhelminthes, rhabditophora) from the algarve (southern portugal).

    PubMed

    Schockaert, Ernest R

    2014-10-13

    Ten species of Macrostomorpha were found in marine environments of the Algarve (Portugal). Six of them were found in the Ria Formosa, a vast intertidal euryhaline lagoon system that dominates the most Eastern coast of the Algarve: two unidentified species of Microstomum Schmidt, 1848, Macrostomum cf. rubrocinctum Ax, 1951 and two unidentified species of Macrostomum Schmidt, 1848, Paromalostomum dubium (de Beauchamps, 1927), Paromalostomum minutum Rieger, 1971 and Cylindromacrostomum faroensis n.sp.. Comparison of this species with C. mediterraneum (Ax, 1955) and the species from Venice, considered to be C. mediterraneum by Rieger (1977), leads to the conclusion that the individuals studied by Rieger are in fact representatives of a separate species, C. riegeri n.sp.. Acanthomacrostomum spiculiferum Papi & Swedmark, 1959 was found in the Atlantic, 10-15 m deep, near the western coast of the Algarve. Haplopharynx papii n. sp. occurs on the beach exposed to the Atlantic as well as in the Ria Formosa. All identified and previously known (marine) species found in the Algarve had been found before, either in the Atlantic or in the Mediterranean basin. 

  14. Checklist of tapeworms (Platyhelminthes, Cestoda) of vertebrates in Finland.

    PubMed

    Haukisalmi, Voitto

    2015-01-01

    A checklist of tapeworms (Cestoda) of vertebrates (fishes, birds and mammals) in Finland is presented, based on published observations, specimens deposited in the collections of the Finnish Museum of Natural History (Helsinki) and the Zoological Museum of the University of Turku, and additional specimens identified by the present author. The checklist includes 170 tapeworm species from 151 host species, comprising 447 parasite species/host species combinations. Thirty of the tapeworm species and 96 of the parasite/host species combinations have not been previously reported from Finland. The total number of tapeworm species in Finland (170 spp.) is significantly lower than the corresponding figure for the Iberian Peninsula (257 spp.), Slovakia (225 spp.) and Poland (279 spp.). The difference between Finland and the other three regions is particularly pronounced for anseriform, podicipediform, charadriiform and passeriform birds, reflecting inadequate and/or biased sampling of these birds in Finland. It is predicted that there are actually ca. 270 species of tapeworms in Finland, assuming that true number of bird tapeworms in Finland corresponds to that in other European countries with more comprehensive knowledge of the local tapeworm fauna. The other main pattern emerging from the present data is the seemingly unexplained absence in (northern) Fennoscandia of several mammalian tapeworms that otherwise have extensive distributions in the Holarctic region or in Eurasia, including the northern regions. Previously unknown type specimens, that is, the holotype of Bothrimonus nylandicus Schneider, 1902 (a junior synonym of Diplocotyle olrikii Krabbe, 1874) (MZH 127096) and the syntypes of Caryophyllaeides fennica (Schneider, 1902) (MZH 127097) were located in the collections of the Finnish Museum of Natural History.

  15. A COCHLEAR MODEL USING THE TIME-AVERAGED LAGRANGIAN AND THE PUSH-PULL MECHANISM IN THE ORGAN OF CORTI

    PubMed Central

    YOON, YONGJIN; PURIA, SUNIL; STEELE, CHARLES R.

    2010-01-01

    In our previous work, the basilar membrane velocity VBM for a gerbil cochlea was calculated and compared with physiological measurements. The calculated VBM showed excessive phase excursion and, in the active case, a best-frequency place shift of approximately two fifths of an octave higher. Here we introduce a refined model that uses the time-averaged Lagrangian for the conservative system to resolve the phase excursion issues. To improve the overestimated best-frequency place found in the previous feed-forward active model, we implement in the new model a push-pull mechanism from the outer hair cells and phalangeal process. Using this new model, the VBM for the gerbil cochlea was calculated and compared with animal measurements, The results show excellent agreement for mapping the location of the maximum response to frequency, while the agreement for the response at a fixed point as a function of frequency is excellent for the amplitude and good for the phase. PMID:20485540

  16. Anatomy and ultrastructure of the female reproductive system of Pleioplana atomata (Platyhelminthes: Polycladida).

    PubMed

    Liana, Marcin K; Litvaitis, Marian K

    2009-03-01

    The ultrastructure of the female reproductive system of the polyclad flatworm Pleioplana atomata is described. Numerous ovaries are scattered throughout the entire body but are mainly concentrated on the dorsal side. Within an ovary, a germinative zone with oogonia and prefolicular cells is located in the dorsal part of the ovary. The remaining part of the gonad is filled with previtellogenic and early vitellogenic oocytes enwrapped by follicular cells. During previtellogenesis, oocytes produce numerous eggshell globules, which are distributed into the cortical area of the cell in later stages. Eventually, these globules release their contents into the space between the eggshell cover and oolemma. Similar types of globules are also found in others flatworms, and may represent useful phylogenetic characters. Entolecital, vitellogenic oocytes pass to paired uteri, where vitellogenesis is completed. The remainder of the female reproductive system consists of paired thin uterine ducts that join a vagina. The distal part of the long, curved vagina forms a large Lang's vesicle, while the proximal part is connected to a female atrium leading to a female gonopore. We hypothesize that Lang's vesicle functions in the digestion of excess sperm received. Two kinds of different shell (cement) glands that release their secretion into the vagina are identified. Both are unicellular glands and each gland cell connects to the lumen of the vagina via an individual canal. Similar glands in other acotylean polyclads have been implicated in the formation of eggshell covers.

  17. Molecular phylogeny and systematics of the Echinostomatoidea Looss, 1899 (Platyhelminthes: Digenea).

    PubMed

    Tkach, Vasyl V; Kudlai, Olena; Kostadinova, Aneta

    2016-03-01

    The Echinostomatoidea is a large, cosmopolitan group of digeneans currently including nine families and 105 genera, the vast majority parasitic, as adults, in birds with relatively few taxa parasitising mammals, reptiles and, exceptionally, fish. Despite the complex structure, diverse content and substantial species richness of the group, almost no attempt has been made to elucidate its phylogenetic relationships at the suprageneric level based on molecules due to the lack of data. Herein, we evaluate the consistency of the present morphology-based classification system of the Echinostomatoidea with the phylogenetic relationships of its members based on partial sequences of the nuclear lsrRNA gene for a broad diversity of taxa (80 species, representing eight families and 40 genera), including representatives of five subfamilies of the Echinostomatidae, which currently exhibits the most complex taxonomic structure within the superfamily. This first comprehensive phylogeny for the Echinostomatoidea challenged the current systematic framework based on comparative morphology. A morphology-based evaluation of this new molecular framework resulted in a number of systematic and nomenclatural changes consistent with the phylogenetic estimates of the generic and suprageneric boundaries and a new phylogeny-based classification of the Echinostomatoidea. In the current systematic treatment: (i) the rank of two family level lineages, the former Himasthlinae and Echinochasminae, is elevated to full family status; (ii) Caballerotrema is distinguished at the family level; (iii) the content and diagnosis of the Echinostomatidae (sensu stricto) (s. str.) are revised to reflect its phylogeny, resulting in the abolition of the Nephrostominae and Chaunocephalinae as synonyms of the Echinostomatidae (s. str.); (iv) Artyfechinostomum, Cathaemasia, Rhopalias and Ribeiroia are re-allocated within the Echinostomatidae (s. str.), resulting in the abolition of the Cathaemasiidae, Rhopaliidae and Ribeiroiinae, which become synonyms of the Echinostomatidae (s. str.); and (v) refinements of the generic boundaries within the Echinostomatidae (s. str.), Psilostomidae and Fasciolidae are made.

  18. Comparative Genomics of Flatworms (Platyhelminthes) Reveals Shared Genomic Features of Ecto- and Endoparastic Neodermata

    PubMed Central

    Hahn, Christoph; Fromm, Bastian; Bachmann, Lutz

    2014-01-01

    The ectoparasitic Monogenea comprise a major part of the obligate parasitic flatworm diversity. Although genomic adaptations to parasitism have been studied in the endoparasitic tapeworms (Cestoda) and flukes (Trematoda), no representative of the Monogenea has been investigated yet. We present the high-quality draft genome of Gyrodactylus salaris, an economically important monogenean ectoparasite of wild Atlantic salmon (Salmo salar). A total of 15,488 gene models were identified, of which 7,102 were functionally annotated. The controversial phylogenetic relationships within the obligate parasitic Neodermata were resolved in a phylogenomic analysis using 1,719 gene models (alignment length of >500,000 amino acids) for a set of 16 metazoan taxa. The Monogenea were found basal to the Cestoda and Trematoda, which implies ectoparasitism being plesiomorphic within the Neodermata and strongly supports a common origin of complex life cycles. Comparative analysis of seven parasitic flatworm genomes identified shared genomic features for the ecto- and endoparasitic lineages, such as a substantial reduction of the core bilaterian gene complement, including the homeodomain-containing genes, and a loss of the piwi and vasa genes, which are considered essential for animal development. Furthermore, the shared loss of functional fatty acid biosynthesis pathways and the absence of peroxisomes, the latter organelles presumed ubiquitous in eukaryotes except for parasitic protozoans, were inferred. The draft genome of G. salaris opens for future in-depth analyses of pathogenicity and host specificity of poorly characterized G. salaris strains, and will enhance studies addressing the genomics of host–parasite interactions and speciation in the highly diverse monogenean flatworms. PMID:24732282

  19. Co-Speciation of the Ectoparasite Gyrodactylus teuchis (Monogenea, Platyhelminthes) and Its Salmonid Hosts

    PubMed Central

    Hahn, Christoph; Weiss, Steven J.; Stojanovski, Stojmir; Bachmann, Lutz

    2015-01-01

    Co-speciation is a fundamental concept of evolutionary biology and intuitively appealing, yet in practice hard to demonstrate as it is often blurred by other evolutionary processes. We investigate the phylogeographic history of the monogenean ectoparasites Gyrodactylus teuchis and G. truttae on European salmonids of the genus Salmo. Mitochondrial cytochrome oxidase subunit 1 and the nuclear ribosomal internal transcribed spacer 2 were sequenced for 189 Gyrodactylus individuals collected from 50 localities, distributed across most major European river systems, from the Iberian- to the Balkan Peninsula. Despite both anthropogenic and naturally caused admixture of the principal host lineages among major river basins, co-phylogenetic analyses revealed significant global congruence for host and parasite phylogenies, providing firm support for co-speciation of G. teuchis and its salmonid hosts brown trout (S. trutta) and Atlantic salmon (S. salar). The major split within G. teuchis, coinciding with the initial divergence of the hosts was dated to ~1.5 My BP, using a Bayesian framework based on an indirect calibration point obtained from the host phylogeny. The presence of G. teuchis in Europe thus predates some of the major Pleistocene glaciations. In contrast, G. truttae exhibited remarkably low intraspecific genetic diversity. Given the direct life cycle and potentially high transmission potential of gyrodactylids, this finding is interpreted as indication for a recent emergence (<60 ky BP) of G. truttae via a host-switch. Our study thus suggests that instances of two fundamentally different mechanisms of speciation (co-speciation vs. host-switching) may have occurred on the same hosts in Europe within a time span of less than 1.5 My in two gyrodactylid ectoparasite species. PMID:26080029

  20. MicroRNA loci support conspecificity of Gyrodactylus salaris and Gyrodactylus thymalli (Platyhelminthes: Monogenea).

    PubMed

    Fromm, Bastian; Burow, Susann; Hahn, Christoph; Bachmann, Lutz

    2014-10-01

    The monogenean flatworm Gyrodactylus salaris is a serious threat to wild and farmed Atlantic salmon stocks in Norway. Morphologically, the closely related but harmless Gyrodactylus thymalli on grayling can hardly be distinguished from G. salaris. Until now, molecular approaches could not resolve unambiguously whether G. salaris and G. thymalli represent just one polytypic species, two polytypic species or a complex of more than two species. In the first known genome-wide analysis utilizing 37 conserved microRNA loci, the genetic differentiation of seven populations of G. salaris and G. thymalli was assessed. The concatenated alignment spanned 21,742bp including 62 variable positions. A neighbor-joining cluster analysis did not support any host-based or mitochondrial haplotype-based grouping of strains. We conclude that a two species concept for G. salaris and G. thymalli does not reflect meaningful biological entities. Instead, G. salaris and G. thymalli are just one species comprising several pathogenic and non-pathogenic strains on various primary hosts. Following the International Code for Zoological Nomenclature, G. salaris Malmberg, 1957 is the valid species name with G. thymalli Žitňan, 1960 becoming the junior synonym. Accordingly, the range of G. salaris is significantly increased, given that formerly G. salaris-free countries such as e.g., Great Britain are now within the species' natural range. The synonymization of G. salaris and G. thymalli implies severe challenges to current disease management routines, which assume that G. salaris and G. thymalli are readily distinguishable. Protocols for reliable identification of pathogenic and non-pathogenic strains of G. salaris need to be developed.

  1. First records of Cotylea (Polycladida, Platyhelminthes) for the Atlantic coast of the Iberian Peninsula

    PubMed Central

    Noreña, Carolina; Marquina, Daniel; Perez, Jacinto; Almon, Bruno

    2014-01-01

    Abstract A study of polyclad fauna of the Atlantic coast of the Iberian Peninsula was carried out from 2010 to 2013. The paper reports nine new records belonging to three Cotylean families: the family Euryleptidae Lang, 1884, Pseudocerotidae Lang, 1884 and the family Prosthiostomidae Lang, 1884, and describes one new species, Euryleptodes galikias sp. n. PMID:24843268

  2. New Dalyelliidae (Platyhelminthes, Rhabditophora) from Buenos Aires Province, Argentina, and their stylet ultrastructure.

    PubMed

    Damborenea, Cristina; Brusa, Francisco; Noreña, Carolina

    2007-08-01

    Two new species of Dalyellidae, Dalyellia callvucurai n. sp. and Gieysztoria namuncurai n. sp., are described from temporary freshwater environments in central Buenos Aires Province, Argentina. The ultrastructure of the stylets of both species is also described. The new species of the genus Dalyellia is the second species of the genus found in the neotropics and the first whose stylet has been studied with scanning electron microscopy. Gieysztoria namuncurai n. sp. joins the seven species of the genus known in Argentina. The ultrastructural characteristics of the stylet place it in the Inaequales group, with complex stylets.

  3. Reproductive strategies, karyology, parasites, and taxonomic status of Dugesia populations from Yemen (Platyhelminthes: Tricladida: Dugesiidae).

    PubMed

    Harrath, Abdul Halim; Sluys, Ronald; Aldahmash, Waleed; Al-Razaki, Abdulkarim; Alwasel, Saleh

    2013-06-01

    We present new data on the distribution, reproductive strategies, karyology, and taxonomic status of populations of freshwater planarians from Yemen. Nine populations were sampled and significant differences in their reproductive strategies and karyology are reported. The present study presents the first fully documented record of a naturally sexual, diploid (2n = 18) population of a Dugesia species in the eastern part of the Afrotropical region. Morphological characters combined with karyological data suggest that these Dugesia populations from Yemen represent a new species, which is herein described as Dugesia arabica Harrath and Sluys, sp. nov. This new species is mainly distinguishable from other Dugesia species that are distributed exclusively in the Mediterranean basin and in the eastern part of the Afrotropical region by the presence of the following features: well-developed and cone-shaped penis papilla, housing an ejaculatory duct that runs ventrally and has a subterminal and ventral opening; a considerably expanded and folded section of the bursal canal at the level of the oviducal openings; absence of a layer of longitudinal muscles on the copulatory bursa and the bursal canal. Specimens from two populations from Yemen were infested with a gregarine Protozoon.

  4. Description of a New Temnocephala Species (Platyhelminthes) from the Southern Neotropical Region.

    PubMed

    de León, Rodrigo Ponce; Vera, Bárbara Berón; Volonterio, Odile

    2015-08-01

    The genus Temnocephala is endemic to the Neotropical region. Temnocephala mexicana and Temnocephala chilensis are the only 2 temnocephalans whose known distribution ranges extend to the south beyond Parallel 40°S. No Temnocephala species has ever been recorded from the extensive area between Parallel 43°S and the southern end of the South American continent, which makes the study of the southern limit of the distribution of the genus a topic of great interest. The southernmost report corresponds to T. chilensis from the Telsen River, Chubut Province, Argentina. In March 2000, several temnocephalans were found on the freshwater anomuran crustacean Aegla neuquensis from the same locality; the specimens were identified as belonging to a new species, which is described here. This species is characterized by possessing an unusually thin-walled, narrow zone that has the appearance of a deep groove connecting the introvert to the shaft of the penial stylet; an introvert with 36 longitudinal rows of spines, each bearing 6-8 spines that are progressively smaller towards the distal end; a distal end of the introvert with a very thin, sclerotized wall without spines; a seminal vesicle that opens sub-polarly into the contractile vesicle; a pair of paranephrocytes at the level of the pharynx and a second pair at the level of the anterior portion of the anterior testes, and eggs with very long stalks. On the basis of their overall morphology, host preference, and geographical distribution, T. chilensis and the new species are closely related, so a diagnostic key for the southern species of Temnocephala is also included. The type locality of the new species is in the southern limit of the known distribution area of T. chilensis, so after this work there are 2 known species marking the southern limit of the distribution of the genus.

  5. Three new species of freshwater Macrostomum (Platyhelminthes, Macrostomida) from southern China.

    PubMed

    Sun, Ting; Zhang, Lv; Wang, An-Tai; Zhang, Yu

    2015-09-02

    Macrostomum is a diverse genus of turbellarians with more than 180 species described from around the world. However, the Macrostomum fauna in China is poorly known. In this study, three new species of freshwater Macrostomum were described from southern China based on morphology of the penis stylet, an important character for species identification in this genus. In M. heyuanensis n. sp., the penis stylet bends 108° leftwards at its 1/2 length then backwards besides the distal opening, and the terminal region is thicker than other parts of penis stylet. In M. dongyuanensis n. sp., the penis stylet is J-shaped, with the opening at the tail end. In M. bicaudatum n. sp., the penis stylet is C-shaped, with the upper margin of the distal end longer but slimmer than the lower margin. In addition, molecular phylogenetic analyses were conducted to aid the classification of the novel species. Finally, their habitat and taxonomic status are compared and discussed.

  6. Comparative genomic analysis of aspartic proteases in eight parasitic platyhelminths: insights into functions and evolution.

    PubMed

    Wang, Shuai; Wei, Wei; Luo, Xuenong; Wang, Sen; Hu, Songnian; Cai, Xuepeng

    2015-03-15

    We performed genome-wide identifications and comparative genomic analyses of the predicted aspartic proteases (APs) from eight parasitic flatworms, focusing on their evolution, potentials as drug targets and expression patterns. The results revealed that: i) More members of family A01 were identified from the schistosomes than from the cestodes; some evidence implied gene loss events along the class Cestoda, which may be related to the different ways to ingest host nutrition; ii) members in family A22 were evolutionarily highly conserved among all the parasites; iii) one retroviral-like AP in family A28 shared a highly similar predicted 3D structure with the HIV protease, implying its potential to be inhibited by HIV inhibitor-like molecules; and iiii) retrotransposon-associated APs were extensively expanded among these parasites. These results implied that the evolutionary histories of some APs in these parasites might relate to adaptations to their parasitism and some APs might have potential serving as intervention targets.

  7. Molecular phylogeny and evolution of the Trypanorhyncha Diesing, 1863 (Platyhelminthes: Cestoda).

    PubMed

    Palm, Harry W; Waeschenbach, Andrea; Olson, Peter D; Littlewood, D Timothy J

    2009-08-01

    Complete ssrDNA and partial lsrDNA (D1-D3) of 31 species, mainly from the Indo-Pacific region, were sequenced and added to 66 species of the marine cestode order Trypanorhyncha; thus 35% of the 277 known species were sampled. The resulting phylogenetic tree resolved two major clades that represent trypanorhynchs originally parasitizing rajiform (skate and ray) or galeoform hosts. The tree topology supports an earlier classification based on morphology that splits the order into the superfamily Eutetrarhynchoidea together with the Tentacularioidea, and the Gymnorhynchoidea together with the Lacistorhynchoidea and Otobothrioidea. Three of the five recognized superfamilies are monophyletic (Tentacularioidea, Gymnorhynchoidea, Otobothrioidea). Nodal support for the Eutetrarhynchidae and Lacistorhynchidae was poor and resulted in paraphyletic clades. Mapping of morphological characters showed the tentacular armature of the scolex to be highly variable within clades, demonstrating that armature patterns used traditionally in classification, are homoplasious. Similarly, the tetrabothriate scolex, currently utilized as a family-distinguishing character in traditional classifications, has developed independently in multiple groups. Synapomorphies for the higher taxa are detailed. Sequence data from duplicate taxa confirmed interoceanic distribution patterns and low intraspecific genetic divergence and host specificity for nine trypanorhynch species belonging to five families and four superfamilies. Four distinct lineages of trypanorhynchs can be recognized with one mainly infecting rajiform hosts whereas the others infecting both, sharks and rays. Eutetrarhynchoids and tentacularioids have secondarily invaded shark hosts whilst utilising the marine food web involving teleost fishes as intermediate hosts. Three cases of host switching from sharks to rays can be inferred within the lacistorhynchoids, in one case caused by a switch from perciform to gadiform intermediate hosts. This likely enabled a radiation into the deep sea environment. Implications of the molecular phylogeny for the classification and evolutionary developments within the order are discussed.

  8. [Fauna of monogeneans (Monogenea, Platyhelminthes) of gudgeons (Gobioninae, Cyprinidae). 1. Composition, structure, and characteristics of distribution].

    PubMed

    Gerasev, P I

    2008-01-01

    Monogeneans parasitize 31 gudgeon species of 130, and 13 gudgeon genera of 30 known. Monogenea from gudgeon comprise 48 species of the genus Dactylogyrus, 1 Bivaginogyrus (Dactylogyridae), 18 Ancyrocephalus s. l. (Ancyrocephalidae), 6 Gyrodactylus (Gyrodactylidae), 3 Paradiplozoon, and 1 species of the genus Sindiplozoon (Diplozoidae). The following characters were used in the morphological analysis: (1) structure of the copulatory organ, (2) morphology of the anchors, marginal hooks and bars, (3) characteristic of attachment on gills. Among the Dactylogyrus species parasitizing gudgeon, 30 monophyletic species groups and 13 levels of morphological organization were established. The first level comprises dactylogyrids without the additional ventral bar of haptor. It includes species with the copulatory organ of pro-cryptomeres type. This type is ancestral for dactylogyrids of the Amur/China fauna. Levels II-IV; VI, etc. are derivates of level I. Levels VII-VIII can be characterized by the jamming type of attachment characteristic for Dactylogyrus sphyrna or D. anchoratus, when marginal hooks penetrate gill filaments towards the anchors. Levels IX-XII include species with the attachment by clasping, when the anchors directed towards each other. Some species groups of Dactylogyrus (V, XIII) switched onto gudgeons from other fishes (Cultrinae, Xenocyprininae, Hypophthalmichthinae). Species of the genus Ancyrocephalus s. l. form two levels of morphological organization and 8 monophyletic groups. Repeated switches of ancyrocephalids from freshwater gobies to gudgeons and their switches from gudgeons to other fishes were shown. Species of the genus Hemibarbus serve as hosts for morphologically peculiar species groups of Dactylogyrus and Ancyrocephalus s. l. We can conclude that gyrodactylids from gudgeons do not form a natural monophyletic group. This parasite fauna originated as a result of multiple switches from phylogenetically distant but ecologically similar hosts, for example sticklebacks, bitterlings, chars, spined loaches, etc. Species of the family Diplozoidae parasitizing gudgeons may invade also many species from other fish taxa.

  9. Investigation of the ultrastructure of Dendrocoelum constrictum (Platyhelminthes, Tricladida) spermatogenesis and mature spermatozoa.

    PubMed

    Harrath, Abdel Halim; Gammoudi, Mehrez; Mansour, Lamjed; Ahmed, Mukhtar; Sirotkin, Alexander V; Al Omar, Suliman Y; Ibrahim, Khalid E; Alwasel, Saleh H

    2014-09-01

    To add to our understanding of dendrocoelid spermatozoa and to describe additional phylogenetic characters, the ultrastructure of the testis was investigated in the subterranean freshwater planarian Dendrocoelum constrictum. This is the first study investigating spermatogenesis and spermatozoon ultrastructure in a subterranean freshwater planarian species. We found that the basic structure of spermatozoa in D. constrictum is similar to that of other Tricladida that have been studied previously. In fact, D. constrictum spermatozoa possess an elongated nucleus, one giant mitochondrion, and two subterminal flagella with a 9+'1' pattern. The flagella emerge together from one side of the spermatozoon. However, D. constrictum has some characteristics that have not yet been described for other freshwater planarians. In fact, the number of cortical microtubules reaches the maximum number in the anterior and middle part of region I, and then decrease until they disappear towards the posterior extremity of the spermatozoon. The extreme tip of the anterior region of the spermatozoon exhibits a specific external ornamentation of the plasma membrane.

  10. Biogeographical implications of Zambezian Cichlidogyrus species (Platyhelminthes: Monogenea: Ancyrocephalidae) parasitizing Congolian cichlids.

    PubMed

    Vanhove, Maarten P M; Van Steenberge, Maarten; Dessein, Steven; Volckaert, Filip A M; Snoeks, Jos; Huyse, Tine; Pariselle, Antoine

    2013-01-22

    Fishes normally restricted to inland waters are valuable model systems for historical biogeography, inter alia, because of their limited dispersal abilities and concordance with the distribution patterns of other freshwater taxa (Zogaris et al. 2009). The comparison of fish species assemblages has been the major biogeographical tool for delineating African aquatic ecoregions as the fossil record is often meagre and merely offers complementary information. This is, for example, the case for the Zambezian and Congolian ichthyofaunal provinces, which display substantial contemporary fish diversity (Stewart 2001). Between both regions lies the Bangweulu-Mweru ecoregion (sensu Scott 2005), known for its high percentage of endemicity. Although hydrographically belonging to the Congo Basin, the Bangweulu-Mweru ecoregion has a high affinity with the Zambezi province (Scott 2005), due to historical river connections (Tweddle 2010). Studies comparing the Zambezi and Congo ichthyofaunal provinces are rare and hampered by lack of data from the Congo Basin. The latter harbours more than 1250 fish species (Snoeks et al. 2011) while in the Zambezi, only 120 freshwater fishes are found (Tweddle 2010). Indeed, species richness declines in all major African teleost families from the Congo Basin southwards, riverine haplochromine cichlids forming a notable exception to this rule (Joyce et al. 2005). Although it was hypothesized by Tweddle (2010) that the origin of many Zambezian fish species is in the Congo Basin, the haplochromines Serranochromis Regan, Sargochromis Regan, Pharyngochromis Greenwood and Chetia Trewavas, together forming the serranochromines, have their centre of diversity in the rivers of the Zambezian ichthyofaunal province (Joyce et al. 2005). Therefore, the biogeographical history of Cichlidae across the Zambezi- Congo watershed is not only key to cichlid biogeography on an African scale, but also complementary to biogeography of all other teleosts in the region. Yet, colonisation and speciation patterns are difficult to unravel due to complex hydrological history (Katongo et al. 2007; Schwarzer et al. 2012).

  11. A new genus with six new species of Typhlopolycystidinae Evdonin, 1977 (Platyhelminthes, Kalyptorhynchia, Polycystididae).

    PubMed

    Schockaert, Ernest R; Martens, Paul M; Revis, Nathalie; Janssen, Toon; Willems, Wim; Artois, Tom J

    2014-01-22

    Five new species of the new taxon Brunetorhynchus n. gen. are described: B. deconincki n. sp., B. microstylis n. sp. and B. complicatus n. sp. are from the Mediterranean, B. canariensis n. sp. is from the Canary Island Lanzarote, B. cannoni n. sp. is from the Australian East coast and one species from the Galapagos, formerly described as Limipolycystis spec., is transferred to the new genus as B. dubius n. sp.. As in Limipolycystis, these species have a single stylet, (accessory stylet type II), an accessory secretion vesicle (type II) and a prostate vesicle (type III) in the male atrium, although the latter vesicle is absent in some species. Unlike the species of Limipolycystis, where the seminal receptacle is a sclerotized tubule, the species of the new taxon have a pear-shaped seminal receptacle on the oviduct. 

  12. Two new species of brackish-water Macrostomum (Platyhelminthes, Macrostomida) from southern China.

    PubMed

    Fang, Chu-Yu; Wang, Lei; Zhang, Yu; Wang, An-Tai

    2016-09-23

    Two new species of brackish-water Macrostomum (M. zhujiangensis n. sp. and M. baoanensis n. sp.) were described based on samples collected from the littoral zone of the Zhujiang Estuary. These are the first records of brackish-water Macrostomum from southern China. Macrostomum zhujiangensis n. sp. and M. baoanensis n. sp. differ from other similar species in the length and morphology of the penis stylet.  The penis stylet of M. zhujiangensis n. sp. is C-shaped and its distal opening has a beveled edge. The penis stylet of M. baoanensis n. sp. is J-shaped and the distal region is thicker than other parts of the penis stylet. Molecular phylogenetic analysis supports the establishment of the new species.

  13. Prey-tracking behavior in the invasive terrestrial planarian Platydemus manokwari (Platyhelminthes, Tricladida).

    PubMed

    Iwai, Noriko; Sugiura, Shinji; Chiba, Satoshi

    2010-11-01

    Platydemus manokwari is a broadly distributed invasive terrestrial flatworm that preys heavily on land snails and has been credited with the demise of numerous threatened island faunas. We examined whether P. manokwari tracks the mucus trails of land snail prey, investigated its ability to determine trail direction, and evaluated prey preference among various land snail species. A plastic treatment plate with the mucus trail of a single species and a control plate without the trail were placed side by side at the exit of cages housing P. manokwari. All trials were then videotaped overnight. The flatworms moved along plates with mucus trails, but did not respond to plates without trails, blank control (distilled water), or with conspecific flatworm trails. When presented at the midpoint of a snail mucus trail, the flatworms followed the trail in a random direction. The flatworms showed a preference when choosing between two plates, each with a mucus trail of different land snail species. Our results suggest that P. manokwari follows snail mucus trails based on chemical cues to increase the chance of encountering prey; however, trail-tracking behavior showed no directionality.

  14. Two new species of freshwater flatworms (Platyhelminthes: Tricladida: Continenticola) from South American caves.

    PubMed

    Souza, Stella; Morais, Ana Laura; Bichuette, Maria Elina; Leal-Zanchet, Ana

    2016-03-14

    The diversity of freshwater triclads in the Neotropical region is considered to be low, but extensive areas of South America remain almost unexplored. Herein we describe two cave-dwelling, new species of Girardia, one from a transition zone of the Cerrado and Caatinga phytophysiognomies and the other from the Cerrado phytophysiognomy. The species from the Cerrado-Caatinga transition is a troglobite, eyeless and whitish; the species from the Cerrado area is possibly a troglophile, since it shows heavily pigmented body and eyes. Each species is easily recognized by a unique combination of features in its external morphology and copulatory apparatus. The two new species of Girardia show a restricted distribution, even the troglophile, and occur in caves without legal protection. Therefore, they must be considered as vulnerable organisms in a conservation context.

  15. Prey-tracking behavior in the invasive terrestrial planarian Platydemus manokwari (Platyhelminthes, Tricladida)

    NASA Astrophysics Data System (ADS)

    Iwai, Noriko; Sugiura, Shinji; Chiba, Satoshi

    2010-11-01

    Platydemus manokwari is a broadly distributed invasive terrestrial flatworm that preys heavily on land snails and has been credited with the demise of numerous threatened island faunas. We examined whether P. manokwari tracks the mucus trails of land snail prey, investigated its ability to determine trail direction, and evaluated prey preference among various land snail species. A plastic treatment plate with the mucus trail of a single species and a control plate without the trail were placed side by side at the exit of cages housing P. manokwari. All trials were then videotaped overnight. The flatworms moved along plates with mucus trails, but did not respond to plates without trails, blank control (distilled water), or with conspecific flatworm trails. When presented at the midpoint of a snail mucus trail, the flatworms followed the trail in a random direction. The flatworms showed a preference when choosing between two plates, each with a mucus trail of different land snail species. Our results suggest that P. manokwari follows snail mucus trails based on chemical cues to increase the chance of encountering prey; however, trail-tracking behavior showed no directionality.

  16. Alternative development in Polystoma gallieni (Platyhelminthes, Monogenea) and life cycle evolution.

    PubMed

    Badets, Mathieu; Du Preez, Louis; Verneau, Olivier

    2013-10-01

    Considering the addition of intermediate transmission steps during life cycle evolution, developmental plasticity, canalization forces and inherited parental effect must be invoked to explain new host colonization. Unfortunately, there is a lack of experimental procedures and relevant models to explore the adaptive value of alternative developmental phenotypes during life cycle evolution. However, within the monogeneans that are characterized by a direct life cycle, an extension of the transmission strategy of amphibian parasites has been reported within species of Polystoma and Metapolystoma (Polyopisthocotylea; Polystomatidae). In this study, we tested whether the infection success of Polystoma gallieni within tadpoles of its specific host, the Stripeless Tree Frog Hyla meridionalis, differs depending on the parental origin of the oncomiracidium. An increase in the infection success of the parasitic larvae when exposed to the same experimental conditions as their parents was expected as an adaptive pattern of non-genetic inherited information. Twice as many parasites were actually recorded from tadpoles infected with oncomiracidia hatching from eggs of the bladder parental phenotype (1.63 ± 0.82 parasites per host) than from tadpoles infected with oncomiracidia hatching from eggs of the branchial parental phenotype (0.83 ± 0.64 parasites per host). Because in natural environments the alternation of the two phenotypes is likely to occur due to the ecology of its host, the differential infection success within young tadpoles could have an adaptive value that favors the parasite transmission over time.

  17. Land flatworms of the genus Pasipha (Platyhelminthes, Geoplanidae) in Argentina, with description of three new species.

    PubMed

    Negrete, Lisandro; Brusa, Francisco

    2016-07-11

    The genus Pasipha Ogren & Kawakatsu, 1990 currently includes 22 species, most of them recorded in the Brazilian Atlantic Forest. Recently, Pasipha hauseri was documented in north-eastern Argentina, thus extending its distribution range. This paper reports new records of the genus Pasipha in the Interior Atlantic Forest ecoregion in Argentina, with the description of three new species: Pasipha atla sp. nov., Pasipha johnsoni sp. nov., and Pasipha mbya sp. nov. These new species exhibit similarities in internal anatomy, such as pharynx cylindrical, extrabulbar prostatic vesicle with folded walls and proximally forked, male atrium highly folded, being at least two times longer than the female atrium and with small folds in their proximal portion. However, they can be distinguished from each other mainly by the secretion types discharged into the prostatic vesicle as well as into the male and female atria. In addition, they have different colour patterns on the dorsal surface.

  18. Patterns of interaction between Neotropical freshwater fishes and their gill Monogenoidea (Platyhelminthes).

    PubMed

    Braga, Mariana P; Araújo, Sabrina B L; Boeger, Walter A

    2014-02-01

    Using network analysis, we looked for broad patterns of distribution of Monogenoidea gill parasites on Neotropical freshwater fishes within a host phylogenetic framework. We analyzed a database of Monogenoidea parasitizing fishes from Neotropical rivers, from 23 watersheds, based on species descriptions published until 2011. Host-parasite interactions were organized into five matrices grouping species at different taxonomic levels. The network of interactions between host families and parasite genera was significantly modular and revealed that each fish order has a unique composition of parasite genera. Hence, interactions between lower taxa were analyzed separately for the largest fish orders (Perciformes, Siluriformes, and Characiformes). Networks tended to be loosely connected and organized in modules. Despite the putative high host specificity of monogenoids, some have a wider host range that includes distantly related host species. Among the hosts, the clade composed by the piranhas (Serrasalmus spp. and related species, Serrasalmidae) stands out in terms of parasite richness per host species, resulting in a more connected network. The history of the lineages of each host order within Neotropical freshwaters seems to have a great influence on the extent of parasite sharing. The observed modularity was influenced by both spatial structure and phylogenetic relatedness of species. In average, 37 % of modules of networks between host species and parasite genera were associated with a particular river basin and 63 % of modules were associated with a host family. Hence, spatial structure determines the co-occurrence of host and parasite species, but their evolutionary history is the main factor defining which interactions are possible.

  19. Two new species of Gieysztoria (Platyhelminthes, Rhabdocoela, Dalyelliidae) from a freshwater artificial lake in Shenzhen, China.

    PubMed

    Lu, Yan-Hong; Wu, Cheng-Chen; Xia, Xiao-Jie; Wang, An-Tai

    2013-12-09

    Two new species of the "Aequales" of genus Gieysztoria were collected and described from an artificial lake on the Shenzhen University campus. Gieysztoria bimaculata n. sp., is distinguished based on two groups clavate pigmentations dorsally between the pharynx and intestine, and has a sclerotic stylet comprising a proximal girdle with 40-46 distal dagger-shape spines, thus has the maximum number of spines within "Aequales" group. Gieysztoria guangdongensis n. sp. has a sclerotic stylet with a proximal girdle and 18 distal blade-shaped spines. Comparison with similar species based mainly on stylet morphology suggests that Gieysztoria bimaculata n. sp. and Gieysztoria guangdongensis n. sp. are apparently different from the known species of Gieysztoria in this moment. In addition, the stability of the amount of distal spines of "Aequales" species is briefly discussed.

  20. Embryonic muscle development in direct and indirect developing marine flatworms (Platyhelminthes, Polycladida).

    PubMed

    Bolaños, D Marcela; Litvaitis, Marian K

    2009-01-01

    We compared embryonic myogenesis of the direct-developing acotylean polyclad Melloplana ferruginea with that of Maritigrella crozieri, a cotylean that develops via a larval stage. Fluorescently labeled F-actin was visualized with laser confocal microscopy. Developmental times are reported as percentages of the time from oviposition to hatching: 7 days for M. crozieri and 22 days for M. ferruginea. The epithelium began to form at 30% development in M. crozieri and at 15% development in M. ferruginea. Random myoblasts appeared in peripheral areas of the embryo at 36% and 22-30% development in M. crozeri and M. ferruginea, respectively. Circular and longitudinal muscle bands formed synchronously at 37-44% development in M. crozieri; yolk obscured observations of early myogenesis in M. ferruginea. An orthogonal muscle grid was established by 45-50% development in both species. Diagonal muscles developed in M. ferruginea at 60-71% development. Hence, juveniles of this species hatch with the same basic body-wall musculature as adults. Larvae of M. crozieri did not hatch with diagonal muscles; these muscles are acquired postmetamorphosis. Additionally, a specialized musculature developed in the larval lobes of M. crozieri. Oral musculature was complex and established by 72% development in both species. Our results are comparable to the muscle differentiation reported for other indirect-developing polyclads and for direct-developing species of macrostomid flatworms. Furthermore, they provide additional support that the orthogonal muscle pattern of circular and longitudinal muscles is a symplesiomorphy of Spiralia.

  1. Co-Speciation of the Ectoparasite Gyrodactylus teuchis (Monogenea, Platyhelminthes) and Its Salmonid Hosts.

    PubMed

    Hahn, Christoph; Weiss, Steven J; Stojanovski, Stojmir; Bachmann, Lutz

    2015-01-01

    Co-speciation is a fundamental concept of evolutionary biology and intuitively appealing, yet in practice hard to demonstrate as it is often blurred by other evolutionary processes. We investigate the phylogeographic history of the monogenean ectoparasites Gyrodactylus teuchis and G. truttae on European salmonids of the genus Salmo. Mitochondrial cytochrome oxidase subunit 1 and the nuclear ribosomal internal transcribed spacer 2 were sequenced for 189 Gyrodactylus individuals collected from 50 localities, distributed across most major European river systems, from the Iberian- to the Balkan Peninsula. Despite both anthropogenic and naturally caused admixture of the principal host lineages among major river basins, co-phylogenetic analyses revealed significant global congruence for host and parasite phylogenies, providing firm support for co-speciation of G. teuchis and its salmonid hosts brown trout (S. trutta) and Atlantic salmon (S. salar). The major split within G. teuchis, coinciding with the initial divergence of the hosts was dated to ~1.5 My BP, using a Bayesian framework based on an indirect calibration point obtained from the host phylogeny. The presence of G. teuchis in Europe thus predates some of the major Pleistocene glaciations. In contrast, G. truttae exhibited remarkably low intraspecific genetic diversity. Given the direct life cycle and potentially high transmission potential of gyrodactylids, this finding is interpreted as indication for a recent emergence (<60 ky BP) of G. truttae via a host-switch. Our study thus suggests that instances of two fundamentally different mechanisms of speciation (co-speciation vs. host-switching) may have occurred on the same hosts in Europe within a time span of less than 1.5 My in two gyrodactylid ectoparasite species.

  2. [Fauna of monogeneans (Monogenea, Platyhelminthes) of gudgeons (Gobioninae, Cyprininae). 2. Coevolution].

    PubMed

    Gerasev, P I

    2009-01-01

    Coevolution of parasites and in particular monogeneans and fishes, was characterized from two related angles--parallel coevolution and host switches, lead to the acquisition of new hosts from taxonomically distant but ecologically similar groups. Modern views on the evolution and taxonomy of gudgeons are discussed. This group is very heterogeneous by morphology and biology, tales unclear taxonomic position in the family Cyprynidae, and can be divided into two tribes or four groups of genera. Analysis of coevolution of dactylogirids, ancyrocephalids, gyrodactylids, and diplozoids with their hosts was carried out. Dactylogyrus spp. and gudgeons show coevolutional connections; in Ancyrocephalus s. l. spp. coevolution and host switches take place; most of Gyrodactylus spp. parasitize fishes of the genus Gobio and are the colonists of gudgeons; and none of the diplozoids parasitize exceptionally gudgeons. From 130 species of 30 genera of the World fauna of gudgeons 31 species 13 genera proved to be infected with monogeneans. We divided the dactylogyrids from gudgeons (49 species) into 13 evolution levels and 30 morphological groups, which were found equal in number with taxonomic groups of hosts. Ancyrocephalids were divided into two evolution levels, which can not be reduced to one initial type, and eight monophyletic groups. Fourteen of 18 species of these monogeneans occurred on the host from the genera Hemibarbus and Squalidus. Different directions of evolution connected with forming of different types of copulatory organ, ventral additional bar, and type of attachment on gills were revealed for Dactylogyrus spp. from different groups of genera of gudgeons (Yang et al., 2006). Monogeneans have lower evolutionary rates, as compared with their hosts, that are expressed in the taxonomic ranks (groups of species in monogeneans and genera or groups of genera in their hosts). Number of species in Dactylogyrus and Ancyrocephalus s. l. usually the same as the number of their host species. However this proportion increases in favor of the parasites owing to the explosion-like speciation of monogeneans parasitizing Hemibarbus and Saurogobio. Distribution of morphological groups of monogeneans on gudgeons in general confirms their grouping into four groups of genera on the base of molecular data. At the same time, in some cases parasitological data agree with the gudgeons' classification based on morphological characters to a greater extent (Banarescu, 1992; Naseca, 1998). The genera Sarcocheilichthys and Gnathopogon take the crucial position in the Sarcocheilichthys group of genera according to the analysis of occurrence of monophyletic groups of Dactylogyrus spp. In the Pseudogobio group of genera, the largest number of the Dactylogyrus spp. groups was found on the genera Saurogobio and Abbottina. The genus Hemibarbus, being the host of some original groups of Dactylogyrus spp. and Ancyrocephalus spp., takes the most isolated position among gudgeons by morphological, molecular, and parasitological data. Relationships of Hemibarbus and Squalidus (both from the Hemibarbus group of genera) are need in further investigations. The Sarcocheilichthys group of genera, which contains the genera Coreius and Paracanthobrama with unclear and ambiguous positions, is situated apart from the Hemibarbus group of genera. High-specialized groups of Dactylogyrus spp. are predominating on the former. The Pseudogobio group of genera is parasitized by numerous primitive groups of Dactylogyrus spp. Groups of Dactylogyrus spp. from the Gobio group of genera are derived undoubtedly from the monogeneans parasitizing the Pseudogobio group of genera, and the Gobio group of genera either derived from the Pseudogobio group of genera or must be included into the latter. Thus, we have one phylum of gudgeons with separate groups of monogeneans (Hemibarbus group of genera) and, contrariwise, other phylum of fish hosts with ancient and specialized monogeneans (Sarcocheilichthys group of genera), which ends in the gudgeons with primitive monogeneans (Pseudogobio group of genera) and evolutionary young monogeneans (Gobio group of genera). The pattern of distribution of the morphological groups of monogeneans by gudgeons is a mirror reflection of modern contradictory views on the taxonomy and evolution of these fishes and may contribute to a more profound understanding of the place of gudgeons in Cyprinidae, their taxonomy and evolution.

  3. A standardised terminology of the embryonic envelopes and associated developmental stages of tapeworms (Platyhelminthes: Cestoda).

    PubMed

    Conn, David Bruce; Swiderski, Zdzisław

    2008-03-01

    Over the past 40 years, much has been published on the ultrastructure and cellular development of embryonic structures in a wide range of cestodes. However, the literature contains many discrepancies in both terminology and interpretations because of the facts that these organisms are phylogenetically diverse within their respective orders and families, the habitats that affect embryonic envelope structure are diverse, and the work has been done in various laboratories around the world. This review and synthesis was initiated by a working group of biologists from around the world convened at the Fifth International Workshop on Cestode Systematics and Phylogeny in Ceské Budejovice, at the Institute of Parasitology of the Biology Centre, Academy of Sciences of the Czech Republic. It brings together the data from published work and establishes a uniform terminology and interpretation based on the data as they are presented. A consensus was reached for standardised definitions of the oncosphere, hexacanth, coracidium, embryonic envelopes, outer envelope, inner envelope, embryophore, vitelline capsule, shell, and outer coat. All of these are defined as components of the embryo or its vitellocyte-derived or uterine-derived coatings.

  4. Comparative genomics of flatworms (platyhelminthes) reveals shared genomic features of ecto- and endoparastic neodermata.

    PubMed

    Hahn, Christoph; Fromm, Bastian; Bachmann, Lutz

    2014-05-01

    The ectoparasitic Monogenea comprise a major part of the obligate parasitic flatworm diversity. Although genomic adaptations to parasitism have been studied in the endoparasitic tapeworms (Cestoda) and flukes (Trematoda), no representative of the Monogenea has been investigated yet. We present the high-quality draft genome of Gyrodactylus salaris, an economically important monogenean ectoparasite of wild Atlantic salmon (Salmo salar). A total of 15,488 gene models were identified, of which 7,102 were functionally annotated. The controversial phylogenetic relationships within the obligate parasitic Neodermata were resolved in a phylogenomic analysis using 1,719 gene models (alignment length of >500,000 amino acids) for a set of 16 metazoan taxa. The Monogenea were found basal to the Cestoda and Trematoda, which implies ectoparasitism being plesiomorphic within the Neodermata and strongly supports a common origin of complex life cycles. Comparative analysis of seven parasitic flatworm genomes identified shared genomic features for the ecto- and endoparasitic lineages, such as a substantial reduction of the core bilaterian gene complement, including the homeodomain-containing genes, and a loss of the piwi and vasa genes, which are considered essential for animal development. Furthermore, the shared loss of functional fatty acid biosynthesis pathways and the absence of peroxisomes, the latter organelles presumed ubiquitous in eukaryotes except for parasitic protozoans, were inferred. The draft genome of G. salaris opens for future in-depth analyses of pathogenicity and host specificity of poorly characterized G. salaris strains, and will enhance studies addressing the genomics of host-parasite interactions and speciation in the highly diverse monogenean flatworms.

  5. Cicerina debrae n. sp. (Platyhelminthes: Kalyptorhynchia, Cicerinidae) from the Southern Atlantic Coast, USA.

    PubMed

    Tucker, Kea; Stevens, Craig; Smith, Julian P S

    2014-06-24

    Cicerina debrae is described as a new species of kalyptorhynch flatworm belonging to the Cicerinidae. This species was found in surface sediment from the lower half of the beach at two sites in North Carolina and is identical to museum material previously collected from North Carolina and from the Atlantic coast of Florida. C. debrae differs from its congeners in the shape of the ductus spermatici and the copulatory cirrus.

  6. Ultrastructural and cytochemical aspects of the germarium and the vitellarium in Syndesmis patagonica (Platyhelminthes, Rhabdocoela, Umagillidae).

    PubMed

    Falleni, Alessandra; Lucchesi, Paolo; Ghezzani, Claudio; Brogger, Martín I

    2014-06-01

    The cytoarchitecture of the female gonad of the endosymbiont umagillid Syndesmis patagonica has been investigated using electron microscopy and cytochemical techniques. The female gonad consists of paired germaria and vitellaria located behind the pharynx in the mid-posterior region of the body. Both the germaria and the vitellaria are enveloped by an outer extracellular lamina and an inner sheath of accessory cells which contribute to the extracellular lamina. Oocyte maturation occurs completely during the prophase of the first meiotic division. Oocyte differentiation is characterized by the appearance of chromatoid bodies and the development of endoplasmic reticulum and Golgi complexes. These organelles appear to be involved in the production of round granules, about 2-2.5 μm in diameter, with a homogeneous electron-dense core surrounded by a granular component and a translucent halo delimited by a membrane. These egg granules migrate to the periphery of mature oocytes, are positive to the cytochemical test for polyphenol detection, are unaffected by protease and have been interpreted as eggshell granules. The mature oocytes also contain a small number of yolk granules, lipid droplets, and glycogen particles scattered throughout the ooplasm. The vitellaria are branched organs composed of vitelline follicles with vitellocytes at different stages of maturation. Developing vitellocytes contain well-developed rough endoplasmic reticulum and small Golgi complexes involved in the production of eggshell and yolk globules. Eggshell globules are round, measure 4-5 μm in diameter, and have a mosaic-like patterned content which contains polyphenols. The yolk globules, 2-3 μm in diameter, show a homogeneous protein content of medium electron density, devoid of polyphenols, and completely digested by protease. The mature vitellocytes also contain glycogen as further reserve material. The presence of polyphenolic eggshell granules in the oocytes and of polyphenolic eggshell globules with a mosaic-like pattern in the vitellocytes have been considered apomorphic features of the Rhabdocoela + Prolecithophora.

  7. First report of the land planarian Diversibipalium multilineatum (Makino & Shirasawa, 1983) (Platyhelminthes, Tricladida, Continenticola) in Europe.

    PubMed

    Mazza, Giuseppe; Menchetti, Mattia; Sluys, Ronald; Solà, Eduard; Riutort, Marta; Tricarico, Elena; Justine, Jean-Lou; Cavigioli, Luca; Mori, Emiliano

    2016-01-26

    Introduction of alien species may significantly affect soil ecosystems, through predation or disruption of components of native ecosystems (Winsor et al. 2004; Álvarez-Presas et al. 2014; Justine et al. 2014). Land planarians have been reported as alien species in soils throughout the world and, among those, some species are considered to be successful invaders, e.g. Platydemus manokwari de Beauchamp, 1963, Arthurdendyus triangulatus (Dendy, 1894), Bipalium adventitium Hyman, 1943, Bipalium kewense Moseley, 1878 and Dolichoplana striata Moseley, 1877 (Winsor et al. 2004; Álvarez-Presas et al. 2014; Justine et al. 2014, 2015). Soil moisture status seems to be an important element for their successful invasion (Fraser & Boag 1998). In Europe at least 18 species of alien land planarians have been recorded since now and some of them are considered as invasive ones, e.g. P. manokwari (cf. Justine et al. 2014). Although the alien land planarian B. kewense has been reported to occur in many greenhouses in Italy (Bello et al. 1995), no data are available on its establishment and/or impact on natural environments. On 28th September 2014, 20 specimens (~1 individual/m2) of the land planarian Diversibipalium multilineatum (Makino & Shirasawa, 1983) (Fig. 1), native to Japan, were collected under pots, branches and plastic materials in a private garden located in the center of Bologna (Emilia Romagna, Central Italy), near the urban park Giardini Margherita (44°29' N, 11°21' E; WGS84). Thirty plant species (both indigenous and alien), mainly cultivated as bonsai (e.g. Lagerstroemia indica L., Juniperus procumbens (Siebold ex Endl.) Miquel), were present in this shady, wet garden (25 m2). Between March 2014 and June 2015, 70 more specimens of D. multilineatum were collected at the same site, mainly at dusk and dawn after rain. Reproduction by fission and regeneration processes were observed in several of those specimens, which were kept for some time in captivity. A specimen of D. multilineatum was also collected in a garden in Léguevin (Haute-Garonne, France), which will be described in a forthcoming paper by Justine et al. (in prep.) (see also Kawakatsu et al. 2014). Specimens without a genital pore were initially ascribed to D. multilineatum on the basis of their external appearance: the dorsal surface was brownish yellow and presented five longitudinal stripes at the head plate and the neck, showing the typical appearance of the species. The middorsal stripe was widened at its anterior end, on the head plate, and at the pharynx level. The ventral pattern of the animals at the pharyngeal region was also characteristic, with the middorsal stripe widened at this level. The Italian Diversibipalium specimens used for the molecular analysis were fixed and preserved in absolute ethanol. Fragments of the mitochondrial gene COI and 28S ribosomal RNA nuclear gene (GenBank Acc. Numbers KU245358 and KU245357, respectively) were obtained using the procedure and COI primers described in Álvarez-Presas et al. (2008) and Solà et al. (2013). The French specimen's COI (Specimen MNHN JL177, GenBank Acc. Number KT922162) was obtained as described in Justine et al. (2015). 28S sequences of 14 Bipaliinae specimens and four Microplana species (outgroup) retrieved from GenBank were included in the phylogenetic analyses (Fig. 2). Sequence alignment was obtained by using the online software MAFFT version 7 (Katoh & Standley 2013), while ambiguously aligned positions were removed using the program Gblocks (Talavera & Castresana 2007) with default settings, excepting the minimum number of sequences for a flank position at the minimum value (set at 10) and with half of the allowed gap positions. The final alignment had a length of 1589 bp. We used two phylogenetic inference approaches: maximum likelihood (ML), using the RaxML 8.2.3 software (Stamatakis 2014), and Bayesian inferences (BI), using MrBayes 3.2.4 (Ronquist et al. 2012). The evolutionary model used, GTR+I+G, was estimated to be the best with the software jModeltest 2.1.7 (Darriba et al. 2012; Guindon & Gascuel 2003), using the Akaike Information Criterion (AIC). MrBayes analyses were performed for 10-milion generation with sampling parameters every 103 and a 25% default burn-in value for the final trees. Convergence of the two runs (average standard deviation of split frequencies << 0.01) and likelihood stationarity were checked. The maximum likelihood analyses were performed under 1000 bootstrap pseudoreplicates. The phylogenetic results show a close and highly supported relationship of the Italian Diversibipalium specimens with those from Japan and South Korea that have been identified as D. multilineatum (Fig. 2). Diversibipalium multilineatum is the sister-group of B. nobile Kawakatsu & Makino, 1982, but with low support. The COI sequences of the French (MNHN JL177) and the Italian Diversibipalium specimens were compared in Geneious v. 8.0.5 (http://www.geneious.com, Kearse et al. 2012) and were found to be identical. These results indicate that the species introduced in both countries is the same, and most probably concerns the species D. multilineatum. The pathways of introduction of D. multilineatum are currently unknown, although a relationship between the horticultural trade and the introduction of alien land planarians is well known (Álvarez-Presas et al. 2014 and references therein). Here we report the first occurrence of individuals of D. multilineatum outside Asia. The GenBank sequence of D. multilineatum from South Korea is not yet supported by a published description of the specimen, while it is debatable whether South Korea should be considered part of the natural range of D. multilineatum, which only seems to include Japan. In the present paper, we consider the South Korean animal to be an introduced specimen. Soil moisture status, temperature, and food availability are considered to be the main factors determining the presence of terrestrial planarians (Boag et al. 1998); the microclimatic conditions of the Italian garden were similar to plant nurseries and greenhouses, while an abundance of food was available, such as isopods [Porcellionides pruinosus (Brandt, 1833)], oligochaetes [Dendrobaena attemsi (Michaelsen, 1902) and several juveniles of Lumbricus spp.] and gastropods [Cernuella cisalpina (Rossmassler, 1837), Cornu aspersum (O.F. Müller 1774), Deroceras reticulatum (O.F. Müller, 1774), Discus rotundatus (O.F. Müller, 1774), Limacus flavus (Linnaeus, 1758), Milax nigricans (Philippi, 1836), Papillifera papillaris (Linnaeus, 1758), Pomatias elegans (O.F. Müller, 1774)]. Moreover, winter 2014 reached the highest temperatures and rainfall of the last two decades (source: CNR-ISAC, Bologna), thus favouring establishment and spread of D. multilineatum. The potential environmental impacts of some invasive flatworms are well documented (Álvarez-Presas et al. 2014; Justine et al. 2014) and, even if these effects have not yet been assessed for D. multilineatum, the adoption of precautionary measures and of early intervention is here strongly recommended (Genovesi & Shine 2004). Finally, knowledge of the introduction pathway(s), together with the analysis of prey preference and possible impact on the invertebrate fauna, will be essential to halt or at least to limit the spread of this introduced land flatworm.

  8. Insight into the role of cetaceans in the life cycle of the tetraphyllideans (Platyhelminthes: Cestoda).

    PubMed

    Aznar, F J; Agustí, C; Littlewood, D T J; Raga, J A; Olson, P D

    2007-02-01

    Four types of tetraphyllidean larvae infect cetaceans worldwide: two plerocercoids differing in size, 'small' (SP) and 'large' (LP), and two merocercoids referred to as Phyllobothrium delphini and Monorygma grimaldii. The latter merocercoid larvae parasitize marine mammals exclusively and exhibit a specialised cystic structure. Adult stages are unknown for any of the larvae and thus the role of cetaceans in the life cycle of these species has been a long-standing problem. The SP and LP forms are thought to be earlier stages of P. delphini and M. grimaldii that are presumed to infect large pelagic sharks that feed on cetaceans. A molecular analysis of the D2 variable region of the large subunit ribosomal DNA gene based on several individuals of each larval type collected from three Mediterranean species of cetaceans showed consistent and unique molecular signatures for each type regardless of host species or site of infection. The degree of divergence suggested that LP, P. delphini and M. grimaldii larvae may represent separate species, whereas SP may be conspecific with M. grimaldii. In all host species, individuals of SP accumulated in the gut areas in which the lymphoid tissue was especially developed. We suggest therefore that these larvae use the lymphatic system to migrate to the abdominal peritoneum and mesenteries where they develop into forms recognizable as M. grimaldii. The plerocercoid stage of P. delphini remains unknown. In a partial phylogenetic tree of the Tetraphyllidea, all larvae formed a clade that included a representative of the genus Clistobothrium, some species of which parasitize sharks such as the great white which is known to feed on cetaceans. A bibliographic examination of tetraphyllidean infections in marine mammals indicated that these larvae are acquired mostly offshore. In summary, the evidence suggests that cetaceans play a significant role in the life cycle of these larvae. In addition, it seems clear that cetaceans act as natural intermediate hosts for P. delphini and M. grimaldii, as within these hosts they undergo development from the plerocercoid stage to the merocercoid stage. Because tetraphyllidean species use fish, cephalopods and other marine invertebrates as intermediate hosts, the inclusion of cetaceans in the life cycle would have facilitated their transmission to apex predators such as the large, lamnid sharks. The biological significance of infections of LP in cetaceans is unclear, but infections do not seem to be accidental as such larvae show high prevalence and abundance as well as a high degree of site specificity, particularly in the anal crypts and bile ducts.

  9. Spermatozoa of tapeworms (Platyhelminthes, Eucestoda): advances in ultrastructural and phylogenetic studies.

    PubMed

    Levron, Céline; Miquel, Jordi; Oros, Mikulás; Scholz, Tomás

    2010-08-01

    New data on spermiogenesis and the ultrastructure of spermatozoa of 'true' tapeworms (Eucestoda) are summarized. Since 2001, more than 50 species belonging to most orders of the Eucestoda have been studied or reinvestigated, particularly members of the Caryophyllidea, Spathebothriidea, Diphyllobothriidea, Bothriocephalidea, Trypanorhyncha, Tetraphyllidea, Proteocephalidea, and Cyclophyllidea. A new classification of spermatozoa of eucestodes into seven basic types is proposed and a key to their identification is given. For the first time, a phylogenetic tree inferred from spermatological characters is provided. New information obtained in the last decade has made it possible to fill numerous gaps in the character data matrix, enabling us to carry out a more reliable analysis of the evolution of ultrastructural characters of sperm and spermiogenesis in eucestodes. The tree is broadly congruent with those based on morphological and molecular data, indicating that convergent evolution of sperm characters in cestodes may not be as common as in other invertebrate taxa. The main gaps in the current knowledge of spermatological characters are mapped and topics for future research are outlined, with special emphasis on those characters that might provide additional information about the evolution of tapeworms and their spermatozoa. Future studies should be focused on representatives of those major groups (families and orders) in which molecular data indicate paraphyly or polyphyly (e.g. 'Tetraphyllidea' and Trypanorhyncha) and on those that have a key phylogenetic position among eucestodes (e.g. Diphyllidea, 'Tetraphyllidea', Lecanicephalidea, Nippotaeniidea).

  10. Redescription and designation of a neotype of Temnocephala talicei Dioni, 1967 (Platyhelminthes: Temnocephalida).

    PubMed

    Volonterio, Odile

    2009-04-01

    Temnocephala talicei was described from Uruguayan material found mainly on Aegla prado. Its original description was based principally on its distinctive penial stylet, and, therefore, many aspects of the species anatomy that are now important in the taxonomy of the genus were not contemplated; type specimens were never designated; and the material used to describe the species has been lost. The present work provides a redescription of the species based upon material collected from the type host and in the type locality. Given the possibility of confusion in its identification, and in order to preserve its taxonomic stability, a neotype of T. talicei is designated. The closest species to T. talicei is Temnocephala mertoni, from which it can be separated by the presence of conspicuous intestinal septa, a markedly asymmetrical sphincter in the vagina, markedly lobed testes, a straight penial stylet with a non-sinuous distal portion of the shaft, a characteristic large, 'mouthpiece'-shaped introvert without discrete thickenings, and approximately 10 crowns of well-developed spines of decreasing length placed throughout the whole extension of the introvert. A comparison of material from Uruguay, Argentina, and Paraguay shows that there is little variation in the morphometry of the species. Finally, a comparison of the post-tentacular syncytia of T. talicei and T. mertoni shows that this is not always a species-specific character.

  11. The first troglobitic species of freshwater flatworm of the suborder Continenticola (Platyhelminthes) from South America

    PubMed Central

    de Souza, Stella Teles; Morais, Ana Laura Nunes; Cordeiro, Lívia Medeiros; Leal-Zanchet, Ana Maria

    2015-01-01

    Abstract Brazilian cave diversity, especially of invertebrates, is poorly known. The Bodoquena Plateau, which is located in the Cerrado Biome in central Brazil, has approximately 200 recorded caves with a rich system of subterranean water resources and high troglobitic diversity. Herein we describe a new troglobitic species of Girardia that represents the first obligate cave-dwelling species of the suborder Continenticola in South America. Specimens of the new species, which occur in a limestone cave in the Bodoquena Plateau, in the Cerrado biome, are unpigmented and eyeless. Species recognition in the genus Girardia is difficult, due to their great morphological resemblance. However, the new species can be easily recognized by a unique feature in its copulatory apparatus, namely a large, branched bulbar cavity with multiple diverticula. PMID:25632242

  12. A new and aberrant species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Madagascar

    PubMed Central

    Stocchino, Giacinta Angela; Sluys, Ronald; Manconi, Renata

    2014-01-01

    Abstract In this paper we report a new species of Dugesia of the family Dugesiidae from Madagascar, representing the fourth species of freshwater planarian known from this global biodiversity hotspot. In some respects the new species is aberrant, when compared with its congeners, being characterized by a head with smoothly rounded auricles, a peculiar course of the oviducts, including the presence of a common posterior extension, and by the asymmetrical openings of the vasa deferentia at about halfway along the seminal vesicle. Further, it is characterized by a ventral course of the ejaculatory duct with a terminal opening, very long spermiducal vesicles and unstalked cocoons. Its diploid chromosome complement with 18 chromosomes represents an uncommon feature among fissiparous species of Dugesia. PMID:25147450

  13. Dugesia sicula (Platyhelminthes, Tricladida): the colonizing success of an asexual Planarian

    PubMed Central

    2013-01-01

    Background Dugesia sicula is the only species of its genus not presenting an endemic or restricted distribution within the Mediterranean area. It mostly comprises fissiparous populations (asexual reproduction by body division and regeneration), most likely sexually sterile, and characterized by an extremely low genetic diversity interpreted as the consequence of a recent anthropic expansion. However, its fissiparous reproduction can result in an apparent lack of diversity within the species, since genetic variation within individuals can be as large as between them because most individuals within a population are clones. We have estimated haplotype and nucleotide diversity of cytochrome oxidase I within and among individuals along the species distribution of a broad sample of D. sicula, including asexual and the two only sexual populations known today; and predicted its potential distribution based on climatic variables. Our aim was to determine the centre of colonisation origin, whether the populations are recent, and whether the species is expanding. Results The species presents 3 most frequent haplotypes, differing in a maximum of 11 base pairs. As expected from their fissiparous mode of reproduction, in half of all the analysed localities many individuals have multiple heteroplasmic haplotypes. The distribution of haplotypes is not geographically structured; however, the distribution of haplotypes and heteroplasmic populations shows higher diversity in the central Mediterranean region. The potential distribution predicted by climatic variables based modelling shows a preference for coastal areas and fits well with the observed data. Conclusions The distribution and frequency of the most frequent haplotypes and the presence of heteroplasmic individuals allow us to gain an understanding of the recent history of the species, together with previous knowledge on its phylogenetic relationships and age: The species most probably originated in Africa and dispersed through the central Mediterranean. After one or multiple populations became triploid and fissiparous, the species colonized the Mediterranean basin, likely both by its own means and helped by human activities. Its present distribution practically fulfils its potential distribution as modelled with climatic variables. Its prevalence in coastal regions with higher water temperatures predicts a likely future expansion to northern and more interior areas following the increase in temperatures due to climate change. PMID:24330464

  14. Aqueous aluminium eliminates Gyrodactylus salaris (Platyhelminthes, Monogenea) infections in Atlantic salmon.

    PubMed

    Soleng, A; Poléo, A B; Alstad, N E; Bakke, T A

    1999-07-01

    This study focuses on the effect of acidic water and aqueous aluminium on the monogenean ectoparasite Gyrodactylus salaris, infecting Atlantic salmon (Salmo salar) parr. G. salaris-infected salmon were exposed to various combinations of acidity and aluminium concentrations. The most pronounced effect was the elimination of parasites after 4 days when 202 micrograms Al/l was added to the water. The effect of aluminium was concentration dependent, but was relatively independent of pH (5.2, 5.6 and 5.9). At the lowest pH of 5.0 the effect of aluminium was enhanced. Acidic aluminium-poor water had no or minor effects on the G. salaris infections except at pH 5.0 where all parasites were eliminated within 9 days. The G. salaris populations increased exponentially in untreated control water. The results show for the first time that aqueous aluminium can, to a limited extent, have a positive effect on fish health. This study emphasizes that basic knowledge about abiotic environmental factors is of importance in order to understand the population dynamics, range extension and dispersal of ectoparasites such as G. salaris. Finally, our results suggest that aluminium treatment could form an effective disinfection method against ectoparasites in hatcheries and laboratories, as well as complementing the controversial rotenone treatments used against natural populations of G. salaris.

  15. A new family of Monostome flukes (Platyhelminths, Digenea) from the dugong, Dugong dugon (Müller).

    PubMed

    Blair, D

    1979-01-01

    The family Labicolidae is erected to contain a new species of Monostome fluke occurring in abcesses in the upper lip of the dugong from northern Australia. Labicola elongata is described as a new species and figured.

  16. Indosolenorchis hirudinaceus Crusz, 1951 (Platyhelminthes; Digenea) from the Dugong, Dugong dugon (Müller) (Mammalia; Sirenia).

    PubMed

    Blair, D

    1980-01-01

    Indosolenorchis hirudinaceus Crusz, 1951 from the caecum and large intestine of the dugong (Dugong dugon Müller) is redescribed from specimens from the Red Sea, East Africa, Sri Lanka, Japan, Indonesia and Australasia. Specimens described by Dollfus (1950) as Zygocotyle species are referred to Indosolenorchis hirudinaceus. There is some doubt concerning the identity of the genus Solenorchis as described by Hilmy (1949), but for the time being, it seems best to retain Solenorchis and Indosolenorchis as separate genera.

  17. Selection of cell fate in the organ of Corti involves the integration of Hes/Hey signaling at the Atoh1 promoter.

    PubMed

    Abdolazimi, Yassan; Stojanova, Zlatka; Segil, Neil

    2016-03-01

    Determination of cell fate within the prosensory domain of the developing cochlear duct relies on the temporal and spatial regulation of the bHLH transcription factor Atoh1. Auditory hair cells and supporting cells arise in a wave of differentiation that patterns them into discrete rows mediated by Notch-dependent lateral inhibition. However, the mechanism responsible for selecting sensory cells from within the prosensory competence domain remains poorly understood. We show in mice that rather than being upregulated in rows of cells, Atoh1 is subject to transcriptional activation in groups of prosensory cells, and that highly conserved sites for Hes/Hey repressor binding in the Atoh1 promoter are needed to select the hair cell and supporting cell fate. During perinatal supporting cell transdifferentiation, which is a model of hair cell regeneration, we show that derepression is sufficient to induce Atoh1 expression, suggesting a mechanism for priming the 3' Atoh1 autoregulatory enhancer needed for hair cell expression.

  18. Conditional Deletion of Atoh1 Reveals Distinct Critical Periods for Survival and Function of Hair Cells in the Organ of Corti

    PubMed Central

    Cai, Tiantian; Seymour, Michelle L.; Zhang, Hongyuan; Pereira, Fred A.

    2013-01-01

    Atonal homolog1 (Atoh1) encodes a basic helix–loop–helix protein that is the first transcription factor to be expressed in differentiating hair cells. Previous work suggests that expression of Atoh1 in prosensory precursors is necessary for the differentiation and survival of hair cells, but it is not clear whether Atoh1 is required exclusively for these processes, or whether it regulates other functions later during hair cell maturation. We used EGFP-tagged Atoh1 knock-in mice to demonstrate for the first time that Atoh1 protein is expressed in hair cell precursors several days before the appearance of differentiated markers, but not in the broad pattern expected of a proneural gene. We conditionally deleted Atoh1 at different points in hair cell development and observe a rapid onset of hair cell defects, suggesting that the Atoh1 protein is unstable in differentiating hair cells and is necessary through an extended phase of their differentiation. Conditional deletion of Atoh1 reveals multiple functions in hair cell survival, maturation of stereociliary bundles, and auditory function. We show the presence of distinct critical periods for Atoh1 in each of these functions, suggesting that Atoh1 may be directly regulating many aspects of hair cell function. Finally, we show that the supporting cell death that accompanies loss of Atoh1 in hair cells is likely caused by the abortive trans-differentiation of supporting cells into hair cells. Together our data suggest that Atoh1 regulates multiple aspects of hair cell development and function. PMID:23761906

  19. Development of a phase-sensitive Fourier domain optical coherence tomography system to measure mouse organ of Corti vibrations in two cochlear turns

    SciTech Connect

    Ramamoorthy, Sripriya; Zhang, Yuan; Jacques, Steven; Petrie, Tracy; Wang, Ruikang; Nuttall, Alfred L.

    2015-12-31

    In this study, we have developed a phase-sensitive Fourier-domain optical coherence tomography system to simultaneously measure the in vivo inner ear vibrations in the hook area and second turn of the mouse cochlea. This technical development will enable measurement of intra-cochlear distortion products at ideal locations such as the distortion product generation site and reflection site. This information is necessary to un-mix the complex mixture of intra-cochlear waves comprising the DPOAE and thus leads to the non-invasive identification of the local region of cochlear damage.

  20. Development of a phase-sensitive Fourier domain optical coherence tomography system to measure mouse organ of Corti vibrations in two cochlear turns

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, Sripriya; Zhang, Yuan; Petrie, Tracy; Jacques, Steven; Wang, Ruikang; Nuttall, Alfred L.

    2015-12-01

    In this study, we have developed a phase-sensitive Fourier-domain optical coherence tomography system to simultaneously measure the in vivo inner ear vibrations in the hook area and second turn of the mouse cochlea. This technical development will enable measurement of intra-cochlear distortion products at ideal locations such as the distortion product generation site and reflection site. This information is necessary to un-mix the complex mixture of intra-cochlear waves comprising the DPOAE and thus leads to the non-invasive identification of the local region of cochlear damage.

  1. Porphyrin mediated photo-modification of the structure and function of human serum albumin

    NASA Astrophysics Data System (ADS)

    Rozinek, Sarah C.

    Photosensitization reactions involve irradiating (with visible light) molecules with a high efficiency for either electron transfer or entering an excited triplet state (photosensitizer). Such reactions are applied to photodynamic cancer therapy, many medical laser-treatments, and a potential array of disinfection and pest elimination techniques. To understand the biophysical mechanisms of how these applications are effective at the protein level, the group of Dr. Brancaleon (UTSA) has investigated the irradiation of several dye-protein combinations, and discovered effects on protein structure and function. To further that work, we have investigated irradiation of the protein, human serum albumin (HSA), photosensitized by either protoporphyrin IX (PPIX) or meso-tetrakis(4-sulfonatophenyl)porphyrin (TSPP). HSA is the most abundant plasma protein, making it a likely substrate in PDT, and it possesses a specific binding pocket for iron-PPIX (heme) and possibly other porphyrin derivatives. The results of our research are summarized as follows. First, a thorough characterization of the binding of each photosensitizer to albumin was completed, elucidating a probable binding location for TSPP. Next, fluorescence lifetime emission of the single tryptophan residue, alongside circular dichroism, found tertiary structural changes around tryptophan and an overall 20% decrease in protein secondary structure after irradiation with TSPP bound. Finally, to determine if protein function was lost after photosensitization, size exclusion chromatography found modified albumin still recognizable by its receptor-protein, and comparative ex vivo up-take studies revealed that modified albumin is not processed the same way as native albumin in live tapeworm larva (Mesocestoides corti). Thus we found that visible light can induce partial unfolding of a protein by using a photo-activated ligand. These small structural modifications were sufficient to affect the protein's biological function.

  2. Use of Molecular Methods for the Rapid Mass Detection of Schistosoma mansoni (Platyhelminthes: Trematoda) in Biomphalaria spp. (Gastropoda: Planorbidae)

    PubMed Central

    Jannotti-Passos, Liana Konovaloffi; Dos Santos Carvalho, Omar

    2017-01-01

    The low stringency-polymerase chain reaction (LS-PCR) and loop-mediated isothermal amplification (LAMP) assays were used to detect the presence of S. mansoni DNA in (1) Brazilian intermediate hosts (Biomphalaria glabrata, B. straminea, and B. tenagophila) with patent S. mansoni infections, (2) B. glabrata snails with prepatent S. mansoni infections, (3) various mixtures of infected and noninfected snails; and (4) snails infected with other trematode species. The assays showed high sensitivity and specificity and could detect S. mansoni DNA when one positive snail was included in a pool of 1,000 negative specimens of Biomphalaria. These molecular approaches can provide a low-cost, effective, and rapid method for detecting the presence of S. mansoni in pooled samples of field-collected Biomphalaria. These assays should aid mapping of transmission sites in endemic areas, especially in low prevalence regions and improve schistosomiasis surveillance. It will be a useful tool to monitor low infection rates of snails in areas where control interventions are leading towards the elimination of schistosomiasis. PMID:28246533

  3. The invasive land planarian Platydemus manokwari (Platyhelminthes, Geoplanidae): records from six new localities, including the first in the USA.

    PubMed

    Justine, Jean-Lou; Winsor, Leigh; Barrière, Patrick; Fanai, Crispus; Gey, Delphine; Han, Andrew Wee Kien; La Quay-Velázquez, Giomara; Lee, Benjamin Paul Yi-Hann; Lefevre, Jean-Marc; Meyer, Jean-Yves; Philippart, David; Robinson, David G; Thévenot, Jessica; Tsatsia, Francis

    2015-01-01

    The land planarian Platydemus manokwari de Beauchamp, 1963 or "New Guinea flatworm" is a highly invasive species, mainly in the Pacific area, and recently in Europe (France). We report specimens from six additional countries and territories: New Caledonia (including mainland and two of the Loyalty Islands, Lifou and Maré), Wallis and Futuna Islands, Singapore, Solomon Islands, Puerto Rico, and Florida, USA. We analysed the COI gene (barcoding) in these specimens with two sets of primers and obtained 909 bp long sequences. In addition, specimens collected in Townsville (Australia) were also sequenced. Two haplotypes of the COI sequence, differing by 3.7%, were detected: the "World haplotype" found in France, New Caledonia, French Polynesia, Singapore, Florida and Puerto Rico; and the "Australian haplotype" found in Australia. The only locality with both haplotypes was in the Solomon Islands. The country of origin of Platydemus manokwari is New Guinea, and Australia and the Solomon Islands are the countries closest to New Guinea from which we had specimens. These results suggest that two haplotypes exist in the area of origin of the species, but that only one of the two haplotypes (the "World haplotype") has, through human agency, been widely dispersed. However, since P. manokwari is now recorded from 22 countries in the world and we have genetic information from only 8 of these, with none from New Guinea, this analysis provides only partial knowledge of the genetic structure of the invasive species. Morphological analysis of specimens from both haplotypes has shown some differences in ratio of the genital structures but did not allow us to interpret the haplotypes as different species. The new reports from Florida and Puerto Rico are firsts for the USA, for the American continent, and the Caribbean. P. manokwari is a known threat for endemic terrestrial molluscs and its presence is a matter of concern. While most of the infected territories reported until now were islands, the newly reported presence of the species in mainland US in Florida should be considered a potential major threat to the whole US and even the Americas.

  4. Differential transcriptomic responses of Biomphalaria glabrata (Gastropoda, Mollusca) to bacteria and metazoan parasites, Schistosoma mansoni and Echinostoma paraensei (Digenea, Platyhelminthes)

    PubMed Central

    Adema, Coen M; Hanington, Patrick C.; Lun, Cheng-Man; Rosenberg, George H.; Aragon, Anthony D; Stout, Barbara A; Richard, Mara L. Lennard; Gross, Paul S.; Loker, Eric S

    2009-01-01

    A 70-mer oligonucleotide-based microarray (1152 features) that emphasizes stress and immune responses factors was constructed to study transcriptomic responses of the snail Biomphalaria glabrata to different immune challenges. In addition to sequences with relevant putative ID and Gene Ontology (GO) annotation, the array features non-immune factors and unknown B. glabrata ESTs for functional gene discovery. The transcription profiles of B. glabrata (3 biological replicates, each a pool of 5 snails) were recorded at 12 hours post wounding, exposure to Gram negative or Gram positive bacteria (Escherichia coli and Micrococcus luteus, respectively), or infection with compatible trematode parasites (S. mansoni or E. paraensei, 20 miracidia/snail), relative to controls, using universal reference RNA. The data were subjected to Significance Analysis for Microarrays (SAM), with a false positive rate (FPR) ≤10%. Wounding yielded a modest differential expression profile (27 up/21 down) with affected features mostly dissimilar from other treatments. Partially overlapping, yet distinct expression profiles were recorded from snails challenged with E. coli (83 up/20 down) or M. luteus (120 up/42 down), mostly showing up-regulation of defense and stress-related features. Significantly altered expression of selected immune features indicates that B. glabrata detects and responds differently to compatible trematodes. Echinostoma paraensei infection was associated mostly with down regulation of many (immune-) transcripts (42 up/68 down), whereas S. mansoni exposure yielded a preponderance of up-regulated features (140 up/23 down), with only few known immune genes affected. These observations may reflect the divergent strategies developed by trematodes during their evolution as specialized pathogens of snails to negate host defense responses. Clearly, the immune defenses of B. glabrata distinguish and respond differently to various immune challenges. PMID:19962194

  5. The evolution of the Proteocephalidea (Platyhelminthes, Eucestoda) based on an enlarged molecular phylogeny, with comments on their uterine development.

    PubMed

    de Chambrier, Alain; Zehnder, Marc; Vaucher, Claude; Mariaux, Jean

    2004-03-01

    We present a molecular phylogeny of the Proteocephalidea based on 28S rDNA sequence data that is a follow-up to the paper by Zehnder & Mariaux (1999). Twenty-three new sequences, including three outgroups are added in our new data-set. The Gangesiinae Mola, 1929 and the Acanthotaeniinae Freze, 1963 appear to be the most primitive clades. They are followed by a robust clade comprising the Palaearctic Proteocephalinae Mola, 1929 from freshwater fishes. The structure of the more derived clades, comprising most Neotropical and Nearctic species, is less resolved. At the nomenclatural level, we erect a new genus, Glanitaenia n. g. for G. osculata (Goeze, 1782) n. comb., previously Proteocephalus osculatus, and define an aggregate for the Palaearctic Proteocephalus Weinland, 1858. After a re-examination of all of the studied taxa, we identify two types of uterine development and show the importance of this character for the systematics of the order. Our phylogeny does not support the classical view of a Neotropical origin for the Proteocephalidea but rather favours an Old World origin of the group either in saurians or Palaearctic Siluriformes.

  6. Temperature-dependent reproduction and survival of Gyrodactylus salaris Malmberg, 1957 (Platyhelminthes: Monogenea) on Atlantic salmon (Salmo salar L.).

    PubMed

    Jansen, P A; Bakke, T A

    1991-02-01

    The relationship of survival and reproduction of Gyrodactylus salaris Malmberg on the Atlantic salmon (Salmo salar) to water temperature (2.5-19.0 degrees C), was studied on the basis of temporal sequence of births and age at death of individual parasites on isolated salmon, and of infrapopulation growth on isolated and grouped salmon. Mean life-span of the parasite was negatively correlated with water temperature: 33.7 days at 2.5 degrees C and 4.5 days at 19.0 degrees C. The average number of offspring per parasite peaked between 6.5 and 13.0 degrees C, and was approximately 2.4 at these two temperatures. Both the period between the successive births of the offspring (max 4) and the estimated generation time were negatively correlated with temperature. The innate capacity for increase (rm) was positively correlated with temperature: from 0.02 (/parasite/day) at 2.5 degrees C to 0.22 (/parasite/day) at 19.0 degrees C. Growth of the infrapopulations was positively correlated with water temperature and was higher on isolated fish than on grouped fish, though less than the potential parasite population growth estimated from rm. In the infrapopulations the mean intensity of parasites continued to increase throughout all the experiments on both isolated fish and on grouped fish.

  7. Comparative analyses within Gyrodactylus (Platyhelminthes: Monogenea) mitochondrial genomes and conserved polymerase chain reaction primers for gyrodactylid mitochondrial DNA.

    PubMed

    Ye, F; Easy, R H; King, S D; Cone, D K; You, P

    2017-04-01

    In this study, we describe the complete mitochondrial genomes of Gyrodactylus brachymystacis and Gyrodactylus parvae infecting rainbow trout (Oncorhynchus mykiss) and the invasive topmouth gudgeon (Pseudorasbora parva), respectively. The two circular genomes have a common genome organization found in other Gyrodactylus species. Comparative analyses of mitochondrial genomes from six Gyrodactylus species were carried out to determine base composition, codon usage, transfer RNA and ribosomal RNA genes, major non-coding regions, and nucleotide diversity within the genus. We also provide the first universal models of the secondary structures of rrnS and rrnL for this group thereby promoting utilization of these genetic markers. Universal primers provided herein can be used to obtain more mitochondrial information for pathogen identification and may reveal different levels of molecular phylogenetic inferences for this lineage.

  8. The first report of Gyrodactylus salaris Malmberg, 1957 (Platyhelminthes, Monogenea) on Italian cultured stocks of rainbow trout (Oncorhynchus mykiss Walbaum).

    PubMed

    Paladini, Giuseppe; Gustinelli, Andrea; Fioravanti, Maria L; Hansen, Haakon; Shinn, Andrew P

    2009-11-12

    The monogenean Gyrodactylus salaris Malmberg, 1957 is considered one of the most important parasites of wild salmonids in the European Community due to the heavy ecological and economical damage it has inflicted on Atlantic salmon (Salmo salar) parr populations. Rainbow trout (Oncorhynchus mykiss) is susceptible to G. salaris and can act as a suitable carrier host and, consequently, its trade in EU territory is restricted in relation to the status of "recognized free" zones. Despite the economic importance of rainbow trout farming in Italy, information on the Italian gyrodactylid fauna is lacking and prior to this study, G. salaris had not been officially reported. During a routine health examination of farmed rainbow trout stock throughout Central and Northern Italy in 2004-2005, five fish farms were found to be infected with G. salaris alongside three other gyrodactylids. Morphological and molecular characterisation confirmed the presence of G. salaris, Gyrodactylus teuchis Lautraite, Blanc, Thiery, Daniel et Vigneulle, 1999 and Gyrodactylus derjavinoides Malmberg, Collins, Cunningham et Jalali, 2007, while Gyrodactylus truttae Gläser, 1974 was identified by morphological analysis only. The findings from this study extend the distribution of G. salaris within Europe and highlight the importance of the rainbow trout trade in its dissemination.

  9. Molecular phylogenetic analysis of the genus Gyrodactylus (Platyhelminthes: Monogenea) inferred from rDNA ITS region: subgenera versus species groups.

    PubMed

    Matejusová, I; Gelnar, M; Verneau, O; Cunningham, C O; Littlewood, D T J

    2003-12-01

    Analyses of small subunit ribosomal RNA gene sequences of representatives of major taxa of Monopisthocotylea were performed to identify the sister group of Gyrodactylus. Nuclear ribosomal DNA sequences from the complete internal transcribed spacer (ITS) region were used to infer phylogeny of 37 Gyrodactylus species and Gyrodactyloides bychowskii, Macrogyrodactylus polypteri and Gyrdicotylus gallieni, using maximum likelihood, parsimony and Bayesian inference. The genus Gyrodactylus appeared to be a monophyletic group in all analyses, based on the present data set. Within the genus, there were 3 major groups recognized by high bootstrap values and posterior probabilities. None of the 6 subgenera appeared to be monophyletic, and the most basal subgenus G. (Gyrodactylus) was paraphyletic. Characteristics of the excretory system of Gyrodactylus do not seem to be conservative enough to reveal subgenera within Gyrodactylus and we suggest abandoning existing subgenera as indicators of phylogeny. The grouping of species based on the morphology of the ventral bar and marginal hooks seems to have sufficient power to infer relationships between the Gyrodactylus species.

  10. Spot the difference: Two cryptic species of Gyrodactylus von Nordmann, 1832 (Platyhelminthes: Monogenea) infecting Astyanax aeneus (Actinopterygii, Characidae) in Mexico.

    PubMed

    Razo-Mendivil, Ulises; García-Vásquez, Adriana; Rubio-Godoy, Miguel

    2016-10-01

    Over the course of one year, undescribed specimens of Gyrodactylus were recovered from banded tetra, Astyanax aeneus collected in the La Antigua and Nautla river basins in central Veracruz, Mexico. Parasites were processed for morphometric and molecular analyses. Morphometrically, Gyrodactylus samples collected in the La Antigua river had slightly smaller haptoral structures than those collected from the Nautla river. During the 12month-collection of samples, however, water temperature varied considerably (ca. 20°C to 30°C), and this abiotic factor is known to affect the size of gyrodactylid attachment structures. Moreover, no clear discrimination was possible between individual parasites collected from the two rivers based on the morphology of the marginal hook, which is recognised as a very informative character to discriminate between species. The morphology of the ventral bar, however, differed between specimens from both rivers: worms from Nautla all had long, rounded processes on the ventral bar, which formed a relatively closed angle with the dorsal edge of the bar proper, while most - but not all - specimens from La Antigua had comparatively slender processes forming a more open angle with respect to the ventral bar. Phylogenetic analyses based on the sequences of the ITS1, 5.8S rRNA gene, and ITS2 of gyrodactylids indicated the existence of two distinct, well-supported lineages whose sequences differ by >4%, one of which was only found in the Nautla basin, while the other was collected in both river systems. A posteriori, principal component analysis (PCA) of the morphometric data of sequenced specimens indicated that features of the dorsal bar, the hamuli and the ventral bar enable discrimination between the two phylogenetic lineages. Based on these independent sources of information (morphometric and molecular data), two new species of Gyrodactylus are described: Gyrodactyluspakan n. sp. and Gyrodactylusteken n. sp. The phylogenetic relationships of both new species to other gyrodactylids infecting characiformes (for which molecular data are available) are presented, which suggests that their closest relative is Gyrodactylus carolinae, a parasite of Characidium lanei in Brazil.

  11. Structural and Population Polymorphism of RT-Like Sequences in Avian Schistosomes Trichobilharzia szidati (Platyhelminthes: Digenea: Schistosomatidae)

    PubMed Central

    Semyenova, S. K.; Chrisanfova, G. G.; Guliaev, A. S.; Yesakova, A. P.; Ryskov, A. P.

    2015-01-01

    Recently we developed the genus-specific markers of the avian schistosomes of the genus Trichobilharzia, the causative agents of human cercarial dermatitis. The 7 novel genome sequences of T. franki, T. regenti, and T. szidati revealed similarity with genome repeat region of African schistosome Schistosoma mansoni. In the present work we analyzed the 37 new T. szidati sequences to study intragenome variability and host specificity for the parasite from three localities of East Europe. DNAs were isolated from cercariae or single sporocysts obtained from 6 lymnaeid snails Lymnaea stagnalis and L. palustris from Belarus and Russia. All sequences formed three diverged groups, one of which consists of the sequences with multiple deletions; other groups involved two paralogous copies with stop codons and frameshift mutations. Strong association between geographical distribution and snail host specificity cannot be established. All studied sequences have homology with the reverse transcriptase domain (RT) of Penelope-like elements (PLE) of S. mansoni and S. japonicum and new members of RT family were identified. We proposed that three diverged groups RT sequences of T. szidati are results of duplication or transposition of PLE during parasite evolution. Implications of the retroelement dynamics in the life history of avian schistosomes are discussed. PMID:26114104

  12. Macrostomida (Platyhelminthes: Rhabditophora) from Argentina, with descriptions of two new species of Macrostomum and of stylet ultrastructure.

    PubMed

    Brusa, Franscisco

    2006-10-01

    In this work, two new species of the genus Macrostomum (M. velastylum n. sp. and M. puntapiedrensis n. sp.) are described from the littoral benthos of the Río de la Plata estuary, Argentina. This is the first description of members of the Macrostomidae from Argentina, and of a species documented from both limnic and brackish-water environments. Macrostomum velastylum differs from its congeners in the fine details of its stylet, which are described using a new technique for stylet isolation and observation (scanning electron microscope). This method provides new information on stylet structure relative to traditional whole-mount techniques. Macrostomum puntapiedrensis differs from others species of the M. orthostylum group in the length and morphology of the distal tip of the stylet. Further details are provided on additional macrostomids from Argentina, including potential conspecifics of M. vejdovskyi, M. viride, and M. lineare.

  13. Morphological and molecular characterisation of Gyrodactylus salmonis (Platyhelminthes, Monogenea) isolates collected in Mexico from rainbow trout (Oncorhynchus mykiss Walbaum).

    PubMed

    Rubio-Godoy, Miguel; Paladini, Giuseppe; Freeman, Mark A; García-Vásquez, Adriana; Shinn, Andrew P

    2012-05-25

    Gyrodactylus salmonis (Yin et Sproston, 1948) isolates collected from feral rainbow trout, Oncorhynchus mykiss (Walbaum) in Veracruz, southeastern Mexico are described. Morphological and molecular variation of these isolates to G. salmonis collected in Canada and the U.S.A. is characterised. Morphologically, the marginal hook sickles of Mexican isolates of G. salmonis closely resemble those of Canadian specimens - their shaft and hook regions align closely with one another; only features of the sickle base and a prominent bridge to the toe permit their separation. The 18S sequence determined from the Mexican specimens was identical to two variable regions of SSU rDNA obtained from a Canadian population of G. salmonis. Internal transcribed spacer (ITS) regions (spanning ITS1, 5.8S and ITS2) of Mexican isolates of G. salmonis are identical to ITS sequences of an American population of G. salmonis and to Gyrodactylus salvelini Kuusela, Ziętara et Lumme, 2008 from Finland. Analyses of the ribosomal RNA gene of Mexican isolates of G. salmonis show 98-99% similarity to those of Gyrodactylus gobiensis Gläser, 1974, Gyrodactylus salaris Malmberg, 1957, and Gyrodactylus rutilensis Gläser, 1974. Mexican and American isolates of G. salmonis are 98% identical, as assessed by sequencing the mitochondrial cox1 gene. Oncorhynchus mykiss is one of the most widely-dispersed fish species in the world and has been shown to be an important vector for parasite/disease transmission. Considering that Mexican isolates of G. salmonis were collected well outside the native distribution range of all salmonid fish, we discuss the possibility that the parasites were translocated with their host through the aquacultural trade. In addition, this study includes a morphological review of Gyrodactylus species collected from rainbow trout and from other salmonid fish of the genus Oncorhynchus which occur throughout North America.

  14. Phylogenetic analysis of dicyemid mesozoans (phylum Dicyemida) from innexin amino acid sequences: dicyemids are not related to Platyhelminthes.

    PubMed

    Suzuki, Takahito G; Ogino, Kazutoyo; Tsuneki, Kazuhiko; Furuya, Hidetaka

    2010-06-01

    Dicyemid mesozoans are endoparasites, or endosymbionts, found only in the renal sac of benthic cephalopod molluscs. The body organization of dicyemids is very simple, consisting of usually 10 to 40 cells, with neither body cavities nor differentiated organs. Dicyemids were considered as primitive animals, and the out-group of all metazoans, or as occupying a basal position of lophotrochozoans close to flatworms. We cloned cDNAs encoding for the gap junction component proteins, innexin, from the dicyemids. Its expression pattern was observed by whole-mount in situ hybridization. In adult individuals, the innexin was expressed in calottes, infusorigens, and infusoriform embryos. The unique temporal pattern was observed in the developing infusoriform embryos. Innexin amino acid sequences had taxon-specific indels which enabled identification of the 3 major protostome lineages, i.e., 2 ecdysozoans (arthropods and nematodes) and the lophotrochozoans. The dicyemids show typical, lophotrochozoan-type indels. In addition, the Bayesian and maximum likelihood trees based on the innexin amino acid sequences suggested dicyemids to be more closely related to the higher lophotrochozoans than to the flatworms. Flatworms were the sister group, or consistently basal, to the other lophotrochozoan clade that included dicyemids, annelids, molluscs, and brachiopods.

  15. A new and alien species of ``oyster leech'' (Platyhelminthes, Polycladida, Stylochidae) from the brackish North Sea Canal, The Netherlands

    NASA Astrophysics Data System (ADS)

    Sluys, Ronald; Faubel, Anno; Rajagopal, Sanjeevi; Velde, Gerard Van Der

    2005-11-01

    A new species of polyclad flatworm, Imogine necopinata Sluys, sp. nov., is described from a brackish habitat in The Netherlands. Taxonomic affinities with Asian species and the ecology of the animals suggest that the species is an introduced, exotic component of the Dutch fauna. The new species belongs to a group of worms with species that are known to predate on oysters.

  16. Mitochondrial haplotype diversity of Gyrodactylus thymalli (Platyhelminthes; Monogenea): extended geographic sampling in United Kingdom, Poland, and Norway reveals further lineages.

    PubMed

    Hansen, Haakon; Bakke, Tor A; Bachmann, Lutz

    2007-05-01

    In recent years, the mitochondrial haplotype diversity of the monogenean ectoparasites Gyrodactylus salaris Malmberg, 1957 on Atlantic salmon and G. thymalli Zitnan, 1960 on grayling has been studied intensively to understand the taxonomy and phylogeography of the two species. According to these studies, neither species can be considered monophyletic, but unfortunately, the geographic sampling has mostly been restricted to Fennoscandia. Only few samples from continental Europe have been analysed, and samples from the United Kingdom have not been included at all. Gyrodactylosis is a notifiable disease in Europe and is in the UK considered the most important exotic disease threat to wild Atlantic salmon populations. In this study, we report six new mitochondrial haplotypes of G. thymalli from England, Poland, and Norway detected by sequencing 745 bp of the cytochrome oxidase I gene. The six new haplotypes add five new clades to a neighbor-joining dendrogram deduced on the basis of the currently known 44 mitochondrial haplotypes for G. thymalli and G. salaris. We conclude that G. thymalli established in the UK along with the immigration of grayling. There is currently no reason to suspect that this parasite is a threat to Atlantic salmon in the UK, although its infectivity to salmon stocks in the UK has not been tested.

  17. Two new species of Temnocephala (Platyhelminthes, Temnocephalida) from the South American snake-necked turtle Hydromedusa tectifera (Testudines, Chelidae).

    PubMed

    Volonterio, Odile

    2010-12-01

    Temnocephala brevicornis Monticelli, 1889 is the only species of the genus Temnocephala Blanchard, 1849 reported from chelonians to date. During a survey of the species of Temnocephala extant in southern Uruguay, two new species were found on the chelonian Hydromedusa tectifera Cope, 1869. They are described here as Temnocephala pereirai n. sp. and Temnocephala cuocoloi n. sp. Both resemble T. brevicornis, but differ in the morphometry of the penial stylet, and in qualitative details of the reproductive complex. Temnocephala pereirai n. sp. differs from T. brevicornis by having a massive, cylindrical sphincter in the distal portion of the vagina, and a seminal vesicle that opens into the subpolar to equatorial portion of the contractile vesicle. In addition, the penial stylet in Temnocephala pereirai n. sp. is large in relation to body size, straight and more slender, having the distal portion of its shaft slightly sinuous, and a smaller introvert equipped with about 16 distal crowns of smaller spines. Temnocephala cuocoloi n. sp. is most similar to T. brevicornis, but differs by having a smaller, curved penial stylet that has a smaller introvert in relation to stylet size, with about 10 distal crowns of smaller spines. A key to the species of the Temnocephala from chelonians is provided. This study supports the validity of the following characters previously proposed for the taxonomy of the genus Temnocephala: the shape of the sphincters in the female reproductive system, the shape of the penial stylet, and the number, size, and position of spines in the introvert.

  18. Host-based identification is not supported by morphometrics in natural populations of Gyrodactylus salaris and G. thymalli (Platyhelminthes, Monogenea).

    PubMed

    Olstad, K; Shinn, A P; Bachmann, L; Bakke, T A

    2007-12-01

    Gyrodactylus salaris is a serious pest of wild pre-smolt Atlantic salmon (Salmo salar) in Norway. The closely related G. thymalli, originally described from grayling (Thymallus thymallus), is assumed harmless to both grayling and salmon. The 2 species are difficult to distinguish using traditional, morphometric methods or molecular approaches. The aim of this study was to explore whether there is a consistent pattern of morphometrical variation between G. salaris and G. thymalli and to analyse the morphometric variation in the context of 'diagnostic realism' (in natural populations). Specimens from the type-material for the 2 species are also included. In total, 27 point-to-point measurements from the opisthaptoral hard parts were used and analysed by digital image processing and uni- and multivariate morphometry. All populations most closely resembled its respective type material, as expected from host species, with the exception of G. thymalli from the Norwegian river Trysilelva. We, therefore, did not find clear support in the morphometrical variation among G. salaris and G. thymalli for an a priori species delineation based on host. The present study also indicates an urgent need for more detailed knowledge on the influence of environmental factors on the phenotype of gyrodactylid populations.

  19. On the systematic position of Collyricloides massanae Vaucher, 1969 (Platyhelminthes: Digenea) with notes on distribution of this trematode species.

    PubMed

    Kanarek, Gerard; Zaleśny, Grzegorz; Czujkowska, Agnieszka; Sitko, Jiljí; Harris, Philip D

    2015-04-01

    The systematic position of the Collyricloides massanae, a rare cyst-dwelling parasite, located on intestinal wall of European birds and rodents, have always been controversial. Based on newly obtained sequences of the 28 sDNA of C. massanae from avian and rodent host from Central Europe, and on the previously published sequences of several genera and families among Microphalloidea, we evaluate its taxonomic position and the phylogenetic relationships within the genera Collyriclum Kossack, 1911 and Collyricloides Vaucher, 1969 which form the family Collyriclidae Ward, 1917. In the cladogram, C. massanae appears among the Pleurogenidae, forming a clade with Gyrabascus amphoraeformis (Modlinger, 1930) and Cortrema magnicaudata (Bykhovskaya-Pavlovskaya, 1950). We reject the commonly accepted placement of Collyricloides as the sister genus to Collyriclum within the Collyriclidae. Besides, we present and discuss the unusual records of C. massanae in the bank vole Myodes glareolus from northeastern Poland.

  20. Sperm ultrastructure of the digenean Aphallus tubarium (Rudolphi, 1819) Poche, 1926 (Platyhelminthes, Cryptogonimidae) intestinal parasite of Dentex dentex (Pisces, Teleostei).

    PubMed

    Foata, J; Quilichini, Y; Greani, S; Marchand, B

    2012-02-01

    The ultrastructural organization of the spermatozoon of a cryptogonimid digenean, Aphallus tubarium, a parasite of Dentex dentex, is described. The spermatozoon possesses the elements found in other digeneans: two axonemes with 9+"1" pattern, a mitochondrion, a nucleus, cortical microtubules, external ornamentation and spine-like bodies. However, the mitochondrion appears as a cord with a bulge; this characteristic has never been described in other studied cryptogonimid and in other digeneans except in one lepocreadiid, Holorchis micracanthum. Likewise, the presence of a thin cytoplasm termination in the anterior part of the spermatozoon has never been pointed out in the cryptogonimids.

  1. Massive parasitism by Gussevia tucunarense (Platyhelminthes: Monogenea: Dactylogyridae) in fingerlings of bujurqui-tucunare cultured in the Peruvian Amazon.

    PubMed

    Mathews, Patrick D; Mertins, Omar; Mathews, John P D; Orbe, Rosa I

    2013-06-01

    A high infestation of the monogenean Gussevia tucunarense in a cultivation of bujurqui-tucunare was reported. The prevalence was 100%. The mean intensity and abundance of the parasite was 164.4 of parasites per individual. This is the first report of a high infestation by G. tucunarense in C. semifasciatus cultured from the Peruvian Amazon.

  2. Cryptostylochus hullensis sp. nov. (Polycladida, Acotylea, Platyhelminthes): A possible case of transoceanic dispersal on a ship's hull

    NASA Astrophysics Data System (ADS)

    Faubel, A.; Gollasch, S.

    1996-12-01

    In July 1993, the car carrier “Faust” entered Bremerhaven after a voyage from the North-American Atlantic coast to Europe. In a dockyard, five living specimens of the order Polycladida were collected from the hull of the ship. This could be a possible case of trans-atlantic dispersal of plathelminths living as fouling organisms of ships. The specimens found represent a new species of the genus Cryptostylochus Faubel, 1983, Cryptostylochus hullensis sp. nov.

  3. Molecular cloning, functional characterization and localization of an annexin from a fish gill fluke Microcotyle sebastis (Platyhelminthes: Monogenea).

    PubMed

    Choi, Seung Hyuk; Kwon, Se Ryun; Lee, Eun Hye; Kim, Ki Hong

    2009-01-01

    The full cDNA of an annexin gene from Microcotyle sebastis (MsANX) was cloned for the first time in monogeneans. The cDNA of MsANX comprises 1199bp with a 29bp 5' untranslated region, an open reading frame of 1062bp, and a 108bp 3' untranslated region. The recombinantly produced MsANX bound phosphatidylserine vesicles in the presence of Ca2+, whereas no MsANX was precipitated in the absence of free Ca2+. Phylogenetically, MsANX formed a cluster with human annexin A13, known as the earliest annexin in vertebrates and expressed mainly in the intestine. The localization of MsANX in M. sebastis was analyzed by Western blotting and immunohistochemistry using the antiserum raised against the recombinant MsANX. In Western blot analysis, rat antiserum bound to a protein corresponding to the MsANX in size when worm crude extracts were used as antigens, but no bands were detected by the antiserum when the excretory/secretory proteins of worms were used as antigens. In immunohistochemistry analysis, significant antibody binding annexin was found in the ovarian region, the pharynx and the intestinal caecum of the worm. Interestingly, the alimentary canal location of MsANX was similar to the location of human annexin A13, and further research is needed to trace evolutionary relationship among helminthic annexins and human annexin A13. Also it remains to be investigated whether immunization of naïve fish with the recombinant MsANX can induce protective immune responses against M. sebastis infection.

  4. A comprehensive molecular phylogeny of dalytyphloplanida (platyhelminthes: rhabdocoela) reveals multiple escapes from the marine environment and origins of symbiotic relationships.

    PubMed

    Van Steenkiste, Niels; Tessens, Bart; Willems, Wim; Backeljau, Thierry; Jondelius, Ulf; Artois, Tom

    2013-01-01

    In this study we elaborate the phylogeny of Dalytyphloplanida based on complete 18S rDNA (156 sequences) and partial 28S rDNA (125 sequences), using a Maximum Likelihood and a Bayesian Inference approach, in order to investigate the origin of a limnic or limnoterrestrial and of a symbiotic lifestyle in this large group of rhabditophoran flatworms. The results of our phylogenetic analyses and ancestral state reconstructions indicate that dalytyphloplanids have their origin in the marine environment and that there was one highly successful invasion of the freshwater environment, leading to a large radiation of limnic and limnoterrestrial dalytyphloplanids. This monophyletic freshwater clade, Limnotyphloplanida, comprises the taxa Dalyelliidae, Temnocephalida, and most Typhloplanidae. Temnocephalida can be considered ectosymbiotic Dalyelliidae as they are embedded within this group. Secondary returns to brackish water and marine environments occurred relatively frequently in several dalyeliid and typhloplanid taxa. Our phylogenies also show that, apart from the Limnotyphloplanida, there have been only few independent invasions of the limnic environment, and apparently these were not followed by spectacular speciation events. The distinct phylogenetic positions of the symbiotic taxa also suggest multiple origins of commensal and parasitic life strategies within Dalytyphloplanida. The previously established higher-level dalytyphloplanid clades are confirmed in our topologies, but many of the traditional families are not monophyletic. Alternative hypothesis testing constraining the monophyly of these families in the topologies and using the approximately unbiased test, also statistically rejects their monophyly.

  5. Ultrastructural study of the male gamete of Pleurogonius truncatus Prudhoe, 1944 (Platyhelminthes, Digenea, Pronocephalidae) parasite of Eretmochelys imbricata (Linnaeus, 1766).

    PubMed

    Ndiaye, Papa Ibnou; Quilichini, Yann; Sène, Aminata; Tkach, Vasyl V; Bâ, Cheikh Tidiane; Marchand, Bernard

    2012-04-01

    In Pronocephaloidea, the spermatozoa of only two species have been studied today. Because of this, we present in this work data concerning to a third specie, Pleurogonius truncatus Prudhoe, 1944. The mature spermatozoon of P. truncatus possesses two axonemes with the 9+"1" pattern typical of Trepaxonemata, mitochondrion, nucleus, parallel cortical microtubules, spinelike bodies, cytoplasmic expansion and an external ornamentation of the plasma membrane. A particularity of the spermatozoon of P. truncatus is in the ultrastructure of the anterior spermatozoon extremity with only cortical microtubules and ornamentation of the plasma membrane. This type of anterior extremity has never been described until today in Pronocephaloidea. On the other hand, the ultrastructure of the posterior extremity of the spermatozoon confirms that already described in Pronocephalidae.

  6. The complete mitochondrial genome of Neobenedenia melleni (Platyhelminthes: Monogenea): mitochondrial gene content, arrangement and composition compared with two Benedenia species.

    PubMed

    Zhang, Juan; Wu, Xiangyun; Li, Yanwei; Zhao, Mengwei; Xie, Mingquan; Li, Anxing

    2014-10-01

    The complete mitochondrial (mt) genome sequences of Neobenedenia melleni were determined and compared with those of Benedenia seriolae and B. hoshinai. This circular genome comprises 13,270 bp and includes all 36 typical mt genes found in flatworms. Total AT content of N. melleni is 75.9 %. ATG is the most common start codon, while nad4L is initiated by GTG. All protein-coding genes are predicted to terminate with TAG and TAA. N. melleni has the trnR with a TCG anticodon, which is the same to B. seriolae but different from B. hoshinai (ACG). The mt gene arrangement of N. melleni is similar to that of B. seriolae and B. hoshinai with the exception of three translocations (trnF, trnT and trnG). The overlapped region between nad4L and nad4 was found in the N. melleni mt genome, which was also reported for the published Gyrodactylus species, but it was not found in those of B. seriolae and B. hoshinai, which are non-coding regions instead. The present study provides useful molecular characters for species or strain identification and systematic studies of this parasite.

  7. Reproduction and survival under different water temperatures of Gyrodactylus mexicanus (Platyhelminthes: Monogenea), a parasite of Girardinichthys multiradiatus in Central Mexico.

    PubMed

    Sereno-Uribe, Ana L; Zambrano, Luis; García-Varela, Martín

    2012-12-01

    Gyrodactylid population growth may depend on abiotic variables such as temperature. We tested the survival and reproductive rate of Gyrodactylus mexicanus, a parasite infecting fins of Girardinichthys multiradiatus, at 3 different water temperatures, 10-13, 19-22, and 24 C. The temporal sequence of birth and age at death of each parasite isolated from the hosts was recorded through at least 8 generations. Our results showed that the average number of offspring per parasite was 2.0 when averaged across all temperatures. However, the generation time was negatively correlated with temperature. The innate capacity for increase (r(m)) was positively correlated with water temperature: from 0.29 parasite/day at 13 C to 0.48 parasite/day at 24 C. These data confirm that water temperature has a direct influence on parasite population dynamics. The current study represents the first contribution to understanding the population ecology of the monogenean G. mexicanus in central Mexico.

  8. Two new species of Pasipha Ogren & Kawakatsu (Platyhelminthes: Continenticola) from areas of deciduous forest in southern Brazil.

    PubMed

    Amaral, Silvana Vargas Do; Leal-Zanchet, Ana Maria

    2016-09-29

    Two new species of Geoplaninae from southern Brazil are described herein. The new species, belonging to the genus Pasipha Ogren & Kawakatsu, 1990, can be distinguished from each other and from their congeners by colour pattern and characteristics of the copulatory apparatus, especially regarding the female organs and prostatic vesicle. Both new species seem to be endemic to areas covered by deciduous forest.

  9. The mitochondrial genome of Gyrodactylus derjavinoides (Platyhelminthes: Monogenea)--a mitogenomic approach for Gyrodactylus species and strain identification.

    PubMed

    Huyse, Tine; Buchmann, Kurt; Littlewood, D T J

    2008-07-01

    Systematists and evolutionary biologists are constantly on the lookout for new sources of characters to discriminate amongst taxa and estimate interrelationships within and between taxa. Entire mitochondrial genomes provide a wealth of data, both at the nucleotide and amino acid level. Molecular markers are of particular utility when applied to small, morphologically conserved taxa, as is the case for many monogenean ectoparasites of fish. Gyrodactylus species display a considerable degree of anatomical conservatism, complicating diagnostics based solely on morphology, and some are significant pests of wild and cultured fish. Here we sequenced the complete mitochondrial genome of Gyrodactylus derjavinoides Malmberg, Collins, Cunningham & Behiar 2007, one of the most frequently found gyrodactylid species on salmonids in Scandinavia, and compared it with the recently published genomes of Gyrodactylus salaris Malmberg, 1957 and Gyrodactylus thymalli Zitnan 1960. Through comparative sliding window analysis we identified regions of high sequence variability and designed new primer sequences. In total, 6 new primer pairs have been developed, amplifying fragments of cox1, cox3, nad1, nad2, nad4, nad5 and atp6. Together, they amplify regions capturing almost half the nucleotide variability present in the complete mitochondrial genome. These degenerate primers should also work for other Gyrodactylus species parasitizing salmonids. In addition, we developed a multiplex assay that simultaneously amplifies four fragments in a single PCR reaction. Besides the diagnostic value, these fragments can be used for studying the transmission dynamics of Gyrodactylus, providing crucial information for an improved understanding of the spread and epidemiology of these important fish pathogens.

  10. Adding resolution to ordinal level relationships of tapeworms (Platyhelminthes: Cestoda) with large fragments of mtDNA.

    PubMed

    Waeschenbach, Andrea; Webster, B L; Littlewood, D T J

    2012-06-01

    The construction of a stable phylogeny for the Cestoda, indicating the interrelationships of recognised orders and other major lineages, has proceeded iteratively since the group first received attention from phylogenetic systematists. Molecular analyses using nuclear ribosomal RNA gene fragments from the small (ssrDNA) and large (lsrDNA) subunits have been used to test competing evolutionary scenarios based on morphological data but could not arbitrate between some key conflicting hypotheses. To the ribosomal data, we have added a contiguous fragment of mitochondrial (mt) genome data (mtDNA) of partial nad1-trnN-trnP-trnI-trnK-nad3-trnS-trnW-cox1-trnT-rrnL-trnC-partial rrnS, spanning 4034-4447 bp, where new data for this region were generated for 18 species. Bayesian analysis of mtDNA and rDNA as nucleotides, and where appropriate as amino acids, demonstrated that these two classes of genes provide complementary signal across the phylogeny. In all analyses, except when using mt amino acids only, the Gyrocotylidea is sister group to all other Cestoda (Nephroposticophora), and Amphilinidea forms the sister group to the Eucestoda. However, an earliest-diverging position of Amphilinidea is strongly supported in the mt amino acid analysis. Amphilinidea exhibit a unique tRNA arrangement (nad1-trnI-trnL2-trnP-trnK-trnV-trnA-trnN-nad3), whereas Gyrocotylidea shares that of the derived lineages, providing additional evidence of the uniqueness of amphilinid genes and genomes. The addition of mtDNA to the rDNA genes supported the Caryophyllidea as the sister group to (Spathebothriidea+remaining Eucestoda), a hypothesis consistently supported by morphology. This relationship suggests a history of step-wise evolutionary transitions from simple monozoic, unsegmented tapeworms to the more familiar polyzoic, externally segmented (strobilate) forms. All our data partitions recovered Haplobothriidea as the sister group to Diphyllobothriidae. The sister-group relationship between Diphyllidea and Trypanorhyncha, as previously established using rDNA, is not supported by the mt data, although it is supported by the combined mt and rDNA analysis. With regards to the more derived taxa, in all except the mt amino acid analysis, the following topology is supported: (Bothriocephalidea (Litobothriidea (Lecanicephalidea (Rhinebothriidea (Tetraphyllidea, (Acanthobothrium, Proteocephalidea), (Nippotaeniidea, Mesocestoididae, Tetrabothriidea, Cyclophyllidea)))))), where the Tetraphyllidea are paraphyletic. Evidence from the mt data provides strong (nucleotides) to moderate (amino acids) support for Tetraphyllidea forming a group to the inclusion of Proteocephalidea, with the latter consistently forming the sister group to Acanthobothrium. The interrelationships among Nippotaeniidea, Mesocestoididae, Tetrabothriidea and Cyclophyllidea remain ambiguous and require further systematic attention. Mitochondrial and nuclear rDNA data provide conflicting signal for certain parts of the cestode tree. In some cases mt data offer results in line with morphological evidence, such as the interrelationships of the early divergent lineages. Also, Tetraphyllidea, although remaining paraphyletic with the inclusion of the Proteocephalidea, does not include the most derived cestodes; a result which has consistently been obtained with rDNA.

  11. Added resolution among ordinal level relationships of tapeworms (Platyhelminthes: Cestoda) with complete small and large subunit nuclear ribosomal RNA genes.

    PubMed

    Waeschenbach, Andrea; Webster, Bonnie L; Bray, Rodney A; Littlewood, D T J

    2007-10-01

    The addition of large subunit ribosomal DNA (lsrDNA) to small subunit ribosomal DNA (ssrDNA) has been shown to add resolution to phylogenies at various taxonomic levels for a diversity of phyla. We added nearly complete lsrDNA (4057-4593bp) sequences to ssrDNA (1940-2228bp) for 26 ingroup and 3 outgroup taxa in an attempt to provide an improved ordinal phylogeny for the Cestoda. Ten lsrDNA and seven ssrDNA sequences were generated from new taxa and 13 existing partial lsrDNA sequences were sequenced to completion. The majority of phylogenetic signal in the combined analysis came from lsrDNA (69.6% of parsimonious informative sites, as opposed to 30.4% obtained from ssrDNA), resulting in almost identical topologies for lsrDNA and lsr+ssrDNA (pairwise symmetric distance=6) in model-based analyses. Topology testing found trees based on partial lsrDNA (domains D1-D3)+ssrDNA and complete lsr+ssrDNA to differ significantly; the addition of lsrDNA domains D4-D12 had a significant effect on topology. Overall nodal support was greatest in the combined analysis and weakest for ssrDNA only. Our molecular phylogenies differed significantly from those based on morphology alone. Acetabulate lineages form a monophyletic group, with the Tetraphyllidea being paraphyletic. Support for the combined data was high for the following topology: (Litobothriidea (Lecanicephalidea (Rhinebothrium/Rhodobothrium (Clistobothrium (Pachybothrium(Acanthobothrium Proteocephalidea) (Mesocestoididae, Nippotaeniidea, Cyclophyllidea, Tetrabothriidea)))))); all genus names refer to tetraphyllidean lineages. Although the interrelationships among the four most derived taxa remain uncertain, overall ambiguity of the acetabulate interrelationships was reduced. The Pseudophyllidea were recovered as polyphyletic, with support for a sister-group relationship between Diphyllobothriidae and Haplobothriidea. The monophyly of the Trypanorhyncha was recovered for the first time based on molecular data. The positions of the Trypanorhyncha, Diphyllidea and "Bothriocephaliidea" in relation to other orders remains ambiguous. Higher congruence was found between trees based on model-based phylogenetic methods than with those constructed under the parsimony criterion. Although some uncertainties remain, the addition of lsrDNA D4-D12 has provided an overall more resolved and better supported cestode phylogeny, which further promotes the utility of complete lsrDNA as phylogenetic marker where ssrDNA alone proves inadequate.

  12. Demonstrating the value and importance of combining DNA barcodes and discriminant morphological characters for polystome taxonomy (Platyhelminthes, Monogenea).

    PubMed

    Héritier, Laurent; Verneau, Olivier; Smith, Kevin G; Coetzer, Carina; Du Preez, Louis H

    2017-03-20

    Polystomes are monogenean parasites that infest mainly semi aquatic vertebrates, such as amphibians and chelonians. Owing to the lack of discriminative morphological characters and because polystomes are considered to be strictly host- and site-specific, host identity is often used as an additional character for parasite identification. Recent genetic studies, however, show that polystomes infecting freshwater turtles in outdoor turtle enclosures and natural environments, are not strictly host-specific. Therefore, we proposed a new procedure for turtle polystome taxonomy based on the combination of Cytochrome c Oxydase I sequences and two discriminant morphological characters, namely the number of genital spines and the testis shape. We tested the validity of this procedure with Polystomoides oris, which was collected from the pharyngeal cavity of the American painted turtle Chrysemys picta and two undescribed species, both collected from the pharyngeal cavity of the American slider Trachemys scripta and two other European turtles, namely the European pond turtle Emys orbicularis and the Mediterranean turtle Mauremys leprosa. A Principal Component Analysis based on both morphological characters allowed the separation of all specimens in three morphological groups, which matched well with the molecular data. As a result, we describe two new polystome species, i.e., Polystomoides soredensis n. sp. and Polystomoides scriptanus n. sp.

  13. Fluvial basin history in the northeastern Mediterranean region underlies dispersal and speciation patterns in the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae).

    PubMed

    Solà, Eduard; Sluys, Ronald; Gritzalis, Konstantinos; Riutort, Marta

    2013-03-01

    In this study we analyzed the phylogenetic relationships of eastern Mediterranean freshwater planarians of the genus Dugesia, estimated divergence times for the various clades, and correlated their phylogeographic patterns with geological and paleoclimatic events, in order to discover which evolutionary processes have shaped the present-day distribution of these animals. Specimens were collected from freshwater courses and lakes in continental and insular Greece. Genetic divergences and phylogenetic relationships were inferred by using the mitochondrial gene subunit I of cytochrome oxidase (COI) and the nuclear ribosomal internal transcribed spacer-1 (ITS-1) from 74 newly collected individuals from Greece. Divergence time estimates were obtained under a Bayesian framework, using the COI sequences. Two alternative geological dates for the isolation of Crete from the mainland were tested as calibration points. A clear phylogeographic pattern was present for Dugesia lineages in the Eastern Mediterranean. Morphological data, combined with information on genetic divergences, revealed that eight out of the nine known species were represented in the samples, while additional new, and still undescribed species were detected. Divergence time analyses suggested that Dugesia species became isolated in Crete after the first geological isolation of the island, and that their present distribution in the Eastern Mediterranean has been shaped mainly by vicariant events but also by dispersal. During the Messinian salinity crisis these freshwater planarians apparently were not able to cross the sea barrier between Crete and the mainland, while they probably did disperse between islands in the Aegean Sea. Their dependence on freshwater to survive suggests the presence of contiguous freshwater bodies in those regions. Our results also suggest a major extinction of freshwater planarians on the Peloponnese at the end of the Pliocene, while about 2Mya ago, when the current Mediterranean climate was established, these Peloponnese populations probably began to disperse again. At the end of the Pliocene or during the Pleistocene, mainland populations of Dugesia colonized the western coast, including the Ionian Islands, which were then part of the continent.

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

    PubMed

    Kuchta, Roman; Pearson, Rebecca; Scholz, Tomás; Ditrich, Oleg; Olson, Peter D

    2014-08-01

    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.e. microtriches). The peculiar morphology of the members of this group, which is today represented by five effectively monotypic genera whose host associations and geographical distribution show little commonality, indicate that it is a relictual group that was once diverse and widespread. The order potentially represents the earliest branch of true tapeworms (i.e. Eucestoda) among extant forms.

  15. The invasive land planarian Platydemus manokwari (Platyhelminthes, Geoplanidae): records from six new localities, including the first in the USA

    PubMed Central

    Winsor, Leigh; Barrière, Patrick; Fanai, Crispus; Gey, Delphine; Han, Andrew Wee Kien; La Quay-Velázquez, Giomara; Lee, Benjamin Paul Yi-Hann; Lefevre, Jean-Marc; Meyer, Jean-Yves; Philippart, David; Robinson, David G.; Thévenot, Jessica; Tsatsia, Francis

    2015-01-01

    The land planarian Platydemus manokwari de Beauchamp, 1963 or “New Guinea flatworm” is a highly invasive species, mainly in the Pacific area, and recently in Europe (France). We report specimens from six additional countries and territories: New Caledonia (including mainland and two of the Loyalty Islands, Lifou and Maré), Wallis and Futuna Islands, Singapore, Solomon Islands, Puerto Rico, and Florida, USA. We analysed the COI gene (barcoding) in these specimens with two sets of primers and obtained 909 bp long sequences. In addition, specimens collected in Townsville (Australia) were also sequenced. Two haplotypes of the COI sequence, differing by 3.7%, were detected: the “World haplotype” found in France, New Caledonia, French Polynesia, Singapore, Florida and Puerto Rico; and the “Australian haplotype” found in Australia. The only locality with both haplotypes was in the Solomon Islands. The country of origin of Platydemus manokwari is New Guinea, and Australia and the Solomon Islands are the countries closest to New Guinea from which we had specimens. These results suggest that two haplotypes exist in the area of origin of the species, but that only one of the two haplotypes (the “World haplotype”) has, through human agency, been widely dispersed. However, since P. manokwari is now recorded from 22 countries in the world and we have genetic information from only 8 of these, with none from New Guinea, this analysis provides only partial knowledge of the genetic structure of the invasive species. Morphological analysis of specimens from both haplotypes has shown some differences in ratio of the genital structures but did not allow us to interpret the haplotypes as different species. The new reports from Florida and Puerto Rico are firsts for the USA, for the American continent, and the Caribbean. P. manokwari is a known threat for endemic terrestrial molluscs and its presence is a matter of concern. While most of the infected territories reported until now were islands, the newly reported presence of the species in mainland US in Florida should be considered a potential major threat to the whole US and even the Americas. PMID:26131377

  16. The preferential accumulation of cadmium in the head portion of the freshwater planarian, Dugesia japonica (Platyhelminthes: Turbellaria).

    PubMed

    Wu, Jui-Pin; Chen, Hon-Cheng; Li, Mei-Hui

    2011-12-01

    Free-living freshwater planarians are considered to have the potential for development as an experimental model for toxicological studies on xenobiotics, including metals. However, little was known about the distribution patterns of metals in the body of treated planarians. This study was conducted to determine the tissue distribution patterns of cadmium (Cd) in different body portions of the treated planarian, Dugesia japonica. Results showed that Cd accumulated in the head of planarians at a significantly higher concentration than in the tail. After examining the level of metallothionein (MT), we suggested that the tissue distribution pattern of Cd might be related to MT induction patterns. In contrast, in planarians treated with copper (Cu), neither the tissue accumulation of Cu nor the multiples of induction of MTs significantly differed between different portions. Furthermore, a higher Cd accumulation rate in the head of planarians caused more-severe oxidative stress to appear in this portion and also a higher susceptibility to a lethal concentration of Cd. Finally, both in vitro and in vivo acetylcholinesterase activities in both body portions of planarians were inhibited by Cd. The present study provides the first report that different metals are distributed in various body portions with different patterns in the planarian.

  17. Freshwater Mussels (Mollusca: Bivalvia: Unionidae) of the Upper Mississippi River: Observations at Selected Sites Within the 9-Foot Navigation Channel Project for the St. Paul District, United States Army Corps of Engineers, 1977 - 1979. Volume I. Text.

    DTIC Science & Technology

    1980-09-10

    Platyhelminthes : Trematoda). This point somewhat coun- ters the idea of this population’s viability. Partially reviewed by Fuller (1974), Nearctic...infestation with flukes, a group of parasitic flatworms ( Platyhelminthes : Trematoda). UM -- Upper Mississippi. Unionicolidae, unionicolid -- the

  18. Clarks Hill Lake Water Quality Study.

    DTIC Science & Technology

    1982-06-01

    MACROINVERTEBRATE TAXONOMIC LIST CLARKS HILL LAKE 1981 Phylum Platyhelminthes Order Diptera Class Turbellaria Ablabesmyia parajanta unidentified Planariidae A...HILL LAKE 1981 Phylum Platyhelminthes Order Diptera (continued) Planaria sp.,’ Bezzia sp. 2 unidentified Planariidae Chaoborus punctipennis unidentified

  19. Biological Survey Along the St. Lawrence River for the St. Lawrence Seaway. Additional Locks and other Navigation Improvements Study.

    DTIC Science & Technology

    1979-01-01

    only one month (Table 6). Nine phylums were represented - Porifera, Coelenterata, Platyhelminthes , Nematoda, Nematomorpha, Firyozoa, Annel-ida...Hydroids) - colonies Phylum Platyhelminthes Class Turbellaria (Flatworms) Phylum Nematoda (Roundworms) Phylum Nematomorpha (Horsehair worms) Phylum

  20. Remedial Investigation/Feasibility Study, Operable Unit 5, Elmendorf AFB, Anchorage, Alaska. Volume 2. Text and Appendices A - J

    DTIC Science & Technology

    1994-03-04

    w.o.h.c. Limnodrilus sp. Lixnnodrilus cf. hoffmeisteri Rhyacodri lus montana PLATYHELMINTHES . Turbel laria Tricladida ARTHOPODA Arachnoidea Hydracanina...sp. Lixunodrilus cf. hoffmeisteri Rhyacodrilus montana PLATYHELMINTHES Turbellaria Tricladida11 ARTHOPODA Arachnoidea Hydracarina1113 Crustacea...w.h.c. Tubificidae w.o.h.c. 2 2 Limnodrilus sp. Limnodrilus cf. hoffmeisteri Rhyacodri lus montana PLATYHELMINTHES Turbel laria Tricladida ARTHOPODA

  1. Invasive Marine and Estuarine Animals of the Pacific Northwest and Alaska

    DTIC Science & Technology

    2005-09-01

    Schyphozoan 1 1 Porifera 6 3 1 7 Anthozoan 1 3 1 3 Platyhelminth 2 2 Polychaete 13 16 2 21 Oligochaete 4 3 6 Bivalve 17...Cercaria batillariae Platyhelminth WA Pseudostylochus ostreaphagus Platyhelminth WA Hobsonia (Amphicteis) florida Polychaete WA OR Capitella

  2. Reduced Leukocyte Infiltration in Absence of Eosinophils Correlates with Decreased Tissue Damage and Disease Susceptibility in ΔdblGATA Mice during Murine Neurocysticercosis

    PubMed Central

    Mishra, Pramod K.; Li, Qun; Munoz, Luis E.; Mares, Chris A.; Morris, Elizabeth G.; Teale, Judy M.; Cardona, Astrid E.

    2016-01-01

    Neurocysticercosis (NCC) is one of the most common helminth parasitic diseases of the central nervous system (CNS) and the leading cause of acquired epilepsy worldwide. NCC is caused by the presence of the metacestode larvae of the tapeworm Taenia solium within brain tissues. NCC patients exhibit a long asymptomatic phase followed by a phase of symptoms including increased intra-cranial pressure and seizures. While the asymptomatic phase is attributed to the immunosuppressive capabilities of viable T. solium parasites, release of antigens by dying organisms induce strong immune responses and associated symptoms. Previous studies in T. solium-infected pigs have shown that the inflammatory response consists of various leukocyte populations including eosinophils, macrophages, and T cells among others. Because the role of eosinophils within the brain has not been investigated during NCC, we examined parasite burden, disease susceptibility and the composition of the inflammatory reaction in the brains of infected wild type (WT) and eosinophil-deficient mice (ΔdblGATA) using a murine model of NCC in which mice were infected intracranially with Mesocestoides corti, a cestode parasite related to T. solium. In WT mice, we observed a time-dependent induction of eosinophil recruitment in infected mice, contrasting with an overall reduced leukocyte infiltration in ΔdblGATA brains. Although, ΔdblGATA mice exhibited an increased parasite burden, reduced tissue damage and less disease susceptibility was observed when compared to infected WT mice. Cellular infiltrates in infected ΔdblGATA mice were comprised of more mast cells, and αβ T cells, which correlated with an abundant CD8+ T cell response and reduced CD4+ Th1 and Th2 responses. Thus, our data suggest that enhanced inflammatory response in WT mice appears detrimental and associates with increased disease susceptibility, despite the reduced parasite burden in the CNS. Overall reduced leukocyte infiltration due to

  3. Electron-Microscopic Examination of the Distribution of Sodium in Corti’s Organ of Animals, That Are Located in the State of Relative Rest and in the Conditions of Sonic Action

    DTIC Science & Technology

    1992-03-18

    1966. Hfigh sodium content of cortical astrocytes. Arch. neurol., 15 : 633-642. - K a ye G., C olIe J. and D o h n A. 1965. microscopy . sodium...in the rabbit gallbladder . J1. cell biol., Va und CI- in Zellen und Geweben. Protoplasma, 55 :414-418. - S mni it h C., ry0. ’and W u M. 1954

  4. Characterization of South American Snails of the Genus Biomphalaria (Basommatophora: Planorbidae) and Schistosoma mansoni (Platyhelminthes: Trematoda) in Molluscs by PCR-RFLP.

    PubMed

    Caldeira, Roberta Lima; Teodoro, Tatiana Maria; Jannotti-Passos, Liana Konovaloff; Lira-Moreira, Pollanah M; Goveia, Christiane De Oliveira; Carvalho, Omar Dos Santos

    2016-01-01

    The identification of snails of the genus Biomphalaria can be done using morphological characteristics which depends on the size of the snails and skill and knowledge of researcher. These methods sometimes are not adequate for identification of species. The PCR-RFLP, using the ITS region of the rDNA, has been used to identify Brazilian species of the genus Biomphalaria. Nevertheless, there is a lack of information about snails from other Latin American countries. In addition, some snails may be infected by Schistosoma mansoni and when submitted to PCR-RFLP they show molecular profiles different from those previously standardized for the other mollusc species. In this work the molecular profiles of 15 species and the subspecies were established by PCR-RFLP of ITS-rDNA with the enzyme DdeI. Moreover, the molecular profiles of host species, B. glabrata, B. straminea, B. tenagophila, and B. prona, infected by S. mansoni were also established. The molluscs were dissected to permit morphological identification. These results contribute to a correct identification of snails of the genus Biomphalaria and detection of these snails infected by S. mansoni.

  5. Discrimination between Gyrodactylus salaris, G. derjavini and G. truttae (Platyhelminthes: Monogenea) using restriction fragment length polymorphisms and an oligonucleotide probe within the small subunit ribosomal RNA gene.

    PubMed

    Cunningham, C O; McGillivray, D M; MacKenzie, K; Melvin, W T

    1995-07-01

    The small subunit ribosomal RNA (srRNA) gene was amplified from Gyrodactylus salaris using the polymerase chain reaction (PCR), cloned, and the complete gene sequence of 1966 bp determined. The V4 region of the srRNA gene was identified and amplified from single specimens of G. salaris, G. derjavini and G. truttae. Comparison of the V4 sequences from these three species revealed sequence differences from which restriction fragment length polymorphisms (RFLPs) were predicted and an oligonucleotide probe (GsV4) specific to G. salaris designed. Digestion of the amplified V4 region of the srRNA gene with Hae III and either Alw I, BstY I, Dde I or Mbo I provided a means of discriminating between G. salaris, G. derjavini and G. truttae. The GsV4 probe was used to detect the srRNA gene from G. salaris in Southern and dot blots of the amplified V4 region.

  6. A large 28S rDNA-based phylogeny confirms the limitations of established morphological characters for classification of proteocephalidean tapeworms (Platyhelminthes, Cestoda)

    PubMed Central

    de Chambrier, Alain; Waeschenbach, Andrea; Fisseha, Makda; Scholz, Tomáš; Mariaux, Jean

    2015-01-01

    Abstract Proteocephalidean tapeworms form a diverse group of parasites currently known from 315 valid species. Most of the diversity of adult proteocephalideans can be found in freshwater fishes (predominantly catfishes), a large proportion infects reptiles, but only a few infect amphibians, and a single species has been found to parasitize possums. Although they have a cosmopolitan distribution, a large proportion of taxa are exclusively found in South America. We analyzed the largest proteocephalidean cestode molecular dataset to date comprising more than 100 species (30 new), including representatives from 54 genera (80%) and all subfamilies, thus significantly improving upon previous works to develop a molecular phylogeny for the group. The Old World origin of proteocephalideans is confirmed, with their more recent expansion in South America. The earliest diverging lineages are composed of Acanthotaeniinae and Gangesiinae but most of the presently recognized subfamilies (and genera) appear not to be monophyletic; a deep systematic reorganization of the order is thus needed and the present subfamilial system should be abandoned. The main characters on which the classical systematics of the group has been built, such as scolex morphology or relative position of genital organs in relation to the longitudinal musculature, are of limited value, as demonstrated by the very weak support for morphologically-defined subfamilies. However, new characters, such as the pattern of uterus development, relative ovary size, and egg structure have been identified, which may be useful in defining phylogenetically well-supported subgroups. A strongly supported lineage infecting various snakes from a wide geographical distribution was found. Although several improvements over previous works regarding phylogenetic resolution and taxon coverage were achieved in this study, the major polytomy in our tree, composed largely of siluriform parasites from the Neotropics, remained unresolved and possibly reflects a rapid radiation. The genus Spasskyellina Freze, 1965 is resurrected for three species of Monticellia bearing spinitriches on the margins of their suckers. PMID:25987870

  7. Species of Gyrodactylus von Nordmann, 1832 (Platyhelminthes: Monogenea) from cichlids from Zambezi and Limpopo river basins in Zimbabwe and South Africa: evidence for unexplored species richness.

    PubMed

    Zahradníčková, Petra; Barson, Maxwell; Luus-Powell, Wilmien J; Přikrylová, Iva

    2016-09-01

    New findings on Gyrodactylus spp. parasitising African cichlids in southern Africa are presented, comprising data from Zimbabwe and South Africa. Morphometry of opisthaptoral hard parts in combination with nuclear ribosomal DNA sequences confirmed the presence of six species of Gyrodactylus von Nordmann, 1832. Three new species are described from fishes in Zimbabwe: Gyrodactylus chitandiri n. sp. from the gill arches of Coptodon rendalli (Boulenger) and Pseudocrenilabrus philander (Weber); Gyrodactylus occupatus n. sp. from the fins of Oreochromis niloticus (L.), Pharyngochromis acuticeps (Steindachner) and P. philander; and Gyrodactylus parisellei n. sp. from the fins of O. niloticus, P. philander and Tilapia sp. Gyrodactylus nyanzae Paperna, 1973 was also identified from the gills of O. niloticus and C. rendalli collected from two localities in Zimbabwe; these findings represent new host and locality records for this parasite. Gyrodactylus sturmbaueri Vanhove, Snoeks, Volckaert & Huyse, 2011 was identified from P. philander collected in South Africa and Zimbabwe thereby providing new host and locality records for this parasite. Finally, Gyrodactylus yacatli García-Vásquez, Hansen, Christison, Bron & Shinn, 2011 was collected from the fins of O. niloticus and P. philander studied in Zimbabwe; this represents the first record of this species from the continent of Africa. Notably, this study improves upon the knowledge of Gyrodactylus spp. parasitising cichlids from these southern African regions. All species studied were recorded from at least two different cichlid host species indicating trend for a wide range of Gyrodactylus hosts in Africa. Accordingly, this supports the idea of intensive host switching in the course of their evolution.

  8. First description of monogenean parasites in Lake Tanganyika: the cichlid Simochromis diagramma (Teleostei, Cichlidae) harbours a high diversity of Gyrodactylus species (Platyhelminthes, Monogenea).

    PubMed

    Vanhove, Maarten P M; Snoeks, Jos; Volckaert, Filip A M; Huyse, Tine

    2011-03-01

    Lake Tanganyika harbours the most diverse endemic cichlid fish assemblage of Africa, but its monogenean fish parasites have not been investigated. Here we report, for the first time, on the Gyrodactylus parasites in this hotspot of fish biodiversity. Haptor morphometrics and nuclear ribosomal DNA sequences revealed 3 new species on Zambian Simochromis diagramma: Gyrodactylus sturmbaueri n. sp., G. thysi n. sp. and G. zimbae n. sp. Their distinct morphology and strong genetic differentiation suggest that they belong to distant lineages within the genus Gyrodactylus, and phylogenetic reconstructions suggest affinities with other genera of gyrodactylids. Additional U-shaped haptoral plates in G. thysi n. sp. and a second large spine-like structure in the male copulatory organ of G. zimbae seem to represent new features for the genus. Such large diversity on a single host species can probably be explained by host-switching events during the course of evolution, in agreement with the generally accepted concept that ecological transfer is an important aspect of gyrodactylid speciation. Additional parasitological surveys on other host species, covering a broader phylogenetic and geographical range, should clarify the evolutionary history of Gyrodactylidae on cichlids in the African Great Lake and other parts of Africa.

  9. Molecular identification of larvae of a tetraphyllidean tapeworm (Platyhelminthes: Eucestoda) in a razor clam as an alternative intermediate host in the life cycle of Acanthobothrium brevissime.

    PubMed

    Holland, Nicholas D; Wilson, Nerida G

    2009-10-01

    Dwarf razor clams (Ensis minor) in the Gulf of Mexico are known to be infected with plerocercoid larvae of a tetraphyllidean tapeworm. Here, we show that these larvae live unencysted in the intestinal lumen of the clam. Morphologically, the larvae are similar to (although significantly larger than) tapeworm larvae previously described living in the gut of amphioxus (Branchiostoma floridae) from the same habitat. Sequence data from the D2 region of the 28S rDNA from clam-infecting larvae were identical to the sequence of Acanthobothrium brevissime isolated as larvae from amphioxus and as adults from a stingray (Dasyatis say). The sequence data leave little doubt that the dwarf razor clam and the amphioxus are alternative intermediate hosts in the life cycle of A. brevissime.

  10. Development and evaluation of a single-step duplex PCR for simultaneous detection of Fasciola hepatica and Fasciola gigantica (family Fasciolidae, class Trematoda, phylum Platyhelminthes).

    PubMed

    Le, Thanh Hoa; Nguyen, Khue Thi; Nguyen, Nga Thi Bich; Doan, Huong Thi Thanh; Le, Xuyen Thi Kim; Hoang, Chau Thi Minh; De, Nguyen Van

    2012-08-01

    A single-step multiplex PCR (here referred to as a duplex PCR) has been developed for simultaneous detection and diagnosis of Fasciola hepatica and F. gigantica. These species overlap in distribution in many countries of North and East Africa and Central and Southeast Asia and are similar in egg morphology, making identification from fecal samples difficult. Based on a comparative alignment of mitochondrial DNA (mtDNA) spanning the region of cox1-trnT-rrnL, two species-specific forward primers were designed, FHF (for F. hepatica) and FGF (for F. gigantica), and a single reverse primer, FHGR (common for both species). Conventional PCR followed by sequencing was applied using species-specific primer pairs to verify the specificity of primers and the identity of Fasciola DNA templates. Duplex PCR (using three primers) was used for testing with the DNA extracted from adult worms, miracidia, and eggs, producing amplicons of 1,031 bp for F. hepatica and 615 bp for F. gigantica. The duplex PCR failed to amplify from DNA of other common liver and intestinal trematodes, including two opisthorchiids, three heterophyids, an echinostomid, another fasciolid, and a taeniid cestode. The sensitivity assay showed that the duplex PCR limit of detection for each Fasciola species was between 0.012 ng and 0.006 ng DNA. Evaluation using DNA templates from 32 Fasciola samples (28 adults and 4 eggs) and from 25 field-collected stools of ruminants and humans revealed specific bands of the correct size and the presence of Fasciola species. This novel mtDNA duplex PCR is a sensitive and fast tool for accurate identification of Fasciola species in areas of distributional and zonal overlap.

  11. Type material of Platyhelminthes (Monogenoidea) housed in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), Rio de Janeiro, Brazil, from 1979 to 2016.

    PubMed

    Lopes, Daniela A; Mainenti, Adriana; Sanches, Magda; Knoff, Marcelo; Gomes, Delir Corrêa

    2016-01-01

    A catalogue of type material of monogenoids deposited in the Helminthological Collection of the Oswaldo Cruz Institute, FIOCRUZ (CHIOC), between 1979 and 2016, is presented, given that the last list of types was produced in 1979. The monogenoid collection comprises type lots for 203 species, distributed across 14 families and 68 genera. Specific names are listed systematically, followed by type host, infection site, type locality, specimens with the collection numbers and references. The classification and the nomenclature of the species have been updated.

  12. First report of the genus Cratera (Platyhelminthes, Geoplanidae) in Argentina, with description of a new species and comments on the species of the genus

    PubMed Central

    Negrete, Lisandro; Brusa, Francisco

    2016-01-01

    Abstract A new species of land planarians of the genus Cratera is described. Cratera viridimaculata sp. n. was recorded in the Atlantic Forest Ecoregion, in north-eastern Argentina, and represents the first report of the genus Cratera outside Brazil. The new species is about 50 mm in length and externally characterized by a color pattern consisting of a light green olive pigmentation on the dorsum, stippled with dark gray fine spots, and dorsal eyes. Other features regarding the internal anatomy are the presence of a glandular margin, Cutaneous Muscular Index (CMI) of 10–13%, pharynx cylindrical, prostatic vesicle extrabulbar, tubular and C-shaped, with a proximal bifurcated portion, penis papilla protrusible with ejaculatory duct widened in its distal portion, and female atrium funnel-shaped. The new species is compared and discussed with its congeners. PMID:27587974

  13. Two new marine flatworms (Platyhelminthes: Rhabditophora: Proseriata) of the genus Otoplana Du Plessis, 1889 from the upper Tuscany sandy shores (Italy).

    PubMed

    Meini, Gianluca

    2013-01-24

    Two new otoplanid species, from the interstitial habitats of the North-Western Mediterranenan sea coast, are described. The specimens show the typical morphological peculiarities of the subfamily Otoplaninae ("Turbellaria", Otoplanidae), but clearly differ from other species described in this group. Otoplana labronica sp. nov. is characterized by a body length of 1.2-1.5 mm, different features of the testes and vitellaries, the male sclerotic apparatus composed of a median aculeus (52-53 μm long) and 16 peculiar spines (19-44 μm long). This new species has the smallest number of spines (17) and the smaller body length, in comparison to all the species of the genus. Otoplana falcataspina sp. nov. is characterized by a body length of 2.3-2.4 mm, distinctive dimensions and arrangement of the vitellaries, the male sclerotic apparatus composed of a median aculeus (50-51 μm long) and 20-21 spines (22-44 μm long). This new species has a limited body length, and only the sexually mature specimens of the new species O. labronica exhibit a smaller size. They were collected below the low water mark on the sandy beaches at Calambrone and Marina di Vecchiano (Pisa, Ligurian Sea, Italy), respectively.

  14. A new species of Unilatus (Platyhelminthes: Monogenoidea) from the gills of Leporacanthicus galaxias Isbrücker et Nijssen (Siluriformes: Loricariidae) from Brazil.

    PubMed

    Branches, Bárbara; Domingues, Marcus V

    2014-03-01

    Unilatus irae sp. nov. (Dactylogyridae) is described from the gills of the armored catfish, Leporacanthicus galaxias Isbrücker et Nijssen (Loricariidae: Ancistrinae), from Guamá river, Pará State, Brazil. The new species can be differentiated from its cogeneners by the combination of the following features: anterior anchor with well-developed superficial root, inconspicuous deep root, shaft bent at midpoint, forming angle of approximately 60°, evenly short curved point; posterior anchor with inconspicuous roots, sclerotized cap of base with small protuberance for articulation to posterior bar; evenly curved shaft and short point; anterior bar broadly V-shaped, with small posteromedial projection; and posterior bar anteriorly expanded on it midportion, with expanded ends slightly curved in posterior direction.

  15. Nomina nova in Platyhelminthes pro Macrorhynchus von Graff, 1882 (non [Gmelin, 1801]; non Dunker, 1843), and Leptocleidus Mueller, 1936 (non Andrews, 1922).

    PubMed

    Hornung, Jahn J

    2016-08-19

    Two genus-group names of flat-worms-Leptocleidus Mueller, 1936 and Macrorhynchus von Graff, 1882-are junior homonyms that are preoccupied by fossil diapsid reptile genera-Leptocleidus Andrews, 1922, and Macrorhynchus Dunker, 1843-and an extant teleost fish genus-Macrorhynchus [Gmelin, 1801] ex La Cépède, 1800. These are replaced by nomina nova (Pharyngodytes nom. nov.; Graffiellus nom. nov.). Macrorhynchus [Gmelin, 1801] is an objective senior synonym of Macrorhyncus Dumeríl, 1805 ex La Cépède, 1800 (syn. nov.), and a senior homonym of Macrorhynchus Dunker, 1843, and Macrorhynchus von Graff, 1882.

  16. The use of geometric morphometrics in understanding shape variability of sclerotized haptoral structures of monogeneans (Platyhelminthes) with insights into biogeographic variability.

    PubMed

    Vignon, Matthias; Sasal, Pierre

    2010-06-01

    The sclerotized attachment organ of monogeneans has been widely used to address fundamental questions in ecology and evolution. However, traditional morphometric techniques appear to be partially inadequate and non-optimal. Traditional linear measurements mainly provide information on the size of sclerites but provide very little information, if any, on their shape. The shape of sclerites is indeed virtually unexplored and its implication for ecological and evolutionary processes remains to be analyzed. This study aims to both introduce and illustrate the use of geometric morphometrics in order to study sclerites of monogeneans in a biogeographic context. To do this, we investigated morphological variation patterns among four populations from the Pacific Ocean and six monogenean species through traditional and geometric morphometric techniques. Unlike the traditional method, the geometric morphometric method yielded a high percentage of individuals correctly classified to the four populations, providing strong evidence for phenotypic variability, divergence and local adaptation among islands without evolutionary constraint. Moreover, the traditional method also resulted in inconsistent interpretations of shape variations. This study highlighted the limitations that may arise when using traditional morphometric techniques and emphasizes that considerable information about the shape of sclerotized haptoral parts is added by using geometric morphometrics. Given the prominent taxonomic, ecological and evolutionary role of the haptor for characterizing monogeneans, we ultimately discuss the potential broad use of geometric morphometrics in a wide variety of ecological and evolutionary contexts. This powerful approach might allow a more robust estimation of the extent to which traditional evolutionary theories based on size of sclerites are congruent with their shape.

  17. The first multi-gene phylogeny of the Macrostomorpha sheds light on the evolution of sexual and asexual reproduction in basal Platyhelminthes.

    PubMed

    Janssen, Toon; Vizoso, Dita B; Schulte, Gregor; Littlewood, D Timothy J; Waeschenbach, Andrea; Schärer, Lukas

    2015-11-01

    The Macrostomorpha-an early branching and species-rich clade of free-living flatworms-is attracting interest because it contains Macrostomum lignano, a versatile model organism increasingly used in evolutionary, developmental, and molecular biology. We elucidate the macrostomorphan molecular phylogeny inferred from both nuclear (18S and 28S rDNA) and mitochondrial (16S rDNA and COI) marker genes from 40 representatives. Although our phylogeny does not recover the Macrostomorpha as a statistically supported monophyletic grouping, it (i) confirms many taxa previously proposed based on morphological evidence, (ii) permits the first placement of many families and genera, and (iii) reveals a number of unexpected placements. Specifically, Myozona and Bradynectes are outside the three classic families (Macrostomidae, Microstomidae and Dolichomacrostomidae) and the asexually fissioning Myomacrostomum belongs to a new subfamily, the Myozonariinae nov. subfam. (Dolichomacrostomidae), rather than diverging early. While this represents the first evidence for asexuality among the Dolichomacrostomidae, we show that fissioning also occurs in another Myozonariinae, Myozonaria fissipara nov. sp. Together with the placement of the (also fissioning) Microstomidae, namely as the sister taxon of Dolichomacrostomidae, this suggests that fissioning is not basal within the Macrostomorpha, but rather restricted to the new taxon Dolichomicrostomida (Dolichomacrostomidae+Microstomidae). Furthermore, our phylogeny allows new insights into the evolution of the reproductive system, as ancestral state reconstructions reveal convergent evolution of gonads, and male and female genitalia. Finally, the convergent evolution of sperm storage organs in the female genitalia appears to be linked to the widespread occurrence of hypodermic insemination among the Macrostomorpha.

  18. Escape from an evolutionary dead end: a triploid clone of Gyrodactylus salaris is able to revert to sex and switch host (Platyhelminthes, Monogenea, Gyrodactylidae).

    PubMed

    Zietara, Marek S; Kuusela, Jussi; Lumme, Jaakko

    2006-12-01

    Diploid parthenogenesis, with rare sex, is considered as the basic mode of reproduction among the hermaphroditic and viviparous Gyrodactylus. A particular strain of the monogenean parasite Gyrodactylus salaris (RBT clone) was recognized by an invariable, unique mitochondrial DNA haplotype in rainbow trout (Oncorhynchus mykiss) farms. The RBT clone was shown to be triploid and asexual by analyzing a 493 bp sequence of a nuclear DNA marker. Three alleles were present as heterozygous in all 237 individuals sampled in years 2001-2005 from five isolated Finnish farms. The triploid clone probably originated from a diploid oocyte fertilized by a non-self hermaphrodite, most probably in a fish farm. Identical mitochondrial COI gene (1606 bp) was also found in G. salaris parasites on landlocked salmon (Salmo salar) in two rivers draining to the lake Kuitozero, Russian Karelia. In the river Pisto, the clone was triploid, but the diagnostic "short" nuclear allele of the RBT clone was replaced by an allele typical for salmon specific parasites in the Lake Onega. The clone in the river Kurzhma was diploid, having lost the "short" allele, but still heterozygous for the other two alleles of the RBT clone. Evidently, the triploid parthenogenetic RBT clone had produced diploid oocytes, when (as a female) stimulated by a non-self mate in the new environment. The genetic reorganization coincided with a switch to the salmon host. Participation of triploids into the gene pool of the species is rarely reported in animals, and the triploidy is generally considered as an irreversible dead-end of the evolution. Liberalism in ploidy level may significantly add to the evolutionary options available for a parasite in ever-changing environments.

  19. Characterization of South American Snails of the Genus Biomphalaria (Basommatophora: Planorbidae) and Schistosoma mansoni (Platyhelminthes: Trematoda) in Molluscs by PCR-RFLP

    PubMed Central

    Teodoro, Tatiana Maria; Jannotti-Passos, Liana Konovaloff; Lira-Moreira, Pollanah M.; Goveia, Christiane De Oliveira; Carvalho, Omar dos Santos

    2016-01-01

    The identification of snails of the genus Biomphalaria can be done using morphological characteristics which depends on the size of the snails and skill and knowledge of researcher. These methods sometimes are not adequate for identification of species. The PCR-RFLP, using the ITS region of the rDNA, has been used to identify Brazilian species of the genus Biomphalaria. Nevertheless, there is a lack of information about snails from other Latin American countries. In addition, some snails may be infected by Schistosoma mansoni and when submitted to PCR-RFLP they show molecular profiles different from those previously standardized for the other mollusc species. In this work the molecular profiles of 15 species and the subspecies were established by PCR-RFLP of ITS-rDNA with the enzyme DdeI. Moreover, the molecular profiles of host species, B. glabrata, B. straminea, B. tenagophila, and B. prona, infected by S. mansoni were also established. The molluscs were dissected to permit morphological identification. These results contribute to a correct identification of snails of the genus Biomphalaria and detection of these snails infected by S. mansoni. PMID:27981045

  20. Land planarians (Platyhelminthes) as a model organism for fine-scale phylogeographic studies: understanding patterns of biodiversity in the Brazilian Atlantic Forest hotspot.

    PubMed

    Alvarez-Presas, M; Carbayo, F; Rozas, J; Riutort, M

    2011-04-01

    The Brazilian Atlantic Forest is one of the richest biodiversity hotspots of the world. Paleoclimatic models have predicted two large stability regions in its northern and central parts, whereas southern regions might have suffered strong instability during Pleistocene glaciations. Molecular phylogeographic and endemism studies show, nevertheless, contradictory results: although some results validate these predictions, other data suggest that paleoclimatic models fail to predict stable rainforest areas in the south. Most studies, however, have surveyed species with relatively high dispersal rates whereas taxa with lower dispersion capabilities should be better predictors of habitat stability. Here, we have used two land planarian species as model organisms to analyse the patterns and levels of nucleotide diversity on a locality within the Southern Atlantic Forest. We find that both species harbour high levels of genetic variability without exhibiting the molecular footprint of recent colonization or population expansions, suggesting a long-term stability scenario. The results reflect, therefore, that paleoclimatic models may fail to detect refugia in the Southern Atlantic Forest, and that model organisms with low dispersal capability can improve the resolution of these models.

  1. Identification of putative insulin-like peptides and components of insulin signaling pathways in parasitic platyhelminths by the use of genome-wide screening.

    PubMed

    Wang, Shuai; Luo, Xuenong; Zhang, Shaohua; Yin, Cai; Dou, Yongxi; Cai, Xuepeng

    2014-02-01

    No endogenous insulin-like peptides in parasitic flatworms have been reported. Insulin receptors from flukes and tapeworms have been shown to interact directly with the host-derived insulin molecule, which suggests the exploitation of host-derived insulin. In this study, a strategy of genome-wide searches followed by comprehensive analyses of strictly conserved features of the insulin family was used to demonstrate the presence of putative insulin-like peptides in the genomes of six tapeworms and two flukes. In addition, whole insulin signaling pathways were annotated on a genome-wide scale. Two putative insulin-like peptide genes in each genome of tapeworms and one insulin-like peptide gene in each genome of flukes were identified. The comprehensive analyses revealed that all of these peptides showed the common features shared by other members of the insulin family, and the phylogenetic analysis implied a putative gene duplication event in the Cestoda during the evolution of insulin-like peptide genes. The quantitative expression analysis and immunolocalization results suggested a putative role of these peptides in reproduction. Entire sets of major components of the classic insulin signaling pathway were successfully identified, suggesting that this pathway in parasitic flatworms might also regulate many other important biological activities. We believe that the identification of the insulin-like peptides gives us a better understanding of the insulin signaling pathway in these parasites, as well as host-parasite interactions.

  2. An analysis of the calcium-binding protein 1 of Fasciola gigantica with a comparison to its homologs in the phylum Platyhelminthes.

    PubMed

    Vichasri-Grams, Suksiri; Subpipattana, Pornpimol; Sobhon, Prasert; Viyanant, Vithoon; Grams, Rudi

    2006-03-01

    A full-length cDNA encoding the Fasciola gigantica calcium-binding protein 1 (FgCaBP1) was cloned from an adult stage cDNA expression library in an immunoscreen using rabbit immune serum against the parasite's excretion/secretion antigens. The deduced amino acid sequence showed 96.3% identity to Fh22CBP of Fasciola hepatica. During development in the mammalian host FgCaBP1 RNA was detected in metacercariae, juveniles and adults and was exclusively localized to the tegumental cell bodies. Immune serum of a rabbit infected with F. gigantica detected recombinant FgCaBP1 starting from the sixth week of infection. Immune sera of mice infected with Schistosoma mansoni and Schistosoma mekongi cross-reacted with recombinant FgCaBP1 in immunoblots. Recombinant FgCaBP1 showed calcium and magnesium-binding activity by a mobility shift during non-denaturing PAGE in the presence of Ca2+ or Mg2+, respectively. A polyclonal mouse anti-rFgCaBP1 antiserum detected the native protein as a major component of the parasite's tegumental antigens in immunoblots and as a strictly tegumental antigen in tissue cross-sections of adult and juvenile parasites. Comparative sequence analysis of homologs from Fasciola and Schistosoma present in the GenBank database revealed sequence signatures specific to these trematode proteins and thereby indicates their origin from a single ancestor. FgCaBP1 contains two adjacent, N-terminal located EF-hands and a C-terminal located domain similar to dynein light chain type 1. Independent structure predictions of the two domains suggest that they will fold according to the already determined structures of the EF-hand motif and the dynein light chain type 1 proteins.

  3. Two new Otoplanid species (Platyhelminthes: Rhabditophora: Proseriata) of the genera Orthoplana Steinböck, 1932 and Postbursoplana Ax, 1956 from the Tuscan coast (Italy).

    PubMed

    Meini, Gianluca

    2015-04-16

    Two new species of marine flatworms, collected on the sandy shores of Tuscany, are described. These species exhibit the morphological characteristics of the subfamilies Otoplaninae and Parotoplaninae ("Turbellaria", Otoplanidae), but clearly differ from other described species. Orthoplana lunae sp. nov., is characterized by a body length of 1.4-1.6 mm, distinctive features of the testes and vitellaries, the male sclerotic apparatus composed of a median stylet (48-49 μm long), and 19 spines (17-44 μm long). Postbursoplana donoraticensis sp. nov., is characterized by a body length of 1.6-1.8 mm, the distribution of testes and vitellaries, the male sclerotic apparatus composed of 10 spines (46-70 μm). This new species has a greater body length relative to other species in this genus. They were collected along the sandy shores at low water mark at Partaccia (Marina di Massa, Ligurian Sea, Italy) and Marina di Donoratico (Livorno, Ligurian Sea, Italy), respectively.

  4. Three new species of Cratera Carbayo et al., 2013 from Araucaria forests with a key to species of the genus (Platyhelminthes, Continenticola)

    PubMed Central

    Rossi, Ilana; Leal-Zanchet, Ana

    2017-01-01

    Abstract Areas of Araucaria moist forest have been considered to constitute hotspots of land flatworm diversity, harbouring a high number of undescribed species. Herein we describe three new species of land flatworms of Cratera Carbayo et al., 2013 occurring in such type of forest in south Brazil. The three species are differentiated from their congeners mainly by their colour pattern, anatomy of the pharynx and prostatic vesicle, and details of the penis papilla and male atrium. An identification key to species of the genus in the Neotropical region is provided. PMID:28144173

  5. The description of Gyrodactylus corleonis sp. n. and G. neretum sp. n. (Platyhelminthes: Monogenea) with comments on other gyrodactylids parasitising pipefish (Pisces: Syngnathidae).

    PubMed

    Paladini, Giuseppe; Cable, Joanne; Fioravanti, Maria Letizia; Faria, Patricia J; Shinn, Andrew P

    2010-03-01

    The current work describes two new species of Gyrodactylus von Nordmann, 1832 collected from pipefish Syngnathus scovelli (Evermann et Kendall) and Syngnathus typhle L. during two separate gyrodactylosis episodes on fish held in a public aquarium located in northern Italy. The gyrodactylids collected from the skin, fins and gills of pipefish were subjected to a morphological analysis of the attachment hooks and the morphometric data were compared to the four species of Gyrodactylus previously described from syngnathid hosts, namely G. eyipayipi Vaughan, Christison, Hansen et Shinn, 2010, G. pisculentui Williams, Kritsky, Dunnigan, Lash et Klein, 2008, G. shorti Holliman, 1963 and G. syngnathi Appleby, 1996. Principal components analysis (PCA) of the morphological data indicated six clusters; two discrete groups among the specimens taken from the pipefisli held in the Italian aquarium and four further groups representing G. eyipayipi, G. pisculentus, G. shorti and G. syngnathi. Molecular sequences of the ribosomal internal transcribed spacers (ITS1 and ITS2) and the 5.8S gene for the new species considered here were then compared with those available for other species in GenBank. The comparison did not reveal any identical match, supporting the morphological analysis that Gyrodactylus corleonis sp. n. from S. typhle and Gyrodactylus neretum sp. n. from S. scovelli represent distinct species. Both G. corleonis and G. neretum possess robust hamuli, marginal hook blades that curve smoothly from their sickle base to a point beyond the toe and, ventral bars with a broad median portion and a reduced membrane. Gyrodactylus corleonis, however, can be distinguished on the basis of its heart-shaped ventral bar; G. neretum has a 1:2 hamulus point:shaft ratio and a rectangular-shaped ventral bar. A redescription of the haptoral hard parts of the four species previously recorded on pipefish is also presented.

  6. Ultrastructural study of the spermatozoon of the digenean Enodiotrema reductum Looss, 1901 (Platyhelminthes, Plagiorchioidea, Plagiorchiidae), parasite of the green turtle Chelonia mydas (Linnaeus, 1758) in Senegal.

    PubMed

    Ndiaye, Papa Ibnou; Quilichini, Yann; Sène, Aminata; Tkach, Vasyl V; Bâ, Cheikh Tidiane; Marchand, Bernard

    2012-08-01

    This study describes the ultrastructural organisation of the spermatozoon of a digenean Enodiotrema reductum (Pligiorchiida: Plagiorchiidae) from the green turtle Chelonia mydas (Linnaeus, 1758). This is the first report of E. reductum from Senegal. The mature spermatozoon of E. reductum is filiform and exhibits two axonemes of the 9 + "1" pattern of the Trepaxonemata, a nucleus, parallel cortical microtubules, an extramembranar ornamentation associated with spine-like bodies and granules of glycogen, among other ultrastructural features. The spermatozoon of E. reductum is distinguished by the presence of a moniliform mitochondrion composed of a bulge associated with a long cord and of a central cytoplasmic expansion. This work represents the first utrastructural study of any representative of the large family Plagiorchiidae. Our results are compared with previously published data on spermatozoa of other digenean taxa.

  7. Discoplana malagasensis sp. nov., a new turbellarian (Platyhelminthes: Polycladida: Leptoplanidae) symbiotic in an ophiuroid (Echinodermata), with a cladistic analysis of the Discoplana/Euplana species.

    PubMed

    Doignon, Gilles; Artois, Tom; Deheyn, Dimitri

    2003-03-01

    A new species of polyclad flatworm from Papua New Guinea is described. It is found symbiotic in the ophiuroid Ophiothrix purpurea von Martens, 1867 (Echinodermata: Ophiuroidea). Apparently it belongs to the taxon Discoplana Bock, 1913 and can be distinguished from the six previously described Discoplana species by its very short ejaculatory duct and a penial papilla covered with a penial sheath, but without any true sclerotised structures such as a stylet or spines. The cladistic analysis of the Discoplana/ Euplana species, based on morphological features and including two outgroups, reveals that all species of Discoplana, except D. pacificola, form a monophyletic taxon, that is not a synonym of Euplana Girard, 1893. Therefore the name Discoplana is conserved and the new species will be described as Discoplana malagasensis sp. nov. A key for the Discoplana/Euplana group is provided. In this key the biogeographical distribution and possible synonyms are given.

  8. Type material of Platyhelminthes (Monogenoidea) housed in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), Rio de Janeiro, Brazil, from 1979 to 2016

    PubMed Central

    Lopes, Daniela A.; Mainenti, Adriana; Sanches, Magda; Knoff, Marcelo; Gomes, Delir Corrêa

    2016-01-01

    Abstract A catalogue of type material of monogenoids deposited in the Helminthological Collection of the Oswaldo Cruz Institute, FIOCRUZ (CHIOC), between 1979 and 2016, is presented, given that the last list of types was produced in 1979. The monogenoid collection comprises type lots for 203 species, distributed across 14 families and 68 genera. Specific names are listed systematically, followed by type host, infection site, type locality, specimens with the collection numbers and references. The classification and the nomenclature of the species have been updated. PMID:27667946

  9. A large 28S rDNA-based phylogeny confirms the limitations of established morphological characters for classification of proteocephalidean tapeworms (Platyhelminthes, Cestoda).

    PubMed

    de Chambrier, Alain; Waeschenbach, Andrea; Fisseha, Makda; Scholz, Tomáš; Mariaux, Jean

    2015-01-01

    Proteocephalidean tapeworms form a diverse group of parasites currently known from 315 valid species. Most of the diversity of adult proteocephalideans can be found in freshwater fishes (predominantly catfishes), a large proportion infects reptiles, but only a few infect amphibians, and a single species has been found to parasitize possums. Although they have a cosmopolitan distribution, a large proportion of taxa are exclusively found in South America. We analyzed the largest proteocephalidean cestode molecular dataset to date comprising more than 100 species (30 new), including representatives from 54 genera (80%) and all subfamilies, thus significantly improving upon previous works to develop a molecular phylogeny for the group. The Old World origin of proteocephalideans is confirmed, with their more recent expansion in South America. The earliest diverging lineages are composed of Acanthotaeniinae and Gangesiinae but most of the presently recognized subfamilies (and genera) appear not to be monophyletic; a deep systematic reorganization of the order is thus needed and the present subfamilial system should be abandoned. The main characters on which the classical systematics of the group has been built, such as scolex morphology or relative position of genital organs in relation to the longitudinal musculature, are of limited value, as demonstrated by the very weak support for morphologically-defined subfamilies. However, new characters, such as the pattern of uterus development, relative ovary size, and egg structure have been identified, which may be useful in defining phylogenetically well-supported subgroups. A strongly supported lineage infecting various snakes from a wide geographical distribution was found. Although several improvements over previous works regarding phylogenetic resolution and taxon coverage were achieved in this study, the major polytomy in our tree, composed largely of siluriform parasites from the Neotropics, remained unresolved and possibly reflects a rapid radiation. The genus Spasskyellina Freze, 1965 is resurrected for three species of Monticellia bearing spinitriches on the margins of their suckers.

  10. Assessment of platyhelminth diversity within amphibians of French Guiana revealed a new species of Nanopolystoma (Monogenea: Polystomatidae) in the caecilian Typhlonectes compressicauda.

    PubMed

    du Preez, Louis H; Badets, Mathieu; Verneau, Olivier

    2014-12-01

    An expedition was undertaken to French Guiana in search of amphibian parasites. Of the 23 anuran species collected and screened for polystomes, the toad Rhinella margaritifera (Laurenti) was the sole species found to be infected with a polystome, namely Wetapolystoma almae Gray, 1983. Of the two caecilian species collected, a new species of Nanopolystoma du Preez, Huyse et Wilkinson, 2008 was discovered from the urinary bladder of the aquatic caecilian Typhlonectes compressicauda (Duméril et Bibron). The small size of the mature worm, two non-diverticulated caeca of equal length that are non-confluent posteriorly, vitelline follicles in two dense lateral fields, a single follicular testis in the middle of the body, small ovary and a single operculated egg in utero, vaginae present and the caecilian host allowed the identification of the specimen as Nanopolystoma. Larger body size, hamulus length, egg diameter and occurrence in the caecilian family Typhlonectidae distinguishes the new species from the two other known polystomes in Nanopolystoma; thus, the description of Nanopolystoma tinsleyi sp. n. is provided within this paper.

  11. Seussapex, a new genus of lecanicephalidean tapeworm (Platyhelminthes: Cestoda) from the stingray genus Himantura (Myliobatiformes: Dasyatidae) in the Indo-West Pacific with investigation of mode of attachment.

    PubMed

    Jensen, Kirsten; Russell, Shelbi L

    2014-06-01

    A new lecanicephalidean genus, Seussapex gen. n., is erected for specimens collected from stingrays from the Indo-West Pacific resembling the little known species Tenia [sic] narinari MacCallum, 1917 from the spotted eagle ray, Aetobatus narinari (Euphrasen). Members of this new genus are unique in their possession of a multi-tiered apical structure comprising a bipartite apical modification of the scolex proper, and an externally bipartite apical organ with anterior and posterior glandular compartments internally. The appearance of the scolex varies dramatically depending on state of protrusion and/or evagination of these different parts which appear to be able to function independently. Seussapex karybares sp. n. parasitizing Himantura uarnak 2 (sensu Naylor et al., 2012) in northern Australia is described as the type species and Tenia [sic] narinari is transferred to the new genus. The two species differ in scolex length and width of the posterior dome-shaped portion of the apical organ. Histological sections of scoleces stained using the periodic acid-Schiff(PAS) reaction showed the surface of the anterior part of the apical organ and the anterior glandular compartment to stain PAS positive, suggesting a chemical mode of attachment to the host's intestinal mucosal surface. Extensive collecting efforts of stingrays in the Indo-West Pacific shows Seussapex gen. n. to be restricted to species of Himantura Miller et Henle and suggests additional diversity in this group of hosts. In addition, the host identity of Seussapex narinari (MacCallum, 1917) comb. n. is called into question.

  12. Anatomical deviation of male organs of land planarians from Rio de Janeiro, Brazil, with description of two new species of Cratera (Platyhelminthes, Tricladida).

    PubMed

    Carbayo, Fernando; Almeida, Ana Laura

    2015-03-11

    Two new land planarian species, collected in the State of Rio de Janeiro, Brazil, are described. Their external aspect is similar to that of Imbira marcusi Carbayo et al., 2013 and Pseudogeoplana theresopolitana (Schirch, 1929), respectively. The analysis of the internal organs, however, revealed they belong to the genus Cratera. The male copulatory organs of one species is very different from any other geoplaninid, for the penis papilla holds a large, distal cavity receiving the ejaculatory duct and, furthermore, the papilla projects vertically downwards from the roof of the male atrium. Thus we consider it as a new species, Cratera cuarassu sp. nov. The second species differs from its congeners in that the dorsal insertion of the penis papilla is anterior to the ventral one, and in that the female atrium is narrowed in the anterior portion. The species was found in the type locality of Pseudogeoplana theresopolitana (Schirch, 1929) and compares well with it in the external features. However, since its internal organs are unknown and the type material of the species is seemingly lost, we describe it as Cratera anamariae Carbayo, sp. nov.

  13. A new species of the genus Bothrioplana (Platyhelminthes: Bothrioplanida: Bothrioplanidae) and a new species of the genus Pentacoelum (Tricladida: Bdellouridae) from southern China.

    PubMed

    He, Yi; Zhao, Jia-Qi; Ning, Wan-Ru; Zhuang, Jie-Yi; Zhang, Yu; Wang, An-Tai

    2016-10-31

    Two new species of turbellarians, Bothrioplana sinensis n. sp., and Pentacoelum sinensis n. sp., were described based on their reproductive behavior, ontogenic development, morphology in whole-mounted and sectioned specimens, and 18S rDNA phylogenetic classification. Bothrioplana sinensis n. sp. represents a newly recorded order in China and the second identified species in the genus Bothrioplana. It is characterized by a pair of spherical-shaped well-developed testes located dorsally behind the pharynx, and the common vas deference located ventrally to the gonopore. Phylogenetic analysis showed that this new species is closely related to parasitic flatworms. Pentacoelum sinensis n. sp. is characterized by two uteri instead of lateral bursae located laterally near the tail end and a lack of connection between the posterior intestinal branches. Each uterus has a ventral receptaculum seminalis (also functioning as bursa copulatrix) which has a muscular vagina externa opening obliquely to the ventral side at the tail end.

  14. A STUDY OF MARINE FOULING IN MONTEREY HARBOR.

    DTIC Science & Technology

    PIERS, *FOULING, *HARBORS, *MARINE BIOLOGY, CALIFORNIA, PACIFIC OCEAN, NAVAL RESEARCH, CRUSTACEA, ANIMALS, PERIODIC VARIATIONS, ENVIRONMENTAL TESTS, TIME, DISTRIBUTION, SEA WATER, PLATYHELMINTHES , OCEANOGRAPHIC DATA.

  15. Ecology and Disease Transmission Potential in the Colombian Amazon Basin.

    DTIC Science & Technology

    BRAZIL, *DISEASE VECTORS, *PARASITIC DISEASES, COLOMBIA, ECOLOGY, COLOMBIA, COLOMBIA, INFECTIOUS DISEASES, DIPTERA, HUMANS, EQUINES, BOVINES, REPTILES, TICKS, ANNELIDA, NEMATODA, PLATYHELMINTHES , FILARIAE.

  16. Invasive Marine and Estuarine Animals of Hawaii and Other Pacific Islands

    DTIC Science & Technology

    2005-08-01

    V E RI CN NY NJ jPA DE ]MD [VA Re n Protozoans 2 2 2 2 3 Sponges 1 2 1 1 1 2 Jellyfish 2 3 4 Anemones 1 2 1 2 3 Hydrozoans 2 1 2 Platyhelminths 1 1...Anemone ME MA VA Sagartia elegans Anemone MA Cordylophora caspia Hydrozoa ME Convoluta convoluta Platyhelminth ME Tubificoides heterochaetus

  17. Long-Term Survival of Enteric Microorganisms in Frozen Wastewater

    DTIC Science & Technology

    2002-10-01

    and Environmental Microbiology, 49(4): 778–781. 54 ERDC/CRREL TR-02-16 APPENDIX A. HELMINTHS The Platyhelminthes are the helminths of the lowest...reproduction, and almost all Platyhelminthes are hermaphroditic. Many of these organisms have special asexual methods of multiplication besides the conven

  18. Monogenoideans (Platyhelminthes) from the gill lamellae of the spotted sea trout, Cynoscion nebulosus (Perciformes, Sciaenidae), from the western coast of the Yucatan Peninsula, Mexico, with redescription of Diplectanum bilobatus Hargis 1955 (Diplectanidae).

    PubMed

    Franco, Edgar F Mendoza; Rodríguez, R E del Rio; Tun, M del C Rosado

    2013-08-01

    The gill lamellae ectoparasites of the spotted sea trout, Cynoscion nebulosus (Sciaenidae), in the western coast of the Yucatán Peninsula, Mexico, revealed three species of Monogenoidea: Cynoscionicola heteracantha (Manter 1938) Price, 1962 (Microcotylidae); Choricotyle cynoscioni (MacCallum, 1917) Llewellyn, 1941 (Diclidophoridae); and Diplectanum bilobatus Hargis, 1955 (Diplectanidae). Brief comments about the current taxonomic status as well as supplemental observations of all these monogenoids originally described and/or reported from the same host fish species found in the USA are provided. New illustrations, prevalence and mean intensity of infection, as well morphological and biometric data based on new specimens are shown. C. heteracantha and C. cynoscioni collected in this study represent the second and first records of the species of these genera for the Atlantic coast of Mexico. The specimens of D. bilobatus are provisionally retained within Diplectanum until an emendation of the genus and a formal revision of all named species of this monogenoidean genus are undertaken.

  19. First report of gastrocotylinean post-oncomiracidia (Platyhelminthes: Monogenoidea: Heteronchoinea) on gills of flyingfish (Exocoetidae), snapper (Lutjanidae), dolphinfish (Coryphaenidae), and amberjack (Carangidae) from the Gulf of Mexico: decoy hosts and the dilution effect.

    PubMed

    Kritsky, Delane C; Bullard, Stephen A; Bakenhaster, Micah D

    2011-09-01

    Larvae, identified as post-oncomiracidia of the suborder Gastrocotylinea (Monogenoidea), were collected from formalin-fixed gills excised from six species of marine fishes captured from the Gulf of Mexico off Mississippi and Florida: common dolphinfish, Coryphaena hippurus and pompano dolphinfish, Coryphaena equiselis (both Perciformes, Coryphaenidae); gray snapper, Lutjanus griseus (Perciformes, Lutjanidae); greater amberjack, Seriola dumerili (Perciformes, Carangidae); and Atlantic flyingfish, Cheilopogon melanurus and sailfin flyingfish, Parexocoetus hillianus (both Beloniformes and Exocoetidae). Based on a combination of diagnostic morphological features, the specimens were divided into two basic forms, each of which was further subdivided into two morphotypes. No gastrocotylinean post-oncomiracidium had been reported previously from these hosts. Of the six host species, only C. hippurus serves as a host (unconfirmed) for the adult of a gastrocotylinean species, suggesting that the recorded fishes from the Gulf of Mexico comprise dead-end hosts acting as decoys for the oncomiracidia. These comparatively non-susceptible "decoy hosts" apparently dilute the susceptible fish-host population and by intercepting infective larvae (oncomiracidia) decrease the abundance of parasites on their typical hosts.

  20. Morphological and molecular description of eight new species of Gyrodactylus von Nordmann, 1832 (Platyhelminthes: Monogenea) from poeciliid fishes, collected in their natural distribution range in the Gulf of Mexico slope, Mexico.

    PubMed

    García-Vásquez, Adriana; Razo-Mendivil, Ulises; Rubio-Godoy, Miguel

    2015-09-01

    Eight new species of Gyrodactylus are described from Poecilia mexicana, Poeciliopsis gracilis, Pseudoxiphophorus bimaculatus [syn. = Heterandria bimaculata], and Xiphophorus hellerii collected in the Nautla and La Antigua River Basins in Veracruz, and in the Tecolutla River Basin in Puebla, Mexico. Analyzing the morphology of the marginal hooks, Gyrodactylus pseudobullatarudis n. sp. and Gyrodactylus xtachuna n. sp. are both very similar to Gyrodactylus bullatarudis; Gyrodactylus takoke n. sp. resembles Gyrodactylus xalapensis; Gyrodactylus lhkahuili n. sp. is similar to Gyrodactylus jarocho; and both Gyrodactylus microdactylus n. sp. and Gyrodactylus actzu n. sp. are similar to Gyrodactylus poeciliae in that all three species possess extremely short shaft points. A hypothesis of the systematic relationships of the eight new Gyrodactylus species and some of the known gyrodactylids infecting poeciliids was constructed with sequences of the Internal Transcribed Spacers (ITS1 and ITS2) and the 5.8S ribosomal gene of the rRNA. Phylogenetic trees showed that the new and previously described species of Gyrodactylus infecting poeciliid fishes do not form a monophyletic assemblage. Trees also showed that the eight new species described morphologically correspond to well-supported monophyletic groups; and that morphologically similar species are also phylogenetically close. Additionally, we correct previous erroneous records of the presence of Gyrodactylus bullatarudis on wild Poecilia mexicana and Xiphophorus hellerii collected in Mexico, as re-examination of the original specimens indicated that these corresponded to Gyrodactylus pseudobullatarudis n. sp. (infecting Poecilia mexicana and Xiphophorus hellerii) and to Gyrodactylus xtachuna n. sp. (on Xiphophorus hellerii). Finally, given the widespread anthropogenic translocation of poeciliid fishes for the aquarium trade and mosquito control programs, as well as the existence of invasive, feral poeciliid populations worldwide, we discuss the possibility that gyrodactylid parasites could be introduced along with the fish hosts-this work provides taxonomic information to assess that possibility, as it describes parasites collected from poeciliid fishes within their native distribution range.

  1. New records of Cotylea (Polycladida, Platyhelminthes) from Lizard Island, Great Barrier Reef, Australia, with remarks on the distribution of the Pseudoceros Lang, 1884 and Pseudobiceros Faubel, 1984 species of the Indo-Pacific Marine Region.

    PubMed

    Marquina, Daniel; Aguado, M Teresa; Noreña, Carolina

    2015-09-18

    In the present work eleven polyclad species of Lizard Island are studied. Seven of them are new records for this locality of the Australian coral reef and one is new to science, Lurymare clavocapitata n. sp. (Family Prosthiostomidae). The remaining recorded species belong to the genera Pseudoceros (P. bimarginatus, P. jebborum, P. stimpsoni, P. zebra, P. paralaticlavus and P. prudhoei) and Pseudobiceros (Pb. hancockanus, Pb. hymanae, Pb. flowersi and Pb. uniarborensis). Regardless of the different distribution patterns, all pseudocerotid species show brilliant colours, but similar internal morphology. Furthermore, differences in the form and size of the stylet are characteristic, because it is a sclerotic structure that is not affected during fixation. In Pseudoceros, the distance between the sucker and the female pore also differs among species. These features do not vary enough to be considered as diagnostic, but they provide information that can help to disentangle similarly coloured species complexes. A key of the genera Pseudoceros and Pseudobiceros of the Indo-Pacific region is provided, in order to facilitate the identification of species from this area.

  2. Seven new species of helminths for reptiles from Armenia.

    PubMed

    Nelli, Sargsyan; Felix, Danielyan; Marine, Arakelyan

    2014-09-01

    Helminthic infections of reptiles habiting in the territory of Armenia are examined. Seven species of helminths new for reptiles from Armenia are registered: Parapharyngodon skrjabini, Oswaldocruzia goezei, Neoxysomatium sp., Telorchis assula, Nematotaenia tarentolae, Mesocestoides lineatus and Spirometra erinacei europea. Descriptions and pictures of them are given.

  3. Hospital Corpsman 3 + 2. Revision

    DTIC Science & Technology

    1981-01-01

    also house the - MASTOID auditory , or hearing organs. The OCCIPITAL BONE forms part of the base and back of the skull and contains a large hole...organ of Corti, the hearing o-zan. The clls ., . lining of the auditory canal contains glands that protruding from the organ of Corti are secrete a waxy...the sounds we hear . o 9 mm in size, which stretches across the inner end of the external auditory canal and separates Other structures of the inner

  4. Gain and frequency tuning within the mouse cochlear apex

    NASA Astrophysics Data System (ADS)

    Oghalai, John S.; Gao, Simon; Lee, Hee Yoon; Raphael, Patrick D.; Groves, Andrew K.; Zuo, Jian; Applegate, Brian E.

    2015-12-01

    Normal mammalian hearing requires cochlear outer hair cell active processes that amplify the traveling wave with high gain and sharp tuning, termed cochlear amplification. We have used optical coherence tomography to study cochlear amplification within the apical turn of the mouse cochlea. We measured not only classical basilar membrane vibratory tuning curves but also vibratory responses from the rest of the tissues that compose the organ of Corti. Basilar membrane tuning was sharp in live mice and broad in dead mice, whereas other regions of the organ of Corti demonstrated phase shifts consistent with additional filtering beyond that provided by basilar membrane mechanics. We use these experimental data to support a conceptual framework of how cochlear amplification is tuned within the mouse cochlear apex. We will also study transgenic mice with targeted mutations that affect different biomechanical aspects of the organ of Corti in an effort to localize the underlying processes that produce this additional filtering.

  5. Gain and frequency tuning within the mouse cochlear apex

    SciTech Connect

    Oghalai, John S.; Raphael, Patrick D.; Gao, Simon; Lee, Hee Yoon; Groves, Andrew K.; Zuo, Jian; Applegate, Brian E.

    2015-12-31

    Normal mammalian hearing requires cochlear outer hair cell active processes that amplify the traveling wave with high gain and sharp tuning, termed cochlear amplification. We have used optical coherence tomography to study cochlear amplification within the apical turn of the mouse cochlea. We measured not only classical basilar membrane vibratory tuning curves but also vibratory responses from the rest of the tissues that compose the organ of Corti. Basilar membrane tuning was sharp in live mice and broad in dead mice, whereas other regions of the organ of Corti demonstrated phase shifts consistent with additional filtering beyond that provided by basilar membrane mechanics. We use these experimental data to support a conceptual framework of how cochlear amplification is tuned within the mouse cochlear apex. We will also study transgenic mice with targeted mutations that affect different biomechanical aspects of the organ of Corti in an effort to localize the underlying processes that produce this additional filtering.

  6. Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory - Processing, Taxonomy, and Quality Control of Benthic Macroinvertebrate Samples

    DTIC Science & Technology

    2000-01-01

    Only a portion of colonial organisms, such as Bryozoa or Porifera , is sorted to document its presence in the sample. Verte- brates, exuviae...Standard Taxonomic Assessment Taxon Level of identification Taxon Level of identification Porifera Family Corduliidae Genus/Species Cnidaria Family...individual taxonomists. The Taxon Level of identification Porifera Family Cnidaria Family Platyhelminthes Class Nematoda Phylum Nemertea Genus

  7. Evolutionary analysis of the cystatin family in three Schistosoma species

    PubMed Central

    Cuesta-Astroz, Yesid; Scholte, Larissa L. S.; Pais, Fabiano Sviatopolk-Mirsky; Oliveira, Guilherme; Nahum, Laila A.

    2014-01-01

    The cystatin family comprises cysteine protease inhibitors distributed in 3 subfamilies (I25A–C). Family members lacking cystatin activity are currently unclassified. Little is known about the evolution of Schistosoma cystatins, their physiological roles, and expression patterns in the parasite life cycle. The present study aimed to identify cystatin homologs in the predicted proteome of three Schistosoma species and other Platyhelminthes. We analyzed the amino acid sequence diversity focused in the identification of protein signatures and to establish evolutionary relationships among Schistosoma and experimentally validated human cystatins. Gene expression patterns were obtained from different developmental stages in Schistosoma mansoni using microarray data. In Schistosoma, only I25A and I25B proteins were identified, reflecting little functional diversification. I25C and unclassified subfamily members were not identified in platyhelminth species here analyzed. The resulting phylogeny placed cystatins in different clades, reflecting their molecular diversity. Our findings suggest that Schistosoma cystatins are very divergent from their human homologs, especially regarding the I25B subfamily. Schistosoma cystatins also differ significantly from other platyhelminth homologs. Finally, transcriptome data publicly available indicated that I25A and I25B genes are constitutively expressed thus could be essential for schistosome life cycle progression. In summary, this study provides insights into the evolution, classification, and functional diversification of cystatins in Schistosoma and other Platyhelminthes, improving our understanding of parasite biology and opening new frontiers in the identification of novel therapeutic targets against helminthiases. PMID:25071834

  8. Macrobenthic Communities of the Dam Neck Disposal Site.

    DTIC Science & Technology

    1985-02-01

    PLATYHELMINTHES TURBELLARIA Turbellaria app. NEMERTEA Nemertea app. ANNELIDA : POLYCHAETA Amastigos caperatus Ewing and Dauer Aupharete arctica Malmgren... ANNELIDA :POLYCHAETA (Contd) Nephtys picta Ehlers Notocirrus spiniferus (Moore) Notomastus hemipodus Hartman Notomastus latericeus Sars Ophelia denticulata...Claparede) Sthenelais limicola (Ehlers) 4 Streblospio benedicti Webster Streptosyllis pettiboneae Perkins Syllides convoluta Webster and Benedict ANNELIDA

  9. Substantial Loss of Conserved and Gain of Novel MicroRNA Families in Flatworms

    PubMed Central

    Fromm, Bastian; Worren, Merete Molton; Hahn, Christoph; Hovig, Eivind; Bachmann, Lutz

    2013-01-01

    Recent studies on microRNA (miRNA) evolution focused mainly on the comparison of miRNA complements between animal clades. However, evolution of miRNAs within such groups is poorly explored despite the availability of comparable data that in some cases lack only a few key taxa. For flatworms (Platyhelminthes), miRNA complements are available for some free-living flatworms and all major parasitic lineages, except for the Monogenea. We present the miRNA complement of the monogenean flatworm Gyrodactylus salaris that facilitates a comprehensive analysis of miRNA evolution in Platyhelminthes. Using the newly designed bioinformatics pipeline miRCandRef, the miRNA complement was disentangled from next-generation sequencing of small RNAs and genomic DNA without a priori genome assembly. It consists of 39 miRNA hairpin loci of conserved miRNA families, and 22 novel miRNAs. A comparison with the miRNA complements of Schmidtea mediterranea (Turbellaria), Schistosoma japonicum (Trematoda), and Echinococcus granulosus (Cestoda) reveals a substantial loss of conserved bilaterian, protostomian, and lophotrochozoan miRNAs. Eight of the 46 expected conserved miRNAs were lost in all flatworms, 16 in Neodermata and 24 conserved miRNAs could not be detected in the cestode and the trematode. Such a gradual loss of miRNAs has not been reported before for other animal phyla. Currently, little is known about miRNAs in Platyhelminthes, and for the majority of the lost miRNAs there is no prediction of function. As suggested earlier they might be related to morphological simplifications. The presence and absence of 153 conserved miRNAs was compared for platyhelminths and 32 other metazoan taxa. Phylogenetic analyses support the monophyly of Platyhelminthes (Turbellaria + Neodermata [Monogenea {Trematoda + Cestoda}]). PMID:24025793

  10. Acoustic Responses after Total Destruction of the Cochlear Receptor: Brainstem and Auditory Cortex

    NASA Astrophysics Data System (ADS)

    Cazals, Yves; Aran, Jean-Marie; Erre, Jean-Paul; Guilhaume, Anne

    1980-10-01

    Acoustically evoked neural activity has been recorded from the brainstem and auditory cortex of guinea pigs after complete destruction of the organ of Corti by the aminoglycosidic antibiotic amikacin. These responses to sound differ in important respects from the evoked potentials normally recorded from the auditory pathways. At the brainstem level they resemble the potentials reported by others after stimulation of the vestibular nerve.

  11. Conditioned pain modulation in women with irritable bowel syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evidence suggests that patients with irritable bowel syndrome (IBS) are more vigilant to pain-associated stimuli. The aims of this study were to compare women with IBS (n = 20) to healthy control (HC, n = 20) women on pain sensitivity, conditioned pain modulation (CPM) efficiency, and salivary corti...

  12. Accelerated Tumor Cell Death by Anglogenic Modifiers

    DTIC Science & Technology

    2005-08-01

    1164, 1994 442--447,1987 36. Brooks PC, Clark RAF, Cheresh DA: Requirement of vas- 20. Pepper MS: Manipulating angiogensis: from basic science cular...tol 22:1-10. stasis in transgenic mice. Genes Dev 9:945-955. 518 Cunha, G.R. and Chung, L.W. (1981) Stromal-epithelial interac- Corty, EW, Ferguson

  13. Comprehensive Development Program of Hunter-Killer Peptides for Prostate Cancer

    DTIC Science & Technology

    2005-05-01

    proliferation by terbinafine . Int J Cancer, 111: 51-59, 2004. Hsu, C. S., Ross, B. D., Chrisp, C. E., Derrowm S. Z., Charles, L. G., Pienta, K. J., Greenberg...by terbinafine . Int J Cancer, 111: 51-59, 2004. 9. Curnis, F., Sacchi, A., Borgna, L., Magni, F., Gasparri, A., and Corti, A. Enhance- ment of tumor

  14. Auditory system

    NASA Technical Reports Server (NTRS)

    Ades, H. W.

    1973-01-01

    The physical correlations of hearing, i.e. the acoustic stimuli, are reported. The auditory system, consisting of external ear, middle ear, inner ear, organ of Corti, basilar membrane, hair cells, inner hair cells, outer hair cells, innervation of hair cells, and transducer mechanisms, is discussed. Both conductive and sensorineural hearing losses are also examined.

  15. Shaping the mammalian auditory sensory organ by the planar cell polarity pathway

    PubMed Central

    Kelly, Michael; Chen, Ping

    2014-01-01

    The human ear is capable of processing sound with a remarkable resolution over a wide range of intensity and frequency. This ability depends largely on the extraordinary feats of the hearing organ, the organ of Corti and its sensory hair cells. The organ of Corti consists of precisely patterned rows of sensory hair cells and supporting cells along the length of the snail-shaped cochlear duct. On the apical surface of each hair cell, several rows of actin-containing protrusions, known as stereocilia, form a “V”-shaped staircase. The vertices of all the “V”-shaped stereocilia point away from the center of the cochlea. The uniform orientation of stereocilia in the organ of Corti manifests a distinctive form of polarity known as planar cell polarity (PCP). Functionally, the direction of stereociliary bundle deflection controls the mechanical channels located in the stereocilia for auditory transduction. In addition, hair cells are tonotopically organized along the length of the cochlea. Thus, the uniform orientation of stereociliary bundles along the length of the cochlea is critical for effective mechanotransduction and for frequency selection. Here we summarize the morphological and molecular events that bestow the structural characteristics of the mammalian hearing organ, the growth of the snail-shaped cochlear duct and the establishment of PCP in the organ of Corti. The PCP of the sensory organs in the vestibule of the inner ear will also be described briefly. PMID:17891715

  16. LMO4 functions as a negative regulator of sensory organ formation in the mammalian cochlea.

    PubMed

    Deng, Min; Luo, Xiong-jian; Pan, Ling; Yang, Hua; Xie, Xiaoling; Liang, Guoqing; Huang, Liang; Hu, Fang; Kiernan, Amy E; Gan, Lin

    2014-07-23

    In mammals, formation of the auditory sensory organ (the organ of Corti) is restricted to a specialized area of the cochlea. However, the molecular mechanisms limiting sensory formation to this discrete region in the ventral cochlear duct are not well understood, nor is it known whether other regions of the cochlea have the competence to form the organ of Corti. Here we identify LMO4, a LIM-domain-only nuclear protein, as a negative regulator of sensory organ formation in the cochlea. Inactivation of Lmo4 in mice leads to an ectopic organ of Corti (eOC) located in the lateral cochlea. The eOC retains the features of the native organ, including inner and outer hair cells, supporting cells, and other nonsensory specialized cell types. However, the eOC shows an orientation opposite to the native organ, such that the eOC appears as a mirror-image duplication to the native organ of Corti. These data demonstrate a novel sensory competent region in the lateral cochlear duct that is regulated by LMO4 and may be amenable to therapeutic manipulation.

  17. Audiogenic seizures and cochlear damage in rats after perinatal antithyroid treatment

    SciTech Connect

    Van Milllesworth, L.; Norris, C.H.

    1980-06-01

    The feeding of goitrogens during pregnancy and lactation causes the offspring of rats to be partially deaf and persistently sensitive to audiogenic seizures. The most potent goitrogen, propylthiouracil, caused severe dysfunction and disorganization of the organ of Corti. Adult seizure-susceptible rats showed increased sensitivity to audiogenic seizures when they were fed propylthiouracil.

  18. Frequency distribution of Echinococcus multilocularis and other helminths of foxes in Kyrgyzstan.

    PubMed

    Ziadinov, I; Deplazes, P; Mathis, A; Mutunova, B; Abdykerimov, K; Nurgaziev, R; Torgerson, P R

    2010-08-04

    Echinococcosis is a major emerging zoonosis in central Asia. A study of the helminth fauna of foxes from Naryn Oblast in central Kyrgyzstan was undertaken to investigate the abundance of Echinococcus multilocularis in a district where a high prevalence of this parasite had previously been detected in dogs. A total of 151 foxes (Vulpes vulpes) were investigated in a necropsy study. Of these 96 (64%) were infected with E. multilocularis with a mean abundance of 8669 parasites per fox. This indicates that red foxes are a major definitive host of E. multilocularis in this country. This also demonstrates that the abundance and prevalence of E. multilocularis in the natural definitive host are likely to be high in geographical regions where there is a concomitant high prevalence in alternative definitive hosts such as dogs. In addition Mesocestoides spp., Dipylidium caninum, Taenia spp., Toxocara canis, Toxascaris leonina, Capillaria and Acanthocephala spp. were found in 99 (66%), 50 (33%), 48 (32%), 46 (30%), 9 (6%), 34 (23%) and 2 (1%) of foxes, respectively. The prevalence but not the abundance of E. multilocularis decreased with age. The abundance of D. caninum also decreased with age. The frequency distribution of E. multilocularis and Mesocestoides spp. followed a zero-inflated negative binomial distribution, whilst all other helminths had a negative binomial distribution. This demonstrates that the frequency distribution of positive counts and not just the frequency of zeros in the data set can determine if a zero-inflated or non-zero-inflated model is more appropriate. This is because the prevalences of E. multolocularis and Mesocestoides spp. were the highest (and hence had fewest zero counts) yet the parasite distribution nevertheless gave a better fit to the zero-inflated models.

  19. Frequency distribution of Echinococcus multilocularis and other helminths of foxes in Kyrgyzstan

    PubMed Central

    I., Ziadinov; P., Deplazes; A., Mathis; B., Mutunova; K., Abdykerimov; R., Nurgaziev; P.R, Torgerson

    2010-01-01

    Echinococcosis is a major emerging zoonosis in central Asia. A study of the helminth fauna of foxes from Naryn Oblast in central Kyrgyzstan was undertaken to investigate the abundance of Echinococcus multilocularis in a district where a high prevalence of this parasite had previously been detected in dogs. A total of 151 foxes (Vulpes vulpes) were investigated in a necropsy study. Of these 96 (64%) were infected with E. multilocularis with a mean abundance of 8669 parasites per fox. This indicates that red foxes are a major definitive host of E. multilocularis in this country. This also demonstrates that the abundance and prevalence of E. multilocularis in the natural definitive host are likely to be high in geographical regions where there is a concomitant high prevalence in alternative definitive hosts such as dogs. In addition Mesocestoides spp., Dipylidium caninum, Taenia spp., Toxocara canis, Toxascaris leonina, Capillaria and Acanthocephala spp. were found in 99 (66%), 50 (33%), 48 (32%), 46 (30%), 9 (6%), 34 (23%) and 2 (1%) of foxes, respectively. The prevalence but not the abundance of E. multilocularis decreased with age. The abundance of Dipylidium caninum also decreased with age. The frequency distribution of E. multilocularis and Mesocestoides spp. followed a zero inflated negative binomial distribution, whilst all other helminths had a negative binomial distribution. This demonstrates that the frequency distribution of positive counts and not just the frequency of zeros in the data set can determine if a zero inflated or non-zero inflated model is more appropriate. This is because the prevalences of E. multolocularis and Mesocestoides spp. were the highest (and hence had fewest zero counts) yet the parasite distribution nevertheless gave a better fit to the zero inflated models. PMID:20434845

  20. Cestode parasites: application of in vivo and in vitro models for studies on the host-parasite relationship.

    PubMed

    Siles-Lucas, Mar; Hemphill, Andrew

    2002-01-01

    Cestode worms, commonly also known as 'flat' worms or tapeworms, are an important class of endoparasitic organisms. In order to complete their life cycle, they infect intermediate and definitive hosts in succession, through oral ingestion of eggs or larvae, respectively. Serious disease in humans or other mammalian hosts is mostly caused by the larval stages. Echinococcus spp. and Taenia spp. have been extensively investigated in the laboratory due to the fact that they represent important veterinary medical challenges and also cause grave diseases in humans. In contrast, Hymenolepis spp. and Mesocestoides spp. infections are relatively rare in humans, but these parasites have been extensively studied because their life cycle stages can be easily cultured in vitro, and can also be conveniently maintained in laboratory animal hosts. Thus they are more easily experimentally accessible, and represent important models for investigating the various aspects of cestode biology. This review will focus on in vitro and in vivo models which have been developed for studies on the host-parasite relationship during infection with Echinococcus, Taenia, Hymenolepis, Mesocestoides and Spirometra, and will cover the use of these models to investigate the morphology and ultrastructure of respective genera, the immunological relationship with the host and the development of vaccination approaches, as well as applications of these models for studies on parasite metabolism, physiology and gene expression. In addition, the use of these models in the development of chemotherapeutic measures against cestode infections is reviewed.

  1. Helminths of red foxes (Vulpes vulpes) in Denmark.

    PubMed

    Saeed, I; Maddox-Hyttel, C; Monrad, J; Kapel, C M O

    2006-06-30

    An epidemiological study of helminths in 1040 red foxes collected from various localities in Denmark during 1997-2002, revealed 21 helminth species at autopsy, including nine nematode species: Capillaria plica (prevalence 80.5%), Capillaria aerophila (74.1%), Crenosoma vulpis (17.4%), Angiostrongylus vasorum (48.6% from Northern Zealand (endemic area)), Toxocara canis (59.4%), Toxascaris leonina (0.6%), Uncinaria stenocephala (68.6%), Ancylostoma caninum (0.6%), and Trichuris vulpis (0.5%); seven cestodes: Mesocestoides sp. (35.6%), a number of Taeniid species (Taenia pisiformis, T. hydatigena, T. taeniaeformis, T. crassiceps, and unidentified Taenia spp.) (22.8%), and Echinococcus multilocularis (0.3%); four trematodes: Alaria alata (15.4%), Cryptocotyle lingua (23.8%), Pseudamphystomum truncatum (3.6% from Northern Zealand), and Echinochasmus perfoliatus (2.4% from Northern Zealand); one acanthocephalan: Polymorphus sp. (1.2%). Significant difference in prevalence was found for T. canis and A. vasorum according to host sex, and for T. canis, U. stenocephala, Mesocestoides sp., Taenia spp., A. alata, A. vasorum, and Capillaria spp. according to age groups (adult, young or cub). Prevalence and average worm intensity for each helminth species varied considerably according to geographical locality, season, and year. Aggregated distribution was found for several helminth species. The two species E. multilocularis and E. perfoliatus are first records for Denmark.

  2. The Parasite Fauna of the Gyrfalcon (Falco rusticolus) in Iceland.

    PubMed

    Christensen, Nanna D; Skirnisson, Karl; Nielsen, Ólafur K

    2015-10-01

    We examined 46 Gyrfalcon (Falco rusticolus) carcasses from Iceland for parasites, including 29 first-year birds and 17 second-year birds and older. Endoparasites observed were the trematodes Cryptocotyle lingua (prevalence 8%), Cryptocotyle concavum (4%), and Strigea sp. (8%); the cestode Mesocestoides sp. (27%); and the nematodes Eucoleus contortus (76%) and Serratospiculum guttatum (7%). Ectoparasites included the astigmatan mite Dubininia accipitrina (47%), a mesostigmatan rhynonyssid mite (4%), the tick Ixodes caledonicus (20%), the mallophagans Degeeriella rufa (90%) and Nosopon lucidum (7%), the flea Ceratophyllus vagabundus (7%), and the louse fly Ornithomya chloropus (7%). Cryptocotyle lingua, C. concavum, S. guttatum, D. accipitrina, I. caledonicus, and N. lucidum are new host records. Of the five most common parasites (prevalence ≥ 20%) only Mesocestoides sp. showed a significant age relationship, being more prevalent in adult falcons (P = 0.021). Eucoleus contortus was also more prevalent in adults with marginal statistical significance (P = 0.058). Frounce, caused by E. contortus (possibly also by Trichomonas gallinae, which was not searched for in the survey) was highly prevalent (43%), but did not show a relationship with host age (P = 0.210). Birds with frounce were in poorer body condition than healthy birds (P = 0.015).

  3. Survey on Helminths in the Small Intestine of Wild Foxes in Qinghai, China

    PubMed Central

    LI, Wei; GUO, Zhihong; DUO, Hong; FU, Yong; PENG, Mao; SHEN, Xiuying; TSUKADA, Hideharu; IRIE, Takao; NASU, Tetsuo; HORII, Yoichiro; NONAKA, Nariaki

    2013-01-01

    ABSTRACT The intestinal helminth fauna of Tibetan sand foxes (Vulpes ferrilata) and red foxes (Vulpes vulpes) inhabiting in Qinghai, China, was evaluated by conducting necropsy of hunted foxes and fecal egg examination of field-collected feces. In northeast and south Qinghai, 36 foxes were necropsied, and the species of foxes and the parasites detected were identified by the DNA barcoding. In 27 red foxes and 9 Tibetan sand foxes examined, Mesocestoides litteratus (total prevalence: 64%), Toxascaris leonina (50%), Taenia pisiformis (8%) and Taenia crassiceps (8%) were found in both species of foxes. Echinococcus shiquicus (8%) and Taenia multiceps (6%) were found only in Tibetan sand foxes. Echinococcus multilocularis (3%) and Alaria alata (8%) were found only in red foxes. In the fecal egg examination of the rectal feces, 100% of taeniid cestodes, 73% of Toxascaris and 27% of Mesocestoides worm-positive samples showed egg-positive, indicating that coprological survey for parasite eggs could only provide partial information of intestinal parasite fauna. For field-collected feces, molecular identification of feces origins and fecal egg examination were performed. In 15 Tibetan sand fox and 30 red fox feces, we found E. multilocularis eggs in one feces of Tibetan sand fox. The present study indicated that the upper intestinal helminth fauna of the two fox species in Qinghai does not differ significantly and both species would play an important role in the maintenance of taeniid cestodes. PMID:23749034

  4. Survey on helminths in the small intestine of wild foxes in Qinghai, China.

    PubMed

    Li, Wei; Guo, Zhihong; Duo, Hong; Fu, Yong; Peng, Mao; Shen, Xiuying; Tsukada, Hideharu; Irie, Takao; Nasu, Tetsuo; Horii, Yoichiro; Nonaka, Nariaki

    2013-10-01

    The intestinal helminth fauna of Tibetan sand foxes (Vulpes ferrilata) and red foxes (Vulpes vulpes) inhabiting in Qinghai, China, was evaluated by conducting necropsy of hunted foxes and fecal egg examination of field-collected feces. In northeast and south Qinghai, 36 foxes were necropsied, and the species of foxes and the parasites detected were identified by the DNA barcoding. In 27 red foxes and 9 Tibetan sand foxes examined, Mesocestoides litteratus (total prevalence: 64%), Toxascaris leonina (50%), Taenia pisiformis (8%) and Taenia crassiceps (8%) were found in both species of foxes. Echinococcus shiquicus (8%) and Taenia multiceps (6%) were found only in Tibetan sand foxes. Echinococcus multilocularis (3%) and Alaria alata (8%) were found only in red foxes. In the fecal egg examination of the rectal feces, 100% of taeniid cestodes, 73% of Toxascaris and 27% of Mesocestoides worm-positive samples showed egg-positive, indicating that coprological survey for parasite eggs could only provide partial information of intestinal parasite fauna. For field-collected feces, molecular identification of feces origins and fecal egg examination were performed. In 15 Tibetan sand fox and 30 red fox feces, we found E. multilocularis eggs in one feces of Tibetan sand fox. The present study indicated that the upper intestinal helminth fauna of the two fox species in Qinghai does not differ significantly and both species would play an important role in the maintenance of taeniid cestodes.

  5. Benthic Community Response to Dredging Borrow Pits, Panama City Beach, Florida.

    DTIC Science & Technology

    1982-03-01

    mollusks (19 percent). The remaining 33 species (9 percent) were divided among 11 groups: Cnidaria , Platyhelminthes, Nemertinea, Nematoda, Phoronida...collected. On a percentage basis, more than half were annelids (55 percent), 19 percent were mollusks, 18 percent were arthropods, Cnidaria and...ISLANC MCTEL (STATICIk 1) - CCNTRCL ANIC EXPERIMENTAL I, l/7e SPECIES -TT -PEClT CNIDARIA ACTINIARIA (SEA ANEMONES) UNIOENTIFIED SP. 3 0.218 0 0.0

  6. DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates.

    PubMed

    Folmer, O; Black, M; Hoeh, W; Lutz, R; Vrijenhoek, R

    1994-10-01

    We describe "universal" DNA primers for polymerase chain reaction (PCR) amplification of a 710-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) from 11 invertebrate phyla: Echinodermata, Mollusca, Annelida, Pogonophora, Arthropoda, Nemertinea, Echiura, Sipuncula, Platyhelminthes, Tardigrada, and Coelenterata, as well as the putative phylum Vestimentifera. Preliminary comparisons revealed that these COI primers generate informative sequences for phylogenetic analyses at the species and higher taxonomic levels.

  7. Bibliography of Venomous and Poisonous Marine Animals and Their Toxins

    DTIC Science & Technology

    1984-02-01

    color printing, that when reproduced in Black and White, may change detail of the original copy. 19. Arthropoda Venomous fishes Bryozoa Sea snakes... BRYOZOA = 3730-Y•17 , ......................... 206 ." S’ •d o,XI..•A •dqAKESt 6316.4•7!14 ............................................ 341 "• "dXIL...cation par les moules. Schweiz. - m~d. Wschr. 107, 226, 1977. 205 CHAPTER Vi ll PLATYHELMINTHES, NEMERTEA, ANNELIDA, ARTHROPODS, AND BRYOZOA :: The phylum

  8. Marine Ecological Index Survey of San Diego Bay

    DTIC Science & Technology

    2013-03-01

    nonindigenous EIS-JL-0040 Bryozoa Smittoidea prolifica 12-Jul-2011 Seasonally Hypersaline EIS-JL-0138 Cephalopoda Octopus bimaculatus/bimaculoides 12-Jul...Jul-2011 Estuarine nonindigenous; on Styela clava EIS-GL-0008 Chordata Molgula ficus 11-Jul-2011 Estuarine nonindigenous EIS-JL-0038 Bryozoa ...Hypersaline, Marine, Thermal Platyhelminthes Eurylepta aurantiaca SP Seasonally Hypersaline, Marine, Thermal Bryozoa Watersipora arcuata SP Seasonally

  9. Immunofluorescent localization of intermediate filaments (IFs) in helminths using anti-mammalian IFs monoclonal antibody.

    PubMed

    Sato, H; Kamiya, H

    2000-08-01

    Intermediate filaments (IFs) make up the cytoskeleton of most eukaryotic cells. In vertebrates, a number of IF proteins have been identified, showing distributions unique to tissue or cell type. Information on helminth IFs is limited to some nematode species. To observe immunofluorescent localization of IFs in helminth tissues, we selected a murine hybridoma clone producing IgM antibody to multiple types of mammalian IF proteins and examined cross-reactivity to helminth proteins. The selected monoclonal antibody (HUSM-9) cross-reacted well with IFs from nematode species such as Toxocara canis, Dirofilaria immitis, Anisakis simplex, and Trichinella britovi; strong immunofluorescence on cryostat sections was detected in the hypodermis, cords, body muscle, smooth muscle of the uterus, and other epithelial structures. In platyhelminths, i.e., adult Schistosoma mansoni, larval Taenia taeniaeformis, adult Taenia crassiceps, and Echinococcus multilocularis protoscolex, the reactivity was weaker than in nematodes, and localized in the body wall muscle and subtegumental tissue. Western blotting of 8 M urea extracts of parasites with the antibody detected a pair of clear bands in nematodes but not in S. mansoni or the cestodes. These results might be explained by sparse distribution of IFs in platyhelminths, or low affinity of the used antibody to platyhelminth IF proteins, or both.

  10. Inner ear hair cells deteriorate in mice engineered to have no or diminished innervation

    PubMed Central

    Kersigo, Jennifer; Fritzsch, Bernd

    2015-01-01

    The innervation of the inner ear critically depends on the two neurotrophins Ntf3 and Bdnf. In contrast to this molecularly well-established dependency, evidence regarding the need of innervation for long-term maintenance of inner ear hair cells is inconclusive, due to experimental variability. Mutant mice that lack both neurotrophins could shed light on the long-term consequences of innervation loss on hair cells without introducing experimental variability, but do not survive after birth. Mutant mice with conditional deletion of both neurotrophins lose almost all innervation by postnatal day 10 and show an initially normal development of hair cells by this stage. No innervation remains after 3 weeks and complete loss of all innervation results in near complete loss of outer and many inner hair cells of the organ of Corti within 4 months. Mutants that retain one allele of either neurotrophin have only partial loss of innervation of the organ of Corti and show a longer viability of cochlear hair cells with more profound loss of inner hair cells. By 10 months, hair cells disappear with a base to apex progression, proportional to the residual density of innervation and similar to carboplatin ototoxicity. Similar to reports of hair cell loss after aminoglycoside treatment, blobbing of stereocilia of apparently dying hair cells protrude into the cochlear duct. Denervation of vestibular sensory epithelia for several months also resulted in variable results, ranging from unusual hair cells resembling the aberrations found in the organ of Corti, to near normal hair cells in the canal cristae. Fusion and/or resorption of stereocilia and loss of hair cells follows a pattern reminiscent of Myo6 and Cdc42 null mice. Our data support a role of innervation for long-term maintenance but with a remarkable local variation that needs to be taken into account when attempting regeneration of the organ of Corti. PMID:25852547

  11. Boko Haram’s Strategy Deconstructed: A Case Study Comparison Between Boko Haram and the Algerian National Liberation Front

    DTIC Science & Technology

    2015-06-12

    PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Major Cortis B. Burgess, USA 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7...stability of West Africa. Boko Haram has stated its objective as the creation of an Islamic State in Nigeria governed by a puritanical form of Salafist... Islam . This research sought to discover whether Boko Haram could usurp the Nigerian Government’s control over Northern Nigeria with their current

  12. Auditory Models for Speech Analysis

    DTIC Science & Technology

    1988-01-01

    the Organ of the Corti, basilar niernbrane, and hair cells [Lindsay and Norman, 1977; Borden and Harris, 1983]. 2.2 The Inner Ear Sound travels from...these two channels separated by the two flexible mem- branes. Reissner’s membrane and the frequency-sensitive basilar mebralle. At the cochlea base, the... basilar ein brane is carrow and stiff, becoming gradually wider and more flaccid toward the apex. These physiological characteristics make high

  13. Role of Integrin-Beta 1 in Polycystic Kidney Disease

    DTIC Science & Technology

    2011-04-01

    conclusions. The kino- cilium, the primary cilium found in inner ear hair cells, is re- quired for proper development of the organ of Corti but it is...shown in in vivo and ex vivo experiments in mice and rabbits (31, 32). During development and repair, inner ear hair cells undergo morphogenesis and...stunted and malformed , but not completely abolished, thus allowing these homozygous mutants to survive within the wean- ing period (24). In contrast

  14. Inner ear histopathology in "nervous Pointer dogs" with severe hearing loss.

    PubMed

    Coppens, Angélique G; Gilbert-Gregory, Shana; Steinberg, Sheldon A; Heizmann, Claus; Poncelet, Luc

    2005-02-01

    Ten puppy dogs (82, 131 or 148 days-old) from a Pointer cross-colony, exhibiting a juvenile severe hearing loss transmitted as an autosomal recessive trait, were used for histopathological characterization of the inner ear lesion. Immunostaining with calbindin, Na,K-ATPase, cytokeratins, S100, S100A1 and S100A6 antisera were helpful in identifying the different cell types in the degenerated cochleae. Lesions, restricted to the Corti's organ and spiral ganglion, were bilateral but sometimes slightly asymmetrical. Mild to severe lesions of the Corti's organ were unevenly distributed among the different parts of the middle and basal cochlear turns while the apical turn remained unaffected at 148 days. In 82 day-old puppies (n = 2), severe lesions of the Corti's organ, meaning that it was replaced by a layer of unidentifiable cells, involved the lower middle and upper basal turns junction area, extending in the upper basal turn. Mild lesions of the Corti's organ, with both hair and supporting cells abnormalities, involved the lower middle turn and extended from the rest of upper basal turn into the lower basal turn. The outer hair cells (ohc) were more affected than the inner hair cell (ihc). The lesions extended towards the basal end of the cochlea in the 131 (n = 5) and 148 (n = 3) day-old puppies. Additionally, the number of spiral ganglion neurons was reduced in the 131 and 148 day-old puppies; it is earlier than observed in most other canine hereditary deafness. These lesions were interpreted as a degeneration of the neuroepithelial type. This possible animal model might provide information about progressive juvenile hereditary deafness and neuronal retrograde degeneration investigations in human.

  15. Progressive deafness and altered cochlear innervation in knock-out mice lacking prosaposin.

    PubMed

    Akil, Omar; Chang, Jolie; Hiel, Hakim; Kong, Jee-Hyun; Yi, Eunyoung; Glowatzki, Elisabeth; Lustig, Lawrence R

    2006-12-13

    After a yeast two-hybrid screen identified prosaposin as a potential interacting protein with the nicotinic acetylcholine receptor (nAChR) subunit alpha10, studies were performed to characterize prosaposin in the normal rodent inner ear. Prosaposin demonstrates diffuse organ of Corti expression at birth, with gradual localization to the inner hair cells (IHCs) and its supporting cells, inner pillar cells, and synaptic region of the outer hair cells (OHCs) and Deiters' cells (DCs) by postnatal day 21 (P21). Microdissected OHC and DC quantitative reverse transcriptase-PCR and immunohistology localizes prosaposin mRNA to DCs and OHCs, and protein predominantly to the apex of the DCs. Subsequent studies in a prosaposin knock-out (KO) (-/-) mouse showed intact but slightly reduced hearing through P19, but deafness by P25 and reduced distortion product otoacoustic emissions from P15 onward. Beginning at P12, the prosaposin KO mice showed histologic organ of Corti changes including cellular hypertrophy in the region of the IHC and greater epithelial ridge, a loss of OHCs from cochlear apex, and vacuolization of OHCs. Immunofluorescence revealed exuberant overgrowth of auditory afferent neurites in the region of the IHCs and proliferation of auditory efferent neurites in the region of the tunnel of Corti. IHC recordings from these KO mice showed normal I-V curves and responses to applied acetylcholine. Together, these results suggest that prosaposin helps maintain normal innervation patterns to the organ of Corti. Furthermore, prosaposin's overlapping developmental expression pattern and binding capacity toward the nAChR alpha10 suggest that alpha10 may also play a role in this function.

  16. Role of p63 and the Notch pathway in cochlea development and sensorineural deafness.

    PubMed

    Terrinoni, Alessandro; Serra, Valeria; Bruno, Ernesto; Strasser, Andreas; Valente, Elizabeth; Flores, Elsa R; van Bokhoven, Hans; Lu, Xin; Knight, Richard A; Melino, Gerry

    2013-04-30

    The ectodermal dysplasias are a group of inherited autosomal dominant syndromes associated with heterozygous mutations in the Tumor Protein p63 (TRP63) gene. Here we show that, in addition to their epidermal pathology, a proportion of these patients have distinct levels of deafness. Accordingly, p63 null mouse embryos show marked cochlea abnormalities, and the transactivating isoform of p63 (TAp63) protein is normally found in the organ of Corti. TAp63 transactivates hairy and enhancer of split 5 (Hes5) and atonal homolog 1 (Atoh1), components of the Notch pathway, known to be involved in cochlear neuroepithelial development. Strikingly, p63 null mice show morphological defects of the organ of Corti, with supernumerary hair cells, as also reported for Hes5 null mice. This phenotype is related to loss of a differentiation property of TAp63 and not to loss of its proapoptotic function, because cochleas in mice lacking the critical Bcl-2 homology domain (BH-3) inducers of p53- and p63-mediated apoptosis--Puma, Noxa, or both--are normal. Collectively, these data demonstrate that TAp63, acting via the Notch pathway, is crucial for the development of the organ of Corti, providing a molecular explanation for the sensorineural deafness in ectodermal dysplasia patients with TRP63 mutations.

  17. A mouse model for human deafness DFNB22 reveals that hearing impairment is due to a loss of inner hair cell stimulation.

    PubMed

    Lukashkin, Andrei N; Legan, P Kevin; Weddell, Thomas D; Lukashkina, Victoria A; Goodyear, Richard J; Welstead, Lindsey J; Petit, Christine; Russell, Ian J; Richardson, Guy P

    2012-11-20

    The gene causative for the human nonsyndromic recessive form of deafness DFNB22 encodes otoancorin, a 120-kDa inner ear-specific protein that is expressed on the surface of the spiral limbus in the cochlea. Gene targeting in ES cells was used to create an EGFP knock-in, otoancorin KO (Otoa(EGFP/EGFP)) mouse. In the Otoa(EGFP/EGFP) mouse, the tectorial membrane (TM), a ribbon-like strip of ECM that is normally anchored by one edge to the spiral limbus and lies over the organ of Corti, retains its general form, and remains in close proximity to the organ of Corti, but is detached from the limbal surface. Measurements of cochlear microphonic potentials, distortion product otoacoustic emissions, and basilar membrane motion indicate that the TM remains functionally attached to the electromotile, sensorimotor outer hair cells of the organ of Corti, and that the amplification and frequency tuning of the basilar membrane responses to sounds are almost normal. The compound action potential masker tuning curves, a measure of the tuning of the sensory inner hair cells, are also sharply tuned, but the thresholds of the compound action potentials, a measure of inner hair cell sensitivity, are significantly elevated. These results indicate that the hearing loss in patients with Otoa mutations is caused by a defect in inner hair cell stimulation, and reveal the limbal attachment of the TM plays a critical role in this process.

  18. Evolution of a novel subfamily of nuclear receptors with members that each contain two DNA binding domains

    PubMed Central

    Wu, Wenjie; Niles, Edward G; Hirai, Hirohisa; LoVerde, Philip T

    2007-01-01

    Background Nuclear receptors (NRs) are important transcriptional modulators in metazoans which regulate transcription through binding to the promoter region of their target gene by the DNA binding domain (DBD) and activation or repression of mRNA synthesis through co-regulators bound to the ligand binding domain (LBD). NRs typically have a single DBD with a LBD. Results Three nuclear receptors named 2DBD-NRs, were identified from the flatworm Schistosoma mansoni that each possess a novel set of two DBDs in tandem with a LBD. They represent a novel NR modular structure: A/B-DBD-DBD-hinge-LBD. The 2DBD-NRs form a new subfamily of NRs, VII. By database mining, 2DBD-NR genes from other flatworm species (Schmidtea mediterranea and Dugesia japonica), from Mollusks (Lottia gigantean) and from arthropods (Daphnia pulex) were also identified. All 2DBD-NRs possess a P-box sequence of CEACKK in the first DBD, which is unique to 2DBD-NRs, and a P-box sequence of CEGCKG in the second DBD. Phylogenetic analyses of both DBD and ligand binding domain sequences showed that 2DBD-NR genes originate from a common two DBD-containing ancestor gene. A single 2DBD-NR orthologue was found in Arthropoda, Platyhelminths and Mollusca. Subsequent 2DBD-NR gene evolution in Mollusks and Platyhelminths involved gene duplication. Chromosome localization of S. mansoni 2DBD-NR genes by Fluorescent in situ hybridization (FISH) suggests that 2DBD-NR genes duplicated on different chromosomes in the Platyhelminths. Dimerization of Sm2DBDα indicates that 2DBD-NRs may act as homodimers, suggesting either that two repeats of a half-site are necessary for each DBD of 2DBD-NRs to bind to its target gene, or that each 2DBD-NR can recognize multiple sites. Conclusion 2DBD-NRs share a common ancestor gene which possessed an extra DBD that likely resulted from a recombination event. After the split of the Arthropods, Mollusks and Platyhelminths, 2DBD-NR underwent a recent duplication in a common ancestor of

  19. New genus, new species of Cestoda (Anoplocephalidae), new species of Nematoda (Cosmocercidae) and other helminths in Cyrtodactylus louisiadensis (Sauria: Gekkonidae) from Papua New Guinea.

    PubMed

    Bursey, Charles R; Goldberg, Stephen R; Kraus, Fred

    2005-08-01

    Gekkotaenia novaeguineaensis n. gen., n. sp. (Cestoda: Anoplocephalidae) from the small intestine and Cosmocerca zugi n. sp. (Nematoda: Cosmocercidae) from the large intestine of the ring-tailed gecko, Cyrtodactylus louisiadensis (Sauria: Gekkonidae) are described and illustrated. Gekkotaenia novaeguineaensis n. gen., n. sp. is unique among the acraspedote Linstowiinae in possessing a poral female reproductory system. Cosmocerca zugi n. sp. is the 22nd species to be assigned to the genus and differs from other species in the genus by possessing 4 pairs of rosette papillae on plectanes and having a gubernaculum longer than the spicules. It is the fifth species to be described from the Australian biogeographical region. Eight additional helminth species were found: the digenean, Allopharynx macallisteri; 2 cestodes, cysticercoids of Cyclophyllidea gen. sp. and tetrathyridia of Mesocestoides sp.; 5 nematodes, larvae in cysts of Abbreviata sp., Aplectana macintoshii, Oswaldocruzia bakeri, Parapharyngodon maplestonei, and an undescribed species of Physalopteroides. Cyrtodactylus louisiadensis represents a new host record for each of these helminths.

  20. Helminth fauna of the Iberian lynx, Lynx pardinus.

    PubMed

    Torres, J; Garciá-Perea, R; Gisbert, J; Feliu, C

    1998-09-01

    Specimens of 12 helminth species were collected from carcasses of eight Lynx pardinus (Temminck, 1827), a carnivore endemic to the Iberian Peninsula. These species included: Brachylaima sp. (12.5%) (Trematoda); Taenia pisiformis (12.5%), T. polyacantha (25%), T. taeniaeformis (25%) and Mesocestoides litteratus (37.5%) (Cestoda); Eucoleus aerophilus (12.5%), Ancylostoma tubaeforme (12.5%), Toxocara cati (37.5%), Toxascaris leonina (62.5%), Vigisospirura potekhina potekhina (12.5%), Mastophorus muris (12.5%) and Physaloptera praeputialis (12.5%) (Nematoda). The helminth fauna in Iberian lynx is compared with that of L. canadensis and L. rufus in America, and for L. lynx in Eurasia. The potential relationships between the parasitological data and some geographical, historical and dietary factors are discussed.

  1. [Red fox (Vulpes vulpes) as reservoir of parasites and source of zoonosis].

    PubMed

    Okulewicz, Anna; Hildebrand, Joanna; Okulewicz, Jerzy; Perec, Agnieszka

    2005-01-01

    Red fox (Vulpes vulpes) as reservoir of parasites and source of zoonosis. This review presents data from Europe and Poland on the prevalence of helminth and protozoan parasites in red foxes (Vulpes vulpes). The most common nematodes were geohelminths: Uncinaria stenocephala, Toxocara canis and Toxocara leonina. As concerning Trichinella genus T. britovi was found more often than T. spiralis. Among tapeworms the following species were recorded: Mesocestoides lineatus, Taenia sp., and Echinococcus multilocularis. Detected cases of E. multilocularis together with an increase of fox population during last few years create a potential human risk of infection. The results of many studies indicate rare presence of trematodes (Alaria alata) and protozoan parasites (Toxoplasma gondii, Neospora caninum, Leishmania spp., Eimeria spp.) in red foxes.

  2. [The raccoon roundworm (Baylisascaris procyonis)--no zoonotic risk for Brandenburg?].

    PubMed

    Schwarz, Sabine; Sutor, Astrid; Mattis, Roswitha; Conraths, Franz Josef

    2015-01-01

    The aim of the present study was to investigate the presence of the raccoon roundworm (Baylisascaris [B.] procyonis), a dangerous zoonotic pathogen for humans, in raccoons living in the federal state of Brandenburg, Germany. In the years 2008 to 2013, a total of 762 raccoons, dating from hunting bags, were examined for intestinal helminths. No raccoon roundworm specimen was detected, but 27 samples were positive for Mesocestoides spp. Earlier studies had proved the presence of B. procyonis in Hesse and since 2005 the parasite has also been found in the western part of Saxony-Anhalt. The migration ability of raccoons may promote a further distribution of this parasite and could increase the risk for zoonotic infections in humans.

  3. Data on the parasitological status of golden jackal (Canis aureus L., 1758) in Hungary.

    PubMed

    Takács, András; Szabó, László; Juhász, Lajos; Takács, András Attila; Lanszki, József; Takács, Péter Tamás; Heltai, Miklós

    2014-03-01

    In Hungary, twenty Canis aureus individuals were submitted to parasitological examinations in 2010-2012. Two Coccidia: Cystoisospora canis (15%) and Toxoplasma-type oocysts (5%), one Trematoda: Alaria alata (10%), six Cestoda: Mesocestoides lineatus (20%), Echinococcus granulosus (10%), Dipylidium caninums (5%), Taenia hydatigena (15%), Taenia pisiformis (20%), Taenia crassiceps (40%), and nine Nematoda: Angiostrongylus vasorum (10%), Crenosoma vulpis (30%), Capillaria aerophila (5%), Toxocara canis (20%), Toxascaris leonina (15%), Trichuris vulpis (10%), Ancylostoma caninum (45%), Uncinaria stenocephala (40%), Capillaria plica (45%) have been identified. Angiostronglyus vasorum has been reported from carnivores in Europe, Africa, South America and North America. The helminth A. vasorum or French heartworm is a metastrongylid nematode, widely distributed in Western Europe, that infects the pulmonary arterial tree of dogs, various species of foxes, wolves, Eurasian badgers, coyotes and stoats. To our knowledge, this is the first report of natural A. vasorum infection in golden jackal.

  4. Increase in number of helminth species from Dutch red foxes over a 35-year period

    PubMed Central

    2014-01-01

    Background The red fox (Vulpes vulpes) is host to a community of zoonotic and other helminth species. Tracking their community structure and dynamics over decades is one way to monitor the long term risk of parasitic infectious diseases relevant to public and veterinary health. Methods We identified 17 helminth species from 136 foxes by mucosal scraping, centrifugal sedimentation/flotation and the washing and sieving technique. We applied rarefaction analysis to our samples and compared the resulting curve to the helminth community reported in literature 35 years ago. Results Fox helminth species significantly increased in number in the last 35 years (p-value <0.025). Toxascaris leonina, Mesocestoides litteratus, Trichuris vulpis and Angiostrongylus vasorum are four new veterinary-relevant species. The zoonotic fox tapeworm (E. multilocularis) was found outside the previously described endemic regions in the Netherlands. Conclusions Helminth fauna in Dutch red foxes increased in biodiversity over the last three decades. PMID:24708710

  5. Helminths of red foxes (Vulpes vulpes) and raccoon dogs (Nyctereutes procyonoides) in Lithuania.

    PubMed

    Bružinskaitė-Schmidhalter, Rasa; Šarkūnas, Mindaugas; Malakauskas, Alvydas; Mathis, Alexander; Torgerson, Paul R; Deplazes, Peter

    2012-01-01

    Red foxes and raccoon dogs are hosts for a wide range of parasites including important zoonotic helminths. The raccoon dog has recently invaded into Europe from the east. The contribution of this exotic species to the epidemiology of parasitic diseases, particularly parasitic zoonoses is unknown. The helminth fauna and the abundance of helminth infections were determined in 310 carcasses of hunted red foxes and 99 of raccoon dogs from Lithuania. Both species were highly infected with Alaria alata (94·8% and 96·5% respectively) and Trichinella spp. (46·6% and 29·3%). High and significantly different prevalences in foxes and raccoon dogs were found for Eucoleus aerophilus (97·1% and 30·2% respectively), Crenosoma vulpis (53·8% and 15·1%), Capillaria plica (93·3% and 11·3%), C. putorii (29·4% and 51·5%), Toxocara canis (40·5% and 17·6%) and Uncinaria stenocephala (76·9% and 98·8%). The prevalences of the rodent-transmitted cestodes Echinococcus multilocularis, Taenia polyacantha, T. crassiceps and Mesocestoides spp. were significantly higher in foxes than in raccoon dogs. The abundances of E. multilocularis, Mesocestoides, Taenia, C. plica and E. aerophilus were higher in foxes than those in raccoon dogs. A. alata, U. stenocephala, C. putorii and Echinostomatidae had higher abundances in raccoon dogs. The difference in prevalence and abundance of helminths in both animals may reflect differences in host ecology and susceptibility. The data are consistent with red foxes playing a more important role than raccoon dogs in the transmission of E. multilocularis in Lithuania.

  6. Thioredoxin Glutathione Reductase as a Novel Drug Target: Evidence from Schistosoma japonicum

    PubMed Central

    Xie, ShuYing; Qian, ChunYan; Wang, Jie; Zhang, Wei; Yin, XuRen; Hua, ZiChun; Yu, ChuanXin

    2012-01-01

    Background Schistosomiasis remains a major public health concern affecting billions of people around the world. Currently, praziquantel is the only drug of choice for treatment of human schistosomiasis. The emergence of drug resistance to praziquantel in schistosomes makes the development of novel drugs an urgent task. Thioredoxin glutathione reductase (TGR) enzymes in Schistosoma mansoni and some other platyhelminths have been identified as alternative targets. The present study was designed to confirm the existense and the potential value of TGR as a target for development of novel antischistosomal agents in Schistosoma japonicum, a platyhelminth endemic in Asia. Methods and Findings After cloning the S. japonicum TGR (SjTGR) gene, the recombinant SjTGR selenoprotein was purified and characterized in enzymatic assays as a multifunctional enzyme with thioredoxin reductase (TrxR), glutathione reductase (GR) and glutaredoxin (Grx) activities. Immunological and bioinformatic analyses confirmed that instead of having separate TrxR and GR proteins in mammalian, S. japonicum only encodes TGR, which performs the functions of both enzymes and plays a critical role in maintaining the redox balance in this parasite. These results were in good agreement with previous findings in Schistosoma mansoni and some other platyhelminths. Auranofin, a known inhibitor against TGR, caused fatal toxicity in S. japonicum adult worms in vitro and reduced worm and egg burdens in S. japonicum infected mice. Conclusions Collectively, our study confirms that a multifunctional enzyme SjTGR selenoprotein, instead of separate TrxR and GR enzymes, exists in S. japonicum. Furthermore, TGR may be a potential target for development of novel agents against schistosomes. This assumption is strengthened by our demonstration that the SjTGR is an essential enzyme for maintaining the thiol-disulfide redox homeostasis of S. japonicum. PMID:22384025

  7. Developmental diversity in free-living flatworms

    PubMed Central

    2012-01-01

    Flatworm embryology has attracted attention since the early beginnings of comparative evolutionary biology. Considered for a long time the most basal bilaterians, the Platyhelminthes (excluding Acoelomorpha) are now robustly placed within the Spiralia. Despite having lost their relevance to explain the transition from radially to bilaterally symmetrical animals, the study of flatworm embryology is still of great importance to understand the diversification of bilaterians and of developmental mechanisms. Flatworms are acoelomate organisms generally with a simple centralized nervous system, a blind gut, and lacking a circulatory organ, a skeleton and a respiratory system other than the epidermis. Regeneration and asexual reproduction, based on a totipotent neoblast stem cell system, are broadly present among different groups of flatworms. While some more basally branching groups - such as polyclad flatworms - retain the ancestral quartet spiral cleavage pattern, most flatworms have significantly diverged from this pattern and exhibit unique strategies to specify the common adult body plan. Most free-living flatworms (i.e. Platyhelminthes excluding the parasitic Neodermata) are directly developing, whereas in polyclads, also indirect developers with an intermediate free-living larval stage and subsequent metamorphosis are found. A comparative study of developmental diversity may help understanding major questions in evolutionary biology, such as the evolution of cleavage patterns, gastrulation and axial specification, the evolution of larval types, and the diversification and specialization of organ systems. In this review, we present a thorough overview of the embryonic development of the different groups of free-living (turbellarian) platyhelminths, including the Catenulida, Macrostomorpha, Polycladida, Lecithoepitheliata, Proseriata, Bothrioplanida, Rhabdocoela, Fecampiida, Prolecithophora and Tricladida, and discuss their main features under a consensus phylogeny

  8. Molecular phylogeny of the animal kingdom.

    PubMed

    Field, K G; Olsen, G J; Lane, D J; Giovannoni, S J; Ghiselin, M T; Raff, E C; Pace, N R; Raff, R A

    1988-02-12

    A rapid sequencing method for ribosomal RNA was applied to the resolution of evolutionary relationships among Metazoa. Representatives of 22 classes in 10 animal phyla were used to infer phylogenetic relationships, based on evolutionary distances determined from pairwise comparisons of the 18S ribosomal RNA sequences. The classical Eumetazoa are divided into two groups. Cnidarians arose from a protist ancestry different from the second group, the Bilateria. Within the Bilateria, an early split gave rise to Platyhelminthes (flatworms) and the coelomate lineage. Coelomates are thus monophyletic, and they radiated rapidly into four groups: chordates, echinoderms, arthropods, and eucoelomate protostomes.

  9. Neurobehavioral toxicity of cadmium sulfate to the planarian Dugesia dorotocephala

    SciTech Connect

    Grebe, E.; Schaeffer, D.J. )

    1991-05-01

    The authors are developing bioassays which use planarians (free-living platyhelminthes) for the rapid determination of various types of toxicity, including acute mortality, tumorigenicity, and short-term neurobehavioral responses. Their motivation for using these animals is due to their importance as components of the aquatic ecology of unpolluted streams their sensitivity to low concentrations of environmental toxicants and the presence of a sensitive neurological system with a true brain which allows for complex social behavior. A previous paper described the results of a neurobehavioral bioassay using phenol in a crossover study. This paper reports a similar crossover study using cadmium sulfate.

  10. Biological and Physical Conditions at a Newly Placed Gravel Bar Habitat in the Tombigbee River.

    DTIC Science & Technology

    1988-03-01

    R., Bruke, T. A., and Keenan, C. 1981. " Bryozoa from Lake Mead and Lake Mohave, Nevada-Arizona," The Southwestern Naturalist, Vol 26, No. 2, p 201...C A L~ugessa sp. S 1’ C 1’ A Nematode worms - U U A Bryozoa Plumatellidae CFF - U. C C FottsielZa erecta CFF - - C C Entoprocta L’rnate’,a gracilz...Oct Coelenterata Rydra sp. P - C U C , ordyZophra Lacustris - - U c Platyhelminthes Duqesta tiorina S - U - C Nematode worms - U U A Bryozoa

  11. Aquatic Resources of Rocky Mountain Arsenal Adams County, Colorado

    DTIC Science & Technology

    1989-09-01

    Platyhelminthes3Turbellaria sp. D D,P D Nematoda sp. D,P** D,P D,P Annelida Hi rundinea Eropobdellidae sp. D,P Gloss iphoni idae Helobdella sp. P D D,P Helobdella stagnalis...D. G. Cook. 1974. Aquatic earthworms ( Annelida ; Cligochaeta). In: Hart, C. W., Jr. and S. L. H. Fuller (Eds.). Pollution e-cology of freshwater...Lakes. August 14, 1953. Klemm, D. J. 1985. A guide to the freshwater Annelida (Polychaeta, Naidid, and Tubificid Oligochaeta, and Hirudinea) of North

  12. 17β-Estradiol reduces nitric oxide production in the Guinea pig cochlea.

    PubMed

    Heinrich, U-R; Brieger, J; Striedter, C; Fischer, I; Schmidtmann, I; Li, H; Mann, W J; Helling, K

    2013-11-01

    Intense noise exposure and the application of ototoxic substances result in increased levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as nitric oxide (NO). In order to reduce the free NO concentration in the inner ear under pathological conditions, the use of natural cytoprotective substances such as 17β-estradiol is a promising therapeutic concept. In male guinea pigs the organ of Corti and the lateral wall were isolated from the cochlea and afterwards incubated for 6 h in cell-culture medium. 17β-Estradiol was adjusted in 2 concentrations to organ cultures of the right ears (12 animals per concentration). The left ears were used as controls. The NO production was quantified in the supernatant by chemiluminescence after incubation. Depending on the concentration, 17β-estradiol reduced NO in the organ of Corti by 43% (p=0.015) and 46% (p=0.026), respectively. In the lateral wall, the NO concentration was reduced by 24%, but without statistical significance (p=0.86). However, when analyzing the association between the 2 cochlear regions for each animal separately, the NO concentrations were lower in nearly all 17β-estradiol-treated ears compared to controls. In order to demonstrate the flexibility of the organ culture system, the NO donor DETA NONOate and the nitric oxide synthase inhibitors L-NAME and L-NMMA were applied. The electron microscopic analysis revealed a well-preserved cochlear cell morphology after incubation. The ability of 17β-estradiol to influence the NO production preferentially in the organ of Corti might offer new therapeutic perspectives for inner ear protection.

  13. Ecological correlates of cortisol levels in two bat species with contrasting feeding habits.

    PubMed

    Lewanzik, Daniel; Kelm, Detlev H; Greiner, Sabine; Dehnhard, Martin; Voigt, Christian C

    2012-05-15

    The immediate release of adrenal glucocorticoids can be crucial for an animal's survival when facing a stressor, but constantly elevated or exceptionally high glucocorticoid levels are usually detrimental for health. Although baseline and maximal secretion of glucocorticoids are regulated within narrow ranges within species, plasma glucocorticoid levels vary largely across vertebrates. We asked what ecological factors affect baseline plasma cortisol levels (CortI) and maximum levels (CortMax) following a physiological challenge through administration of adrenocorticotropic hormone (ACTH). Specifically, we studied whether seasonal fluctuations in food abundance correlate with the capacity of cortisol increases in two phyllostomid bat species with contrasting feeding habits: the sanguinivorous vampire bat (Desmodus rotundus) and the frugivorous short-tailed fruit bat (Carollia perspicillata). Both species coexist in habitats with various levels of seasonality (dry and rainforest). On a seasonal basis, resource abundance is more stable for vampire than for fruit bats, but previous studies suggested that daily foraging success may vary more for vampire than for fruit bats. CortI and CortMax varied seasonally in C. perspicillata from dry and rainforests, with the exception of CortMax in rainforest bats. Although we expected food availability to be stable year-round for vampire bats, we found CortI and CortMax of vampires to be higher during the rainy season than during the dry season. Also, we found CortMax to be higher in vampires from the rainforest than in those from the dry forest. CortMax of vampires were among the highest measured for a free-ranging mammal; a pattern that could be related to the species' vulnerability to starvation. We conclude that food availability modulates cortisol levels in free-ranging species that face seasonally fluctuating resources; in species, however, that benefit from food which is constantly abundant, other factors than food may

  14. Deficiency of angulin-2/ILDR1, a tricellular tight junction-associated membrane protein, causes deafness with cochlear hair cell degeneration in mice.

    PubMed

    Higashi, Tomohito; Katsuno, Tatsuya; Kitajiri, Shin-Ichiro; Furuse, Mikio

    2015-01-01

    Tricellular tight junctions seal the extracellular spaces of tricellular contacts, where the vertices of three epithelial cells meet, and are required for the establishment of a strong barrier function of the epithelial cellular sheet. Angulins and tricellulin are known as specific protein components of tricellular tight junctions, where angulins recruit tricellulin. Mutations in the genes encoding angulin-2/ILDR1 and tricellulin have been reported to cause human hereditary deafness DFNB42 and DFNB49, respectively. To investigate the pathogenesis of DFNB42, we analyzed mice with a targeted disruption of Ildr1, which encodes angulin-2/ILDR1. Ildr1 null mice exhibited profound deafness. Hair cells in the cochlea of Ildr1 null mice develop normally, but begin to degenerate by two weeks after birth. Tricellulin localization at tricellular contacts of the organ of Corti in the cochlea was retained in Ildr1 null mice, but its distribution along the depth of tricellular contacts was affected. Interestingly, compensatory tricellular contact localization of angulin-1/LSR was observed in the organ of Corti in Ildr1 null mice although it was hardly detected in the organ of Corti in wild-type mice. The onset of hair cell degeneration in Ildr1 null mice was earlier than that in the reported Tric mutant mice, which mimic one of the tricellulin mutations in DFNB49 deafness. These results indicate that the angulin-2/ILDR1 deficiency causes the postnatal degenerative loss of hair cells in the cochlea, leading to human deafness DFNB42. Our data also suggest that angulin family proteins have distinct functions in addition to their common roles of tricellulin recruitment and that the function of angulin-2/ILDR1 for hearing cannot be substituted by angulin-1/LSR.

  15. Viral vector tropism for supporting cells in the developing murine cochlea.

    PubMed

    Sheffield, Abraham M; Gubbels, Samuel P; Hildebrand, Michael S; Newton, Stephen S; Chiorini, John A; Di Pasquale, Giovanni; Smith, Richard J H

    2011-07-01

    Gene-based therapeutics are being developed as novel treatments for genetic hearing loss. One roadblock to effective gene therapy is the identification of vectors which will safely deliver therapeutics to targeted cells. The cellular heterogeneity that exists within the cochlea makes viral tropism a vital consideration for effective inner ear gene therapy. There are compelling reasons to identify a viral vector with tropism for organ of Corti supporting cells. Supporting cells are the primary expression site of connexin 26 gap junction proteins that are mutated in the most common form of congenital genetic deafness (DFNB1). Supporting cells are also primary targets for inducing hair cell regeneration. Since many genetic forms of deafness are congenital it is necessary to administer gene transfer-based therapeutics prior to the onset of significant hearing loss. We have used transuterine microinjection of the fetal murine otocyst to investigate viral tropism in the developing inner ear. For the first time we have characterized viral tropism for supporting cells following in utero delivery to their progenitors. We report the inner ear tropism and potential ototoxicity of three previously untested vectors: early-generation adenovirus (Ad5.CMV.GFP), advanced-generation adenovirus (Adf.11D) and bovine adeno-associated virus (BAAV.CMV.GFP). Adenovirus showed robust tropism for organ of Corti supporting cells throughout the cochlea but induced increased ABR thresholds indicating ototoxicity. BAAV also showed tropism for organ of Corti supporting cells, with preferential transduction toward the cochlear apex. Additionally, BAAV readily transduced spiral ganglion neurons. Importantly, the BAAV-injected ears exhibited normal hearing at 5 weeks of age when compared to non-injected ears. Our results support the use of BAAV for safe and efficient targeting of supporting cell progenitors in the developing murine inner ear.

  16. Hearing loss following exposure during development to polychlorinated biphenyls: a cochlear site of action.

    PubMed

    Crofton, K M; Ding, D; Padich, R; Taylor, M; Henderson, D

    2000-06-01

    Maternal exposure to polyhalogenated hydrocarbons results in early postnatal hypothyroxenemia and a low-frequency hearing loss in adult offspring (Goldey et al., 1995a. Toxicol. Appl. Pharmacol. 135, 67-76; Herr et al., 1996. Fundam. Appl. Toxicol. 33, 120-128). The purpose of the present work was to determine whether the site-of-action of this auditory impairment was within the cochlea. Primiparous Long-Evans rats were given daily oral doses of corn oil (control) or 8 mg/kg of the commercial PCB mixture Aroclor 1254 (A1254) from gestation day (GD) 6 through postnatal day (PND) 21. Auditory thresholds for 1-, 4-, 16-, and 40-kHz tones were assessed using reflex modification audiometry in young adult offspring on postnatal days (PND) 92-110. Approximately 6 weeks after auditory assessments, a subset of animals (n=4 per group) were killed for histological assessment of the cochlea. Surface preparations of the organ of Corti were prepared from one cochlea per animal and modiolar sections were prepared from the opposite cochlea. Consistent with previous findings, auditory thresholds for 1-kHz tones were elevated by approximately 25 dB in the A1254-exposed animals. Thresholds for all higher frequencies were not different compared to controls. Surface preparations of the organ of Corti revealed a mild to moderate loss of outer hair cells in the upper-middle and apical turns. Inner hair cells were not affected. Modiolar sections failed to reveal alterations in any other cochlear structures. There was also no apparent loss of ganglion cells. These data clearly link the loss of low-frequency hearing caused by exposure during development to A1254 to a loss of outer hair cells in the organ of Corti. The mechanism that underlies this developmental ototoxicity remains to be determined. These data provide the first evidence of a structural deficit in the nervous system of adult animals exposed to PCBs during development.

  17. Deformation of the Outer Hair Cells and the Accumulation of Caveolin-2 in Connexin 26 Deficient Mice

    PubMed Central

    Anzai, Takashi; Fukunaga, Ichiro; Hatakeyama, Kaori; Fujimoto, Ayumi; Kobayashi, Kazuma; Nishikawa, Atena; Aoki, Toru; Noda, Tetsuo; Minowa, Osamu; Ikeda, Katsuhisa; Kamiya, Kazusaku

    2015-01-01

    Background Mutations in GJB2, which encodes connexin 26 (Cx26), a cochlear gap junction protein, represent a major cause of pre-lingual, non-syndromic deafness. The degeneration of the organ of Corti observed in Cx26 mutant—associated deafness is thought to be a secondary pathology of hearing loss. Here we focused on abnormal development of the organ of Corti followed by degeneration including outer hair cell (OHC) loss. Methods We investigated the crucial factors involved in late-onset degeneration and loss of OHC by ultrastructural observation, immunohistochemistry and protein analysis in our Cx26-deficient mice (Cx26f/fP0Cre). Results In ultrastructural observations of Cx26f/fP0Cre mice, OHCs changed shape irregularly, and several folds or notches were observed in the plasma membrane. Furthermore, the mutant OHCs had a flat surface compared with the characteristic wavy surface structure of OHCs of normal mice. Protein analysis revealed an increased protein level of caveolin-2 (CAV2) in Cx26f/fP0Cre mouse cochlea. In immunohistochemistry, a remarkable accumulation of CAV2 was observed in Cx26f/fP0Cre mice. In particular, this accumulation of CAV2 was mainly observed around OHCs, and furthermore this accumulation was observed around the shrunken site of OHCs with an abnormal hourglass-like shape. Conclusions The deformation of OHCs and the accumulation of CAV2 in the organ of Corti may play a crucial role in the progression of, or secondary OHC loss in, GJB2-associated deafness. Investigation of these molecular pathways, including those involving CAV2, may contribute to the elucidation of a new pathogenic mechanism of GJB2-associated deafness and identify effective targets for new therapies. PMID:26492081

  18. Enkephalin-like immunoreactivity of olivocochlear nerve fibers in cochlea of guinea pig and cat

    PubMed Central

    Fex, Jörgen; Altschuler, Richard A.

    1981-01-01

    The distribution of enkephalin-like immunoreactivity in the cochlea of the guinea pig and cat was studied. Indirect immunofluorescence immunohistochemistry using antisera generated against a methionine enkephalin-bovine thyroglobulin conjugate was applied to surface preparations of the organ of Corti and cryostat sections of the whole of the cochlea. In the cochlear osseous spiral lamina, immunofluorescence was localized to unmyelinated fibers of the intraganglionic spiral bundle. In the organ of Corti, immunofluorescence was localized to a small number of fibers at inner hair cells, the inner spiral bundle, and tunnel spiral bundle, to tunnel crossing fibers at the level of the tunnel floor, to an occasional spiral outer fiber, and to the synaptic region of outer hair cells in the three rows of the basal turn of the cochlea. Less immunofluorescence was found in this region as one progressed towards the apex, with none seen at the apex. At the most apical region the inner spiral bundle became patchy and the tunnel spiral bundle developed arcades. There was no immunofluorescence found in spiral ganglion cells, in auditory nerve fibers, or in the hair cells of the organ of Corti. The findings were the same in cat as in guinea pig, the latter being studied in more detail. It was concluded that efferent, olivocochlear neurons of the cochlea, synapsing predominantly with primary auditory nerve fibers from the inner sensory cells or with the sensory cells, contain enkephalin-like immunoreactivity. Also, the findings indicate that endings of olivocochlear neurons that synapse predominantly with outer hair cells contain enkephalin-like immunoreactivity. It has previously been shown that olivocochlear neurons are likely to be cholinergic. Images PMID:7015329

  19. Timed conditional null of connexin26 in mice reveals temporary requirements of connexin26 in key cochlear developmental events before the onset of hearing.

    PubMed

    Chang, Qing; Tang, Wenxue; Kim, Yeunjung; Lin, Xi

    2015-01-01

    Mutations in the Gjb2 gene, which encodes a gap junction protein connexin26 (Cx26), are the most prevalent form of hereditary deafness in humans and represent about half of non-syndromic congenital deafness cases in many ethnic populations. Cochlear potassium (K+) recycling in mature cochlea is required for normal hearing. It is thought that gap junctions are essential for K+ recycling and that Gjb2 mutations cause Gjb2-associated deafness by disrupting K+ recycling in mature cochlea. Here we present evidence showing that Gjb2 is required for normal development of the neonatal organ of Corti prior to the onset of the hearing in mice. In the conditional Gjb2 null (cCx26 null) mice, ribbon synapses in inner hair cells remained poorly developed, the afferent type I fibers failed to finish the refinement process to form convergent innervation to individual inner hair cells. The spontaneous depolarizing activities in the supporting cells, which normally diminish in the wild type cochleae after postnatal day 8 (P8), remained strong in the cochlea after P8 in the mutant mice. Furthermore, the deafness phenotype was readily generated only if the Cx26 expression in the organ of Corti was significantly reduced before P6. Similar amount of Cx26 reduction in more mature cochleae had a much weaker effect in damaging the hearing sensitivity. Our findings indicated that Cx26 plays essential roles in the maturation process of the organ of Corti prior to the establishment of high K+ in the endolymph and the onset of hearing. These results suggest that successful treatment of Cx26 deafness requires early intervention before the cochlea fully matures.

  20. Cochlear transduction: an integrative model and review

    PubMed Central

    Brownell, William E.

    2009-01-01

    A model for cochlear transduction is presented that is based on considerations of the cell biology of its receptor cells, particularly the mechanisms of transmitter release at recepto-neural synapses. Two new interrelated hypotheses on the functional organization of the organ of Corti result from these considerations, one dealing with the possibility of electrotonic interaction between inner and outer hair cells and the other with a possible contributing source to acoustic emissions of cochlear origin that results from vesicular membrane turnover. PMID:6282796

  1. [Ludwig van Beethoven: an autoimmune deafness?].

    PubMed

    Davies, P J

    1995-01-01

    The author reminds us of the great moments of Beethoven's life and of the different stages of his deafness onset, until to last instants. The post-mortem examination, performed by doctor Wagner, and the scientific studies of the remains, during the exhumations, are reported. Beethoven's deafness was clearly a sensorineural impairment and the previously suggested prevalent hypotheses are discussed. A new theory is emphasized, based on modern studies about autoimmune sensorineural hearing losses in relation with chronic inflammatory bowel ailment. Conclusion is that Beethoven's deafness was probably owing to a primary autoimmune degeneration of the organ of Corti, giving rise to atrophy of the auditory nerve.

  2. Histopathology of the human inner ear in Alström's syndrome.

    PubMed

    Nadol, Joseph B; Marshall, Jan D; Bronson, Roderick T

    2015-01-01

    Alström's syndrome is an autosomal recessive syndromic genetic disorder caused by mutations in the ALMS1 gene. Sensorineural hearing loss occurs in greater than 85% of patients. Histopathology of the inner ear abnormalities in the human has not previously been fully described. Histopathology of the inner ear in Alström's syndrome is presented in 2 genetically confirmed cases. The predominant histopathologic correlates of the sensorineural loss were degeneration of the organ of Corti, both inner and outer hair cells, degeneration of spiral ganglion cells, and atrophy of the stria vascularis and spiral ligament.

  3. Mammalian Cochlear Hair Cell Regeneration and Ribbon Synapse Reformation

    PubMed Central

    2016-01-01

    Hair cells (HCs) are the sensory preceptor cells in the inner ear, which play an important role in hearing and balance. The HCs of organ of Corti are susceptible to noise, ototoxic drugs, and infections, thus resulting in permanent hearing loss. Recent approaches of HCs regeneration provide new directions for finding the treatment of sensor neural deafness. To have normal hearing function, the regenerated HCs must be reinnervated by nerve fibers and reform ribbon synapse with the dendrite of spiral ganglion neuron through nerve regeneration. In this review, we discuss the research progress in HC regeneration, the synaptic plasticity, and the reinnervation of new regenerated HCs in mammalian inner ear. PMID:28119785

  4. Treatment of Desquamative Gingivitis with Free Gingival Graft: A Case Report

    PubMed Central

    Vatankhah, Mehdi; Taghi Chitsazi, Mohammad; Mehdipour, Masoumeh; Taghavi Zenouz, Ali; Estakhri, Rasoul

    2010-01-01

    Recalcitrant gingival erythematous lichen planus lesions comprise a considerable therapeutic problem. This case of chronic desquamative gingivitis in a 25-year-old woman with erosive oral lichen planus was treated with topical and systemic corti-costeroid administration, followed by placement of a free gingival graft on right upper quadrant. Although recurrence of the lesions was observed following both treatment modalities, free gingival graft despite being an aggressive therapy, proved more effective and with fewer side effects compared with topical or systemic steroid therapy, and seems to be a promising treatment modality with the benefit of more stable results, among others. PMID:22991593

  5. Vibration Measurement on Reticular Lamina and Basilar Membrane at Multiple Longitudinal Locations

    NASA Astrophysics Data System (ADS)

    Chen, Fangyi; Zha, Dingjun; Choudhury, Niloy; Fridberger, Anders; Nuttall, Alfred L.

    2011-11-01

    The longitudinal distribution of the organ of Corti vibration is important for both understanding the energy delivery and the timing of the cochlear amplification. Recent development on low coherence interferomtry technique allows measuring vibration inside the cochlea. The reticular lamina (RL) vibration spectrum demonstrates that RL vibration leads the basilar membrane (BM). This phase lead is consistent with the idea that the active process may lead the BM vibration. In this study, measurements on multiple longitudinal locations demonstrated similar phase lead. Results on this study suggests that there may be another longitudinal coupling mechanism inside the cochlea other than the traveling wave on BM.

  6. [Effect of a 6-week vitamin A-deficient diet on the sensory cells of the inner ear. Light and electron microscopic studies].

    PubMed

    Löhle, E

    1980-09-01

    Histologic studies of the inner ear in rats with chronic vitamin A deficiency have produced contradicting results. In our own electronmicroscope investigations of the inner ear of young rats after a six week vitamin A deficit diet we found a lacking of the cuticle in the outer hair cells and a subtotally lacking of the cuticle in the inner hair cells. Furthermore, we found changes in the reticular system of the intermediate zone. These morphologic changes together with the recent findings of high concentrations of vitamin A in the corti organ support the hypothesis that the acoustic sensory receptors contain or functionally depend upon vitamin A.

  7. Infrared neural stimulation (INS) inhibits electrically evoked neural responses in the deaf white cat

    NASA Astrophysics Data System (ADS)

    Richter, Claus-Peter; Rajguru, Suhrud M.; Robinson, Alan; Young, Hunter K.

    2014-03-01

    Infrared neural stimulation (INS) has been used in the past to evoke neural activity from hearing and partially deaf animals. All the responses were excitatory. In Aplysia californica, Duke and coworkers demonstrated that INS also inhibits neural responses [1], which similar observations were made in the vestibular system [2, 3]. In deaf white cats that have cochleae with largely reduced spiral ganglion neuron counts and a significant degeneration of the organ of Corti, no cochlear compound action potentials could be observed during INS alone. However, the combined electrical and optical stimulation demonstrated inhibitory responses during irradiation with infrared light.

  8. Identification of members of several homeobox genes in a planarian using a ligation-mediated polymerase chain reaction technique.

    PubMed Central

    Balavoine, G

    1996-01-01

    I have used a novel single-sided specific polymerase chain reaction (PCR) strategy inspired by ligation-mediated PCR to clone fragments of divergent homeobox genes from a flatworm, the planarian Polycelis nigra. Eight homeobox-containing fragments were amplified, belonging to the Hox, msh, NK-1 and NK-2 classes. Together with the results obtained from several genomes of platyhelminths, my screening shows the presence of the same array of homeodomain developmental regulators in planarians, traditionally regarded as primitive metazoans in terms of body plan, as in coelomate organisms. However, the presence of a Ubx/abd-A homolog may indicate that platyhelminths are more closely related to protostomes than to deuterostomes and supports the idea that flatworms have inherited an elaborate HOX cluster (seven or eight genes) from their ancestor. Likely homologs of the fly genes tinman, bagpipe and S59 suggest that the mesoderm might be patterned by the same genes in all bilaterally symmetrical animals. Finally, a msh-like gene, a family known to be involved in inductive mechanisms in vertebrates, has been found. These results support the hypothesis that the tremendous diversity of metazoan body plans is specified by a largely conserved array of homeobox-containing developmental genes. PMID:8628690

  9. Phylogenetic position of phylum Nemertini, inferred from 18S rRNA sequences: molecular data as a test of morphological character homology.

    PubMed

    Turbeville, J M; Field, K G; Raff, R A

    1992-03-01

    Partial 18S rRNA sequence of the nemertine Cerebratulus lacteus was obtained and compared with those of coelomate metazoans and acoelomate platyhelminths to test whether nemertines share a most recent common ancestor with the platyhelminths, as traditionally has been implied, or whether nemertines lie within a protostome coelomate clade, as suggested by more recent morphological analyses. Maximum-parsimony analysis supports the inclusion of the nemertine within a protostome-coelomate clade that falls within a more inclusive coelomate clade. Bootstrap analysis indicates strong support for a monophyletic Coelomata composed of a deuterostome and protostome-coelomate clade. Support for a monophyletic protostome Coelomata is weak. Inference by distance analysis is consistent with that of maximum parsimony. Analysis of down-weighted paired sites by maximum parsimony reveals variation in topology only within the protostome-coelomate clade. The relationships among the protostome coelomates cannot be reliably inferred from the partial sequences, suggesting that coelomate protostomes diversified rapidly. Results with evolutionary parsimony are consistent with the inclusion of the nemertine in a coelomate clade. The molecular inference corroborates recent morphological character analyses that reveal no synapomorphies of nemertines and flatworms but instead suggest that the circulatory system and rhynchocoel of nemertines are homologous to coelomic cavities of protostome coelomates, thus supporting the corresponding hypothesis that nemertines belong within a protostome-coelomate clade. The sequence data provide an independent test of morphological character homology.

  10. Early evolution of the bilateria.

    PubMed

    Hausdorf, B

    2000-03-01

    The phylogeny of the Bilateria and especially the early steps in the evolution of the bilaterian bauplan are still a controversial topic. In this context the relationships of the platyhelminths and the nematodes play a crucial role. Previous molecular studies of the relationships of these groups, which were based on 18S ribosomal DNA sequences, yielded conflicting results. In the present study a new framework is developed for the phylogenetic analysis of bilaterian relationships, using concatenated amino acid sequences of several nuclear genes. In this analysis, the rhabditophoran platyhelminths are probably the sister group of all other analyzed Bilateria, the Eubilateria, which are characterized by a one-way intestine with an anus. The Eubilateria are split into the nematode lineage and the coelomates. The phylogenetic results of the present study indicate that genetic features found in the model organisms Caenorhabditis and Drosophila might be found in all Eubilateria. Estimations of the divergence times show that the major bilaterian phyla did not originate in an explosive radiation during the Cambrian but rather that the Bilateria have a several hundred million years long Precambrian history.

  11. Functional visualization of the excretory system of adult Schistosoma mansoni by the fluorescent marker resorufin.

    PubMed

    Sato, H; Kusel, J R; Thornhill, J

    2002-12-01

    Excretion of metabolic wastes as well as xenobiotics is a major concern of all living organisms, and the Platyhelminthes including Schistosoma mansoni possess the protonephridial excretory system for their survival. Except for some ultra-structural and biochemical information, little is known about the protonephridium of platyhelminths due to a lack of established techniques for exploring the excretory activity. This study describes a new technique to assess the excretory activity of S. mansoni by use of the fluorescent marker resorufin, which is a potential substrate of the drug efflux pump, P-glycoprotein. After simple diffusion into the schistosome body, fluorescent resorufin was concentrated in the excretory tubules by an energy-dependent mechanism and excreted via the nephridiopore. The present technique of labelling functionally the excretory system was applicable to adult worms, but not schistosomula or cercariae. A variety of modulators known to interfere with mammalian P-glycoprotein function perturbed resorufin excretion from male adult schistosomes, including cyclosporin A, Ro11-2933, verapamil, or nifedipine. This technique of labelling the excretory system with fluorescent resorufin has enabled us to study aspects of the physiological function, hitherto unknown, of the protonephridial system of S. mansoni.

  12. Spliced-leader trans-splicing in freshwater planarians.

    PubMed

    Zayas, Ricardo M; Bold, Tyler D; Newmark, Phillip A

    2005-10-01

    trans-Splicing, in which a spliced-leader (SL) RNA is appended to the most 5' exon of independently transcribed pre-mRNAs, has been described in a wide range of eukaryotes, from protozoans to chordates. Here we describe trans-splicing in the freshwater planarian Schmidtea mediterranea, a free-living member of the phylum Platyhelminthes. Analysis of an expressed sequence tag (EST) collection from this organism showed that over 300 transcripts shared one of two approximately 35-base sequences (Smed SL-1 and SL-2) at their 5' ends. Examination of genomic sequences encoding representatives of these transcripts revealed that these shared sequences were transcribed elsewhere in the genome. RNA blot analysis, 5' and 3' rapid amplification of cDNA ends, as well as genomic sequence data showed that 42-nt SL sequences were derived from small RNAs of approximately 110 nt. Similar sequences were also found at the 5' ends of ESTs from the planarian Dugesia japonica. trans-Splicing has already been described in numerous representatives of the phylum Platyhelminthes (trematodes, cestodes, and polyclads); its presence in two representatives of the triclads supports the hypothesis that this mode of RNA processing is ancestral within this group. The upcoming complete genome sequence of S. mediterranea, combined with this animal's experimental accessibility and susceptibility to RNAi, provide another model organism in which to study the function of the still-enigmatic trans-splicing.

  13. Schistosome sex matters: a deep view into gonad-specific and pairing-dependent transcriptomes reveals a complex gender interplay

    PubMed Central

    Lu, Zhigang; Sessler, Florian; Holroyd, Nancy; Hahnel, Steffen; Quack, Thomas; Berriman, Matthew; Grevelding, Christoph G.

    2016-01-01

    As a key event for maintaining life cycles, reproduction is a central part of platyhelminth biology. In case of parasitic platyhelminths, reproductive processes can also contribute to pathology. One representative example is the trematode Schistosoma, which causes schistosomiasis, an infectious disease, whose pathology is associated with egg production. Among the outstanding features of schistosomes is their dioecious lifestyle and the pairing-dependent differentiation of the female gonads which finally leads to egg synthesis. To analyze the reproductive biology of Schistosoma mansoni in-depth we isolated complete ovaries and testes from paired and unpaired schistosomes for comparative RNA-seq analyses. Of >7,000 transcripts found in the gonads, 243 (testes) and 3,600 (ovaries) occurred pairing-dependently. Besides the detection of genes transcribed preferentially or specifically in the gonads of both genders, we uncovered pairing-induced processes within the gonads including stem cell-associated and neural functions. Comparisons to work on neuropeptidergic signaling in planarian showed interesting parallels but also remarkable differences and highlights the importance of the nervous system for flatworm gonad differentiation. Finally, we postulated first functional hints for 235 hypothetical genes. Together, these results elucidate key aspects of flatworm reproductive biology and will be relevant for basic as well as applied, exploitable research aspects. PMID:27499125

  14. Structural analysis of the α subunit of Na(+)/K(+) ATPase genes in invertebrates.

    PubMed

    Thabet, Rahma; Rouault, J-D; Ayadi, Habib; Leignel, Vincent

    2016-01-01

    The Na(+)/K(+) ATPase is a ubiquitous pump coordinating the transport of Na(+) and K(+) across the membrane of cells and its role is fundamental to cellular functions. It is heteromer in eukaryotes including two or three subunits (α, β and γ which is specific to the vertebrates). The catalytic functions of the enzyme have been attributed to the α subunit. Several complete α protein sequences are available, but only few gene structures were characterized. We identified the genomic sequences coding the α-subunit of the Na(+)/K(+) ATPase, from the whole-genome shotgun contigs (WGS), NCBI Genomes (chromosome), Genomic Survey Sequences (GSS) and High Throughput Genomic Sequences (HTGS) databases across distinct phyla. One copy of the α subunit gene was found in Annelida, Arthropoda, Cnidaria, Echinodermata, Hemichordata, Mollusca, Placozoa, Porifera, Platyhelminthes, Urochordata, but the nematodes seem to possess 2 to 4 copies. The number of introns varied from 0 (Platyhelminthes) to 26 (Porifera); and their localization and length are also highly variable. Molecular phylogenies (Maximum Likelihood and Maximum Parsimony methods) showed some clusters constituted by (Chordata/(Echinodermata/Hemichordata)) or (Plathelminthes/(Annelida/Mollusca)) and a basal position for Porifera. These structural analyses increase our knowledge about the evolutionary events of the α subunit genes in the invertebrates.

  15. Put a tiger in your tank: the polyclad flatworm Maritigrella crozieri as a proposed model for evo-devo

    PubMed Central

    2013-01-01

    Polyclad flatworms are an early branching clade within the rhabditophoran Platyhelminthes. They provide an interesting system with which to explore the evolution of development within Platyhelminthes and amongst Spiralia (Lophotrochozoa). Unlike most other flatworms, polyclads undergo spiral cleavage (similar to that seen in some other spiralian taxa), they are the only free-living flatworms where development via a larval stage occurs, and they are the only flatworms in which embryos can be reared outside of their protective egg case, enabling embryonic manipulations. Past work has focused on comparing early cleavage patterns and larval anatomy between polyclads and other spiralians. We have selected Maritigrella crozieri, the tiger flatworm, as a suitable polyclad species for developmental studies, because it is abundant and large in size compared to other species. These characteristics have facilitated the generation of a transcriptome from embryonic and larval material and are enabling us to develop methods for gene expression analysis and immunofluorescence techniques. Here we give an overview of M. crozieri and its development, we highlight the advantages and current limitations of this animal as a potential evo-devo model and discuss current lines of research. PMID:24107307

  16. Molecular phylogeny of metazoan intermediate filament proteins.

    PubMed

    Erber, A; Riemer, D; Bovenschulte, M; Weber, K

    1998-12-01

    We have cloned cytoplasmic intermediate filament (IF) proteins from a large number of invertebrate phyla using cDNA probes, the monoclonal antibody IFA, peptide sequence information, and various RT-PCR procedures. Novel IF protein sequences reported here include the urochordata and nine protostomic phyla, i.e., Annelida, Brachiopoda, Chaetognatha, Echiura, Nematomorpha, Nemertea, Platyhelminthes, Phoronida, and Sipuncula. Taken together with the wealth of data on IF proteins of vertebrates and the results on IF proteins of Cephalochordata, Mollusca, Annelida, and Nematoda, two IF prototypes emerge. The L-type, which includes 35 sequences from 11 protostomic phyla, shares with the nuclear lamins the long version of the coil 1b subdomain and, in most cases, a homology segment of some 120 residues in the carboxyterminal tail domain. The S-type, which includes all four subfamilies (types I to IV) of vertebrate IF proteins, lacks 42 residues in the coil 1b subdomain and the carboxyterminal lamin homology segment. Since IF proteins from all three phyla of the chordates have the 42-residue deletion, this deletion arose in a progenitor prior to the divergence of the chordates into the urochordate, cephalochordate, and vertebrate lineages, possibly already at the origin of the deuterostomic branch. Four phyla recently placed into the protostomia on grounds of their 18S rDNA sequences (Brachiopoda, Nemertea, Phoronida, and Platyhelminthes) show IF proteins of the L-type and fit by sequence identity criteria into the lophotrochozoic branch of the protostomia.

  17. Finite element cochlea box model - Mechanical and electrical analysis of the cochlea

    NASA Astrophysics Data System (ADS)

    Nikolic, Milica; Teal, Paul D.; Isailovic, Velibor; Filipović, Nenad

    2015-12-01

    The primary role of the cochlea is to transform external sound stimuli into mechanical vibrations and then to neural impulses which are sent to the brain. A simplified cochlea box model was developed using the finite element method. Firstly, a mechanical model of the cochlea was analyzed. The box model consists of the basilar membrane and two fluid chambers - the scala vestibuli and scala tympani. The third chamber, the scala media, was neglected in the mechanical analysis. The best agreement with currently available analytical and experimental results was obtained when behavior of the fluid in the chambers was described using the wave acoustic equation and behavior of the basilar membrane was modeled with Newtonian dynamics. The obtained results show good frequency mapping. The second approach was to use an active model of the cochlea in which the Organ of Corti was included. The operation of the Organ of Corti involves the generation of current, caused by mechanical vibration. This current in turn causes a force applied to the basilar membrane, creating in this way an active feedback mechanism. A state space representation of the electro-mechanical model from existing literature was implemented and a first comparison with the finite element method is presented.

  18. Quantitative imaging of platinum based on laser ablation-inductively coupled plasma-mass spectrometry to investigate toxic side effects of cisplatin.

    PubMed

    Köppen, C; Reifschneider, O; Castanheira, I; Sperling, M; Karst, U; Ciarimboli, G

    2015-12-01

    This work presents a quantitative bioimaging method for platinum based on laser ablation-inductively coupled plasma-mass spectrometry and its application for a biomedical study concerning toxic side effects of cisplatin. To trace the histopathology back to cisplatin, platinum was localized and quantified in major functional units of testicle, cochlea, kidney, nerve and brain sections from cisplatin treated mice. The direct consideration of the histology enables precise interpretation of the Pt images and the novel quantitative evaluation approach allows significantly more precise investigations than the pure image. For the first time, platinum was detected and quantified in all major injured structures including organ of Corti of cochlea and seminiferous tubule of testicle. In this way, proximal tubule in kidney, Leydig cells in testicle, stria vascularis and organ of Corti in cochlea and nerve fibers in sciatic nerves are confirmed as targets of cisplatin in these organs. However, the accumulation of platinum in almost all investigated structures also raises questions about more complex pathogenesis including direct and indirect interruption of several biological processes.

  19. Power Efficiency of Outer Hair Cell Somatic Electromotility

    PubMed Central

    Rabbitt, Richard D.; Clifford, Sarah; Breneman, Kathryn D.; Farrell, Brenda; Brownell, William E.

    2009-01-01

    Cochlear outer hair cells (OHCs) are fast biological motors that serve to enhance the vibration of the organ of Corti and increase the sensitivity of the inner ear to sound. Exactly how OHCs produce useful mechanical power at auditory frequencies, given their intrinsic biophysical properties, has been a subject of considerable debate. To address this we formulated a mathematical model of the OHC based on first principles and analyzed the power conversion efficiency in the frequency domain. The model includes a mixture-composite constitutive model of the active lateral wall and spatially distributed electro-mechanical fields. The analysis predicts that: 1) the peak power efficiency is likely to be tuned to a specific frequency, dependent upon OHC length, and this tuning may contribute to the place principle and frequency selectivity in the cochlea; 2) the OHC power output can be detuned and attenuated by increasing the basal conductance of the cell, a parameter likely controlled by the brain via the efferent system; and 3) power output efficiency is limited by mechanical properties of the load, thus suggesting that impedance of the organ of Corti may be matched regionally to the OHC. The high power efficiency, tuning, and efferent control of outer hair cells are the direct result of biophysical properties of the cells, thus providing the physical basis for the remarkable sensitivity and selectivity of hearing. PMID:19629162

  20. Cockayne syndrome group B (Csb) and group a (Csa) deficiencies predispose to hearing loss and cochlear hair cell degeneration in mice.

    PubMed

    Nagtegaal, A Paul; Rainey, Robert N; van der Pluijm, Ingrid; Brandt, Renata M C; van der Horst, Gijsbertus T J; Borst, J Gerard G; Segil, Neil

    2015-03-11

    Sensory hair cells in the cochlea, like most neuronal populations that are postmitotic, terminally differentiated, and non-regenerating, depend on robust mechanisms of self-renewal for lifelong survival. We report that hair cell homeostasis requires a specific sub-branch of the DNA damage nucleotide excision repair pathway, termed transcription-coupled repair (TCR). Cockayne syndrome (CS), caused by defects in TCR, is a rare DNA repair disorder with a broad clinical spectrum that includes sensorineural hearing loss. We tested hearing and analyzed the cellular integrity of the organ of Corti in two mouse models of this disease with mutations in the Csb gene (CSB(m/m) mice) and Csa gene (Csa(-/-) mice), respectively. Csb(m/m) and Csa(-/-) mice manifested progressive hearing loss, as measured by an increase in auditory brainstem response thresholds. In contrast to wild-type mice, mutant mice showed reduced or absent otoacoustic emissions, suggesting cochlear outer hair cell impairment. Hearing loss in Csb(m/m) and Csa(-/-) mice correlated with progressive hair cell loss in the base of the organ of Corti, starting between 6 and 13 weeks of age, which increased by 16 weeks of age in a basal-to-apical gradient, with outer hair cells more severely affected than inner hair cells. Our data indicate that the hearing loss observed in CS patients is reproduced in mouse models of this disease. We hypothesize that accumulating DNA damage, secondary to the loss of TCR, contributes to susceptibility to hearing loss.

  1. Nanomedicine strategy for optimizing delivery to outer hair cells by surface-modified poly(lactic/glycolic acid) nanoparticles with hydrophilic molecules

    PubMed Central

    Wen, Xingxing; Ding, Shan; Cai, Hui; Wang, Junyi; Wen, Lu; Yang, Fan; Chen, Gang

    2016-01-01

    Targeted drug delivery to outer hair cells (OHCs) in the cochlea by nanomedicine strategies forms an effective therapeutic approach for treating hearing loss. Surface chemistry plays a deciding role in nanoparticle (NP) biodistribution, but its influence on such distribution in the cochlea remains largely unknown. Herein, we report the first systematic comparison of poly(lactic/glycolic acid) nanoparticles (PLGA NPs) with or without surface modification of hydrophilic molecules for optimizing the delivery to OHCs both in vitro and in vivo. NPs that were surface modified with poloxamer 407 (P407), chitosan, or methoxy poly(ethylene glycol) and the unmodified NPs were highly biocompatible with L929 and House Ear Institute-organ of Corti 1 cells as well as cochlear tissues. Interestingly, among all the examined NPs, P407-PLGA NPs showed the greatest cellular uptake and prominent fluorescence in cochlear imaging. More importantly, we provide novel evidence that the surface-modified NPs reached the organ of Corti and were transported into the OHCs at a higher level. Together, these observations suggest that surface modification with hydrophilic molecules will allow future clinical applications of PLGA NPs, especially P407-PLGA NPs, in efficient hearing loss therapy. PMID:27877041

  2. cDNA cloning, tissue distribution, and chromosomal localization of Ocp2, a gene encoding a putative transcription-associated factor predominantly expressed in the auditory organs

    SciTech Connect

    Chen, Hong; Thalmann, I.; Thalmann, R.

    1995-06-10

    We report the cloning of the Ocp2 gene encoding OCP-II from a guinea pig organ-of-Corti cDNA library. The predicted open reading frame encodes a protein of 163 amino acids with an estimated molecular mass of 18.6 kDa. A homology search revealed that Ocp2 shares significant sequence similarity with p15, a sub-unit of transcription factor SIII that regulates the activity of the RNA polymerase II elongation complex. The Ocp2 messenger RNA is expressed abundantly in the cochlea while not significantly in any other tissues examined, including brain, eye, heart, intestine, kidney, liver, lung, thigh muscle, and testis, demonstrating that the expression of this gene may be restricted to auditory organs. A polyclonal antiserum was raised against the N-terminal region of OCP-II. Immunohistochemical staining of paraffin-embedded sections of the cochlea showed that OCP-II is localized abundantly in nonsensory cells in the organ of Corti; in addition, it was also detected, at a lower concentration, in vestibular sensory organs, as well as auditory and vestibular brain stem nuclei. The Ocp2 gene was mapped to mouse chromosome 4 as well as 11. Our results suggest that OCP-II may be involved in transcription regulation for the development or maintenance of specialized functions of the inner ear. 40 refs., 5 figs.

  3. Reduced Connexin26 in the Mature Cochlea Increases Susceptibility to Noise-Induced Hearing Loss in Mice

    PubMed Central

    Zhou, Xing-Xing; Chen, Sen; Xie, Le; Ji, Yu-Zi; Wu, Xia; Wang, Wen-Wen; Yang, Qi; Yu, Jin-Tao; Sun, Yu; Lin, Xi; Kong, Wei-Jia

    2016-01-01

    Connexin26 (Cx26, encoded by GJB2) mutations are the most common cause of non-syndromic deafness. GJB2 is thought to be involved in noise-induced hearing loss (NIHL). However, the role of Cx26 in NIHL is still obscure. To explore the association between Cx26 and NIHL, we established a Cx26 knockdown (KD) mouse model by conditional knockdown of Cx26 at postnatal day 18 (P18), and then we observed the auditory threshold and morphologic changes in these mice with or without noise exposure. The Cx26 KD mice did not exhibit substantial hearing loss and hair cell degeneration, while the Cx26 KD mice with acoustic trauma experienced higher hearing loss than simple noise exposure siblings and nearly had no recovery. Additionally, extensive outer hair cell loss and more severe destruction of the basal organ of Corti were observed in Cx26 KD mice after noise exposure. These data indicate that reduced Cx26 expression in the mature mouse cochlea may increase susceptibility to noise-induced hearing loss and facilitate the cell degeneration in the organ of Corti. PMID:26927086

  4. The basilar membrane acts as a passive support structure at the cochlear apex

    NASA Astrophysics Data System (ADS)

    Warren, Rebecca L.; Fridberger, Anders

    2015-12-01

    The precise mechanical behavior of the basilar membrane (BM) at low frequencies is still unknown. To address this issue we use an in vitro preparation of the guinea pig temporal bone to investigate the mechanical behaviour of the organ of Corti at the apex of the cochlea. Confocal laser interferometry is used to record the nanometre displacements of both Hensen's cells (HeC) and the BM in response to sound and electrical stimulation. We show that at low frequencies, the BM exhibits greatly reduced sound-evoked movement (˜35dB less) and no current-evoked movement, when compared to the HeC at the same position along the spiral. The BM best frequency is found to be an average of 52Hz (0.35 octave) higher than the HeC best frequency. In addition, we demonstrate that BM motion is not affected by inhibition of somatic electromotility or by blocking the mechanoelectrical transduction channels.We therefore propose that the BM primarily acts as a passive support structure at the cochlear apex. We suggest that the micromechanics of the cochlea that are vital to low-frequency amplification and frequency selectivity take place predominantly at the surface of the organ of Corti.

  5. Signaling regulating inner ear development: cell fate determination, patterning, morphogenesis, and defects.

    PubMed

    Nakajima, Yuji

    2015-02-01

    The membranous labyrinth of the inner ear is a highly complex organ that detects sound and balance. Developmental defects in the inner ear cause congenital hearing loss and balance disorders. The membranous labyrinth consists of three semicircular ducts, the utricle, saccule, and endolymphatic ducts, and the cochlear duct. These complex structures develop from the simple otic placode, which is established in the cranial ectoderm adjacent to the neural crest at the level of the hindbrain at the early neurula stage. During development, the otic placode invaginates to form the otic vesicle, which subsequently gives rise to neurons for the vestibulocochlear ganglion, the non-sensory and sensory epithelia of the membranous labyrinth that includes three ampullary crests, two maculae, and the organ of Corti. Combined paracrine and autocrine signals including fibroblast growth factor, Wnt, retinoic acid, hedgehog, and bone morphogenetic protein regulate fate determination, axis formation, and morphogenesis in the developing inner ear. Juxtacrine signals mediated by Notch pathways play a role in establishing the sensory epithelium, which consists of mechanosensory hair cells and supporting cells. The highly differentiated organ of Corti, which consists of uniformly oriented inner/outer hair cells and specific supporting cells, develops during fetal development. Developmental alterations/arrest causes congenital malformations in the inner ear in a spatiotemporal-restricted manner. A clearer understanding of the mechanisms underlying inner ear development is important not only for the management of patients with congenital inner ear malformations, but also for the development of regenerative therapy for impaired function.

  6. In vivo imaging and vibration measurement of Guinea pig cochlea

    NASA Astrophysics Data System (ADS)

    Choudhury, Niloy; Chen, Fangyi; Zheng, Jiefu; Nuttall, Alfred L.; Jacques, Steven L.

    2008-02-01

    An optical coherence tomography (OCT) system was built to acquire in vivo, both images and vibration measurements of the organ of Corti of the guinea pig. The organ of Corti was viewed through a ~500-μm diameter hole in the bony wall of the scala tympani of the first cochlear turn. In imaging mode, the image was acquired as reflectance R(x,z). In vibration mode, the basilar membrane (BM) or reticular lamina (RL) was selected based on the image. Under software control, the system would move the scanning mirrors to bring the sensing volume of the measurement to the desired tissue location. To address the gain stability problem of the homodyne OCT system, arising from the system moving in and out of the quadrature point and also to resolve the 180 degree ambiguity in the phase measurement using an interferometer, a vibration calibration method is developed by adding a vibrating source to the reference arm to monitor the operating point of the interferometric system. Amplitude gain and phase of various cochlear membranes was measured for different sound pressure level (SPL) varying from 65dB SPL to 93 dB SPL.

  7. Neural Stem Cells Injected into the Sound-Damaged Cochlea Migrate Throughout the Cochlea and Express Markers of Hair Cells, Supporting Cells, and Spiral Ganglion Cells

    PubMed Central

    Corliss, Deborah A.; Gray, Brianna; Anderson, Julia K.; Bobbin, Richard P.; Snyder, Evan Y.; Cotanche, Douglas A.

    2007-01-01

    Most cases of hearing loss are caused by the death or dysfunction of one of the many cochlear cell types. We examined whether cells from a neural stem cell line could replace cochlear cell types lost after exposure to intense noise. For this purpose, we transplanted a clonal stem cell line into the scala tympani of sound damaged mice and guinea pigs. Utilizing morphological, protein expression and genetic criteria, stem cells were found with characteristics of both neural tissues (satellite, spiral ganglion and Schwann cells) and cells of the organ of Corti (hair cells, supporting cells). Additionally, noise-exposed, stem cell-injected animals exhibited a small but significant increase in the number of satellite cells and Type I spiral ganglion neurons compared to non-injected noise-exposed animals. These results indicate that cells of this neural stem cell line migrate from the scala tympani to Rosenthal's canal and the organ of Corti. Moreover, it suggests that cells of this neural stem cell line may derive some information needed from the microenvironment of the cochlea to differentiate into replacement cells in the cochlea. PMID:17659854

  8. Virally expressed connexin26 restores gap junction function in the cochlea of conditional Gjb2 knockout mice.

    PubMed

    Yu, Q; Wang, Y; Chang, Q; Wang, J; Gong, S; Li, H; Lin, X

    2014-01-01

    Mutations in GJB2, which codes for the gap junction (GJ) protein connexin26 (Cx26), are the most common causes of human nonsyndromic hereditary deafness. We inoculated modified adeno-associated viral (AAV) vectors into the scala media of early postnatal conditional Gjb2 knockout mice to drive exogenous Cx26 expression. We found extensive virally expressed Cx26 in cells lining the scala media, and intercellular GJ network was re-established in the organ of Corti of mutant mouse cochlea. Widespread ectopic Cx26 expression neither formed ectopic GJs nor affected normal hearing thresholds in wild-type (WT) mice, suggesting that autonomous cellular mechanisms regulate proper membrane trafficking of exogenously expressed Cx26 and govern the functional manifestation of them. Functional recovery of GJ-mediated coupling among the supporting cells was observed. We found that both cell death in the organ of Corti and degeneration of spiral ganglion neurons in the cochlea of mutant mice were substantially reduced, although auditory brainstem responses did not show significant hearing improvement. This is the first report demonstrating that virally mediated gene therapy restored extensive GJ intercellular network among cochlear non-sensory cells in vivo. Such a treatment performed at early postnatal stages resulted in a partial rescue of disease phenotypes in the cochlea of the mutant mice.

  9. Mu-opioid receptor (MOR) expression in the human spiral ganglia

    PubMed Central

    Nguyen, Kimanh D.; Mowlds, Donald; Lopez, Ivan A.; Hosokawa, Seiji; Ishiyama, Akira; Ishiyama, Gail

    2015-01-01

    Opioid peptides and their receptors have been localized to the inner ear of the rat and guinea pig mammalian models. The expression of mu opioid receptor (MOR) in the human and mouse cochlea is not yet known. We present MOR protein localization by immunohistochemistry and mRNA expression by in situ hybridization in the human and mouse spiral ganglia (SG) and organ of Corti. In the human most of the (SG) neurons were immunoreactive; a subset was non-immunoreactive. In situ hybridization revealed a similar labeling pattern across the neurons of the SG. A similar distribution MOR pattern was demonstrated in the mouse SG. In the mouse organ of Corti MOR was expressed in inner and outer hair cells. Fibers underneath the inner hair cells were also MOR immunoreactive. These results are consistent with a role of MOR in neuro-modulation of the auditory periphery. The present results show that the expression of MORs is well-conserved across multiple mammalian species, indicative of an important role in auditory processing. PMID:25278190

  10. [The safety evaluation of fradiomycin-gramicidin S troches "Meiji" (author's transl)].

    PubMed

    Yokota, M; Odaki, M; Koeda, T; Sato, K; Akiyoshi, M

    1976-09-01

    The troches "Meiji" contain fradiomycin (neomycin), an aminoglycoside antibiotic, and gramicidin S, and are effective against gram-negative and -positive bacteria. In this paper the safety evaluation of the troches is reported. In this study male guinea pigs of Hartley strain were used, and fradiomycin (FRM) and gramicidin S (GRMN) were administered orally for 35 days consecutively except Sunday. The PRYER'S reflex test was carried out with frequency range of 10,000 approximately 15,000 Hz before, during and after the administration. After the last administration the animals underwent vital perfusion with physiological saline and then with Wittmack's fixative. Bilateral temporal bones were removed and fixed in the same fixative for several days. Using a conventional method, serial celloidin horinzontal sections were prepared and stained with hematoxyline-eosine to observe histopathological effect of the medicines on the organs of CORTI. The results were as follows: 1) There were no remarkable differences in the treated animals from the initial states. No animal died at all the doses tested. 2) All of the guinea pigs received 10 and 50 mg/kg of FRM and 4 and 20 mg/kg of GRMN for 35 days indicated positive pinna reflex in the extensive frequency range of 10,000 approximately 15,000 Hz. There was no remarkable damage in the organ of CORTI on histopathological examination. 3) It was concluded from these results that the troches are highly safe.

  11. Transcriptomic Analysis of Mouse Cochlear Supporting Cell Maturation Reveals Large-Scale Changes in Notch Responsiveness Prior to the Onset of Hearing

    PubMed Central

    Maass, Juan C.; Gu, Rende; Cai, Tiantian; Wan, Ying-Wooi; Cantellano, Silvia C.; Asprer, Joanna S. T.; Zhang, Hongyuan; Jen, Hsin-I; Edlund, Renée K.; Liu, Zhandong; Groves, Andrew K.

    2016-01-01

    Neonatal mouse cochlear supporting cells have a limited ability to divide and trans-differentiate into hair cells, but this ability declines rapidly in the two weeks after birth. This decline is concomitant with the morphological and functional maturation of the organ of Corti prior to the onset of hearing. However, despite this association between maturation and loss of regenerative potential, little is known of the molecular changes that underlie these events. To identify these changes, we used RNA-seq to generate transcriptional profiles of purified cochlear supporting cells from 1- and 6-day-old mice. We found many significant changes in gene expression during this period, many of which were related to regulation of proliferation, differentiation of inner ear components and the maturation of the organ of Corti prior to the onset of hearing. One example of a change in regenerative potential of supporting cells is their robust production of hair cells in response to a blockade of the Notch signaling pathway at the time of birth, but a complete lack of response to such blockade just a few days later. By comparing our supporting cell transcriptomes to those of supporting cells cultured in the presence of Notch pathway inhibitors, we show that the transcriptional response to Notch blockade disappears almost completely in the first postnatal week. Our results offer some of the first molecular insights into the failure of hair cell regeneration in the mammalian cochlea. PMID:27918591

  12. Results of parasitological examinations of faecal samples from cats and dogs in Germany between 2003 and 2010.

    PubMed

    Barutzki, Dieter; Schaper, Roland

    2011-08-01

    In a retrospective study, the results of parasitological examinations of faecal samples from 8,560 cats and 24,677 dogs between January 2003 and December 2010 in Germany were analysed. 30.4 % of the examined dogs and 22.8 % of the cats were infected with endoparasites. The examination of the faecal samples from dogs revealed stages of Giardia spp. (18.6 %), Toxocara canis (6.1 %), Toxascaris leonina (0.6 %), Ancylostomatidae (2.2 %), Trichuris vulpis (1.2 %), Capillaria spp. (1.3 %), Crenosoma vulpis (0.4 %), Angiostrongylus vasorum (0.5 %), Taeniidae (0.4 %), Dipylidiidae (< 0.1 %), Mesocestoides spp. (< 0.1 %), Isospora spp. (5.6 %), I. ohioensis-complex (3.9 %), I. canis (2.4 %), Sarcocystis spp. (2.2 %) and Hammondia heydorni/Neospora caninum (0.3 %). Dogs in the age groups up to 3 months and > 3 up to 6 months of age showed significantly higher infection rates with Giardia spp. (37.5 % and 38.2 %, respectively), Toxocara canis (12.0 % and 12.4 %, respectively), Toxascaris leonina (1.1 % and 1.6 %, respectively), Isospora spp. (23.4 % and 11.8 %, respectively), I. ohioensis-complex (15.6 % and 7.2 %, respectively) and I. canis (11.8 % and 5.2 %, respectively) compared to older dogs. In faecal samples from cats, stages of Giardia spp. (12.6 %), Toxocara cati (4.7 %), Toxascaris leonina (0.1 %), Ancylostoma tubaeforme (0.2 %), Aelurostrongylus abstrusus (0.5 %), Capillaria spp. (1.0 %), Taeniidae (0.6 %), Dipylidium caninum (< 0.1 %) Mesocestoides spp. (< 0.1 %), Isospora spp. (6.0 %), I. felis (4.4 %), I. rivolta (2.2 %), Toxoplasma gondii/Hammondia hammondi (0.8 %) and Sarcocystis spp. (0.3 %) were detected. Cats in the age groups up to 3 months and > 3 up to 6 months of age showed significantly higher infection rates with Giardia spp. (19.5 % and 24.0 %, respectively), T. cati (8.1 % and 6.9 %, respectively), Isospora spp. (12.8 % and 8.6 %, respectively), I. felis (10.0 % and 5.9%, respectively) and I. rivolta (4.6 % and 2.9%, respectively) compared to older

  13. Intestinal helminth communities in the green lizard, lacerta viridis, from bulgaria

    PubMed

    Biserkov; Kostadinova

    1998-09-01

    A data set comprising individual host/parasite lists from 100 Lacerta viridis (Reptilia: Lacertidae) belonging to four isolated populations in Bulgaria was studied. A total of seven helminth species was recovered (Leptophallus nigrovenosus, Plagiorchis molini, Oswaldocruzia filiformis, Spauligodon extenuatus, Skrjabinelazia hoffmanni, Physaloptera clausa and Mesocestoides sp.). Lacerta viridis is a new host record for the first five of these species. Communities of intestinal helminths of L. viridis consist of a few species which resulted in a low species richness, abundance and diversity of infracommunities, which exhibit substantial homogeneity among the four samples. A similar pattern of dominance of two nematode species leading to a relatively high community similarity at both infra- and component community levels was observed. While intestinal helminth communities in lizards from 'marginal' habitats were dominated by the host generalist, O. filiformis, those in hosts from 'typical' habitats were dominated by the lizard specialist S. extenuatus. The results indicate that the characteristics of the host's habitat are important in determining the composition rather than structure of intestinal helminth communities in L. viridis.

  14. Helminth parasites of the endangered Iberian lynx (Lynx pardinus) and sympatric carnivores.

    PubMed

    Millán, Javier; Casanova, Joan Carles

    2007-12-01

    Five critically endangered Iberian lynxes (Lynx pardinus) and 35 other sympatric carnivores (19 feral cats Felis catus, 12 Egyptian mongooses Herpestes ichneumon, and 4 common genets Genetta genetta) were analysed for helminths in Sierra Morena and Doñana area (southern Spain). Ancylostoma tubaeforme, which was believed to be harmful for lynx cubs according to a previous study, was present in the only lynx and in 53% of cats analysed in Doñana (80% in adult cats). Other species shared in both areas were Toxocara cati (1 lynx, 31% of cats), Joyeuxiella pasqualei (1 lynx, 21% of cats) and Mesocestoides sp. (2 lynxes, 5% of cats). Only one mongoose was parasitized, harbouring larvae of two acantocephalan species not previously reported in the Iberian peninsula (Centrorhynchus (Sphaerirostris) lancea and Centrorhynchus (Longirostris) undulatus). Feral cats may be a reservoir for hookworms and other helminths affecting the Iberian lynx. In contrast, mongooses and genets may not play a role in the epidemiology of these species.

  15. Helminth parasites of the wolf Canis lupus from Latvia.

    PubMed

    Bagrade, G; Kirjusina, M; Vismanis, K; Ozoliņs, J

    2009-03-01

    Thirty-four wolves were collected between 2003 and 2008 from throughout Latvia and examined for helminths. A total of 17 helminth species were recorded: the trematode Alaria alata (85.3%); the cestodes Diphyllobothrium latum (2.9%), Echinococcus granulosus (2.9%), Echinococcus multilocularis (5.9%), Mesocestoides lineatus (5.9%), Taenia crassiceps (8.8%), Taenia hydatigena (41.2%), Taenia (ovis) krabbei (8.8%), Taenia multiceps (47.1%), Taenia pisiformis (20.6%), Taenia polyacantha (11.8%), Taenia spp. (8.8%); and the nematodes Ancylostoma caninum (2.9%), Crenosoma vulpis (9.1%), Eucoleus aerophilus (36.4%), Pearsonema plica (41.4%), Trichinella spp. (69.7%), Toxocara canis (5.8%), and Uncinaria stenocephala (41.2%). Alaria alata presented the highest mean intensity (403.8). All animals were infected with at least one species of parasite, while the maximum recorded in one specimen was eight. No differences in the intensity or prevalence of any helminth species were found among the host based on age and gender, except for T. multiceps which was more prevalent in adults than in juveniles.

  16. First detection of Echinococcus multilocularis in dogs in a highly endemic area of Poland.

    PubMed

    Karamon, Jacek; Samorek-Pierog, Malgorzata; Kochanowski, Maciej; Dabrowska, Joanna; Sroka, Jacek; Golab, Elzbieta; Umhang, Gerald; Cencek, Tomasz

    2016-06-02

    The aim of the investigation was to estimate the epizootic situation concerning infection by the cestode Echinococcus multilocularis Leuckart, 1863 in dogs (Canis lupus familiaris Linnaeus) from a Polish region where this parasite is highly prevalent in red foxes. Faecal samples (n = 148) were collected from rural dogs in Podkarpackie Province. Samples were examined through nested PCR (for E. multilocularis), multiplex PCR (E. multilocularis, species of Taenia Linnaeus, 1758) and PCR [E. granulosus (Batsch, 1786)]. Specific products were sequenced. Faeces were also examined coproscopically. In samples from two dogs (1.4%), there were positive PCR results for E. multilocularis. Taenia-specific PCR products were found in nine dogs (6.1%). Sequencing identified Taenia serialis (Gervais, 1847), T. hydatigena Pallas, 1766, T. pisiformis (Bloch, 1780) and Hydatigera taeniaeformis (Batsch, 1786). One sample (0.7%) was identified as Mesocestoides litteratus (Batsch, 1786). All samples were negative for E. granulosus with PCR. Taking into account coproscopic and PCR results, 28% of dogs were infected with helminths (8% with tapeworms). It should be stressed that one of the infected with E. multilocularis dogs shed eggs of the Taenia type and had a habit of preying on rodents. This investigation revealed the presence of E. multilocularis in dogs for the first time in Poland.

  17. Infections with cardiopulmonary and intestinal helminths and sarcoptic mange in red foxes from two different localities in Denmark.

    PubMed

    Al-Sabi, Mohammad N S; Halasa, Tariq; Kapel, Christian M O

    2014-03-01

    Monitoring parasitic infections in the red fox is essential for obtaining baseline knowledge on the spread of diseases of veterinary and medical importance. In this study, screening for cardiopulmonary and intestinal helminths and sarcoptic mange (Sarcoptes scabiei) was done on 118 foxes originating from two distinct localities in Denmark, (Copenhagen) greater area and southern Jutland. Fifteen parasite species were recorded in 116 foxes (98.3%), nine parasitic species are of zoonotic potential. Parasite diversity was greater in foxes of Copenhagen in terms of overall parasite species richness and species richness of all helminth groups individually: trematodes; cestodes; and nematodes. Six parasite species were recovered from foxes of Copenhagen, but not from foxes of Southern Jutland: Echinochasmus perfoliatus; Echinostoma sp.; Pseudamphistomum truncatum; Dipylidium caninum; Angiostrongylus vasorum; and Sarcoptes scabiei, but Toxascaris leonina was only recorded in foxes of southern Jutland. A high prevalence and abundance of A. vasorum in foxes of Copenhagen was observed. The prevalence of four nematode species; Eucoleus (Capillaria) aerophilus, Uncinaria stenocephala, Toxocara canis, and Crenosoma vulpis, in foxes of both localities were comparable and ranging from 22.9% to 89%. The prevalence of Mesocestoides sp. was significantly higher in foxes of Copenhagen. Taenia spp. were detected using morphological and molecular analysis, which revealed the dominance of T. polyacantha in foxes of both localities. Infections with sarcoptic mange were evident only among foxes of Copenhagen (44.9%), which significantly affected the average weight of the infected animals. Further remarks on the zoonotic and veterinary implications of the parasites recovered are given.

  18. Fecal shedding of Toxocara canis and other parasites in foxes and coyotes on Prince Edward Island, Canada.

    PubMed

    Wapenaar, Wendela; Barkema, Herman W; O'Handley, Ryan

    2013-04-01

    Knowledge of parasites shed by wild canids can assist in recognizing risk to human and domestic animal health. Our aim was to estimate the prevalence of patent infections with Toxocara canis and other parasites in foxes (Vulpes vulpes) and coyotes (Canis latrans) in Prince Edward Island, Canada. Identification of parasite species was based on microscopic examination of feces, with the use of a sucrose fecal flotation method. Sample collection was performed in winter on carcasses of 271 and 185 hunted or trapped foxes and coyotes, respectively. One or more parasite species were observed in 242 (89%) foxes and 128 (69%) coyotes. Toxocara canis, Uncinaria stenocephala, Capillaria spp., Mesocestoides, Taenidd spp., Alaria spp., Cryptocotyle lingua, Sarcocystis spp., Neospora caninum-like coccidia, and other coccidia were identified. A third of juvenile foxes were shedding T. canis and had a high prevalence of Capillaria spp., especially in juvenile foxes (69%). Taenidd eggs, Alaria spp. and Sarcocystis spp. were more common in coyotes (24, 18, and 9%, respectively) than foxes (8, 11, and 1%, respectively). Despite the limitations of fecal flotation to identify parasite species, the high prevalence of T. canis warrants the attention of public health professionals.

  19. Intestinal parasites of the red fox (Vulpes vulpes) in Slovenia.

    PubMed

    Vergles Rataj, Aleksandra; Posedi, Janez; Zele, Diana; Vengušt, Gorazd

    2013-12-01

    In the present study, 428 foxes were collected and examined for intestinal helminths using the washing-out method. Parasites were found in 93.2% of the examined animals. The most frequently identified nematodes were Uncinaria stenocephala (58.9%), Toxocara canis (38.3%) and Molineus patens (30.6%). Other nematodes found were Pterygodermatites affinis (4.2%), Capillaria sp. (2.8%), Crenosoma vulpis (2.8%), Toxascaris leonina (2.5%), Trichuris vulpis (0.7%) and Physaloptera sp. (0.2%). Mesocestoides sp. (27.6%) and Taenia crassiceps (22.2%) were the most prevalent cestodes, followed by T. polyacantha (6.5%), Hymenolepis nana (2.1%), T. pisiformis (2.1%) and Dipylidium caninum (1.4%). The study also revealed four trematode species: Rossicotrema donicum (1.6%), Heterophyes heterophyes (1.1%), Metagonimus yokogawai (1.1%), Prohemistomum appendiculatum (0.4%) and two protozoan species: oocysts of Sarcocystis (2.8%) and Isospora (0.4%). This is the first extensive study on the intestinal parasites of the red fox (Vulpes vulpes) in Slovenia. The 2.6% prevalence of Echinococcus multilocularis in the same sample population as investigated herein has been reported previously (Vergles Rataj et al., 2010).

  20. Helminth Infections of Meriones persicus (Persian Jird), Mus musculus (House Mice) and Cricetulus migratorius (Grey Hamster): A Cross-Sectional Study in Meshkin-Shahr District, Northwest Iran

    PubMed Central

    ZAREI, Zabiholah; MOHEBALI, Mehdi; HEIDARI, Zahra; DAVOODI, Jaber; SHABESTARI, Afshin; MOTEVALLI HAGHI, Afsaneh; KHANALIHA, Khadijeh; KIA, Eshrat Beigom

    2016-01-01

    Background: Rodents have important role as reservoirs of different parasites. The aim of this study was to determine helminth parasites of abundant rodents in Meshkin-Shahr, Ardabil Province northwest Iran. Methods: From April 2014 to March 2015; 205 rodents including 118 Meriones persicus, 63 Mus musculus and 24 Cricetulus migratorius were collected, using live traps. All rodents were dissected and their different tissues examined for infectivity with helminth parasites. Results: Overall, 74.2% of rodents were infected with helminth parasites. The rate of infectivity in M. persicus, M. musculus and C. migratorius was 82.2%, 61.9%, 66.7%, respectively. In general, among all 205 rodents, the species and infection rates of helminthes were as follows: Nematoda: Trichuris sp. (46.8%), Capillaria hepatica (18.1%), Syphacia frederici (14.2%), Aspicularis tetraptera (3.4%), Trichuris rhombomidis (2%), Heligmosomom sp. (2%), Streptopharagus kuntzi (0.5%), Spiruridae gen. sp. (0.5%); Cestoda: Hymenolepis nana fraterna (16.6%) Hymenolepis diminuta (7.3%) tetratiridium of Mesocestoides sp. (1%), Paranoplocephala sp. (0.5%), Cysticercus fasciolaris (0.5%), Taenia endothoracicus larva (0.5%), and Acanthocephala: Moniliformis moniliformis (18.5%). Conclusions: Variable species of helminthes circulate in the rodents of the study area. Presence of several zoonotic species highlights the potential risk of infections for public health. PMID:28096855

  1. Wild Red Foxes (Vulpes vulpes) as Sentinels of Parasitic Diseases in the Province of Soria, Northern Spain.

    PubMed

    Lledó, Lourdes; Giménez-Pardo, Consuelo; Saz, José Vicente; Serrano, José Luis

    2015-12-01

    Four hundred red foxes (Vulpes vulpes) were examined for ecto- (arthropods) and endoparasites (Leishmania spp., Trichinella spp., and intestinal parasites). Different species of flea (total prevalence, 40.50%), tick (16.25%), mite (7.25%), and fly (1.50%) were identified. The most prevalent flea was Pulex irritans (found on 29% of the foxes); the most prevalent tick, mite, and fly were Ixodes canisuga (on 5%), Sarcoptes scabiei (on 5.25%), and Hippobosca equina (on 1%), respectively. The endoparasites identified included Leishmania spp. (found in 12% of the foxes), Trichinella spp. (in 15.5%, with T. britovi the most prevalent species in 15.25%), Cestoda (in 72.75%, with Mesocestoides spp. the most prevalent in 69.50%), and intestinal ascarids (in 73.25%, with Ancylostoma caninum the most prevalent in 12.50%). No animal was free of parasites. The present results suggest that foxes can act as sentinels of diseases transmitted by ecto- and endoparasites.

  2. Endoparasites in dogs and cats in Germany 1999-2002.

    PubMed

    Barutzki, D; Schaper, R

    2003-07-01

    Infections with endoparasites in dogs and cats have been determined by analysing the results of faecal examinations (Flotation, MIFC, sedimentation, Baermann, smear, ProSpecT Giardia Microplate Assay). Samples of 8438 dogs and 3167 cats from the years 1999 until 2002 have been included in the investigation. 2717 dogs (32.2%) and 771 cats (24.3%) have been infected with endoparasites. In the infected dogs the following parasites have been identified: Class Nematodea: Toxocara canis: 22.4%, Toxascaris leonina: 1.8%, Ancylostomatidae: 8.6%, Trichuris vulpis: 4.0%, Capillaria spp.: 2.3%, Crenosoma vulpis: 0.9%, Angiostrongylus vasorum: 0.3%; Class Cestodea: Taeniidae: 1.2%, Dipylidium caninum: 0.4%, Diplopylidium/Joyeuxiella: 0.1%, Mesocestoides: 0.2%, Diphyllobothrium latum: < 0.1%; Class Sporozoea: Sarcocystis spp.: 9.0%, Cystoisospora spp.: 22.3%, C. canis: 8.0%, C. ohioensis: 17.0%, Hammondia/Neospora: 1.7%; Class Zoomastigophorea: Giardia spp.: 51.6%. In the 771 infected cats the following prevalences of parasites have been found: Class Nematodea: Toxocara mystax: 26.2%, Ancylostoma tubaeforme: 0.3%, Capillaria spp.: 7.0%, Aelurostrongylus abstrusus: 2.7%; Class Cestodea: Taeniidae: 2.6%, Dipylidium caninum: 0.1%; Class Sporozoea: Sarcocystis spp.: 2.2%, Cystoisospora spp.: 21.9%, C. felis: 15.3%, C. rivolta: 7.9%, Toxoplasma/Hammondia: 4.5%; Class Zoomastigophorea: Giardia spp.: 51.6%.

  3. Endoparasites of the Eurasian lynx (Lynx lynx) in Finland.

    PubMed

    Deksne, Gunita; Laakkonen, Juha; Näreaho, Anu; Jokelainen, Pikka; Holmala, Katja; Kojola, Ilpo; Sukura, Antti

    2013-04-01

    We sampled 339 fecal samples, 296 intestines, and 82 lungs from 371 lynx hunted during the 2010-2011 season in Finland. The fecal samples were analyzed for endoparasites by a quantitative flotation method, and helminths from intestines were studied morphologically, while lungs were investigated for pulmonary parasites. From fecal samples, eggs and oocysts of at least 6 different endoparasite species were identified, with a mean of 1.5 (range 0-4) parasite species per host. In the intestines, at least 4 different helminth species were found, with the mean of 2.0 (range 1-4) species per infected host. The prevalence of eggs in feces and the prevalence of worms in intestines were 71% and 93% for Toxocara cati , 29% and 68% for Taenia spp., and 5% and 2% for Diphyllobothrium sp., respectively. Only eggs were detected for Capillaria sp. (46%) and Uncinaria sp. (0.6%) nematodes, and only adults were detected for Mesocestoides sp. cestodes (0.3%). Significant positive correlations were evident between the number of T. cati (r = 0.664; P = 0.01) and Diphyllobothrium sp. (r = 0.645; P = 0.01) eggs per gram of feces and adult worms detected in intestine. In addition to the metazoan parasites, protozoan Isospora sp. oocysts were also found (0.6%). Pulmonary samples were all negative for parasites. These data demonstrate that lynx commonly harbor various endoparasites, some of which are zoonotic.

  4. Transmission ecology of taeniid larval cestodes in rodents in Sweden, a low endemic area for Echinococcus multilocularis.

    PubMed

    Miller, Andrea L; Olsson, Gert E; Sollenberg, Sofia; Walburg, Marion R; Skarin, Moa; Höglund, Johan

    2017-03-09

    Although local prevalence of Echinococcus multilocularis may be high, this zoonotic parasite has an overall low prevalence in foxes and rodents in Sweden. To better understand opportunities for E. multilocularis transmission in the Swedish environment, the aim of this study was to investigate other taeniid cestodes and to relate observed patterns to E. multilocularis. Cestode parasites were examined in fox feces and rodents caught in different habitats from four regions of Sweden. Arvicola amphibius and Microtus agrestis were parasitized with Versteria mustelae, Hydatigera taeniaeformis s. l., and E. multilocularis, whereas Myodes glareolus and Apodemus spp. were parasitized with V. mustelae, Taenia polyacantha, H. taeniaeformis s.l., and Mesocestoides spp. Rodents caught in field habitat (Ar. amphibius, Mi. agrestis) were more likely (OR 10, 95% CI 5-19) to be parasitized than rodents caught in forest habitat (My. glareolus, Apodemus spp.). The parasite preference for each rodent species was present regardless of the type of background contamination from fox feces. These results further support the importance of both ecological barriers and individual species susceptibility in parasite transmission, and indicate that future monitoring for E. multilocularis in the Swedish environment should focus in field habitats where Mi. agrestis and Ar. amphibius are abundant.

  5. An epidemiological survey on intestinal helminths of stray dogs in Mashhad, North-east of Iran.

    PubMed

    Emamapour, Seyed Rasoul; Borji, Hassan; Nagibi, Abolghasem

    2015-06-01

    This research was conducted to determine the prevalence of gastrointestinal helminths in stray dogs in the northeast of Iran, with special attention to those parasites that can be transmitted to human. In this experiment, a total of 72 adult and 18 juvenile stray dogs were collected and necropsied for the presence of helminth parasites from October 2011 to August 2012. The overall prevalence of gastrointestinal helminths was 86 % (95 % CI: 79.2-92.8 %). The observed helminths of the gastrointestinal tract were listed as follows: Toxocara canis (29 %), Toxascaris leonina (7 %), Ancylostoma caninum (2 %), Taenia hydatigena (43 %), Dipylidium caninum (39 %), Echinococcus granulosus (38 %), Mesocestoides lineatus (16 %), Taenia multiceps (11 %), Taenia ovis (3 %). There were no significant differences for the prevalence of gastrointestinal helminths between female (83.6 %) and male (89.7 %) and between young (89 %) and adult (72.2 %) animals. However, the prevalence of E. granulosus, T. hydatigena and D. caninum showed an increasing trend with increasing host age, significantly. Based on our data, it is important to point out the presence of zoonotic agents, namely E. granulosus and T. canis in stray dogs in the investigated area. Due to its impact on public health, appropriate control measures should be taken and it is recommended to determine the most appropriate preventive methods.

  6. A survey study on gastrointestinal parasites of stray cats in Azarshahr, (East Azerbaijan province, Iran).

    PubMed

    Hajipour, Nasser; Imani Baran, Aabbas; Yakhchali, Mohammad; Banan Khojasteh, Seyed Mehdi; Sheikhzade Hesari, Farzam; Esmaeilnejad, Bijan; Arjmand, Jafar

    2016-12-01

    Gastrointestinal parasites are among the most common parasitic infections found in stray cats, which might act potential helminthic parasites to domestic cats. The objective of this study was to determine the prevalence of gastrointestinal parasites in stray cats in the city of Azarshahr, which is located in East Azerbaijan province, Iran. A cross-sectional study was conducted on 50 necropsied stray cats, trapped and collected from different geographic regions of Azarshahr. From a total 50 stray cats examined, 15 (30 %) were female and 35 (70 %) were male. Overall 47 cats (94 %) were identified as infected with at least one of the endoparasites. The prevalence of parasites found were: Taenia taeniaeformis (60 %), Dipylidium caninum (58 %), Taenia hydatigera (24 %), Mesocestoides lineatus (78 %), Ancylostoma tubaeforme (14 %), Toxascaris leonina (30 %), Toxocara cati (78 %), Physaloptera praeputialis (10 %), and Syphacia obvelata (10 %). Contamination rate for zoonotic parasites of cat was greater than expected in AzarShahr region. Therefore, appropriate control measures should be taken and preventive methods should be applied.

  7. Intestinal and lung parasites in owned dogs and cats from central Italy.

    PubMed

    Riggio, Francesca; Mannella, Riccardo; Ariti, Gaetano; Perrucci, Stefania

    2013-03-31

    Prevalence and risk factors of intestinal and lung parasites were investigated in 239 owned dogs and 81 owned cats from central Italy. In 36 dogs and 20 cats found infected by nematodes, pre and post-treatment faecal egg count (FEC) was also evaluated. About 31% of dogs and about 35% of cats resulted positive for at least one intestinal or lung parasitic species. Helminthic, intestinal and zoonotic infections resulted prevalent in examined animals. Examined dogs resulted infected by Toxocara canis (13.0%), Toxascaris leonina (1.7%), Trichuris vulpis (3.3%), Ancylostoma caninum (2.0%), Uncinaria stenocephala (1.25%), Strongyloides stercoralis (0.8%), Angiostrongylus vasorum (0.4%), Dipylidium caninum (1.25%), Taeniidae eggs (0.4%), Giardia duodenalis (3.8%), and Cystoisospora (Isospora) spp. (7.5%). Examined cats were infected by Toxocara cati (22.2%), Capillaria aerophila (1.2%), Ancylostoma tubaeformae (1.2%), U. stenocephala (3.7%), Aelurostrongylus abstrusus (1.2%), Mesocestoides sp. (1.2%), D. caninum (1.2%), G. duodenalis (1.2%) and Cystoisospora spp. (4.5%). The presence of clinical signs and the young age (less than 6 months) were identified as risk factors by univariate and multivariate statistical analysis. In 63.9% treated dogs and in 80.0% treated cats, percentages of post-treatment FEC reduction higher than 90% were found. Results obtained in this study are discussed.

  8. Field evaluation of the efficacy and safety of emodepside plus praziquantel tablets (Profender tablets for dogs) against naturally acquired nematode and cestode infections in dogs.

    PubMed

    Altreuther, Gertraut; Radeloff, Isabelle; LeSueur, Christophe; Schimmel, Annette; Krieger, Klemens J

    2009-08-01

    A controlled, blinded and randomised multicentre field study evaluated the efficacy and safety of a new anthelmintic tablet formulation containing emodepside plus praziquantel (Profender tablets for dogs) in the treatment of gastrointestinal nematode and cestode infections in dogs in France, Germany, Portugal and Slovakia. Dogs positive for nematodes and/or cestodes (demonstrated by faecal egg counts and/or the presence of proglottids) were treated with emodepside plus praziquantel tablets (n = 239) or the reference product containing milbemycin oxime and praziquantel (Milbemax [n = 115]) at the recommended dose rate. Two faecal samples collected between 7 and 13 days after treatment were evaluated for proglottids, nematode and cestode eggs. No suspected adverse drug reactions were observed in the study. The following parasite species were identified: Trichuris vulpis, Toxocara canis, Toxascaris leonina, Uncinaria stenocephala, Ancylostoma caninum, Dipylidium caninum, Taeniidae and Mesocestoides spp. Geometric mean nematode egg counts in dogs treated with emodepside plus praziquantel tablets were reduced by 99.9 % compared with a reduction of 99.6 % for the reference product. Statistical analysis demonstrated noninferiority of investigational versus reference product (p = 0.0342). None of the dogs treated with emodepside plus praziquantel or reference product remained positive for cestodes after treatment. The study demonstrated that emodepside plus praziquantel tablets are safe and highly efficacious against a broad spectrum of nematodes and cestodes under field conditions.

  9. Parasites of the arctic fox (Alopex lagopus) in Iceland.

    PubMed

    Skírnisson, K; Eydal, M; Gunnarsson, E; Hersteinsson, P

    1993-07-01

    Forty-four of 50 arctic foxes (Alopex lagopus) in Iceland harbored 15 species of intestinal parasites, including Protozoa: Eimeria sp. or Isospora sp. (in 4%); Trematoda: Cryptocotyle lingua (24%), Plagiorchis elegans (4%), Brachylaemus sp. (12%), Tristriata sp. (10%), and Spelotrema sp. (8%); Cestoda: Mesocestoides canislagopodis (72%), Schistocephalus solidus (2%), and Diphyllobothrium dendriticum (4%); Nematoda: Toxascaris leonina (50%), Toxocara canis (2%), Uncinaria stenocephala (4%), and eggs of the lung worm Capillaria aerophila (6%); and Acanthocephala: Polymorphus meyeri (8%) and Corynosoma hadweni (2%). Only four of the species previously had been recorded in Iceland. Eleven species are new records in Iceland and six appear to be new host records. Two additional nematodes, Stegophorus stercorarii and Syphacia sp., probably were ingested accidentally with the prey. Foxes from coastal habitats harbored 14 parasitic species while only five species were found in foxes from inland habitats. Arctic foxes from coastal habitats generally had higher helminth burdens and harbored more parasitic species per fox than foxes from inland habitats.

  10. Intestinal helminth parasites of the grey wolf (Canis lupus L.) in Serbia.

    PubMed

    Ćirović, Duško; Pavlović, Ivan; Penezić, Aleksandra

    2015-06-01

    The grey wolf (Canis lupus L.) is the most widespread large carnivore in Europe with large populations in the Eastern part of Europe and the Balkan Peninsula. In this study, a total of 102 wolves were examined for intestinal helminth parasites. The carcasses were collected within the Serbian part of the wolf's range during the period 2009-2014. Nine helminth species were found: one nematode, Toxocara canis (3.9%), one trematode, Alaria alata (1.0%), and seven cestodes, Taenia pisiformis (1.0%), T. hydatigena (9.8%), T. polyacantha (2.9%), T. taeniaeformis (2.0%), T. (syn. Multiceps) multiceps (3.9%), T. serialis (1.0%) and Mesocestoides litteratus (1.0%). Taenia (syn. Hydatigera) taeniaeformis has been registered for the first time in a wolf from Europe. An overall moderate prevalence (16.7%) of infected wolves was recorded. There was no statistically significant difference in prevalence between sexes. Of the years studied, the highest prevalence was found in 2014 (57.1%). The maximum number of helminth species per host specimen was four.

  11. Mutations in Cockayne Syndrome-Associated Genes (Csa and Csb) Predispose to Cisplatin-Induced Hearing Loss in Mice

    PubMed Central

    Rainey, Robert N.; Ng, Sum-yan; Llamas, Juan; van der Horst, Gijsbertus T. J.

    2016-01-01

    Cisplatin is a common and effective chemotherapeutic agent, yet it often causes permanent hearing loss as a result of sensory hair cell death. The causes of sensitivity to DNA-damaging agents in nondividing cell populations, such as cochlear hair and supporting cells, are poorly understood, as are the specific DNA repair pathways that protect these cells. Nucleotide excision repair (NER) is a conserved and versatile DNA repair pathway for many DNA-distorting lesions, including cisplatin-DNA adducts. Progressive sensorineural hearing loss is observed in a subset of NER-associated DNA repair disorders including Cockayne syndrome and some forms of xeroderma pigmentosum. We investigated whether either of the two overlapping branches that encompass NER, transcription-coupled repair or global genome repair, which are implicated in Cockayne syndrome and xeroderma pigmentosum group C, respectively, modulates cisplatin-induced hearing loss and cell death in the organ of Corti, the auditory sensory epithelium of mammals. We report that cochlear hair cells and supporting cells in transcription-coupled repair-deficient Cockayne syndrome group A (Csa−/−) and group B (Csb−/−) mice are hypersensitive to cisplatin, in contrast to global genome repair-deficient Xpc−/− mice, both in vitro and in vivo. We show that sensory hair cells in Csa−/− and Csb−/− mice fail to remove cisplatin-DNA adducts efficiently in vitro; and unlike Xpc−/− mice, Csa−/− and Csb−/− mice lose hearing and manifest outer hair cell degeneration after systemic cisplatin treatment. Our results demonstrate that Csa and Csb deficiencies predispose to cisplatin-induced hearing loss and hair/supporting cell damage in the mammalian organ of Corti, and emphasize the importance of transcription-coupled DNA repair in the protection against cisplatin ototoxicity. SIGNIFICANCE STATEMENT The utility of cisplatin in chemotherapy remains limited due to serious side effects, including

  12. Why does infection with some helminths cause cancer?

    PubMed Central

    Brindley, Paul J.; da Costa, José M. Correia; Sripa, Banchob

    2015-01-01

    Infections with Opisthorchis viverrini, Clonorchis sinensis and Schistosoma haematobium are classified as Group 1 biological carcinogens: definitive causes of cancer. These worms are metazoan eukaryotes, unlike the other Group 1 carcinogens including human papilloma virus, hepatitis C virus, and Helicobacter pylori. By contrast, infections with phylogenetic relatives of these helminths, also trematodes of the phylum Platyhelminthes and major human pathogens, are not carcinogenic. These inconsistencies prompt several questions, including how might these infections cause cancer? And why is infection with only a few helminth species carcinogenic? Here we present an interpretation of mechanisms contributing to the carcinogenicity of these helminth infections, including roles for catechol estrogen- and oxysterol-metabolites of parasite origin as initiators of carcinogenesis. PMID:26618199

  13. Animal Fascioliasis: Perspectives from high altitudinal regions.

    PubMed

    Lyngdoh, Damanbha; Sharma, Sunil; Roy, Bishnupada; Tandon, Veena

    2016-12-15

    The parasitic flukes of the genus Fasciola (Platyhelminthes: Trematoda: Digenea) cause fascioliasis or liver-rot disease in ruminant livestock in tropical and sub-tropical regions of the world. Classically, two species of Fasciola- F. hepatica and F. gigantica, are universally recognized as taxonomically valid species. Our survey studies on ovid and bovid animals including yak and mithun from high altitudinal mountainous regions in Northeast India revealed the occurrence of Fasciola gigantica and also Fasciola sp.- an intermediate form, at altitudes between 5000 and 14,085 feet above sea level (asl). Two morphotypes- F. hepatica - like and F. gigantica - like, of Fasciola species were reported from the high altitudinal areas of Northeast India; most of these locales constitute new-locality and first records for the occurrence of these liver flukes.

  14. Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness (Addenda 2013).

    PubMed

    Zhang, Zhi-Qiang

    2013-01-01

    The kingdom Animalia is here estimated to have a total of 1,659,420 described species (including 133,692 fossil species) in 40 phyla. Among these, the most successful phylum Arthropoda alone represents 1,302,809 species, or about 78.5% of the total. The second largest phylum, Mollusca (118,061 species), is <10% of Arthropoda in diversity, but it is still much more diverse than other successful invertebrate phyla Platyhelminthes (29,488 species), Nematoda (25,043 species), Echinodermata (20,550 species), Annelida (17,426 species), Cnidaria (16,363 species), Bryozoa (11,474 species) and Porifera (10,876 species). The phylum Craniata, including the vertebrates, represents 85,432 species (including 19,974 fossil species): among these, 35,644 species of "fishes", 7,171 species of amphibians, 15,507 species of reptiles, 11,087 species of birds, and 16,014 species of mammals.

  15. The evolution of the serotonergic nervous system.

    PubMed Central

    Hay-Schmidt, A

    2000-01-01

    The pattern of development of the serotonergic nervous system is described from the larvae of ctenophores, platyhelminths, nemerteans, entoprocts, ectoprocts (bryozoans), molluscs, polychaetes, brachiopods, phoronids, echinoderms, enteropneusts and lampreys. The larval brain (apical ganglion) of spiralian protostomes (except nermerteans) generally has three serotonergic neurons and the lateral pair always innervates the ciliary band of the prototroch. In contrast, brachiopods, phoronids, echinoderms and enteropneusts have numerous serotonergic neurons in the apical ganglion from which the ciliary band is innervated. This pattern of development is much like the pattern seen in lamprey embryos and larvae, which leads the author to conclude that the serotonergic raphe system found in vertebrates originated in the larval brain of deuterostome invertebrates. Further, the neural tube of chordates appears to be derived, at least in part, from the ciliary band of deuterostome invertebrate larvae. The evidence shows no sign of a shift in the dorsal ventral orientation within the line leading to the chordates. PMID:10885511

  16. 18S rRNA suggests that Entoprocta are protostomes, unrelated to Ectoprocta.

    PubMed

    Mackey, L Y; Winnepenninckx, B; De Wachter, R; Backeljau, T; Emschermann, P; Garey, J R

    1996-05-01

    The Ento- and Ectoprocta are sometimes placed together in the Bryozoa, which have variously been regarded as proto- or deuterostomes. However, Entoprocta have also been allied to the pseudocoelomates, while Ectoprocta are often united with the Brachiopoda and Phoronida in the (super)phylum Lophophorata. Hence, the phylogenetic relationships of these taxa are still much debated. We determined complete 18S rRNA sequences of two entoprocts, an ectoproct, an inarticulate brachiopod, a phoronid, two annelids, and a platyhelminth. Phylogenetic analyses of these data show that (1) entoprocts and lophophorates have spiralian, protostomous affinities, (2) Ento- and Ectoprocta are not sister taxa, (3) phoronids and brachiopods form a monophyletic clade, and (4) neither Ectoprocta or Annelida appear to be monophyletic. Both deuterostomous and pseudocoelomate features may have arisen at least two times in evolutionary history. These results advocate a Spiralia-Radialia-based classification rather than one based on the Protostomia-Deuterostomia concept.

  17. Temperature-dependent structural variability of RNAs: spliced leader RNAs and their evolutionary history.

    PubMed

    Marz, Manja; Vanzo, Nathalie; Stadler, Peter F

    2010-02-01

    The structures attained by RNA molecules depend not only on their sequence but also on environmental parameters such as their temperature. So far, this effect has been largely neglected in bioinformatics studies. Here, we show that structural comparisons can be facilitated and more coherent structural models can be obtained when differences in environmental parameters are taken into account. We re-evaluate the secondary structures of the spliced leader (SL) RNAs from the seven eukaryotic phyla in which SL RNA trans-splicing has been described. Adjusting structure prediction to the natural growth temperatures and considering energetically similar secondary structures, we observe striking similarities among Euglenida, Kinetoplastida, Dinophyceae, Cnidaria, Rotifera, Nematoda, Platyhelminthes, and Tunicata that cannot be explained easily by the independent innovation of SL RNAs in each of these phyla. Supplementary Table is available at http://www.worldscinet.com/jbcb/.

  18. The revised microRNA complement of Fasciola hepatica reveals a plethora of overlooked microRNAs and evidence for enrichment of immuno-regulatory microRNAs in extracellular vesicles.

    PubMed

    Fromm, B; Trelis, M; Hackenberg, M; Cantalapiedra, F; Bernal, D; Marcilla, A

    2015-09-01

    MicroRNAs (miRNAs) are gene regulators that have recently been shown to down-regulate the immune response via extracellular vesicles in the mammalian host of helminthic parasites. Using the miRNA prediction pipeline miRCandRef, we expanded the current miRNA set of the liver fluke Fasciola hepatica (Platyhelminthes, Trematoda) from 16 to 54 miRNAs (42 conserved and 13 novel). Comparing the cellular expression levels with extracellular vesicles, we found all miRNAs expressed and enriched for miRNAs with immuno-regulatory function, tissue growth and cancer. Our findings support the hypothesis that miRNAs are the molecular mediators of the previously demonstrated immune modulatory function of extracellular vesicles.

  19. Investigation of molluscan phylogeny on the basis of 18S rRNA sequences.

    PubMed

    Winnepenninckx, B; Backeljau, T; De Wachter, R

    1996-12-01

    The 18S rRNA sequences of 12 molluscs, representing the extant classes Gastropoda, Bivalvia, Polyplacophora, Scaphopoda, and Caudofoveata, were determined and compared with selected known 18S rRNA sequences of Metazoa, including other Mollusca. These data do not provide support for a close relationship between Platyhelminthes (Turbellaria) and Mollusca, but rather suggest that the latter group belongs to a clade of eutrochozoan coelomates. The 18S rRNA data fail to recover molluscan, bivalve, or gastropod monophyly. However, the branching pattern of the eutrochozoan phyla and classes is unstable, probably due to the explosive Cambrian radiation during which these groups arose. Similarly, the 18S rRNA data do not provide a reliable signal for the molluscan interclass relationships. Nevertheless, we obtained strong preliminary support for phylogenetic inferences at more restricted taxonomic levels, such as the monophyly of Polyplacophora, Caenogastropoda, Euthyneura, Heterodonta, and Arcoida.

  20. New approaches for understanding mechanisms of drug resistance in schistosomes

    PubMed Central

    GREENBERG, ROBERT M.

    2013-01-01

    SUMMARY Schistosomes are parasitic flatworms that cause schistosomiasis, a neglected tropical disease that affects hundreds of millions worldwide. Treatment and control of schistosomiasis relies almost entirely on the single drug praziquantel (PZQ), making the prospect of emerging drug resistance particularly worrisome. This review will survey reports of PZQ (and other drug) resistance in schistosomes and other platyhelminths, and explore mechanisms by which drug resistance might develop. Newer genomic and post-genomic strategies that offer the promise of better understanding of how drug resistance might arise in these organisms will be discussed. These approaches could also lead to insights into the mode of action of these drugs and potentially provide markers for monitoring the emergence of resistance. PMID:23552512

  1. Lophotrochozoan mitochondrial genomes

    SciTech Connect

    Valles, Yvonne; Boore, Jeffrey L.

    2005-10-01

    Progress in both molecular techniques and phylogeneticmethods has challenged many of the interpretations of traditionaltaxonomy. One example is in the recognition of the animal superphylumLophotrochozoa (annelids, mollusks, echiurans, platyhelminthes,brachiopods, and other phyla), although the relationships within thisgroup and the inclusion of some phyla remain uncertain. While much ofthis progress in phylogenetic reconstruction has been based on comparingsingle gene sequences, we are beginning to see the potential of comparinglarge-scale features of genomes, such as the relative order of genes.Even though tremendous progress is being made on the sequencedetermination of whole nuclear genomes, the dataset of choice forgenome-level characters for many animals across a broad taxonomic rangeremains mitochondrial genomes. We review here what is known aboutmitochondrial genomes of the lophotrochozoans and discuss the promisethat this dataset will enable insight into theirrelationships.

  2. Platyzoan mitochondrial genomes.

    PubMed

    Wey-Fabrizius, Alexandra R; Podsiadlowski, Lars; Herlyn, Holger; Hankeln, Thomas

    2013-11-01

    Platyzoa is a putative lophotrochozoan (spiralian) subtaxon within the protostome clade of Metazoa, comprising a range of biologically diverse, mostly small worm-shaped animals. The monophyly of Platyzoa, the relationships between the putative subgroups Platyhelminthes, Gastrotricha and Gnathifera (the latter comprising at least Gnathostomulida, "Rotifera" and Acanthocephala) as well as some aspects of the internal phylogenies of these subgroups are highly debated. Here we review how complete mitochondrial (mt) genome data contribute to these debates. We highlight special features of the mt genomes and discuss problems in mtDNA phylogenies of the clade. Mitochondrial genome data seem to be insufficient to resolve the position of the platyzoan clade within the Spiralia but can help to address internal phylogenetic questions. The present review includes a tabular survey of all published platyzoan mt genomes.

  3. Analysis of 18S rRNA gene sequences suggests significant molecular differences between Macrodasyida and Chaetonotida (Gastrotricha).

    PubMed

    Manylov, Oleg G; Vladychenskaya, Natalia S; Milyutina, Irina A; Kedrova, Olga S; Korokhov, Nikolai P; Dvoryanchikov, Gennady A; Aleshin, Vladimir V; Petrov, Nikolai B

    2004-03-01

    Partial 18S rRNA gene sequences of four macrodasyid and one chaetonotid gastrotrichs were obtained and compared with the available sequences of other gastrotrich species and representatives of various metazoan phyla. Contrary to the earlier molecular data, the gastrotrich sequences did not comprise a monophyletic group but formed two distinct clades, corresponding to the Macrodasyida and Chaetonotida, with the basal position occupied by the sequences of Tetranchyroderma sp. and Xenotrichula sp., respectively. Depending on the taxon sampling and methods of analysis, the two clades were separated by various combinations of clades Rotifera, Gnathostomulida, and Platyhelminthes, and never formed a clade with Nematoda. Thus, monophyly of the Gastrotricha is not confirmed by analysis of the presently available molecular data.

  4. Mini review on chemotherapy of taeniasis and cysticercosis due to Taenia solium in Asia, and a case report with 20 tapeworms in China.

    PubMed

    Ito, A; Li, T; Chen, X; Long, C; Yanagida, T; Nakao, M; Sako, Y; Okamoto, M; Wu, Y; Raoul, F; Giraudoux, P; Craig, P S

    2013-06-01

    A 43-year-old Tibetan woman living in northwest Sichuan, China, confirmed to be a taeniasis carrier of Taenia solium was treated with pumpkin seeds combined with Areca nut extract in October 2009. All 20 tapeworms except one without scolex were expelled under good conditions. She was free of secondary cysticercosis within one year follow up. Although the first choice for treatment of taeniasis is still praziquantel, it may often cause serious side effect on asymptomatic cysticercosis cases to suddenly become symptomatic within a half day of the treatment. Therefore, the problems in treatment of taeniasis and/or cysticercosis in Asia are briefly overviewed, since other platyhelminthic diseases including schistosomiasis, opisthorchiasis etc. are more common and praziquantel is strongly recommended for mass treatment of these trematodiases with no idea on the co-infection with eggs of T. solium which cause asymptomatic cysticercosis.

  5. Diversity and distribution of fish tapeworms of the "Bothriocephalidea" (Eucestoda).

    PubMed

    Kuchta, R; Scholz, T

    2007-09-01

    Recent studies have demonstrated the invalidity of the Pseudophyllidea, a long-term recognised order of tapeworms (Platyhelminthes: Cestoda), typical in possessing two dorsoventrally situated attachment organs called bothria. In fact, cestodes parasitic in tetrapods, especially mammals including man, form a relatively basal group called provisionally the "Diphyllobothriidea", whereas tapeworms occurring in freshwater and marine fish, with a few taxa known from amphibians (frogs and newts), belong to a more derived clade, for which the name "Bothriocephalidea" is tentatively proposed. Revision of the "Bothriocephalidea", based on literary data, study of type- and voucher specimens and extensive newly collected material made it possible to critically review the species composition of the group and to prepare a tentative list of its valid species. Out of 305 nominal taxa, only 125 species are considered to be valid. In addition, the spectrum of definitive hosts and geographical distribution of bothriocephalideans are briefly discussed.

  6. Eukaryotic opportunists dominate the deep-subsurface biosphere in South Africa.

    PubMed

    Borgonie, G; Linage-Alvarez, B; Ojo, A O; Mundle, S O C; Freese, L B; Van Rooyen, C; Kuloyo, O; Albertyn, J; Pohl, C; Cason, E D; Vermeulen, J; Pienaar, C; Litthauer, D; Van Niekerk, H; Van Eeden, J; Sherwood Lollar, B; Onstott, T C; Van Heerden, E

    2015-11-24

    Following the discovery of the first Eukarya in the deep subsurface, intense interest has developed to understand the diversity of eukaryotes living in these extreme environments. We identified that Platyhelminthes, Rotifera, Annelida and Arthropoda are thriving at 1.4 km depths in palaeometeoric fissure water up to 12,300 yr old in South African mines. Protozoa and Fungi have also been identified; however, they are present in low numbers. Characterization of the different species reveals that many are opportunistic organisms with an origin due to recharge from surface waters rather than soil leaching. This is the first known study to demonstrate the in situ distribution of biofilms on fissure rock faces using video documentation. Calculations suggest that food, not dissolved oxygen is the limiting factor for eukaryal population growth. The discovery of a group of Eukarya underground has important implications for the search for life on other planets in our solar system.

  7. Cholinergic, serotoninergic and peptidergic components of the nervous system of Discocotyle sagittata (Monogenea:Polyopisthocotylea).

    PubMed

    Cable, J; Marks, N J; Halton, D W; Shaw, C; Johnston, C F; Tinsley, R C; Gannicott, A M

    1996-12-01

    Cholinergic, serotoninergic (5-HT) and peptidergic neuronal pathways have been demonstrated in both central and peripheral nervous systems of adult Discocotyle sagittata, using enzyme histochemistry and indirect immunocytochemistry in conjunction with confocal scanning laser microscopy. Antisera to 2 native flatworm neuropeptides, neuropeptide F and the FMRFamide-related peptide (FaRP), GNFFRFamide, were employed to detect peptide immunoreactivity. The CNS is composed of paired cerebral ganglia and connecting dorsal commissure, together with several paired longitudinal nerve cords. The main longitudinal nerve cords (lateral, ventral and dorsal) are interconnected at intervals by a series of annular cross-connectives, producing a ladder-like arrangement typical of the platyhelminth nervous system. At the level of the haptor, the ventral cords provide nerve roots which innervate each of the 9 clamps. Cholinergic and peptidergic neuronal organisation was similar, but distinct from that of the serotoninergic components. The PNS and reproductive system are predominantly innervated by peptidergic neurones.

  8. Molecular characterization of the unique Mesostephanus appendiculatus (Trematoda: Cyathocotylidae) by small ribosomal RNA from Egypt.

    PubMed

    El-Bahy, Nasr M; Bazh, Eman K; Sorour, Shimaa S; Elhawary, Nagwa M

    2017-04-01

    M esostephanus appendiculatus (Family: Cyathocotylidae) is one of the unique trematodes that complete their cycles in human and animal intestines in many countries of the world. The main source of its transmission is eating raw or undercooked infected fish muscle. Earliest analyses of genes to different parasites supported the analysis of helminthes either biological or morphological. This paper detected M. appendiculatus sequence with GenBank accession number gb (KY026782). Comparison of M. appendiculatus with other helminthes using BioEdit 7 and MEGA7 program shows some similarity in different points along its sequence. The phylogenetic analysis clarifies that it was closely related to both trematodes (Clinostomum complanatum and Echinochasmus japonicus) and some cestodes of fish origin such as Polyonchobothrium polypteri, Bothriocephalus sp., and Haplobothrium globuliforme. The obtained results provide a good source for genome analysis of M. appendiculatus in relation to other Platyhelminthes.

  9. Multigene analysis of lophophorate and chaetognath phylogenetic relationships.

    PubMed

    Helmkampf, Martin; Bruchhaus, Iris; Hausdorf, Bernhard

    2008-01-01

    Maximum likelihood and Bayesian inference analyses of seven concatenated fragments of nuclear-encoded housekeeping genes indicate that Lophotrochozoa is monophyletic, i.e., the lophophorate groups Bryozoa, Brachiopoda and Phoronida are more closely related to molluscs and annelids than to Deuterostomia or Ecdysozoa. Lophophorates themselves, however, form a polyphyletic assemblage. The hypotheses that they are monophyletic and more closely allied to Deuterostomia than to Protostomia can be ruled out with both the approximately unbiased test and the expected likelihood weights test. The existence of Phoronozoa, a putative clade including Brachiopoda and Phoronida, has also been rejected. According to our analyses, phoronids instead share a more recent common ancestor with bryozoans than with brachiopods. Platyhelminthes is the sister group of Lophotrochozoa. Together these two constitute Spiralia. Although Chaetognatha appears as the sister group of Priapulida within Ecdysozoa in our analyses, alternative hypothesis concerning chaetognath relationships could not be rejected.

  10. Replacement names for Eutrigaster (Graffia) Csuzdi & Zicsi, 1991 and Dichogaster (Malawia) Csuzdi, 2010 (Oligochaeta, Acanthodrilidae).

    PubMed

    Csuzdi, Csaba

    2014-05-30

    The earthworm genus Eutrigaster Cognetti, 1904 has long been in synonymy with Dichogaster Beddard, 1888 until Sims (1987) resurrected it for the Central American Dichogaster-like species possessing a muscular proventriculus in segment 5. Today the genus consists of some 50 species distributed in two subgenera (Csuzdi 2012). The subgenus Eutrigaster (Graffia) Csuzdi & Zicsi, 1991 was erected for species that differ from the type species of the genus in possessing penial setae. According to the summary by Fragoso & Brown (2007) the subgenus Graffia contained 27 taxa. Later, further three species were described (Sherlock et al. 2011; Sherlock & Csuzdi 2013). However, the subgenus name Graffia is a junior homonym of the turbellarian genus Graffia Levinsen, 1879. (A further junior homonym Graffia Ihering, 1880 (Platyhelminthes: Turbellaria) has already been renamed as Graffilla Ihering, 1880). Here the replacement name Eutrigaster (Graffiona) nom. nov. is proposed for the earthworm subgenus Eutrigaster (Graffia).

  11. Eukaryotic opportunists dominate the deep-subsurface biosphere in South Africa

    PubMed Central

    Borgonie, G.; Linage-Alvarez, B.; Ojo, A. O.; Mundle, S.O.C.; Freese, L B.; Van Rooyen, C.; Kuloyo, O.; Albertyn, J.; Pohl, C.; Cason, E. D.; Vermeulen, J.; Pienaar, C.; Litthauer, D.; Van Niekerk, H.; Van Eeden, J.; Lollar, B. Sherwood.; Onstott, T. C.; Van Heerden, E.

    2015-01-01

    Following the discovery of the first Eukarya in the deep subsurface, intense interest has developed to understand the diversity of eukaryotes living in these extreme environments. We identified that Platyhelminthes, Rotifera, Annelida and Arthropoda are thriving at 1.4 km depths in palaeometeoric fissure water up to 12,300 yr old in South African mines. Protozoa and Fungi have also been identified; however, they are present in low numbers. Characterization of the different species reveals that many are opportunistic organisms with an origin due to recharge from surface waters rather than soil leaching. This is the first known study to demonstrate the in situ distribution of biofilms on fissure rock faces using video documentation. Calculations suggest that food, not dissolved oxygen is the limiting factor for eukaryal population growth. The discovery of a group of Eukarya underground has important implications for the search for life on other planets in our solar system. PMID:26597082

  12. Venus kinase receptors: prospects in signaling and biological functions of these invertebrate kinases.

    PubMed

    Dissous, Colette; Morel, Marion; Vanderstraete, Mathieu

    2014-01-01

    Venus kinase receptors (VKRs) form a family of invertebrate receptor tyrosine kinases (RTKs) initially discovered in the parasitic platyhelminth Schistosoma mansoni. VKRs are single transmembrane receptors that contain an extracellular venus fly trap structure similar to the ligand-binding domain of G protein-coupled receptors of class C, and an intracellular tyrosine kinase domain close to that of insulin receptors. VKRs are found in a large variety of invertebrates from cnidarians to echinoderms and are highly expressed in larval stages and in gonads, suggesting a role of these proteins in embryonic and larval development as well as in reproduction. VKR gene silencing could demonstrate the function of these receptors in oogenesis as well as in spermatogenesis in S. mansoni. VKRs are activated by amino acids and are highly responsive to arginine. As many other RTKs, they form dimers when activated by ligands and induce intracellular pathways involved in protein synthesis and cellular growth, such as MAPK and PI3K/Akt/S6K pathways. VKRs are not present in vertebrates or in some invertebrate species. Questions remain open about the origin of this little-known RTK family in evolution and its role in emergence and specialization of Metazoa. What is the meaning of maintenance or loss of VKR in some phyla or species in terms of development and physiological functions? The presence of VKRs in invertebrates of economical and medical importance, such as pests, vectors of pathogens, and platyhelminth parasites, and the implication of these RTKs in gametogenesis and reproduction processes are valuable reasons to consider VKRs as interesting targets in new programs for eradication/control of pests and infectious diseases, with the main advantage in the case of parasite targeting that VKR counterparts are absent from the vertebrate host kinase panel.

  13. Venus Kinase Receptors: Prospects in Signaling and Biological Functions of These Invertebrate Kinases

    PubMed Central

    Dissous, Colette; Morel, Marion; Vanderstraete, Mathieu

    2014-01-01

    Venus kinase receptors (VKRs) form a family of invertebrate receptor tyrosine kinases (RTKs) initially discovered in the parasitic platyhelminth Schistosoma mansoni. VKRs are single transmembrane receptors that contain an extracellular venus fly trap structure similar to the ligand-binding domain of G protein-coupled receptors of class C, and an intracellular tyrosine kinase domain close to that of insulin receptors. VKRs are found in a large variety of invertebrates from cnidarians to echinoderms and are highly expressed in larval stages and in gonads, suggesting a role of these proteins in embryonic and larval development as well as in reproduction. VKR gene silencing could demonstrate the function of these receptors in oogenesis as well as in spermatogenesis in S. mansoni. VKRs are activated by amino acids and are highly responsive to arginine. As many other RTKs, they form dimers when activated by ligands and induce intracellular pathways involved in protein synthesis and cellular growth, such as MAPK and PI3K/Akt/S6K pathways. VKRs are not present in vertebrates or in some invertebrate species. Questions remain open about the origin of this little-known RTK family in evolution and its role in emergence and specialization of Metazoa. What is the meaning of maintenance or loss of VKR in some phyla or species in terms of development and physiological functions? The presence of VKRs in invertebrates of economical and medical importance, such as pests, vectors of pathogens, and platyhelminth parasites, and the implication of these RTKs in gametogenesis and reproduction processes are valuable reasons to consider VKRs as interesting targets in new programs for eradication/control of pests and infectious diseases, with the main advantage in the case of parasite targeting that VKR counterparts are absent from the vertebrate host kinase panel. PMID:24860549

  14. Evolutionary implications of morphogenesis and molecular patterning of the blind gut in the planarian Schmidtea polychroa.

    PubMed

    Martín-Durán, José María; Romero, Rafael

    2011-04-01

    The formation of a through-gut was a key innovation in the evolution of metazoans. There is still controversy regarding the origin of the anus and how it may have been either gained or lost during evolution in different bilaterian taxa. Thus, the study of groups with a blind gut is of great importance for understanding the evolution of this organ system. Here, we describe the morphogenesis and molecular patterning of the blind gut in the sexual triclad Schmidtea polychroa. We identify and analyze the expression of goosecoid, commonly associated with the foregut, and the GATA, ParaHox and T-box genes, members of which commonly are associated with gut regionalization. We show that GATA456a is expressed in the blind gut of triclads, while GATA456b is localized in dorsal parenchymal cells. Goosecoid is expressed in the central nervous system, and the unique ParaHox gene identified, Xlox, is detected in association with the nervous system. We have not isolated any brachyury gene in the T-box complement of S. polychroa, which consists of one tbx1/10, three tbx2/3 and one tbx20. Furthermore, the absence of genes like brachyury and caudal is also present in other groups of Platyhelminthes. This study suggests that GATA456, in combination with foxA, is a gut-specific patterning mechanism conserved in the triclad S. polychroa, while the conserved gut-associated expression of foregut, midgut and hindgut markers is absent. Based on these data and the deviations in spiral cleavage found in more basal flatworms, we propose that the lack of an anus is an innovation of Platyhelminthes. This may be associated with loss of gut gene expression or even gene loss.

  15. A Transcriptomic-Phylogenomic Analysis of the Evolutionary Relationships of Flatworms

    PubMed Central

    Egger, Bernhard; Lapraz, François; Tomiczek, Bartłomiej; Müller, Steven; Dessimoz, Christophe; Girstmair, Johannes; Škunca, Nives; Rawlinson, Kate A.; Cameron, Christopher B.; Beli, Elena; Todaro, M. Antonio; Gammoudi, Mehrez; Noreña, Carolina; Telford, Maximilian J.

    2015-01-01

    Summary The interrelationships of the flatworms (phylum Platyhelminthes) are poorly resolved despite decades of morphological and molecular phylogenetic studies [1, 2]. The earliest-branching clades (Catenulida, Macrostomorpha, and Polycladida) share spiral cleavage and entolecithal eggs with other lophotrochozoans. Lecithoepitheliata have primitive spiral cleavage but derived ectolecithal eggs. Other orders (Rhabdocoela, Proseriata, Tricladida and relatives, and Bothrioplanida) all have derived ectolecithal eggs but have uncertain affinities to one another. The orders of parasitic Neodermata emerge from an uncertain position from within these ectolecithal classes. To tackle these problems, we have sequenced transcriptomes from 18 flatworms and 5 other metazoan groups. The addition of published data produces an alignment of >107,000 amino acids with less than 28% missing data from 27 flatworm taxa in 11 orders covering all major clades. Our phylogenetic analyses show that Platyhelminthes consist of the two clades Catenulida and Rhabditophora. Within Rhabditophora, we show the earliest-emerging branch is Macrostomorpha, not Polycladida. We show Lecithoepitheliata are not members of Neoophora but are sister group of Polycladida, implying independent origins of the ectolecithal eggs found in Lecithoepitheliata and Neoophora. We resolve Rhabdocoela as the most basally branching euneoophoran taxon. Tricladida, Bothrioplanida, and Neodermata constitute a group that appears to have lost both spiral cleavage and centrosomes. We identify Bothrioplanida as the long-sought closest free-living sister group of the parasitic Neodermata. Among parasitic orders, we show that Cestoda are closer to Trematoda than to Monogenea, rejecting the concept of the Cercomeromorpha. Our results have important implications for understanding the evolution of this major phylum. PMID:25866392

  16. Visualization and 3D Reconstruction of Flame Cells of Taenia solium (Cestoda)

    PubMed Central

    Valverde-Islas, Laura E.; Arrangoiz, Esteban; Vega, Elio; Robert, Lilia; Villanueva, Rafael; Reynoso-Ducoing, Olivia; Willms, Kaethe; Zepeda-Rodríguez, Armando; Fortoul, Teresa I.; Ambrosio, Javier R.

    2011-01-01

    Background Flame cells are the terminal cells of protonephridial systems, which are part of the excretory systems of invertebrates. Although the knowledge of their biological role is incomplete, there is a consensus that these cells perform excretion/secretion activities. It has been suggested that the flame cells participate in the maintenance of the osmotic environment that the cestodes require to live inside their hosts. In live Platyhelminthes, by light microscopy, the cells appear beating their flames rapidly and, at the ultrastructural, the cells have a large body enclosing a tuft of cilia. Few studies have been performed to define the localization of the cytoskeletal proteins of these cells, and it is unclear how these proteins are involved in cell function. Methodology/Principal Findings Parasites of two different developmental stages of T. solium were used: cysticerci recovered from naturally infected pigs and intestinal adults obtained from immunosuppressed and experimentally infected golden hamsters. Hamsters were fed viable cysticerci to recover adult parasites after one month of infection. In the present studies focusing on flame cells of cysticerci tissues was performed. Using several methods such as video, confocal and electron microscopy, in addition to computational analysis for reconstruction and modeling, we have provided a 3D visual rendition of the cytoskeletal architecture of Taenia solium flame cells. Conclusions/Significance We consider that visual representations of cells open a new way for understanding the role of these cells in the excretory systems of Platyhelminths. After reconstruction, the observation of high resolution 3D images allowed for virtual observation of the interior composition of cells. A combination of microscopic images, computational reconstructions and 3D modeling of cells appears to be useful for inferring the cellular dynamics of the flame cell cytoskeleton. PMID:21412407

  17. Larval stages of trematodes in gastropods from Lake Chicnahuapan, State of Mexico, Mexico.

    PubMed

    Barragán-Sáenz, Francisco Adrián; Sánchez-Nava, Petra; Hernández-Gallegos, Oswaldo; Salgado-Maldonado, Guillermo

    2009-10-01

    During the period from January to December (2007), 1,095 freshwater molluscs of four species were captured (Lymnaea stagnalis, Stagnicola elodes, Physella cubensis and Physa acuta) in Lake Chicnahuapan, State of Mexico, Mexico. Two hundred seventy-two (24.84% prevalence) of these molluscs were parasitised by 11 trematode species (from which two were not identified at the species level) having six cercariae species and five metacercariae species represented in five families. The cercariae Telorchis corti (Plagiorchiidae) and the metacercariae Cotylurus cornutus (Strigeidae) were the species with the highest prevalence among the examined snails. The highest percentage of infection was observed in L. stagnalis (27.45% of prevalence, n = 572) and P. cubensis (23.96%, n = 455). Twenty-one of the examined snails had multiple infections with up to three trematode species.

  18. Visualizing Cochlear Mechanics Using Confocal Microscopy

    NASA Astrophysics Data System (ADS)

    Ulfendahl, M.; Boutet de Monvel, J.; Fridberger, A.

    2003-02-01

    The sound-evoked vibration pattern of the hearing organ is based on complex mechanical interactions between different cellular structures. To explore the structural changes occurring within the organ of Corti during basilar-membrane motion, stepwise alterations of the scala tympani pressure were applied in an in vitro preparation of the guinea-pig temporal bone. Confocal images were acquired at each pressure level. In this way, the motion of several structures could be simultaneously observed with high resolution in a nearly intact system. Images were analyzed using a novel wavelet-based optical-flow estimation algorithm. Under the present experimental conditions, the reticular lamina moved as a stiff plate with a center of rotation in the region of the inner hair cells. The outer hair cells appeared non-rigid and the basal, synaptic regions of these cells displayed significant radial motion indicative of cellular bending and internal shearing.

  19. Molecular mechanisms of sound amplification in the mammalian cochlea.

    PubMed

    Ashmore, J F; Géléoc, G S; Harbott, L

    2000-10-24

    Mammalian hearing depends on the enhanced mechanical properties of the basilar membrane within the cochlear duct. The enhancement arises through the action of outer hair cells that act like force generators within the organ of Corti. Simple considerations show that underlying mechanism of somatic motility depends on local area changes within the lateral membrane of the cell. The molecular basis for this phenomenon is a dense array of particles that are inserted into the basolateral membrane and that are capable of sensing membrane potential field. We show here that outer hair cells selectively take up fructose, at rates high enough to suggest that a sugar transporter may be part of the motor complex. The relation of these findings to a recent candidate for the molecular motor is also discussed.

  20. Mechanosensitive ion channels investigated simultaneously by scanning probe microscopy and patch clamp.

    PubMed

    Langer, Matthias G

    2007-01-01

    Mechanosensitive ion channels play an important role for the perception of mechanical signals such as touch, balance, or sound. Here, a new experimental strategy is presented providing well-defined access to single mechanosensitive ion channels in living cells. As a representative example, the investigation of mechanosensitive transduction channels in cochlear hair cells is discussed in detail including all essential technical aspects. Three different techniques were combined: atomic force microscopy (AFM) as a device for local mechanical stimulation, patch clamp for recording the current response of mechanosensitive ion channels, and differential interference contrast (DIC) microscopy equipped with an upright water-immersion objective lens. A major challenge was to adapt the mechanical design of the AFM setup to the small working distance of the light microscope and the electrical design of the AFM electronics. Various protocols for the preparation and investigation of the organ of Corti with AFM are presented.

  1. Dissection of the Mechanical Impedance Components of the Outer Hair Cell Using a Chloride-Channel Blocker

    NASA Astrophysics Data System (ADS)

    Harasztosi, Csaba; Gummer, Anthony W.

    2011-11-01

    The voltage-dependent chloride-channel blocker anthracene-9-carboxylic acid (9AC) has been found to reduce the imaginary but not the real part of the mechanical impedance of the organ of Corti, suggesting that the effective stiffness of outer hair cells (OHCs) is reduced by 9AC. To examine whether 9AC interacts directly with the motor protein prestin to reduce the membrane component of the impedance, the patch-clamp technique in whole-cell configuration was used to measure the nonlinear capacitance (NLC) of isolated OHCs and, as control, prestin-transfected human embryonic kidney 293 (HEK293) cells. Extracellular application of 9AC significantly reduced the NLC of both OHCs and HEK293 cells. Intracellular 9AC did not influence the blocking effect of the extracellular applied drug. These results suggest that 9AC interacts directly with prestin, reducing the effective stiffness of the motor, and that the interaction is extracellular.

  2. Instrumentation for Studies of Cochlear Mechanics: From von Békésy forward

    PubMed Central

    Nuttall, Alfred L; Fridberger, Anders

    2012-01-01

    Georg von Békésy designed the instruments needed for his research. He also created physical models of the cochlea allowing him to manipulate the parameters (such as volume elasticity) that could be involved in controlling traveling waves. This review is about the specific devices that he used to study the motion of the basilar membrane thus allowing the analysis that lead to his Nobel Prize Award. The review moves forward in time mentioning the subsequent use of von Békésy’s methods and later technologies important for motion studies of the organ of Corti. Some of the seminal findings and the controversies of cochlear mechanics are mentioned in relation to the technical developments. PMID:22975360

  3. The second filter's second coming

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, Sripriya; Chen, Fangyi; Zha, Dingjun; Jacques, Steven L.; Wang, Ruikang; Choudhoury, Niloy; Nuttall, Alfred L.; Fridberger, Anders

    2015-12-01

    We measured sound-evoked vibrations at the stereociliary side of inner and outer hair cells and their surrounding supporting cells, using optical coherence tomography interferometry in living anesthetized guinea pigs. Our measurements demonstrate a gradient in frequency tuning among different cell types, going from a high best frequency at the inner hair cells to a lower one at the Hensen cells. This causes the locus of maximum inner hair cell activation to be shifted toward the apex of the cochlea as compared to the outer hair cells. These observations show that additional processing and filtering of acoustic signals occurs within the organ of Corti prior to inner hair cell excitation, thus reinstating a transformed second filter as a mechanism contributing to cochlear frequency tuning.

  4. Absolute measurement of subnanometer scale vibration of cochlear partition of an excised guinea pig cochlea using spectral-domain phase-sensitive optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Subhash, Hrebesh M.; Choudhury, Niloy; Jacques, Steven L.; Wang, Ruikang K.; Chen, Fangyi; Zha, Dingjun; Nuttall, Alfred L.

    2012-01-01

    Direct measurement of absolute vibration parameters from different locations within the mammalian organ of Corti is crucial for understanding the hearing mechanics such as how sound propagates through the cochlea and how sound stimulates the vibration of various structures of the cochlea, namely, basilar membrane (BM), recticular lamina, outer hair cells and tectorial membrane (TM). In this study we demonstrate the feasibility a modified phase-sensitive spectral domain optical coherence tomography system to provide subnanometer scale vibration information from multiple angles within the imaging beam. The system has the potential to provide depth resolved absolute vibration measurement of tissue microstructures from each of the delay-encoded vibration images with a noise floor of ~0.3nm at 200Hz.

  5. Active Outer Hair Cells Affect the Sound-Evoked Vibration of the Reticular Lamina

    NASA Astrophysics Data System (ADS)

    Jacob, Stefan; Fridberger, Anders

    2011-11-01

    It is well established that the organ of Corti uses active mechanisms to enhance its sensitivity and frequency selectivity. Two possible mechanisms have been identified, both capable of producing mechanical forces, which can alter the sound-evoked vibration of the hearing organ. However, little is known about the effect of these forces on the sound-evoked vibration pattern of the reticular lamina. Current injections into scala media were used to alter the amplitude of the active mechanisms in the apex of the guinea pig temporal bone. We used time-resolved confocal imaging to access the vibration pattern of individual outer hair cells. During positive current injection the the sound-evoked vibration of outer hair cell row three increased while row one showed a small decrease. Negative currents reversed the observed effect. We conclude that the outer hair cell mediated modification of reticular lamina vibration patterns could contribute to the inner hair cell stimulation.

  6. Optical coherence tomography (OCT) leading to more insight into cochlear mechanics

    NASA Astrophysics Data System (ADS)

    de Boer, Egbert; Chen, Fangyi; Zha, Dingjun; Nuttall, Alfred L.

    2015-12-01

    Optical Coherence Tomography (OCT) was used to measure vibrations of the basilar membrane (BM) and the Reticular Lamina (RL) in the cochlea of the guinea pig, at frequencies up to 25 kHz. Because of the difficulty of the experiments the data have limited sets of parameters and are subject to high noise levels. In a viable guinea-pig cochlea, the RL moves in the region of maximum response with a larger amplitude than the BM. We cannot rule out that some of that difference is due to a geometrical factor. We also found a consistent increase of this amplitude difference with frequency, which points to a low-pass filtering process. That process might be linked to the mass of the fluid contained in the Organ of Corti channel (OoC channel).

  7. A MEMS AlN transducer array with flexible interconnections for use as a cochlear implant

    NASA Astrophysics Data System (ADS)

    Knisely, Katherine; Zhao, Chuming; Grosh, Karl

    2015-12-01

    A completely implantable artificial organ of Corti (CIAO) was fabricated using batch MEMS processing techniques. A silicon backbone supports five piezoelectric cantilevers, each of which is designed to have an in vivo resonance corresponding to its tonotopic location in the guinea pig ST (20-40 kHz). An attachable polymer ribbon cable extends 4cm from the probe to an electrode bay, where electrical connections to each cantilever are accessed. The actuation responses of the fabricated devices were measured using laser vibrometry confirming the fluid-loaded resonance conforming to the straight section of the first turn of the guinea pig cochlea. First generation devices have been fabricated and the actuated resonances were measured to range from 80.3-134.2kHz in air and 24.3-41.0 kHz in water.

  8. Imaging vibration of the cochlear partition of an excised guinea pig cochlea using phase-sensitive Fourier domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Choudhury, Niloy; Zeng, Yaguang; Fridberger, Anders; Chen, Fangyi; Zha, Dingjun; Nuttall, Alfred L.; Wang, Ruikang K.

    2011-03-01

    Studying the sound stimulated vibrations of various membranes that form the complex structure of the organ of Corti in the cochlea of the inner ear is essential for understanding how the travelling sound wave of the basilar membrane couples its energy to the organ structures. In this paper we report the feasibility of using phase-sensitive Fourier domain optical coherence tomography (FD-OCT) to image the vibration of various micro-structures of the cochlea at the same time. An excised cochlea of a guinea pig was stimulated using sounds at various frequencies and vibration image was obtained. When measuring the apex area, vibration signal from different turns, which have different best response frequencies are obtained in the same image. The method has the potential to measure the response from a much wider region of the cochlea than any other currently used method. The noise floor for vibration image for the system at 200 Hz was ~0.3nm.

  9. Optical coherence tomography (OCT) leading to more insight into cochlear mechanics

    SciTech Connect

    Boer, Egbert de; Chen, Fangyi; Zha, Dingjun; Nuttall, Alfred L.

    2015-12-31

    Optical Coherence Tomography (OCT) was used to measure vibrations of the basilar membrane (BM) and the Reticular Lamina (RL) in the cochlea of the guinea pig, at frequencies up to 25 kHz. Because of the difficulty of the experiments the data have limited sets of parameters and are subject to high noise levels. In a viable guinea-pig cochlea, the RL moves in the region of maximum response with a larger amplitude than the BM. We cannot rule out that some of that difference is due to a geometrical factor. We also found a consistent increase of this amplitude difference with frequency, which points to a low-pass filtering process. That process might be linked to the mass of the fluid contained in the Organ of Corti channel (OoC channel)

  10. Instrumentation for studies of cochlear mechanics: from von Békésy forward.

    PubMed

    Nuttall, Alfred L; Fridberger, Anders

    2012-11-01

    Georg von Békésy designed the instruments needed for his research. He also created physical models of the cochlea allowing him to manipulate the parameters (such as volume elasticity) that could be involved in controlling traveling waves. This review is about the specific devices that he used to study the motion of the basilar membrane thus allowing the analysis that lead to his Nobel Prize Award. The review moves forward in time mentioning the subsequent use of von Békésy's methods and later technologies important for motion studies of the organ of Corti. Some of the seminal findings and the controversies of cochlear mechanics are mentioned in relation to the technical developments.

  11. A computational study on traveling waves in the gerbil cochlea generated by electrical impulse

    NASA Astrophysics Data System (ADS)

    Nam, Jong-Hoon; Liu, Yanju; Gracewski, Sheryle M.

    2015-12-01

    Through model simulations, we investigated the cochlear traveling waves formed by outer hair cell (OHC) motility. Two sets of governing equations, one representing the solid domain of the organ of Corti complex (OCC) and the other representing the fluid domain, were solved simultaneously in the time domain. The OHCs incorporated electro-mechanical motility driven by prestin molecules. The combined fluid-solid interaction model was verified by simulating passive traveling waves along the cochlear coil. When stimulated with an electrical impulse, the OCC formed traveling waves propagating toward the apex. Without the Y-shaped structures in the OCC formed by the OHCs and the Deiter's cell processes, the active OHCs form dispersive waves rather than traveling waves upon electrical stimulation.

  12. Apical phosphatidylserine externalization in auditory hair cells.

    PubMed

    Shi, Xiaorui; Gillespie, Peter G; Nuttall, Alfred L

    2007-01-01

    In hair cells of the inner ear, phosphatidylserine (PS), detected with fluorescent annexin V labeling, was rapidly exposed on the external leaflet of apical plasma membranes upon dissection of the organ of Corti. PS externalization was unchanged by caspase inhibition, suggesting that externalization did not portend apoptosis or necrosis. Consistent with that conclusion, mitochondrial membrane potential and hair-cell nuclear structure remained normal during externalization. PS externalization was triggered by forskolin, which raises cAMP, and blocked by inhibitors of adenylyl cyclase. Blocking Na(+) influx by inhibiting the mechanoelectrical transduction channels and P2X ATP channels also inhibited external PS externalization. Diminished PS externalization was also seen in cells exposed to LY 294002, which blocks membrane recycling in hair cells by inhibiting phosphatidylinositol 3-kinase. These results indicate that PS exposure on the external leaflet, presumably requiring vesicular transport, results from elevation of intracellular cAMP, which can be triggered by Na(+) entry into hair cells.

  13. Inheritance patterns of progressive hearing loss in laboratory strains of mice.

    PubMed

    Noben-Trauth, Konrad; Johnson, Kenneth R

    2009-06-24

    Positional cloning of mouse deafness mutations uncovered a plethora of proteins that have important functions in the peripheral auditory system in particular in the cochlear organ of Corti and stria vascularis. Most of these mutant variants follow a monogenic form of inheritance and are rare, highly penetrant, and deleterious alleles. Inbred and heterogenous strains of mice, in contrast, present with non-syndromic hearing impairment due to the effects of multiple genes and hypomorphic and less penetrant alleles that are often transmitted in a non-Mendelian manner. Here we review hearing loss inheritance patterns as they were discovered in different strains of mice and discuss the relevance of candidate genes to late-onset progressive hearing impairment in mouse and human.

  14. The spiral ganglion: connecting the peripheral and central auditory systems

    PubMed Central

    Nayagam, Bryony A; Muniak, Michael A; Ryugo, David K

    2011-01-01

    In mammals, the initial bridge between the physical world of sound and perception of that sound is established by neurons of the spiral ganglion. The cell bodies of these neurons give rise to peripheral processes that contact acoustic receptors in the organ of Corti, and the central processes collect together to form the auditory nerve that projects into the brain. In order to better understand hearing at this initial stage, we need to know the following about spiral ganglion neurons: (1) their cell biology including cytoplasmic, cytoskeletal, and membrane properties, (2) their peripheral and central connections including synaptic structure; (3) the nature of their neural signaling; and (4) their capacity for plasticity and rehabilitation. In this report, we will update the progress on these topics and indicate important issues still awaiting resolution. PMID:21530629

  15. The second filter’s second coming

    SciTech Connect

    Ramamoorthy, Sripriya; Jacques, Steven L.; Choudhoury, Niloy; Nuttall, Alfred L.; Chen, Fangyi; Zha, Dingjun; Wang, Ruikang; Fridberger, Anders

    2015-12-31

    We measured sound-evoked vibrations at the stereociliary side of inner and outer hair cells and their surrounding supporting cells, using optical coherence tomography interferometry in living anesthetized guinea pigs. Our measurements demonstrate a gradient in frequency tuning among different cell types, going from a high best frequency at the inner hair cells to a lower one at the Hensen cells. This causes the locus of maximum inner hair cell activation to be shifted toward the apex of the cochlea as compared to the outer hair cells. These observations show that additional processing and filtering of acoustic signals occurs within the organ of Corti prior to inner hair cell excitation, thus reinstating a transformed second filter as a mechanism contributing to cochlear frequency tuning.

  16. Is Stereocilia Velocity or Displacement Feedback Used in the Cochlear Amplifier?

    NASA Astrophysics Data System (ADS)

    Lu, Shan; Mountain, David; Hubbard, Allyn

    2009-02-01

    Outer hair cells (OHC) play an important role in cochlear amplification. The OHC senses stereocilia motion and creates a force feedback to the organ of Corti. It is largely accepted that the stereocilia displacement drives the OHC apical conductance change, which, in turn, drives somatic motility. Recent research shows that the tension gated OHC current exhibits fast adaptation in response to stereocilia displacement. Such an adaptation process resembles a high-pass filter or differentiator, at least for the inward current. Since velocity is the derivative of displacement, fast adaptation may indicate that it is the stereocilia velocity, rather than displacement is the more important driver of the OHC apical conductance. We changed our multi-compartment, piezo-electro-mechanical model to sense stereocilia velocity rather than displacement. This new model can well match measured basilar membrane velocity and our own cochlear microphonic data.

  17. A Physiological Signal Transmission Model to be Used for Specific Diagnosis of Cochlear Impairments

    NASA Astrophysics Data System (ADS)

    Saremi, Amin; Stenfelt, Stefan

    2011-11-01

    Many of the sophisticated characteristics of human auditory system are attributed to cochlea. Also, most of patients with a hearing loss suffer from impairments that originate from cochlea (sensorineural). Despite this, today's clinical diagnosis methods do not probe the specific origins of such cochlear lesions. The aim of this research is to introduce a physiological signal transmission model to be clinically used as a tool for diagnosis of cochlear losses. This model enables simulation of different bio-mechano-electrical processes which occur in the auditory organ of Corti inside the cochlea. What makes this model different from many available computational models is its loyalty to physiology since the ultimate goal is to model each single physiological phenomenon. This includes passive BM vibration, outer hair cells' performances such as nonlinear mechanoelectrical transduction (MET), active amplifications by somatic motor, as well as vibration to neural conversion at the inner hair cells.

  18. Effects of high linear energy transfer radiation on the cochlea of C3H/He mouse during postnatal developmental course.

    PubMed

    Nitta, Yumiko; Araki, Nobukazu; Nitta, Kohsaku; Harada, Toshihide; Ishizaki, Fumiko; Ando, Juko

    2005-03-01

    To investigate the biological effectiveness of neutrons at energies below 1MeV with regard to ear toxicity, we exposed mice to 1.0 Gy of monoenergetic neutrons (1.026 MeV) or 137Cs gamma rays at 7 days of age, and observed subsequent morphological changes in the inner ear with light and scanning electron microscopes. Monoenergetic neutrons, but not gamma rays, caused acute changes in the ear. The epithelium of the greater epithelial ridge in the organ of Corti showed degeneration around 6 hours and disappeared by 72 hours post-irradiation. The apoptotic cell death of the epithelium of the greater epithelial ridge was inducible by the radiation at 3 or 4 days of age. The hair cells formed the protrusion structures of the surface by 72 hours post-irradiation. Neutron-irradiation also caused acute otitis media until 10 weeks of age.

  19. The influence of a chronic vitamin A deficiency on the acoustic sensory cells and the ganglion spirale cochleae of the rat. An electron microscope study.

    PubMed

    Löhle, E

    1980-01-01

    Microscope studies of the inner ear in rats with chronic vitamin A deficiency have rendered contradicting results. In our electron microscope study of the sensory cells of the inner ear in young rats with vitamin A deficiency we found that the cuticle is missing in outer hair cells. In the inner hair cells the cuticle is subtotally lacking. Furthermore, we found changes in the reticular system of the intermediate zone and massive degenerative changes in the afferent nerve system including the ganglion cells of the ganglion spirale cochleae. These morphological changes together with the recent findings of high concentrations of vitamin A in Corti's organ support the hypothesis that the acoustic sensory receptors contain of functionally depend upon vitamin A.

  20. Interaural correlations in normal and traumatized cochleas: length and sensory cell loss

    SciTech Connect

    Bohne, B.A.; Bozzay, D.G.; Harding, G.W.

    1986-12-01

    Sizable intraspecies variations have been found in both the length of the organ of Corti (OC) and the amount of damage resulting from exposure to a particular ototraumatic agent. These variations have made it difficult to address certain research questions such as the susceptibility of the previously injured ear to further damage. If intra-animal correlation is high, the variability problem could be circumvented by using the two ears from a given animal for different aspects of the same study. Therefore, correlation coefficients were calculated for OC length and for percentage of missing inner (IHCs) and outer hair cells (OHCs) in a large sample of chinchillas which included controls and animals which had been exposed to noise or treated with ionizing radiation. The correlation coefficients were +0.96 for OC length, +0.93 for IHC loss, and +0.97 for OHC loss.

  1. Delayed effects of ionizing radiation on the ear

    SciTech Connect

    Bohne, B.A.; Marks, J.E.; Glasgow, G.P.

    1985-07-01

    The question of damage to the ear from exposure to ionizing radiation was addressed by exposing groups of chinchillas to fractioned doses of radiation (2 Gy per day) for total doses ranging from 40 to 90 Gy. In order to allow any delayed effects of radiation to become manifest, the animals were sacrificed two years after completion of treatment and their temporal bones were prepared for microscopic examination. The most pronounced effect of treatment was degeneration of sensory and supporting cells and loss of eighth nerve fibers in the organ of Corti. Damage increased with increasing dose of radiation. The degree of damage found in many of these ears was of sufficient magnitude to produce a permanent sensorineural hearing loss.

  2. Place pitch versus electrode location in a realistic computational model of the implanted human cochlea.

    PubMed

    Kalkman, Randy K; Briaire, Jeroen J; Dekker, David M T; Frijns, Johan H M

    2014-09-01

    Place pitch was investigated in a computational model of the implanted human cochlea containing nerve fibres with realistic trajectories that take the variable distance between the organ of Corti and spiral ganglion into account. The model was further updated from previous studies by including fluid compartments in the modiolus and updating the electrical conductivity values of (temporal) bone and the modiolus, based on clinical data. Four different cochlear geometries are used, modelled with both lateral and perimodiolar implants, and their neural excitation patterns were examined for nerve fibres modelled with and without peripheral processes. Additionally, equations were derived from the model geometries that describe Greenwood's frequency map as a function of cochlear angle at the basilar membrane as well as at the spiral ganglion. The main findings are: (I) in the first (basal) turn of the cochlea, cochlear implant induced pitch can be predicted fairly well using the Greenwood function. (II) Beyond the first turn this pitch becomes increasingly unpredictable, greatly dependent on stimulus level, state of the cochlear neurons and the electrode's distance from the modiolus. (III) After the first turn cochlear implant induced pitch decreases as stimulus level increases, but the pitch does not reach values expected from direct spiral ganglion stimulation unless the peripheral processes are missing. (IV) Electrode contacts near the end of the spiral ganglion or deeper elicit very unpredictable pitch, with broad frequency ranges that strongly overlap with those of neighbouring contacts. (V) The characteristic place pitch for stimulation at either the organ of Corti or the spiral ganglion can be described as a function of cochlear angle by the equations presented in this paper.

  3. Involvement of Ubiquitin-Editing Protein A20 in Modulating Inflammation in Rat Cochlea Associated with Silver Nanoparticle-Induced CD68 Upregulation and TLR4 Activation

    NASA Astrophysics Data System (ADS)

    Feng, Hao; Pyykkö, Ilmari; Zou, Jing

    2016-05-01

    Silver nanoparticles (AgNPs) were shown to temporarily impair the biological barriers in the skin of the external ear canal, mucosa of the middle ear, and inner ear, causing partially reversible hearing loss after delivery into the middle ear. The current study aimed to elucidate the molecular mechanism, emphasizing the TLR signaling pathways in association with the potential recruitment of macrophages in the cochlea and the modulation of inflammation by ubiquitin-editing protein A20. Molecules potentially involved in these signaling pathways were thoroughly analysed using immunohistochemistry in the rat cochlea exposed to AgNPs at various concentrations through intratympanic injection. The results showed that 0.4 % AgNPs but not 0.02 % AgNPs upregulated the expressions of CD68, TLR4, MCP1, A20, and RNF11 in the strial basal cells, spiral ligament fibrocytes, and non-sensory supporting cells of Corti's organ. 0.4 % AgNPs had no effect on CD44, TLR2, MCP2, Rac1, myosin light chain, VCAM1, Erk1/2, JNK, p38, IL-1β, TNF-α, TNFR1, TNFR2, IL-10, or TGF-β. This study suggested that AgNPs might confer macrophage-like functions on the strial basal cells and spiral ligament fibrocytes and enhance the immune activities of non-sensory supporting cells of Corti's organ through the upregulation of CD68, which might be involved in TLR4 activation. A20 and RNF11 played roles in maintaining cochlear homeostasis via negative regulation of the expressions of inflammatory cytokines.

  4. Effects of growth factors on the hair cells after ototoxic treatment of the neonatal mammalian cochlea in vitro.

    PubMed

    Romand, R; Chardin, S

    1999-04-17

    The aim of this study was to test the possible regenerative potential of several molecules and growth factors such as retinoic acid (RA), insulin, epidermal growth factor (EGF) and transforming growth factors alpha (TGFalpha) and beta (TGFbeta) on the neonatal cochlea in vitro after neomycin intoxication. Our studies show that cochlear sensory epithelium behaves differently while maintained in various culture conditions, although we did not observe regeneration whatever the molecules or growth factors tested. The ototoxic action of neomycin in vitro produced a specific death of hair cells, except in the apical region. Organ of Corti of rats 3 days after birth always presented two regions that responded differently to the antibiotic: a widespread scar region extending from the basal cochlea up to the beginning of the apical turn, where most hair cells had disappeared, and a second region called the resistance region localized in the apex, and which was more or less developed depending on culture conditions. The length of the resistance region was modulated by molecules or growth factors added to the feeding solution suggesting that some of them could produce a protective action on hair cells against neomycin. Slight protection effects may be found with RA and insulin, however, the most definite protection results from the combination of insulin with TGFalpha as shown by the large increase in the length of the resistance region compared to organ of Corti treated with antibiotic alone. The tested molecules and growth factors did not promote cochlear hair cell regeneration in vitro after neomycin treatment, however some of them may offer a protective action against ototoxicity.

  5. Postnatal development, maturation and aging in the mouse cochlea and their effects on hair cell regeneration.

    PubMed

    Walters, Bradley J; Zuo, Jian

    2013-03-01

    The organ of Corti in the mammalian inner ear is comprised of mechanosensory hair cells (HCs) and nonsensory supporting cells (SCs), both of which are believed to be terminally post-mitotic beyond late embryonic ages. Consequently, regeneration of HCs and SCs does not occur naturally in the adult mammalian cochlea, though recent evidence suggests that these cells may not be completely or irreversibly quiescent at earlier postnatal ages. Furthermore, regenerative processes can be induced by genetic and pharmacological manipulations, but, more and more reports suggest that regenerative potential declines as the organ of Corti continues to age. In numerous mammalian systems, such effects of aging on regenerative potential are well established. However, in the cochlea, the problem of regeneration has not been traditionally viewed as one of aging. This is an important consideration as current models are unable to elicit widespread regeneration or full recovery of function at adult ages yet regenerative therapies will need to be developed specifically for adult populations. Still, the advent of gene targeting and other genetic manipulations has established mice as critically important models for the study of cochlear development and HC regeneration and suggests that auditory HC regeneration in adult mammals may indeed be possible. Thus, this review will focus on the pursuit of regeneration in the postnatal and adult mouse cochlea and highlight processes that occur during postnatal development, maturation, and aging that could contribute to an age-related decline in regenerative potential. Second, we will draw upon the wealth of knowledge pertaining to age related senescence in tissues outside of the ear to synthesize new insights and potentially guide future research aimed at promoting HC regeneration in the adult cochlea.

  6. The paracrine effect of mesenchymal human stem cells restored hearing in β-tubulin induced autoimmune sensorineural hearing loss.

    PubMed

    Yoo, T J; Du, Xiaoping; Zhou, Bin

    2015-12-01

    The aim of this study was to examine the activities of hASCs (Human Adipose tissue Derived Stem Cells) on experimental autoimmune hearing loss (EAHL) and how human stem cells regenerated mouse cochlea cells. We have restored hearing in 19 years old white female with autoimmune hearing loss with autologous adipose tissue derived stem cells and we wish to understand the mechanism of restoration of hearing in animal model. BALB/c mice underwent to develop EAHL; mice with EAHL were given hASCs intraperitoneally once a week for 6 consecutive weeks. ABR were examined over time. The helper type 1 autoreactive responses and T-reg cells were examined. H&E staining or immunostaining with APC conjugated anti-HLA-ABC antibody were conducted. The organ of Corti, stria vascularis, spira ligament and spiral ganglion in stem cell group are normal. In control group, without receiving stem cells, the organ of Corti is replaced by a single layer of cells, atrophy of stria vascularis. Systemic infusion of hASCs significantly improved hearing function and protected hair cells in established EAHL. The hASCs decreased the proliferation of antigen specific Th1/Th17 cells and induced the production of anti-inflammatory cytokine interleukin10 in splenocytes. They also induced the generation of antigen specific CD4(+)CD25(+)Foxp3(+)T-reg cells. The experiment showed the restoration is due to the paracrine activities of human stem cells, since there are newly regenerated mice spiral ganglion cells, not human mesenchymal stem cells derived tissue given by intraperitoneally.

  7. A non-canonical pathway from cochlea to brain signals tissue-damaging noise.

    PubMed

    Flores, Emma N; Duggan, Anne; Madathany, Thomas; Hogan, Ann K; Márquez, Freddie G; Kumar, Gagan; Seal, Rebecca P; Edwards, Robert H; Liberman, M Charles; García-Añoveros, Jaime

    2015-03-02

    Intense noise damages the cochlear organ of Corti, particularly the outer hair cells (OHCs) [1]; however, this epithelium is not innervated by nociceptors of somatosensory ganglia, which detect damage elsewhere in the body. The only sensory neurons innervating the organ of Corti originate from the spiral ganglion, roughly 95% of which innervate exclusively inner hair cells (IHCs) [2-4]. Upon sound stimulation, IHCs release glutamate to activate AMPA-type receptors on these myelinated type-I neurons, which carry the neuronal signals to the cochlear nucleus. The remaining spiral ganglion cells (type IIs) are unmyelinated and contact OHCs [2-4]. Their function is unknown. Using immunoreactivity to cFos, we documented neuronal activation in the brainstem of Vglut3(-/-) mice, in which the canonical auditory pathway (activation of type-I afferents by glutamate released from inner hair cells) is silenced [5, 6]. In these deaf mice, we found responses to noxious noise, which damages hair cells, but not to innocuous noise, in neurons of the cochlear nucleus, but not in the vestibular or trigeminal nuclei. This response originates in the cochlea and not in other areas also stimulated by intense noise (middle ear and vestibule) as it was absent in CD1 mice with selective cochlear degeneration but normal vestibular and somatosensory function. These data imply the existence of an alternative neuronal pathway from cochlea to brainstem that is activated by tissue-damaging noise and does not require glutamate release from IHCs. This detection of noise-induced tissue damage, possibly by type-II cochlear afferents, represents a novel form of sensation that we term auditory nociception.

  8. Noise alters hair-bundle mechanics at the cochlear apex

    NASA Astrophysics Data System (ADS)

    Strimbu, C. Elliott; Fridberger, Anders

    2015-12-01

    Exposure to loud sounds can lead to both permanent and short term changes in auditory sensitivity. Permanent hearing loss is often associated with gross changes in cochlear morphology including the loss of hair cells and auditory nerve fibers while the mechanisms of short term threshold shifts are much less well understood and may vary at different locations across the cochlea. Previous reports suggest that exposure to loud sounds leads to a decrease in the cochlear microphonic potential and in the stiffness of the organ of Corti. Because the cochlear microphonic reflects changes in the membrane potential of the hair cells, this suggests that hair-bundle motion should be reversibly altered following exposure to loud sounds. Using an in vitro preparation of the guinea pig temporal bone we investigate changes in the micro-mechanical response near the cochlear apex following a brief (up to 10 - 20 minutes) exposure to loud (˜ 120 dB) tones near the best frequency at this location. We use time-resolved confocal imaging to record the motion of outer hair cell bundles before and after acoustic overstimulation. We have also recorded larger-scale structural views of the organ of Corti before and after exposure to the loud sound. Conventional electrophysiological techniques are used measure the cochlear microphonic potential. As has been previously reported, following acoustic overexposure the cochlear microphonic declines in value and typically recovers on the order of 30 - 60 minutes. Hair-bundle trajectories are affected following the loud sound and typically recover on a somewhat faster time scale than the microphonic potential, although the results vary considerably across preparations. Preliminary results also suggest reversible changes in the hair cell's resting potential following the loud sound.

  9. Loss of the tectorial membrane protein CEACAM16 enhances spontaneous, stimulus-frequency, and transiently evoked otoacoustic emissions.

    PubMed

    Cheatham, Mary Ann; Goodyear, Richard J; Homma, Kazuaki; Legan, P Kevin; Korchagina, Julia; Naskar, Souvik; Siegel, Jonathan H; Dallos, Peter; Zheng, Jing; Richardson, Guy P

    2014-07-30

    α-Tectorin (TECTA), β-tectorin (TECTB), and carcinoembryonic antigen-related cell adhesion molecule 16 (CEACAM) are secreted glycoproteins that are present in the tectorial membrane (TM), an extracellular structure overlying the hearing organ of the inner ear, the organ of Corti. Previous studies have shown that TECTA and TECTB are both required for formation of the striated-sheet matrix within which collagen fibrils of the TM are imbedded and that CEACAM16 interacts with TECTA. To learn more about the structural and functional significance of CEACAM16, we created a Ceacam16-null mutant mouse. In the absence of CEACAM16, TECTB levels are reduced, a clearly defined striated-sheet matrix does not develop, and Hensen's stripe, a prominent feature in the basal two-thirds of the TM in WT mice, is absent. CEACAM16 is also shown to interact with TECTB, indicating that it may stabilize interactions between TECTA and TECTB. Although brain-stem evoked responses and distortion product otoacoustic emissions are, for most frequencies, normal in young mice lacking CEACAM16, stimulus-frequency and transiently evoked emissions are larger. We also observed spontaneous otoacoustic emissions (SOAEs) in 70% of the homozygous mice. This incidence is remarkable considering that <3% of WT controls have SOAEs. The predominance of SOAEs >15 kHz correlates with the loss of Hensen's stripe. Results from mice lacking CEACAM16 are consistent with the idea that the organ of Corti evolved to maximize the gain of the cochlear amplifier while preventing large oscillations. Changes in TM structure appear to influence the balance between energy generation and dissipation such that the system becomes unstable.

  10. Co-localisation of K(ir)4.1 and AQP4 in rat and human cochleae reveals a gap in water channel expression at the transduction sites of endocochlear K(+) recycling routes.

    PubMed

    Eckhard, Andreas; Gleiser, Corinna; Rask-Andersen, Helge; Arnold, Heinz; Liu, Wei; Mack, Andreas; Müller, Marcus; Löwenheim, Hubert; Hirt, Bernhard

    2012-10-01

    Sensory transduction in the cochlea depends on perilymphatic-endolymphatic potassium (K(+)) recycling. It has been suggested that the epithelial supporting cells (SCs) of the cochlear duct may form the intracellular K(+) recycling pathway. Thus, they must be endowed with molecular mechanisms that facilitate K(+) uptake and release, along with concomitant osmotically driven water movements. As yet, no molecules have been described that would allow for volume-equilibrated transepithelial K(+) fluxes across the SCs. This study describes the subcellular co-localisation of the K(ir)4.1 K(+) channel (K(ir)4.1) and the aquaporin-4 water channel (AQP4) in SCs, on the basis of immunohistochemical double-labelling experiments in rat and human cochleae. The results of this study reveal the expression of K(ir)4.1 in the basal or basolateral membranes of the SCs in the sensory domain of the organ of Corti that are adjacent to hair cells and in the non-sensory domains of the inner and outer sulci that abut large extracellular fluid spaces. The SCs of the inner sulcus (interdental cells, inner sulcus cells) and the outer sulcus (Hensen's cells, outer sulcus cells) display the co-localisation of K(ir)4.1 and AQP4 expression. However, the SCs in the sensory domain of the organ of Corti reveal a gap in the expression of AQP4. The outer pillar cell is devoid of both K(ir)4.1 and AQP4. The subcellular co-localisation of K(ir)4.1 and AQP4 in the SCs of the cochlea described in this study resembles that of the astroglia of the central nervous system and the glial Mueller cells in the retina.

  11. Evidence for active, nonlinear, negative feedback in the vibration response of the apical region of the in-vivo guinea-pig cochlea.

    PubMed

    Zinn, C; Maier, H; Zenner, H; Gummer, A W

    2000-04-01

    The transverse vibration response of the organ of Corti near the apical end of the guinea-pig cochlea was measured in vivo. For cochleae in good physiological condition, as ascertained with threshold compound action potentials and the endocochlear potential, increasing amounts of attenuation and phase lag were found as the intensity was decreased below 80 dB SPL. These nonlinear phenomena disappeared post mortem. The data suggest that an active, nonlinear damping mechanism exists at low intensities at the apex of the cochlea. The phase nonlinearity, evident at all frequencies except at the best frequency (BF), was limited to a total phase change of 0.25 cycles, implying negative feedback of electromechanical force from the outer hair cells into a compliant organ of Corti. The amplitude nonlinearity was largest above BF, possibly due to interaction with a second vibration mode. The high-frequency flank of the amplitude response curve was shifted to lower frequencies by as much as 0.6 octave (oct) for a 50-dB reduction of sound intensity; the reduction of BF was 0.3 oct, but there was no change of relative bandwidth (Q(10 dB)). Detailed frequency responses measured at 60 dB SPL were consistent with non-dispersive, travelling-wave motion: travel time to the place of BF (400 Hz at 60 dB SPL) was 2.9 ms, Q(10 dB) was 1.0; standing-wave motion occurred above 600 Hz. Based on comparison with neural and mechanical data from the base of the cochlea, amplitudes at the apex appear to be sufficient to yield behavioural thresholds. It is concluded that active negative feedback may be a hallmark of the entire cochlea at low stimulus frequencies and that, in contrast to the base, the apex does not require active amplification.

  12. Intestinal helminths of golden jackals and red foxes from Tunisia.

    PubMed

    Lahmar, Samia; Boufana, Belgees; Ben Boubaker, Sarra; Landolsi, Faouzi

    2014-08-29

    Forty wild canids including 31 golden jackals (Canis aureus Linné, 1758) and 9 red foxes (Vulpes vulpes Linné, 1758) collected between 2008 and 2011 in the northeast, northwest and center of Tunisia were necropsied and examined for intestinal helminth parasites. All jackals and foxes were found infected with a prevalence rate of 95% for cestodes, 82.5% for nematodes and 7.5% for acanthocephalans. A total of twelve helminth species were recorded in red foxes: cestodes, Dipylidium caninum (55.6%), Diplopylidium noelleri (55.6%), Mesocestoïdes lineatus (55.6%), Mesocestoïdes litteratus (33%), Mesocestoïdes corti (22%); nematodes, Ancylostoma caninum (11%), Uncinaria stenocephala (44%), Spirura rytipleurites (11%), Trichuris vulpis (33%), Pterygodermatites affinis (67%), Oxynema linstowi (33%) and the acanthocephalan Macracanthorhynchus hirudinaceus (22%). The fifteen recovered helminth species in jackals were Echinococcus granulosus (9.7%), D. caninum (16%), D. noelleri (16%), M. lineatus (74%), M. litteratus (23%), M. corti (12.9%), Taenia pisiformis (3.2%), Taenia spp. (19%), Toxocara canis (16%), Toxascaris leonina (6.5%), A. caninum (9.7%), U. stenocephala (68%), P. affinis (6.5%), O. linstowi (3.2%) and Macracanthorhynchus hirudinaceus (3.2%). This is the first report on the presence of P. affinis, D. noelleri and O. linstowi in Tunisia. E. granulosus was found in young jackals, aged less than 4 years old, with a higher abundance in females (8.9 worms). M. lineatus presented the highest mean intensity of 231.86 and 108.8 tapeworms respectively in jackals and foxes. Canids from the northwest region had the highest prevalence (77.5%) and highest intensity (243.7) of helminth species compared to those from the northeast and central areas. U. stenocephala and O. linstowi had the highest mean intensity for nematodes in both jackals and foxes at 14.3 and 88 worms respectively.

  13. Epigenetic regulation of Atoh1 guides hair cell development in the mammalian cochlea

    PubMed Central

    Stojanova, Zlatka P.; Kwan, Tao; Segil, Neil

    2015-01-01

    In the developing cochlea, sensory hair cell differentiation depends on the regulated expression of the bHLH transcription factor Atoh1. In mammals, if hair cells die they do not regenerate, leading to permanent deafness. By contrast, in non-mammalian vertebrates robust regeneration occurs through upregulation of Atoh1 in the surviving supporting cells that surround hair cells, leading to functional recovery. Investigation of crucial transcriptional events in the developing organ of Corti, including those involving Atoh1, has been hampered by limited accessibility to purified populations of the small number of cells present in the inner ear. We used µChIP and qPCR assays of FACS-purified cells to track changes in the epigenetic status of the Atoh1 locus during sensory epithelia development in the mouse. Dynamic changes in the histone modifications H3K4me3/H3K27me3, H3K9ac and H3K9me3 reveal a progression from poised, to active, to repressive marks, correlating with the onset of Atoh1 expression and its subsequent silencing during the perinatal (P1 to P6) period. Inhibition of acetylation blocked the increase in Atoh1 mRNA in nascent hair cells, as well as ongoing hair cell differentiation during embryonic organ of Corti development ex vivo. These results reveal an epigenetic mechanism of Atoh1 regulation underlying hair cell differentiation and subsequent maturation. Interestingly, the H3K4me3/H3K27me3 bivalent chromatin structure observed in progenitors persists at the Atoh1 locus in perinatal supporting cells, suggesting an explanation for the latent capacity of these cells to transdifferentiate into hair cells, and highlighting their potential as therapeutic targets in hair cell regeneration. PMID:26487780

  14. Sox2 and JAGGED1 expression in normal and drug-damaged adult mouse inner ear.

    PubMed

    Oesterle, Elizabeth C; Campbell, Sean; Taylor, Ruth R; Forge, Andrew; Hume, Clifford R

    2008-03-01

    Inner ear hair cells detect environmental signals associated with hearing, balance, and body orientation. In humans and other mammals, significant hair cell loss leads to irreversible hearing and balance deficits, whereas hair cell loss in nonmammalian vertebrates is repaired by the spontaneous generation of replacement hair cells. Research in mammalian hair cell regeneration is hampered by the lack of in vivo damage models for the adult mouse inner ear and the paucity of cell-type-specific markers for non-sensory cells within the sensory receptor epithelia. The present study delineates a protocol to drug damage the adult mouse auditory epithelium (organ of Corti) in situ and uses this protocol to investigate Sox2 and Jagged1 expression in damaged inner ear sensory epithelia. In other tissues, the transcription factor Sox2 and a ligand member of the Notch signaling pathway, Jagged1, are involved in regenerative processes. Both are involved in early inner ear development and are expressed in developing support cells, but little is known about their expressions in the adult. We describe a nonsurgical technique for inducing hair cell damage in adult mouse organ of Corti by a single high-dose injection of the aminoglycoside kanamycin followed by a single injection of the loop diuretic furosemide. This drug combination causes the rapid death of outer hair cells throughout the cochlea. Using immunocytochemical techniques, Sox2 is shown to be expressed specifically in support cells in normal adult mouse inner ear and is not affected by drug damage. Sox2 is absent from auditory hair cells, but is expressed in a subset of vestibular hair cells. Double-labeling experiments with Sox2 and calbindin suggest Sox2-positive hair cells are Type II. Jagged1 is also expressed in support cells in the adult ear and is not affected by drug damage. Sox2 and Jagged1 may be involved in the maintenance of support cells in adult mouse inner ear.

  15. Gastrointestinal parasites of stray cats in Kashan, Iran.

    PubMed

    Mohsen, A; Hossein, H

    2009-04-01

    Considering the role of parasites in contamination of human beings and domestic animals and lack of information in the region, the present study was performed to investigate the infection status of helminthes and protozoa of stray cats in central Iran. A cross - sectional study was conducted on 113 stray cats trapped from different geographic regions of Kashan during four seasons and were necropsied. Different organs including: kidney, heart, liver, lungs, gastrointestinal tract and abdominal cavity were inspected for helminthes and protozoa infection. Animal's characters including: genus, weight, and season, location, microscopic and macroscopic findings were recorded in a special form. Data were classified and statistically analyzed with a confidence interval of 95%. Chi- Squire Test was used to show the relationship between different factors and parasitic infection. From a total 113 stray cats examined, 67(59.3%) were male and 46(40.7%) were female. Fifteen species of endoparasite including helminthes and protozoa were detected in intestine and fecal sample of the examined cats. There were six protozoa, five cestodes and four nematodes. All endoparasite were localized in the gastrointestinal tract. Overall 108 cats (95.6%) have been infected with at least one of the endoparasites. Prevalences of parasites found were Nematodea: Toxocara cati 13.3%, Physaloptera preputialis 39.8%, Rictularia 52.2% and Uncinaria stenocephala 1.8%; Cestodea: Mesocestoides lineatus 7.1%, Taenia taeniaformis 15%, Diplopylidium nolleri 64.6%, Dipylidium caninum 68.1% and Joyeuxiella echinorhyncoides 85%; Sporozoea: Isospora rivolta 5.3%, Isospora felis 5.3%, Sarcocystis spp 8%, Blastocystis spp 16.8% and Zoomastigophorea: Giardia felis 0.9% and Trichomonas spp 1.8%. Contamination rate for zoonotic parasites of cat was greater than expected in Kashan region. In this respect, appropriate control measures should be taken and it is recommended to determine the most appropriate preventive

  16. Development of novel valerolactam-benzimidazole hybrids anthelmintic derivatives: Diffusion and biotransformation studies in helminth parasites.

    PubMed

    Munguía, Beatriz; Michelena, Mauricio; Melian, Elisa; Saldaña, Jenny; Ures, Ximena; Manta, Eduardo; Domínguez, Laura

    2015-06-01

    In the search for new anthelmintics able to overcome the resistance problem against all available drugs in livestock, the synthesis of novel valerolactam-benzimidazole hybrid compounds was reported. This allowed us to obtain these in vitro and in vivo bioactive compounds using Nippostrongylus brasiliensis rat model by integrating physiology-based assays and ex vivo diffusion studies. In order to further study those novel hybrid molecules, Haemonchus contortus (a sheep gastrointestinal nematode of interest) and Mesocestoides vogae tetrathyridia (a useful system to study the efficacy of anthelmintic drugs against cestoda) were used as parasite models to compare the ex vivo patterns of diffusion and biotransformation of benzimidazoles and their valerolactam-benzimidazole hybrid derivatives. On average, a nine-fold higher intraparasitic concentration of compounds was found in M. vogae compared with H.contortus, with similarities regarding the order of entry of compounds, highlighting febendazole (FEB) and its hybrid compound 10, while valerolactam compound 2 practically did not penetrate the parasites. Interestingly, sulphoxidation drug metabolism was observed and measured, revealing percentages of oxidation of 8.2% and 14.5% for albendazole (ABZ) and febendazole respectively in M. vogae, while this effect was more relevant in H. contortus parasite. More importantly, significant differences were observed between anthelmintic-susceptible adult parasites (Hc S) and those from sheep farms (Hc U). In fact, the percentages of oxidation of FEB and the hybrid compound 8 were higher in Hc U (25.5%, 54.1%, respectively) than in Hc S (8.8%, 38.2%). Interestingly, sulphoxidation of hybrid compound 10 was neither observed in M. vogae nor in H. contortus parasites, suggesting that increased drug metabolism (oxidation reactions) could not be used by these parasites as a defense mechanism against this novel drug.

  17. Coprological survey of alimentary tract parasites in dogs from Zambia and evaluation of a coproantigen assay for canine echinococcosis.

    PubMed

    Nonaka, N; Nakamura, S; Inoue, T; Oku, Y; Katakura, K; Matsumoto, J; Mathis, A; Chembesofu, M; Phiri, I G K

    2011-10-01

    Faecal samples were collected from the rectum of 540 domestic dogs from four districts (Lusaka, Katete, Petauke and Luangwa) in Zambia between 2005 and 2006 and prevalences of canine alimentary tract parasites were determined by coprological examination. Thirteen different ova and parasites including strongyle (43.3%), Spirocerca lupi (18.7%), taeniid (13.1%), Toxocara canis (7.6%), Sarcocystis sp.* (7.5%), Isospora sp.* (5.7%), Physaloptera sp.* (4.6%), Capillaria sp.* (2.8%), Dipylidium caninum (2.2%), Mesocestoides sp.* (2.0%), Ascaris sp.* (1.7%), Trichuris vulpis* (0.4%) and Schistosoma mansoni* (0.4%) were detected, Ascaris and Schistosoma probably originating from coprophagy. The species with asterisks and later-described Taenia multiceps are for the first time reported from dogs in Zambia. A coproantigen enzyme-linked immunosorbent assay (CoproAg-ELISA) developed for Echinococcus spp. revealed 43 positive dogs and 37 of these harboured taeniid eggs. From 63 of the 71 taeniid egg-positive samples, eggs and DNA thereof were isolated and subjected to a multiplex polymerase chain reaction for differentiating E. granulosus sensu lato, E. multilocularis and Taenia spp. Amplicons indicative for Taenia spp. were obtained from 60 samples. Sequencing of amplicons spanning part of the mitochondrial cytochrome c oxidase subunit 1 gene, which was possible with 38 samples, revealed 35 infections with T. hydatigena and 3 with T. multiceps. Therefore, the CoproAg-ELISA showed some positives, but concrete evidence for the existence of canine E. granulosus infection could not be established. Comparison of the results of the CoproAg-ELISA and Taenia species identification indicated that the CoproAg-ELISA cross-reacts with patent infections of T. hydatigena (57%) and T. multiceps (33%).

  18. Gastrointestinal parasites of cats in Denmark assessed by necropsy and concentration McMaster technique.

    PubMed

    Takeuchi-Storm, N; Mejer, H; Al-Sabi, M N S; Olsen, C S; Thamsborg, S M; Enemark, H L

    2015-12-15

    The large population of feral cats in Denmark may potentially transmit pathogens to household cats and zoonotic parasites to humans. A total of 99 euthanized cats; feral cats (n=92) and household cats with outdoor access (n=7), were collected from March to May 2014 from the Zealand region, Denmark. The sedimentation and counting technique (SCT) was used to isolate helminths and coproscopy was done by concentration McMaster technique (c-McMaster). Overall, 90.1% of the cats were infected and a total of 10 species were recorded by SCT: 5 nematode species: Toxocara cati (84.8%), Ollulanus tricuspis (13.1%), Aonchotheca putorii (7.1%), Paersonema spp. (3.0%), Strongyloides spp. (1.0%); 3 cestodes: Hydatigera taeniaeformis (36.4%), Mesocestoides sp. (3.0%), Dipylidium caninum (1.0%); and 2 trematodes: Cryptocotyle spp. (5.1%) and Pseudamphistomum truncatum (1.0%). O. tricuspis was the second most common gastrointestinal nematode of cats but had the highest intensity of infection. For T. cati, prevalence and worm burden were significantly higher in feral than household cats. No juvenile cats were infected with H. taeniaeformis, and age thus had a significant effect on prevalence and worm burdens of this species. Rural cats had a higher prevalence and worm burden of A. putorii than urban cats. By c-McMaster, ascarid, capillarid, strongylid or taeniid type eggs were found in 77.9% of the cats while Cystoisospora felis was found in 2.1%. The sensitivity of the c-McMaster was 82.5% for T. cati but 26.5% for taeniid eggs, using the SCT as gold standard. A positive correlation between faecal egg counts and worm burdens was seen for T. cati, but not for taeniid eggs (assumed to be H. taeniaeformis). Coprological examination also detected the eggs of extraintestinal Capillariidae species including Eucoleus aerophilus and Eucoleus boehmi, but further necropsy studies are needed to confirm these findings.

  19. Small rodents as paratenic or intermediate hosts of carnivore parasites in Berlin, Germany

    PubMed Central

    Maaz, Denny; Demeler, Janina; Ramünke, Sabrina; Antolová, Daniela; Schaper, Roland; von Samson-Himmelstjerna, Georg

    2017-01-01

    Rodents are important intermediate and paratenic hosts for carnivore parasites, including the important zoonotic agents Toxoplasma, Echinococcus and Toxocara. Monitoring of such parasites in rodents can be used to detect increasing risks for human and veterinary public health. Rodents were trapped at four sites in Berlin, two near the city center, two at the periphery. PCRs were conducted to detect Coccidia (target ITS-1) and specifically Toxoplasma gondii (repetitive element) in brain and ascarids (ITS-2) in muscle or brain tissue. During necropsies, metacestodes were collected and identified using ITS-2 and 12S rRNA PCRs. An ELISA to detect antibodies against Toxocara canis ES antigens was performed. Within the 257 examined rodents, the most frequently observed parasite was Frenkelia glareoli predominantly found in Myodes glareolus. T. gondii was only detected in 12 rodents and Microtus spp. (although strongly underrepresented) had a significantly increased chance of being positive. Neither Echinococcus nor typical Taenia parasites of dogs and cats were found but Mesocestoides litteratus and Taenia martis metacestodes were identified which can cause severe peritoneal or ocular cysticercosis in dogs, primates and humans. Using PCR, the ascarids T. canis (n = 8), Toxocara cati (4) and Parascaris sp. (1) were detected predominantly in muscles. Seroprevalence of T. canis was 14.2% and ELISA was thus more sensitive than PCR to detect infection with this parasite. Non-parametric multidimensional scaling and cluster analysis revealed that parasite communities could be grouped into an urban and a peri-urban cluster with high frequency of ascarid-positive rodents in urban and high frequency of F. glareoli in peri-urban sites. Prevalence rates of parasites in rodents with potential impact for human or veterinary public health are considerable and the monitoring of transmission cycles of carnivore parasites in intermediate rodent hosts is recommended to estimate the health

  20. A diagnostic study of Echinococcus multilocularis in red foxes (Vulpes vulpes) from Great Britain.

    PubMed

    Learmount, J; Zimmer, I A; Conyers, C; Boughtflower, V D; Morgan, C P; Smith, G C

    2012-12-21

    Alveolar echinococcosis is caused by a parasitic tapeworm Echinococcus multilocularis and is a serious disease with high fatality in humans. The definitive primary host is the red fox (Vulpes vulpes) but domestic animals (dogs and to a lesser extent cats) as well as several genera of rodents can also be infected with the parasite. There is, to date, no evidence of indigenous cases of E. multilocularis in Great Britain (GB) but in most of continental Europe the parasite is considered to be endemic and/or slowly spreading. All pet dogs entering the United Kingdom (UK) under the pet travel scheme (PETS) are therefore currently treated with an anthelmintic effective against Echinococcus spp. Surveillance of red foxes is required to demonstrate disease freedom and maintain this regulation to prevent further geographical spread of the parasite to free areas within the EU. A study of 588 wild red foxes collected from across Great Britain (GB) between October 1999 and November 2000 found no Echinococcus spp. This report describes a further study of GB foxes collected predominately during 2005 and 2006. Fox faecal samples (n=384) were examined for both E. multilocularis and Echinococcus granulosus using an egg isolation procedure followed by PCR method, based on published primer sets. A non-specific primer set that amplifies Taenia spp. as well as Mesocestoides, Dipylidium and Diphyllobothrium was also included in the assay to validate the test procedure as these parasites are expected to be more common in wild fox populations. All faecal samples tested negative for both E. multilocularis and E. granulosus but results for approximately 35% of the samples indicated the presence of Taenia spp. or other closely related cestodes. This data contributes to the evidence that suggests that E. multilocularis is not present in mainland Britain and justifies the requirement for ongoing surveillance to demonstrate disease freedom.

  1. Gastrointestinal helminths of free-ranging Florida panthers (Puma concolor coryi) and the efficacy of the current anthelmintic treatment protocol.

    PubMed

    Foster, Garry W; Cunningham, Mark W; Kinsella, John M; McLaughlin, Grace; Forrester, Donald J

    2006-04-01

    Thirty-five Florida panthers (Puma concolor coryi [Bangs, 1899]) collected from six counties in southern Florida between 1978 and 2003 were examined at necropsy for gastrointestinal helminths. The panthers were placed into two groups: 1) treated with anthelmintics (n = 17), and 2) untreated (n = 18). Nine species of helminths (one trematode, six nematodes, and two cestodes) were identified in the untreated panthers. The most prevalent helminths were Alaria marcianae (LaRue, 1917) (100%), Spirometra mansonoides (Mueller, 1935) (91%), and Ancylostoma pluridentatum (Alessandrini, 1905) (89%). Ancylostoma caninum (Ercolani, 1859) is reported from the Florida panther for the first time. The intensities of helminths with prevalences >10% did not differ between untreated panthers collected in 1978-1983 and 1996-2003. Treated panthers had helminth faunas similar to those of untreated panthers. The current anthelmintic treatment being used reduced the intensity of both A. marcianae and A. pluridentatum in panthers < or =6 mo posttreatment (PT); however, treated panthers between 6 and 9 mo PT, and >9 mo PT were similar to untreated panthers. Treatment was less effective on S. mansonoides and Taenia omissa Lühe, 1910. Treated panthers had slightly lower intensities of S. mansonoides at < or =6 mo PT; however, between 6 and 9 mo PT and >9 mo PT they had significantly higher intensities than untreated panthers. At all periods PT, the intensity of T. omissa for the treated panthers was similar to that of untreated panthers. We suggest that Mesocestoides sp. may not be present in the Florida panther population as reported earlier by Forrester et al. (1985), due to parasite misidentification by those authors.

  2. Coprological survey of alimentary tract parasites in dogs from Zambia and evaluation of a coproantigen assay for canine echinococcosis

    PubMed Central

    Nonaka, N; Nakamura, S; Inoue, T; Oku, Y; Katakura, K; Matsumoto, J; Mathis, A; Chembesofu, M; Phiri, I G K

    2011-01-01

    Faecal samples were collected from the rectum of 540 domestic dogs from four districts (Lusaka, Katete, Petauke and Luangwa) in Zambia between 2005 and 2006 and prevalences of canine alimentary tract parasites were determined by coprological examination. Thirteen different ova and parasites including strongyle (43.3%), Spirocerca lupi (18.7%), taeniid (13.1%), Toxocara canis (7.6%), Sarcocystis sp.* (7.5%), Isospora sp.* (5.7%), Physaloptera sp.* (4.6%), Capillaria sp.* (2.8%), Dipylidium caninum (2.2%), Mesocestoides sp.* (2.0%), Ascaris sp.* (1.7%), Trichuris vulpis* (0.4%) and Schistosoma mansoni* (0.4%) were detected, Ascaris and Schistosoma probably originating from coprophagy. The species with asterisks and later-described Taenia multiceps are for the first time reported from dogs in Zambia. A coproantigen enzyme-linked immunosorbent assay (CoproAg-ELISA) developed for Echinococcus spp. revealed 43 positive dogs and 37 of these harboured taeniid eggs. From 63 of the 71 taeniid egg-positive samples, eggs and DNA thereof were isolated and subjected to a multiplex polymerase chain reaction for differentiating E. granulosus sensu lato, E. multilocularis and Taenia spp. Amplicons indicative for Taenia spp. were obtained from 60 samples. Sequencing of amplicons spanning part of the mitochondrial cytochrome c oxidase subunit 1 gene, which was possible with 38 samples, revealed 35 infections with T. hydatigena and 3 with T. multiceps. Therefore, the CoproAg-ELISA showed some positives, but concrete evidence for the existence of canine E. granulosus infection could not be established. Comparison of the results of the CoproAg-ELISA and Taenia species identification indicated that the CoproAg-ELISA cross-reacts with patent infections of T. hydatigena (57%) and T. multiceps (33%). PMID:22185947

  3. Protozoan and helminth parasite fauna of free-living Croatian wild wolves (Canis lupus) analyzed by scat collection.

    PubMed

    Hermosilla, Carlos; Kleinertz, Sonja; Silva, Liliana M R; Hirzmann, Jörg; Huber, Djuro; Kusak, Josip; Taubert, Anja

    2017-01-15

    The European wolf (Canis lupus) is a large carnivore species present in limited areas of Europe with several small populations still being considered as endangered. Wolves can be infected by a wide range of protozoan and metazoan parasites with some of them affecting free-living wolf health condition. On this account, an epidemiological survey was conducted to analyze the actual parasite fauna in Croatian wild wolves. In total, 400 individual faecal samples were collected during field studies on wolf ecology in the years 2002-2011. Parasite stages were identified by the sodium acetate acetic acid formalin (SAF)-technique, carbolfuchsin-stained faecal smears and Giardia/Cryptosporidium coproantigen-ELISAs. A subset of taeniid eggs-positive wolf samples was additionally analyzed by PCR and subsequent sequencing to identify eggs on Echinococcus granulosus/E. multilocularis species level. In total 18 taxa of parasites were here detected. Sarcocystis spp. (19.1%) occurred most frequently in faecal samples, being followed by Capillaria spp. (16%), ancylostomatids (13.1%), Crenosoma vulpis (4.6%), Angiostrongylus vasorum (3.1%), Toxocara canis (2.8%), Hammondia/Neospora spp. (2.6 %), Cystoisospora ohioensis (2.1%), Giardia spp. (2.1%), Cystoisospora canis (1.8%), Cryptosporidium spp. (1.8%), Trichuris vulpis (1.5%), Taenia spp. (1.5%), Diphyllobothrium latum (1.5%), Strongyloides spp. (0.5%), Opisthorchis felineus (0.5%), Toxascaris leonina (0.3%), Mesocestoides litteratus (0.3%) and Alaria alata (0.3%). Some of the here identified parasites represent relevant pathogens for wolves, circulating between these carnivorous definitive hosts and a variety of mammalian intermediate hosts, e. g. Taenia spp. and Sarcocystis spp., while others are considered exclusively pathogenic for canids (e.g. A. vasorum, C. vulpis, T. vulpis, Cystoisospora spp.). This study provides first records on the occurrence of the two relevant anthropozoonotic parasites, Giardia spp. and Cryptosporidium

  4. Endoparasites of Stray Dogs in Mashhad, Khorasan Razavi Province, Northeast Iran with Special Reference to Zoonotic Parasites

    PubMed Central

    ADINEZADEH, Amir; KIA, Eshrat Beigom; MOHEBALI, Mehdi; SHOJAEE, Saideh; ROKNI, Mohammad Bagher; ZAREI, Zabihollah; MOWLAVI, Golamreza

    2013-01-01

    Background To find out different species of helminthes and blood/tissue protozoan parasites of stray dogs and their potential role for transmission of zoonotic species to human in Mashhad, Khorasan Razavi Province, northeast Iran, during 2008-2009. Methods Totally, 100 stray dogs were selected among Mashhad municipal collection from different sites of the city. Internal organs were examined for any parasites. Helminthes were identified based on morphological characteristics. Smears prepared from peripheral blood as well as liver, spleen and any skin lesion were stained by Giemsa and examined microscopically. Samples obtained from spleen were aseptically cultured in three culture media including NNN, Schneider's Drosophila (HIMEDIA) and RPMI1640 (GIBCO) for isolation of Leishmania spp. The titer of anti-Leishmania and anti-Toxoplasma antibodies were measured by direct agglutination test (DAT) and indirect fluorescent antibody test (IFAT), respectively. Results 84% of dogs were infected at least with one species of intestinal helminthes. The species of parasites and rate of infection were as follows: Taenia hydatigena (61%), Dipylidium caninum (46%), Mesocestoides lineatus (19%), Echinococcus granulosus (10%), Toxascaris leonina (53%) and Toxocara canis (7%). Anti-Leishmania antibodies were detected by DAT in 8 dogs (8%) at 1:320 titers and higher. Forty seven dogs (47%) showed anti-Toxoplasma titer at 1:10 and 17 (17%) showed titer of ≥1:100. No blood parasites were found in prepared blood smears. Conclusion The high rate of parasitic infection and presence of zoonotic species especially E. granulosus and T. canis emphasizes the risk of diseases spread in urban areas by stray dogs PMID:24454441

  5. [Parasitological fecal studies of equids, dogs, cats and hedgehogs during the years 1984-1991].

    PubMed

    Epe, C; Ising-Volmer, S; Stoye, M

    1993-11-01

    The results of the coproscopical examinations in horses, dogs, cats and hedgehogs between 1984 and 1991 are presented. In 9192 samples from horses 55.5% stages of strongylids, 4.0% of Parascaris equorum, 2.2% of anoplocephalids, 1.6% Strongyloides westeri, 0.7% of Oxyuris equi, 0.6% of Eimeria leuckarti, 0.2% of Fasciola hepatica and 0.04% of Dictyocaulus arnfieldi were found. In 48.0% of the 46 samples from donkeys eggs from strongylids were detected, in 17.4% larvae from Dictyocaulus arnfieldi, in 2.2% eggs from Strongyloides westeri, Parascaris equorum and oocysts from Eimeria leuckarti, respectively. In 3329 samples of dogs 6.9% developmental stages of Toxocara canis, 6.0% of Giardia spp., 4.2% of Isospora spp., 3.0% of Sarcocystis spp., 2.5% each of ancylostomids and Trichuris vulpis, 1.1% of Toxascaris leonina and 1.1% of Dipylidium canium, up to 1.0% of taeniids, 0.6% of each Mesocestoides spp. and Metastrongylidae, 0.3% of Strongyloides stercoralis and 0.2% of Capillaria spp. and Hammondia heydorni were detected. In 9.5% of the 1147 samples of cats eggs from Toxocara mystax were found, in 4.7% eggs of taeniids, in 4.6% cysts of Isospora spp., in 2.4% of Giardia spp., in 1.4% eggs of Dipylidium caninum, in 1.0% of Capillaria spp. and Aelurostrongylus abstrusus, in 0.6% development stages of Toxoplasma gondii, in 0.5% of ancylostomids and in 0.3% of Sarcocystis spp. and Opisthorchis felineus. In 1175 samples of hedgehogs 48.8% eggs of Capillaria spp., 35.9% of Crenosoma striatum, 17.9% oocysts of Isospora spp., 2.3% eggs of Brachylaemus erinacei were found.

  6. Effect of short-term coyote removal on populations of coyote helminths.

    PubMed

    Henke, Scott E; Pence, Danny B; Bryant, Fred C

    2002-01-01

    Coyote (Canis latrans) removal programs often are initiated despite the potential population regulatory mechanism of parasitism with increased coyote density. We investigated the effect of intensive, short-term coyote removal on population levels of helminths in juvenile and adult coyotes from western Texas. Coyotes were killed by aerial gunning every 3 mo for 2 yr on two 5,000 ha areas, which reduced the overall coyote density of these areas by about 50%. Two other 5,000 ha areas were used as comparison sites where a limited number of coyotes were killed each season. Densities on comparison sites remained stable throughout the study at a mean +/- 1 SE of 0.14 +/- 0.01 coyotes/km2. Twelve helminth species consisting of seven nematodes (Ancylostoma caninum, Physaloptera rara, Toxascaris leonina, Dirofilaria immitis, Spirocerca lupi, Oslerus osleri, and Capillaria aerophila), three cestodes (Taenia pisiformis, Taenia multiceps, and Mesocestoides sp.), one acanthocephalan (Oncicola canis), and one trematode (Alaria marcianae) were found in 252 coyotes. Of these, A. caninum, P. rara, T. multiceps, T. pisiformis, T. leonina, and S. lupi were common species. Rank-transformed values for the mean abundances of A. caninum and T. multiceps and A. caninum, T. multiceps, and S. lupi were reduced in juvenile and adult coyotes, respectively, from the removal sites compared to respective helminth abundances in similar age class coyotes from comparison sites. Because A. caninum has been suggested as a population regulator of coyotes, a coyote removal program that results in a reduced density of coyotes and at the same time causes a reduced abundance of A. caninum, may in fact negate the regulatory effect that A. caninum has on coyote populations.

  7. Modular evolution of glutathione peroxidase genes in association with different biochemical properties of their encoded proteins in invertebrate animals

    PubMed Central

    Bae, Young-An; Cai, Guo-Bin; Kim, Seon-Hee; Zo, Young-Gun; Kong, Yoon

    2009-01-01

    Background Phospholipid hydroperoxide glutathione peroxidases (PHGPx), the most abundant isoforms of GPx families, interfere directly with hydroperoxidation of lipids. Biochemical properties of these proteins vary along with their donor organisms, which has complicated the phylogenetic classification of diverse PHGPx-like proteins. Despite efforts for comprehensive analyses, the evolutionary aspects of GPx genes in invertebrates remain largely unknown. Results We isolated GPx homologs via in silico screening of genomic and/or expressed sequence tag databases of eukaryotic organisms including protostomian species. Genes showing strong similarity to the mammalian PHGPx genes were commonly found in all genomes examined. GPx3- and GPx7-like genes were additionally detected from nematodes and platyhelminths, respectively. The overall distribution of the PHGPx-like proteins with different biochemical properties was biased across taxa; selenium- and glutathione (GSH)-dependent proteins were exclusively detected in platyhelminth and deuterostomian species, whereas selenium-independent and thioredoxin (Trx)-dependent enzymes were isolated in the other taxa. In comparison of genomic organization, the GSH-dependent PHGPx genes showed a conserved architectural pattern, while their Trx-dependent counterparts displayed complex exon-intron structures. A codon for the resolving Cys engaged in reductant binding was found to be substituted in a series of genes. Selection pressure to maintain the selenocysteine codon in GSH-dependent genes also appeared to be relaxed during their evolution. With the dichotomized fashion in genomic organizations, a highly polytomic topology of their phylogenetic trees implied that the GPx genes have multiple evolutionary intermediate forms. Conclusion Comparative analysis of invertebrate GPx genes provides informative evidence to support the modular pathways of GPx evolution, which have been accompanied with sporadic expansion/deletion and exon

  8. Purification and kinetic analysis of cytosolic and mitochondrial thioredoxin glutathione reductase extracted from Taenia solium cysticerci.

    PubMed

    Plancarte, Agustin; Nava, Gabriela

    2015-02-01

    Thioredoxin glutathione reductases (TGRs) (EC 1.8.1.9) were purified to homogeneity from the cytosolic (cTsTGR) and mitochondrial (mTsTGR) fractions of Taenia solium, the agent responsible for neurocysticercosis, one of the major central nervous system parasitic diseases in humans. TsTGRs had a relative molecular weight of 132,000, while the corresponding value per subunit obtained under denaturing conditions, was of 62,000. Specific activities for thioredoxin reductase and glutathione reductase substrates for both TGRs explored were in the range or lower than values obtained for other platyhelminths and mammalian TGRs. cTsTGR and mTsTGR also showed hydroperoxide reductase activity using hydroperoxide as substrate. Km(DTNB) and Kcat(DTNB) values for cTsTGR and mTsTGR (88 µM and 1.9 s(-1); 45 µM and 12.6 s(-1), respectively) and Km(GSSG) and Kcat(GSSG) values for cTsTGR and mTsTGR (6.3 µM and 0.96 s(-1); 4 µM and 1.62 s(-1), respectively) were similar to or lower than those reported for mammalian TGRs. Mass spectrometry analysis showed that 12 peptides from cTsTGR and seven from mTsTGR were a match for gi|29825896 thioredoxin glutathione reductase [Echinococcus granulosus], confirming that both enzymes are TGRs. Both T. solium TGRs were inhibited by the gold compound auranofin, a selective inhibitor of thiol-dependent flavoreductases (I₅₀ = 3.25, 2.29 nM for DTNB and GSSG substrates, respectively for cTsTGR; I₅₀ = 5.6, 25.4 nM for mTsTGR toward the same substrates in the described order). Glutathione reductase activity of cTsTGR and mTsTGR exhibited hysteretic behavior with moderate to high concentrations of GSSG; this result was not observed either with thioredoxin, DTNB or NADPH. However, the observed hysteretic kinetics was suppressed with increasing amounts of both parasitic TGRs. These data suggest the existence of an effective substitute which may account for the lack of the detoxification enzymes glutathione reductase

  9. The invasive New Guinea flatworm Platydemus manokwari in France, the first record for Europe: time for action is now.

    PubMed

    Justine, Jean-Lou; Winsor, Leigh; Gey, Delphine; Gros, Pierre; Thévenot, Jessica

    2014-01-01

    Non-indigenous terrestrial flatworms (Platyhelminthes) have been recorded in thirteen European countries. They include Bipalium kewense and Dolichoplana striata that are largely restricted to hothouses and may be regarded as non-invasive species. In addition there are species from the southern hemisphere such as the invasive New Zealand flatworm Arthurdendyus triangulatus in the United Kingdom, Eire and the Faroe Islands, the Australian flatworm Australoplana sanguinea alba in Eire and the United Kingdom, and the Australian Blue Garden flatworm Caenoplana coerulea in France, Menorca and the United Kingdom. The United Kingdom has some twelve or more non-indigenous species most of which are Australian and New Zealand species. These species may move to an invasive stage when optimum environmental and other conditions occur, and the flatworms then have the potential to cause economic or environmental harm. In this paper, we report the identification (from morphology and molecular analysis of COI sequences) of non-indigenous terrestrial flatworms found in a hothouse in Caen (France) as the New Guinea flatworm Platydemus manokwari de Beauchamp, 1963 (Platyhelminthes, Continenticola, Geoplanidae, Rhynchodeminae). Platydemus manokwari is among the "100 World's Worst Invader Alien Species". Lists of World geographic records, prey in the field and prey in laboratories of P. manokwari are provided. This species is considered a threat to native snails wherever it is introduced. The recent discovery of P. manokwari in France represents a significant extension of distribution of this Invasive Alien Species from the Indo-Pacific region to Europe. If it escaped the hothouse, the flatworm might survive winters and become established in temperate countries. The existence of this species in France requires an early warning of this incursion to State and European Union authorities, followed by the eradication of the flatworm in its locality, tightening of internal quarantine measures

  10. The invasive New Guinea flatworm Platydemus manokwari in France, the first record for Europe: time for action is now

    PubMed Central

    Winsor, Leigh; Gey, Delphine; Gros, Pierre; Thévenot, Jessica

    2014-01-01

    Non-indigenous terrestrial flatworms (Platyhelminthes) have been recorded in thirteen European countries. They include Bipalium kewense and Dolichoplana striata that are largely restricted to hothouses and may be regarded as non-invasive species. In addition there are species from the southern hemisphere such as the invasive New Zealand flatworm Arthurdendyus triangulatus in the United Kingdom, Eire and the Faroe Islands, the Australian flatworm Australoplana sanguinea alba in Eire and the United Kingdom, and the Australian Blue Garden flatworm Caenoplana coerulea in France, Menorca and the United Kingdom. The United Kingdom has some twelve or more non-indigenous species most of which are Australian and New Zealand species. These species may move to an invasive stage when optimum environmental and other conditions occur, and the flatworms then have the potential to cause economic or environmental harm. In this paper, we report the identification (from morphology and molecular analysis of COI sequences) of non-indigenous terrestrial flatworms found in a hothouse in Caen (France) as the New Guinea flatworm Platydemus manokwari de Beauchamp, 1963 (Platyhelminthes, Continenticola, Geoplanidae, Rhynchodeminae). Platydemus manokwari is among the “100 World’s Worst Invader Alien Species”. Lists of World geographic records, prey in the field and prey in laboratories of P. manokwari are provided. This species is considered a threat to native snails wherever it is introduced. The recent discovery of P. manokwari in France represents a significant extension of distribution of this Invasive Alien Species from the Indo-Pacific region to Europe. If it escaped the hothouse, the flatworm might survive winters and become established in temperate countries. The existence of this species in France requires an early warning of this incursion to State and European Union authorities, followed by the eradication of the flatworm in its locality, tightening of internal quarantine

  11. ATP-gamma-S shifts the operating point of outer hair cell transduction towards scala tympani.

    PubMed

    Bobbin, Richard P; Salt, Alec N

    2005-07-01

    ATP receptor agonists and antagonists alter cochlear mechanics as measured by changes in distortion product otoacoustic emissions (DPOAE). Some of the effects on DPOAEs are consistent with the hypothesis that ATP affects mechano-electrical transduction and the operating point of the outer hair cells (OHCs). This hypothesis was tested by monitoring the effect of ATP-gamma-S on the operating point of the OHCs. Guinea pigs anesthetized with urethane and with sectioned middle ear muscles were used. The cochlear microphonic (CM) was recorded differentially (scala vestibuli referenced to scala tympani) across the basal turn before and after perfusion (20 min) of the perilymph compartment with artificial perilymph (AP) and ATP-gamma-S dissolved in AP. The operating point was derived from the cochlear microphonics (CM) recorded in response low frequency (200 Hz) tones at high level (106, 112 and 118 dB SPL). The analysis procedure used a Boltzmann function to simulate the CM waveform and the Boltzmann parameters were adjusted to best-fit the calculated waveform to the CM. Compared to the initial perfusion with AP, ATP-gamma-S (333 microM) enhanced peak clipping of the positive peak of the CM (that occurs during organ of Corti displacements towards scala tympani), which was in keeping with ATP-induced displacement of the transducer towards scala tympani. CM waveform analysis quantified the degree of displacement and showed that the changes were consistent with the stimulus being centered on a different region of the transducer curve. The change of operating point meant that the stimulus was applied to a region of the transducer curve where there was greater saturation of the output on excursions towards scala tympani and less saturation towards scala vestibuli. A significant degree of recovery of the operating point was observed after washing with AP. Dose response curves generated by perfusing ATP-gamma-S (333 microM) in a cumulative manner yielded an EC(50) of 19.8 micro

  12. Changes in cochlear responses in guinea pig with changes in perilymphatic K+. Part I: summating potentials, compound action potentials and DPOAEs.

    PubMed

    Marcon, Simon; Patuzzi, Robert

    2008-03-01

    We have measured the effects of changing perilymphatic K+ by perfusing scala tympani in guinea pigs with salt solutions high or low in K+, while monitoring the distortion product otoacoustic emissions (DPOAEs) in the ear canal (a measure of mechanical vibration of the organ of Corti), the summating potential (SP) evoked by high-frequency tone-bursts (taken to be a measure of pre-synaptic electrical activity of the inner hair cells) and the compound action potential (CAP) of the auditory nerve (taken to be a measure of post-synaptic neural activity). We have attempted to investigate the osmotic effects of our perfusates by comparison with simple hyperosmotic sucrose perfusates and iso-osmotic versions of perfusates, and for the effects of changes in other ions (e.g. Na+ and Cl-) by keeping these constant in some perfusates while elevating K+. We have found that changing the K+ concentration over the range 0-30mM elevated the SP and CAP thresholds almost equally in normal animals, and not at all in animals devoid of outer hair cells (OHCs), showing that OHCs are sensitive to the perfusates we have used, but the inner hair cells (IHCs) and the type I afferent dendrites are not, presumably because IHCs are shielded from perilymph by supporting cells, and the membranes of the afferent dendrite membranes exposed directly to our perfusates are dominated by Cl(-) permeability, rather than by K+ permeability. This view is supported by experiments in which the perilymphatic Cl(-) concentration was reduced, producing a large elevation in CAP threshold, but a much smaller elevation of SP threshold, suggesting disruption of action potential initiation. The view that threshold elevations with changes in perilymphatic K+ are due almost solely to a disruption of OHC function and a consequent change in the mechanical sensitivity of the organ of Corti was supported by measurements of amplitude of the 2f1-f2 distortion product otoacoustic emission. During elevations in K+, DPOAEs

  13. Inner ear labyrinth anatomy of monotremes and implications for mammalian inner ear evolution.

    PubMed

    Schultz, Julia A; Zeller, Ulrich; Luo, Zhe-Xi

    2017-02-01

    is characterized by a straight or slightly curved osseous cochlear canal, a lagenar macula, lagenar nerve fibers separated from a larger bundle of cochlear nerve fibers, the presence of an organ of Corti and an intra-otic cochlear ganglion suspended by membranous connective tissue. Among the major Mesozoic clades of crown mammals, cladotherians and gondwanatherians most likely acquired a fully functioning organ of Corti but lost the sensory lagenar macula, like extant therians. However, Mesozoic spalacotherioids, multituberculates and eutriconodonts likely retained the mammaliaform condition. J. Morphol. 278:236-263, 2017. © 2016 Wiley Periodicals,Inc.

  14. Laboratory maintenance of the bacterial endosymbiont, Neorickettsia sp., through the life cycle of a digenean, Plagiorchis elegans.

    PubMed

    Greiman, Stephen E; Tkach, Maksym; Vaughan, Jefferson A; Tkach, Vasyl V

    2015-10-01

    The Digenea (Platyhelminthes: Trematoda) are a diverse and complex group of internal metazoan parasites. These parasites can serve as hosts to obligate intracellular bacteria belonging to the genus Neorickettsia (Family: Anaplasmataceae). Neorickettsiae persist within all stages of the fluke life cycle and thus are maintained through vertical transmission. However, the low prevalence of Neorickettsia in nature limits study of their transmission biology at different steps of digenean life cycles. To resolve this dilemma, we have developed for the first time a laboratory model allowing to maintain Neorickettsia sp. through the whole life cycle of a digenean, Plagiorchis elegans. The laboratory life cycle of P. elegans consists of a snail first intermediate host, Lymnaea stagnalis, an aquatic arthropod second intermediate host, Culex pipiens (mosquito larva), and a vertebrate definitive host, Mesocricetus auratus (Syrian hamster). This paper focuses on the development of the laboratory life cycle, as well as outlines its potential uses in studying the transmission biology of Neorickettsia and its evolutionary relationship within its digenean host.

  15. The complete mitochondrial genome of the onychophoran Epiperipatus biolleyi reveals a unique transfer RNA set and provides further support for the ecdysozoa hypothesis.

    PubMed

    Podsiadlowski, Lars; Braband, Anke; Mayer, Georg

    2008-01-01

    Onychophora (velvet worms) play a crucial role in current discussions on position of arthropods. The ongoing Articulata/Ecdysozoa debate is in need of additional ground pattern characters for Panarthropoda (Arthropoda, Tardigrada, and Onychophora). Hence, Onychophora is an important outgroup taxon in resolving the relationships among arthropods, irrespective of whether morphological or molecular data are used. To date, there has been a noticeable lack of mitochondrial genome data from onychophorans. Here, we present the first complete mitochondrial genome sequence of an onychophoran, Epiperipatus biolleyi (Peripatidae), which shows several characteristic features. Specifically, the gene order is considerably different from that in other arthropods and other bilaterians. In addition, there is a lack of 9 tRNA genes usually present in bilaterian mitochondrial genomes. All these missing tRNAs have anticodon sequences corresponding to 4-fold degenerate codons, whereas the persisting 13 tRNAs all have anticodons pairing with 2-fold degenerate codons. Sequence-based phylogenetic analysis of the mitochondrial protein-coding genes provides a robust support for a clade consisting of Onychophora, Priapulida, and Arthropoda, which confirms the Ecdysozoa hypothesis. However, resolution of the internal ecdysozoan relationships suffers from a cluster of long-branching taxa (including Nematoda and Platyhelminthes) and a lack of data from Tardigrada and further nemathelminth taxa in addition to nematodes and priapulids.

  16. Triploid planarian reproduces truly bisexually with euploid gametes produced through a different meiotic system between sex.

    PubMed

    Chinone, Ayako; Nodono, Hanae; Matsumoto, Midori

    2014-06-01

    Although polyploids are common among plants and some animals, polyploidization often causes reproductive failure. Triploids, in particular, are characterized by the problems of chromosomal pairing and segregation during meiosis, which may cause aneuploid gametes and results in sterility. Thus, they are generally considered to reproduce only asexually. In the case of the Platyhelminthes Dugesia ryukyuensis, populations with triploid karyotypes are normally found in nature as both fissiparous and oviparous triploids. Fissiparous triploids can also be experimentally sexualized if they are fed sexual planarians, developing both gonads and other reproductive organs. Fully sexualized worms begin reproducing by copulation rather than fission. In this study, we examined the genotypes of the offspring obtained by breeding sexualized triploids and found that the offspring inherited genes from both parents, i.e., they reproduced truly bisexually. Furthermore, meiotic chromosome behavior in triploid sexualized planarians differed significantly between male and female germ lines, in that female germ line cells remained triploid until prophase I, whereas male germ line cells appeared to become diploid before entry into meiosis. Oocytes at the late diplotene stage contained not only paired bivalents but also unpaired univalents that were suggested to produce diploid eggs if they remained in subsequent processes. Triploid planarians may therefore form euploid gametes by different meiotic systems in female and male germ lines and thus are be able to reproduce sexually in contrast to many other triploid organisms.

  17. Gastrointestinal Parasites of Ecuadorian Mantled Howler Monkeys (Alouatta palliata aequatorialis) Based on Fecal Analysis.

    PubMed

    Helenbrook, William D; Wade, Susan E; Shields, William M; Stehman, Stephen V; Whipps, Christopher M

    2015-06-01

    An analysis of gastrointestinal parasites of Ecuadorian mantled howler monkeys, Alouatta palliata aequatorialis, was conducted based on examination of fecal smears, flotations, and sedimentations. At least 1 type of parasite was detected in 97% of the 96 fecal samples screened across 19 howler monkey groups using these techniques. Samples averaged 3.6 parasite species per individual (±1.4 SD). Parasites included species representing genera of 2 apicomplexans: Cyclospora sp. (18% of individual samples) and Isospora sp. (3%); 6 other protozoa: Balantidium sp. (9%), Blastocystis sp. (60%), Chilomastix sp. (4%), Dientamoeba sp. (3%), Entamoeba species (56%), Iodamoeba sp. (5%); 4 nematodes: Enterobius sp. (3%), Capillaria sp. (78%), Strongyloides spp. (88%) which included 2 morphotypes, Trypanoxyuris sp. (12%); and the platyhelminth Controrchis sp. (15%). A statistically significant positive correlation was found between group size and each of 3 different estimators of parasite species richness adjusted for sampling effort (ICE: r(2) = 0.24, P = 0.05; Chao2: r(2) = 0.25, P = 0.05, and Jackknife: r(2) = 0.31, P = 0.03). Two significant associations between co-infecting parasites were identified. Based on the prevalence data, individuals infected with Balantidium sp. were more likely to also be infected with Isospora sp. (χ(2) = 6.02, P = 0.01), while individuals harboring Chilomastix sp. were less likely to have Capillaria sp. present (χ(2) = 4.03, P = 0.04).

  18. Gene fishing: the use of a simple protocol to isolate multiple homeodomain classes from diverse invertebrate taxa.

    PubMed

    Lee, Shannon E; Gates, Ruth D; Jacobs, David K

    2003-04-01

    Comparison of relevant gene sequence and functional data is central to understanding the evolution of metazoan development. The conservation of portions of regulatory genes, such as homeoboxes, allows for the design of PCR-based sequence isolation and amplification strategies. Here we describe a simple protocol that uses a degenerate primer pair to isolate a variety of homeobox-containing genes from diverse metazoan taxa. In a nonexhaustive survey, we have isolated 28 gene sequence fragments from 15 taxa, representing eight invertebrate phyla (Mollusca, Echiura, Annelida, Platyhelminth, Acoela, Ctenophora, Cnidaria, and Porifera). Based on BLAST and parsimony analyses, these gene fragments affiliate with several gene groups (PAIRED-like, HOX, and ParaHOX) and several single genes, including pancreas/duodenum homeoboxes (Pdx), empty spiracles (ems/Emx), gastrulation brain homeoboxes (Gbx), hematopoietically expressed homeoboxes (HEX), brain specific homeobox (bsh/BarH1/BarH2), NK-1 (NK-1/s59/slouch), and ladybird (Lbl/Lbe/Lbx). In several cases, these fragments represent the first reported orthologue for the phylum or superphyletic group (i.e., Lophotrochozoa).

  19. Inter-phyla studies on neuropeptides: the potential for broad-spectrum anthelmintic and/or endectocide discovery.

    PubMed

    Mousley, A; Maule, A G; Halton, D W; Marks, N J

    2005-01-01

    Flatworm, nematode and arthropod parasites have proven their ability to develop resistance to currently available chemotherapeutics. The heavy reliance on chemotherapy and the ability of target species to develop resistance has prompted the search for novel drug targets. In view of its importance to parasite/pest survival, the neuromusculature of parasitic helminths and pest arthropod species remains an attractive target for the discovery of novel endectocide targets. Exploitation of the neuropeptidergic system in helminths and arthropods has been hampered by a limited understanding of the functional roles of individual peptides and the structure of endogenous targets, such as receptors. Basic research into these systems has the potential to facilitate target characterization and its offshoots (screen development and drug identification). Of particular interest to parasitologists is the fact that selected neuropeptide families are common to metazoan pest species (nematodes, platyhelminths and arthropods) and fulfil specific roles in the modulation of muscle function in each of the three phyla. This article reviews the inter-phyla activity of two peptide families, the FMRFamide-like peptides and allatostatins, on motor function in helminths and arthropods and discusses the potential of neuropeptide signalling as a target system that could uncover novel endectocidal agents.

  20. HelmCoP: an online resource for helminth functional genomics and drug and vaccine targets prioritization.

    PubMed

    Abubucker, Sahar; Martin, John; Taylor, Christina M; Mitreva, Makedonka

    2011-01-01

    A vast majority of the burden from neglected tropical diseases result from helminth infections (nematodes and platyhelminthes). Parasitic helminthes infect over 2 billion, exerting a high collective burden that rivals high-mortality conditions such as AIDS or malaria, and cause devastation to crops and livestock. The challenges to improve control of parasitic helminth infections are multi-fold and no single category of approaches will meet them all. New information such as helminth genomics, functional genomics and proteomics coupled with innovative bioinformatic approaches provide fundamental molecular information about these parasites, accelerating both basic research as well as development of effective diagnostics, vaccines and new drugs. To facilitate such studies we have developed an online resource, HelmCoP (Helminth Control and Prevention), built by integrating functional, structural and comparative genomic data from plant, animal and human helminthes, to enable researchers to develop strategies for drug, vaccine and pesticide prioritization, while also providing a useful comparative genomics platform. HelmCoP encompasses genomic data from several hosts, including model organisms, along with a comprehensive suite of structural and functional annotations, to assist in comparative analyses and to study host-parasite interactions. The HelmCoP interface, with a sophisticated query engine as a backbone, allows users to search for multi-factorial combinations of properties and serves readily accessible information that will assist in the identification of various genes of interest. HelmCoP is publicly available at: http://www.nematode.net/helmcop.html.

  1. Parasites of the mangrove mussel Mytella guyanensis (Bivalvia: Mytilidae) in Camamu Bay, Bahia, Brazil.

    PubMed

    Ceuta, L O; Boehs, G

    2012-08-01

    This contribution reports the parasites found in the mangrove mussel Mytella guyanensis in Camamu Bay, Bahia, Brazil. Samples were collected monthly from September 2006 through October 2007. A total of 460 individuals were collected, fixed in Davidson's solution, and processed by standard histological techniques, and the sections were stained with Harris hematoxylin and eosin (H&E). The water temperature ranged from 23.5 to 31.6 ºC, and the salinity from 25 to 37‰. Microscopic analysis showed Rickettsia-like organisms (RLOs), Nematopsis sp. (Apicomplexa), and Platyhelminthes, including a turbellarian, sporocysts of Bucephalus sp., metacercariae, and metacestodes of Tylocephalum sp. Parasites were observed mainly in the gills, mantle, and digestive gland. The prevalence of Nematopsis sp. was 100%, and in heavily infected mussels the tissues of the labial palps were damaged. RLOs occurred in high prevalence and intensity of infection in some periods. The digenean sporocysts showed moderate prevalence but high intensity of infection, and caused parasitic castration. In general, there was no significant spatial or temporal variation (p > 0.05) of the parasites, which is probably attributable to the small variations of temperature and salinity in the region.

  2. Parasitic incidence in a cyprinid fish Labeo rohita (Ham.) at river Song in Doon valley (Uttarakhand).

    PubMed

    Upadhyay, Jayti; Jauhari, R K; Pemola Devi, N

    2012-04-01

    On examining 144 specimens of Labeo rohita (Ham.) for parasites occurrence; as many as 34 fish were found positive to harbour ciliophorans (Trichodina sp. and Ichthyophthirius multifilis Fouquet, 1876), monogeneans (Haplocleidus vachi Tripathi, 1959 and Dactylogyrus glossogobii Jain, 1960), trematode (Allocreadium mahaseri Pandey, 1939), nematode (Camallanus (Zeylanema) anabantis Pearse, 1933) and acanthocephalan (Sachalinorhynchus sp). Highest prevalence was shown by platyhelminthes (18.75%) followed by ciliophorans (10.41%), nematode (4.16%) and acanthocephalan (2.77%) in succession. Maximum mean intensity and abundance has been shown by C. (Zeylanema) anabantis Pearse, 1933 while the monogenean H. vachi was on the 2nd rank. On the other hand, the least intensity and abundance was shown by Ichthyophthirius multifilis. The prevalence was recorded more in monsoon (52.77%) followed by post-monsoon (22.22%), summer (19.44%) and winter (8.33%) in succession. Further, the unit-wise intensity of parasites was recorded more in males than the females.

  3. Characterization of Schistosome Tegumental Alkaline Phosphatase (SmAP)

    PubMed Central

    Bhardwaj, Rita; Skelly, Patrick J.

    2011-01-01

    Schistosomes are parasitic platyhelminths that currently infect over 200 million people globally. The parasites can live for years in a putatively hostile environment - the blood of vertebrates. We have hypothesized that the unusual schistosome tegument (outer-covering) plays a role in protecting parasites in the blood; by impeding host immunological signaling pathways we suggest that tegumental molecules help create an immunologically privileged environment for schistosomes. In this work, we clone and characterize a schistosome alkaline phosphatase (SmAP), a predicted ∼60 kDa glycoprotein that has high sequence conservation with members of the alkaline phosphatase protein family. The SmAP gene is most highly expressed in intravascular parasite life stages. Using immunofluorescence and immuno-electron microscopy, we confirm that SmAP is expressed at the host/parasite interface and in internal tissues. The ability of living parasites to cleave exogenous adenosine monophosphate (AMP) and generate adenosine is very largely abolished when SmAP gene expression is suppressed following RNAi treatment targeting the gene. These results lend support to the hypothesis that schistosome surface enzymes such as SmAP could dampen host immune responses against the parasites by generating immunosuppressants such as adenosine to promote their survival. This notion does not rule out other potential functions for the adenosine generated e.g. in parasite nutrition. PMID:21483710

  4. A comprehensive analysis of bilaterian mitochondrial genomes and phylogeny.

    PubMed

    Bernt, Matthias; Bleidorn, Christoph; Braband, Anke; Dambach, Johannes; Donath, Alexander; Fritzsch, Guido; Golombek, Anja; Hadrys, Heike; Jühling, Frank; Meusemann, Karen; Middendorf, Martin; Misof, Bernhard; Perseke, Marleen; Podsiadlowski, Lars; von Reumont, Björn; Schierwater, Bernd; Schlegel, Martin; Schrödl, Michael; Simon, Sabrina; Stadler, Peter F; Stöger, Isabella; Struck, Torsten H

    2013-11-01

    About 2800 mitochondrial genomes of Metazoa are present in NCBI RefSeq today, two thirds belonging to vertebrates. Metazoan phylogeny was recently challenged by large scale EST approaches (phylogenomics), stabilizing classical nodes while simultaneously supporting new sister group hypotheses. The use of mitochondrial data in deep phylogeny analyses was often criticized because of high substitution rates on nucleotides, large differences in amino acid substitution rate between taxa, and biases in nucleotide frequencies. Nevertheless, mitochondrial genome data might still be promising as it allows for a larger taxon sampling, while presenting a smaller amount of sequence information. We present the most comprehensive analysis of bilaterian relationships based on mitochondrial genome data. The analyzed data set comprises more than 650 mitochondrial genomes that have been chosen to represent a profound sample of the phylogenetic as well as sequence diversity. The results are based on high quality amino acid alignments obtained from a complete reannotation of the mitogenomic sequences from NCBI RefSeq database. However, the results failed to give support for many otherwise undisputed high-ranking taxa, like Mollusca, Hexapoda, Arthropoda, and suffer from extreme long branches of Nematoda, Platyhelminthes, and some other taxa. In order to identify the sources of misleading phylogenetic signals, we discuss several problems associated with mitochondrial genome data sets, e.g. the nucleotide and amino acid landscapes and a strong correlation of gene rearrangements with long branches.

  5. Reconstruction of cyclooxygenase evolution in animals suggests variable, lineage-specific duplications, and homologs with low sequence identity.

    PubMed

    Havird, Justin C; Kocot, Kevin M; Brannock, Pamela M; Cannon, Johanna T; Waits, Damien S; Weese, David A; Santos, Scott R; Halanych, Kenneth M

    2015-04-01

    Cyclooxygenase (COX) enzymatically converts arachidonic acid into prostaglandin G/H in animals and has importance during pregnancy, digestion, and other physiological functions in mammals. COX genes have mainly been described from vertebrates, where gene duplications are common, but few studies have examined COX in invertebrates. Given the increasing ease in generating genomic data, as well as recent, although incomplete descriptions of potential COX sequences in Mollusca, Crustacea, and Insecta, assessing COX evolution across Metazoa is now possible. Here, we recover 40 putative COX orthologs by searching publicly available genomic resources as well as ~250 novel invertebrate transcriptomic datasets. Results suggest the common ancestor of Cnidaria and Bilateria possessed a COX homolog similar to those of vertebrates, although such homologs were not found in poriferan and ctenophore genomes. COX was found in most crustaceans and the majority of molluscs examined, but only specific taxa/lineages within Cnidaria and Annelida. For example, all octocorallians appear to have COX, while no COX homologs were found in hexacorallian datasets. Most species examined had a single homolog, although species-specific COX duplications were found in members of Annelida, Mollusca, and Cnidaria. Additionally, COX genes were not found in Hemichordata, Echinodermata, or Platyhelminthes, and the few previously described COX genes in Insecta lacked appreciable sequence homology (although structural analyses suggest these may still be functional COX enzymes). This analysis provides a benchmark for identifying COX homologs in future genomic and transcriptomic datasets, and identifies lineages for future studies of COX.

  6. [Soil microfauna diversity among Cunninghamia lanceolata plantations based on pyrosequencing].

    PubMed

    Wang, Sheng-Jie; Liu, Jun-Ang; He, Yuan-Hao; Zhou, Guo-Ying; Tan, Yi-Min; Zhou, Jie-Chen

    2014-06-01

    In order to study the function of soil microfauna and its responses to environmental changes, we used metagenome analyses of the 18S rDNA gene region to identify differences in microfauna diversity and community structure among fifteen soil samples belonging to five different Cunninghamia lanceolate plantations. The plantations were located in Youxian County, Hunan Province in central China. The trees in these plantations were of different ages (3, 13, and 26 years) and belonged to different ecological successions (first, second, and third successions). The total dataset comprised 94922 high quality sequences with an average length of 436 bp. The dominant taxonomic groups across all samples were Chordata, Annelida, Arthropoda, Nematoda, Rotifera and Platyhelminthes with each accounting for 60.8%, 24.0%, 7.4%, 3.6%, 1.5% and 1.2% of the sequences, respectively. There were significant differences in ACE index and Shannon index among the five plantations. The lowest diversity of soil microfauna was in the 13-year old plantation of the first ecological succession. The correlation analysis showed that both ACE and available potassium concentration were negatively correlated to the Chaol index. However, there were no significant correlations between the Shannon, Simpson indices and the physical-chemical properties of soil. Overall, the Jaccard's similarity coefficient was less than 0.4 among samples at each site, and significant differences were found among plantations.

  7. Fasciola gigantica thioredoxin glutathione reductase: Biochemical properties and structural modeling.

    PubMed

    Gupta, Ankita; Kesherwani, Manish; Velmurugan, Devadasan; Tripathi, Timir

    2016-08-01

    Platyhelminth thioredoxin glutathione reductase (TGR) is a multifunctional enzyme that crosstalk between the conventional thioredoxin (Trx) and glutathione (GSH) system. It has been validated as a potential drug target in blood flukes. In the present study, we have performed a biochemical study on Fasciola gigantica TGR with substrates DTNB and GSSG. The Michaelis constant (Km) with DTNB was found to be 4.34±0.12μM while it was 61.15±1.50μM with GSSG. The kinetic results were compared with the TGR activities of other helminths. FgTGR showed typical hysteretic behavior with GSSG as other TGRs. We also described a homology-based structure of FgTGR. The cofactors (NADPH and FAD) and substrates (GSSG and DTNB) were docked, and two possible binding sites for substrates were identified in a single chain. The substrates were found to bind more favorably in the second site of TrxR domains. We also presented the first report on binding interaction of DTNB with a TGR. DTNB forms H-bond with His204 and Arg450 of chain A, Sec597, and Gly598 from chain B, salt-bridge with Lys124, and numerous other hydrophobic interactions. Helminth TGR represents an important enzyme in the redox and antioxidant system; hence, its inhibition can be used as an effective strategy against liver flukes.

  8. Ectocommensal and ectoparasites in goldfish Carassius auratus (Linnaeus, 1758) in farmed in the State of São Paulo.

    PubMed

    Moyses, Carla Renata Serantoni; Spadacci-Morena, Diva Denelle; Xavier, José Guilherme; Antonucci, Antonio Mataresio; Lallo, Maria Anete

    2015-01-01

    Concomitant infections by several parasitic genera are rare, very debilitating and often lethal to fish reared under commercial breeding conditions. Were describe a multiple and concurrent parasite infestation in cultured goldfish Carassius auratus with skin damage (nodules and/or ulceration). Fish with skin lesions underwent necropsy, and the skin and gills were scraped and examined. Histopathological examination with Hematoxylin-Eosin and Giemsa stain, and an ultrastructure study using transmission and scanning electron microscopy were conducted. In the skin, we identified multiple-parasite infestations by Gyrodactylidae, Epistylis sp., Trichodina sp., Ichthyophthirius multifiliis, Tetrahymena sp. and Ichthyobodo necator,associated with epithelial cell hyperplasia and epidermal sloughing. Although no gross lesions were observed, were identified a large number of parasites in the gills (Epistylis sp., Piscinoodinium sp., Ichthyophthirius multifiliis, Trichodina sp., Apiosoma sp., Hexamitasp. and cysts of a trematode digenean). The observed trematodes were not identified. The associated microscopic lesions were epithelial hypertrophic and hyperplasic and exhibited fusion of secondary lamellae and epithelial cell detachment. This is the first description of a protozoan Vorticella sp. parasitizing goldfish in Brazil. Multiple ectoparasitism by protozoa and Platyhelminthes, with or without apparent tissue damage, can be fatal for goldfish raised on farms with poor management.

  9. Modelling a 3D structure for EgDf1 from shape Echinococcus granulosus: putative epitopes, phosphorylation motifs and ligand

    NASA Astrophysics Data System (ADS)

    Paulino, M.; Esteves, A.; Vega, M.; Tabares, G.; Ehrlich, R.; Tapia, O.

    1998-07-01

    EgDf1 is a developmentally regulated protein from the parasite Echinococcus granulosus related to a family of hydrophobic ligand binding proteins. This protein could play a crucial role during the parasite life cycle development since this organism is unable to synthetize most of their own lipids de novo. Furthermore, it has been shown that two related protein from other parasitic platyhelminths (Fh15 from Fasciola hepatica and Sm14 from Schistosoma mansoni) are able to confer protective inmunity against experimental infection in animal models. A three-dimensional structure would help establishing structure/function relationships on a knowledge based manner. 3D structures for EgDf1 protein were modelled by using myelin P2 (mP2) and intestine fatty acid binding protein (I-FABP) as templates. Molecular dynamics techniques were used to validate the models. Template mP2 yielded the best 3D structure for EgDf1. Palmitic and oleic acids were docked inside EgDf1. The present theoretical results suggest definite location in the secondary structure of the epitopic regions, consensus phosphorylation motifs and oleic acid as a good ligand candidate to EgDf1. This protein might well be involved in the process of supplying hydrophobic metabolites for membrane biosynthesis and for signaling pathways.

  10. Isolation and characterization of species-specific DNA probes from Taenia solium and Taenia saginata and their use in an egg detection assay.

    PubMed

    Chapman, A; Vallejo, V; Mossie, K G; Ortiz, D; Agabian, N; Flisser, A

    1995-05-01

    Cysticercosis results from ingestion of the eggs of the tapeworm Taenia solium. Reduction of the incidence of human and swine cysticercosis requires identification and treatment of individuals who carry the adult tapeworm. T. solium and Taenia saginata eggs cannot be differentiated on the basis of morphology; thus, in order to improve existing methods for the diagnosis of taeniasis, we have developed highly sensitive, species-specific DNA probes which differentiate T. solium and T. saginata. Recombinant clones containing repetitive DNA sequences which hybridize specifically with genomic DNAs from either species were isolated and characterized. T. solium-specific DNA sequences contained complete and truncated forms of a tandemly repeated 158-bp DNA sequence. An unrelated T. saginata DNA sequence was also characterized and shown to encode a portion of the mitochondrial cytochrome c oxidase I gene. T. solium- and T. saginata-specific DNA probes did not hybridize in dot blot assays either with genomic DNA from the platyhelminths Taenia hydatigena, Taenia pisiformis, Taenia taeniaeformis, Echinococcus granulosus, and Schistosoma mansoni or with genomic DNA from other eukaryotes, including Saccharomyces cerevisiae, Candida albicans, Cryptosporidium parvum, Entamoeba histolytica, Trypanosoma gambiense, Trypanosoma brucei, and Giardia lamblia, Caenorhabditis elegans, and human DNA. By using these T. solium and T. saginata DNA probes, a rapid, highly sensitive and specific dot blot assay for the detection of T. solium eggs was developed.

  11. Ultrastructural study of the spermatozoon of Taenia taeniaeformis (Batsch, 1786) (Cestoda, Cyclophyllidea, Taeniidae), an intestinal parasite of Felis catus from La Palma (Canary Islands, Spain).

    PubMed

    Miquel, Jordi; Foronda, Pilar; Torres, Jordi; Swiderski, Zdzisław; Feliu, Carlos

    2009-06-01

    The ultrastructural characters of the mature spermatozoon of Taenia taeniaeformis are described by means of transmission electron microscopy. Materials were obtained from a naturally infected road-killed cat (Felis catus) from La Palma (Canary Islands, Spain). The mature spermatozoon of T. taeniaeformis is a filiform cell, which is tapered at both extremities and lacks mitochondria. It is characterised by the presence of (1) a single spirallised crested body about 140 nm thick, (2) a single axoneme of the 9+'1' pattern of trepaxonematan Platyhelminthes, (3) a twisted (40 degrees ) layer of submembranous cortical microtubules, (4) a periaxonemal sheath surrounding the axoneme, (5) transverse intracytoplasmic walls and (6) a spirallised nucleus encircling the axoneme. The mature spermatozoon of T. taeniaeformis is also characterised by the presence of an apical cone in its anterior extremity and by the disorganisation of the axoneme in its posterior extremity. The ultrastructural characters of the mature spermatozoon of T. taeniaeformis are compared with those of other cestodes studied to date, with particular emphasis on other representatives of the family Taeniidae.

  12. Embryonic development of the nervous system in the planarian Schmidtea polychroa.

    PubMed

    Monjo, Francisco; Romero, Rafael

    2015-01-15

    The development of a nervous system is a key innovation in the evolution of metazoans, which is illustrated by the presence of a common developmental toolkit for the formation of this organ system. Neurogenesis in the Spiralia, in particular the Platyhelminthes, is, however, poorly understood when compared with other animal groups. Here, we characterize embryonic neurogenesis in the freshwater flatworm Schmidtea polychroa and analyze the expression of soxB and a set of proneural bHLH genes, which are gene families with a well-established role in metazoan early neural development. We show that the nervous system is fully de novo assembled after the early embryo ingests the maternal nutrients. At early stages of neurogenesis, soxB1 genes are expressed in putative neural progenitor cells, whereas soxB2 and neural bHLH genes (achaete-scute, neuroD and beta3) are associated with late neurogenesis and the specification of neural subpopulations of the central and peripheral nervous system. Our findings are consistent with the role of proneural genes in other bilaterians, suggesting that the ancestral neural-specific gene regulatory network is conserved in triclads, despite exhibiting a divergent mode of development.

  13. Reinvestigation of the ultrastructure of spermiogenesis and the spermatozoon of Hymenolepis nana (Cestoda, Cyclophyllidea), parasite of the small intestine of Rattus rattus.

    PubMed

    Bâ, C T; Marchand, B

    1992-09-01

    Spermiogenesis in Hymenolepsis nana begins with the formation of a differentiation zone. This is limited at the front by arched membranes, is surrounded by cortical microtubules associated with 12 crested-like bodies, and contains a single centriole made up of doublets. The distal centriole gives rise to a flagellum that grows at the same pace as the cortical microtubules. Migration of the nucleus takes place after the formation of the flagellum. It is followed by the separation of the old spermatid from the residual cytoplasm. The mature H. nana spermatozoon is filiform and lacks mitochondria. The axoneme, of the 9 + "1" pattern of the Platyhelminthes, does not reach the extremities of the spermatozoon. The nucleus is electron dense and is in close contact with the axoneme around which it coils in a spiral making an angle of 10 degrees to 15 degrees with the spermatozoon axis. The cortical microtubules follow a 10 degrees to 15 degrees helicoidal path along almost their whole length, except at their posterior extremity, where they are parallel to the spermatozoon axis. H. nana is distinguished by the early development of 12 crested-like bodies of different lengths and by the existence of a single centriole in the differentiation zone. Such a high number of crested-like bodies had never previously been reported in a cestode.

  14. Trace Fossil Evidence of Trematode-Bivalve Parasite-Host Interactions in Deep Time.

    PubMed

    Huntley, John Warren; De Baets, Kenneth

    2015-01-01

    Parasitism is one of the most pervasive phenomena amongst modern eukaryotic life and yet, relative to other biotic interactions, almost nothing is known about its history in deep time. Digenean trematodes (Platyhelminthes) are complex life cycle parasites, which have practically no body fossil record, but induce the growth of characteristic malformations in the shells of their bivalve hosts. These malformations are readily preserved in the fossil record, but, until recently, have largely been overlooked by students of the fossil record. In this review, we present the various malformations induced by trematodes in bivalves, evaluate their distribution through deep time in the phylogenetic and ecological contexts of their bivalve hosts and explore how various taphonomic processes have likely biased our understanding of trematodes in deep time. Trematodes are known to negatively affect their bivalve hosts in a number of ways including castration, modifying growth rates, causing immobilization and, in some cases, altering host behaviour making the host more susceptible to their own predators. Digeneans are expected to be significant agents of natural selection. To that end, we discuss how bivalves may have adapted to their parasites via heterochrony and suggest a practical methodology for testing such hypotheses in deep time.

  15. Polyethyleneimine (PEI) Mediated siRNA Gene Silencing in the Schistosoma mansoni Snail Host, Biomphalaria glabrata

    PubMed Central

    Knight, Matty; Miller, Andre; Liu, Yijia; Scaria, Puthupparampil; Woodle, Martin; Ittiprasert, Wannaporn

    2011-01-01

    An in vivo, non-invasive technique for gene silencing by RNA interference (RNAi) in the snail, Biomphalaria glabrata, has been developed using cationic polymer polyethyleneimine (PEI) mediated delivery of long double-stranded (ds) and small interfering (si) RNA. Cellular delivery was evaluated and optimized by using a ‘mock’ fluorescent siRNA. Subsequently, we used the method to suppress expression of Cathepsin B (CathB) with either the corresponding siRNA or dsRNA of this transcript. In addition, the knockdown of peroxiredoxin (Prx) at both RNA and protein levels was achieved with the PEI-mediated soaking method. B. glabrata is an important snail host for the transmission of the parasitic digenean platyhelminth, Schistosoma mansoni that causes schistosomiasis in the neotropics. Progress is being made to realize the genome sequence of the snail and to uncover gene expression profiles and cellular pathways that enable the snail to either prevent or sustain an infection. Using PEI complexes, a convenient soaking method has been developed, enabling functional gene knockdown studies with either dsRNA or siRNA. The protocol developed offers a first whole organism method for host-parasite gene function studies needed to identify key mechanisms required for parasite development in the snail host, which ultimately are needed as points for disrupting this parasite mediated disease. PMID:21765961

  16. Phylogeny and mitochondrial gene order variation in Lophotrochozoa in the light of new mitogenomic data from Nemertea

    PubMed Central

    Podsiadlowski, Lars; Braband, Anke; Struck, Torsten H; von Döhren, Jörn; Bartolomaeus, Thomas

    2009-01-01

    Background The new animal phylogeny established several taxa which were not identified by morphological analyses, most prominently the Ecdysozoa (arthropods, roundworms, priapulids and others) and Lophotrochozoa (molluscs, annelids, brachiopods and others). Lophotrochozoan interrelationships are under discussion, e.g. regarding the position of Nemertea (ribbon worms), which were discussed to be sister group to e.g. Mollusca, Brachiozoa or Platyhelminthes. Mitochondrial genomes contributed well with sequence data and gene order characters to the deep metazoan phylogeny debate. Results In this study we present the first complete mitochondrial genome record for a member of the Nemertea, Lineus viridis. Except two trnP and trnT, all genes are located on the same strand. While gene order is most similar to that of the brachiopod Terebratulina retusa, sequence based analyses of mitochondrial genes place nemerteans close to molluscs, phoronids and entoprocts without clear preference for one of these taxa as sister group. Conclusion Almost all recent analyses with large datasets show good support for a taxon comprising Annelida, Mollusca, Brachiopoda, Phoronida and Nemertea. But the relationships among these taxa vary between different studies. The analysis of gene order differences gives evidence for a multiple independent occurrence of a large inversion in the mitochondrial genome of Lophotrochozoa and a re-inversion of the same part in gastropods. We hypothesize that some regions of the genome have a higher chance for intramolecular recombination than others and gene order data have to be analysed carefully to detect convergent rearrangement events. PMID:19660126

  17. The Global Invertebrate Genomics Alliance (GIGA): developing community resources to study diverse invertebrate genomes.

    PubMed

    Bracken-Grissom, Heather; Collins, Allen G; Collins, Timothy; Crandall, Keith; Distel, Daniel; Dunn, Casey; Giribet, Gonzalo; Haddock, Steven; Knowlton, Nancy; Martindale, Mark; Medina, Mónica; Messing, Charles; O'Brien, Stephen J; Paulay, Gustav; Putnam, Nicolas; Ravasi, Timothy; Rouse, Greg W; Ryan, Joseph F; Schulze, Anja; Wörheide, Gert; Adamska, Maja; Bailly, Xavier; Breinholt, Jesse; Browne, William E; Diaz, M Christina; Evans, Nathaniel; Flot, Jean-François; Fogarty, Nicole; Johnston, Matthew; Kamel, Bishoy; Kawahara, Akito Y; Laberge, Tammy; Lavrov, Dennis; Michonneau, François; Moroz, Leonid L; Oakley, Todd; Osborne, Karen; Pomponi, Shirley A; Rhodes, Adelaide; Santos, Scott R; Satoh, Nori; Thacker, Robert W; Van de Peer, Yves; Voolstra, Christian R; Welch, David Mark; Winston, Judith; Zhou, Xin

    2014-01-01

    Over 95% of all metazoan (animal) species comprise the "invertebrates," but very few genomes from these organisms have been sequenced. We have, therefore, formed a "Global Invertebrate Genomics Alliance" (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site (http://giga.nova.edu) has been launched to facilitate this collaborative venture.

  18. WormBase 2016: expanding to enable helminth genomic research

    PubMed Central

    Howe, Kevin L.; Bolt, Bruce J.; Cain, Scott; Chan, Juancarlos; Chen, Wen J.; Davis, Paul; Done, James; Down, Thomas; Gao, Sibyl; Grove, Christian; Harris, Todd W.; Kishore, Ranjana; Lee, Raymond; Lomax, Jane; Li, Yuling; Muller, Hans-Michael; Nakamura, Cecilia; Nuin, Paulo; Paulini, Michael; Raciti, Daniela; Schindelman, Gary; Stanley, Eleanor; Tuli, Mary Ann; Van Auken, Kimberly; Wang, Daniel; Wang, Xiaodong; Williams, Gary; Wright, Adam; Yook, Karen; Berriman, Matthew; Kersey, Paul; Schedl, Tim; Stein, Lincoln; Sternberg, Paul W.

    2016-01-01

    WormBase (www.wormbase.org) is a central repository for research data on the biology, genetics and genomics of Caenorhabditis elegans and other nematodes. The project has evolved from its original remit to collect and integrate all data for a single species, and now extends to numerous nematodes, ranging from evolutionary comparators of C. elegans to parasitic species that threaten plant, animal and human health. Research activity using C. elegans as a model system is as vibrant as ever, and we have created new tools for community curation in response to the ever-increasing volume and complexity of data. To better allow users to navigate their way through these data, we have made a number of improvements to our main website, including new tools for browsing genomic features and ontology annotations. Finally, we have developed a new portal for parasitic worm genomes. WormBase ParaSite (parasite.wormbase.org) contains all publicly available nematode and platyhelminth annotated genome sequences, and is designed specifically to support helminth genomic research. PMID:26578572

  19. Kicking in the Guts: Schistosoma mansoni Digestive Tract Proteins are Potential Candidates for Vaccine Development

    PubMed Central

    Figueiredo, Barbara Castro-Pimentel; Ricci, Natasha Delaqua; de Assis, Natan Raimundo Gonçalves; de Morais, Suellen Batistoni; Fonseca, Cristina Toscano; Oliveira, Sergio Costa

    2015-01-01

    Schistosomiasis is a debilitating disease that represents a major health problem in at least 74 tropical and subtropical countries. Current disease control strategies consist mainly of chemotherapy, which cannot prevent recurrent re-infection of people living in endemic area. In the last decades, many researchers made a remarkable effort in the search for an effective vaccine to provide long-term protection. Parasitic platyhelminthes of Schistosoma genus, which cause the disease, live in the blood vessels of definitive hosts where they are bathed in host blood for many years. Among the most promising molecules as vaccine candidates are the proteins present in the host–parasite interface, so numerous tegument antigens have been assessed and the achieved protection never got even close to 100%. Besides the tegument, the digestive tract is the other major site of host–parasite interface. Since parasites feed on blood, they need to swallow a considerable amount of blood for nutrient acquisition. Host blood ingested by schistosomes passes through the esophagus and reaches the gut where many peptidases catalyze the proteolysis of blood cells. Recent studies show the emergence of antigens related to the parasite blood feeding, such as esophageal gland proteins, proteases, and other proteins related to nutrient uptake. Herein, we review what is known about Schistosoma mansoni digestive tract proteins, emphasizing the ones described as potential vaccine candidates. PMID:25674091

  20. Diagnostic PCR can be used to illuminate meiofaunal diets and trophic relationships.

    PubMed

    Maghsoud, Hanna; Weiss, Austin; Smith, Julian P S; Litvaitis, Marian K; Fegley, Stephen R

    2014-06-01

    Analysis of the meiofaunal food web is hampered because few prey have features that persist long enough in a predator's digestive tract to allow identification to species. Hence, at least for platyhelminth predators, direct observations of prey preference are almost nonexistent, and where they occur, prey identification is often limited to phylum. Studies using an in vitro approach are rare because they are extremely time-consuming and are subject to the criticism that predators removed from their natural environment may exhibit altered behaviors. Although PCR-based approaches have achieved wide application in food-web analysis, their application to meiofaunal flatworms suffers from a number of limitations. Most importantly, the microscopic size of both the predator and prey does not allow for removal of prey material from the digestive tract of the predator, and thus the challenge is to amplify prey sequences in the presence of large quantities of predator sequence. Here, we report on the successful use of prey-taxon-specific primers in diagnostic PCR to identify, to species level, specific prey items of 13 species of meiofaunal flatworms. Extension of this method will allow, for the first time, the development of a species-level understanding of trophic interactions among the meiofauna.