Sample records for planarians platyhelminthes tricladida

  1. Colonization and extinction of land planarians (Platyhelminthes, Tricladida) in a Brazilian Atlantic Forest regrowth remnant

    Microsoft Academic Search

    Fernando Carbayo; Júlio Pedroni; Eudóxia Maria Froehlich

    2008-01-01

    Long-term assessments of species assemblages are valuable tools for detecting species ecological preferences and their dispersal\\u000a tracks, as well as for assessing the possible effects of alien species on native communities. Here we report a 50-year-long\\u000a study on population dynamics of the four species of land flatworms (Platyhelminthes, Tricladida, Terricola) that have colonized\\u000a or become extinct in a 70-year-old Atlantic

  2. Integrative taxonomy of a new species of planarian from the Lake Ohrid basin, including an analysis of biogeographical patterns in freshwater triclads from the Ohrid region (Platyhelminthes, Tricladida, Dugesiidae)

    PubMed Central

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

    2013-01-01

    Abstract A new species of the genus Dugesia is described from the Lake Ohrid region in the western part of the Balkan Peninsula, forming the first fully documented species description for this genus in the Ohrid area. The morphological species delimitation is supported by complementary molecular, karyological, and cytogenetic data available from the literature. Therefore, species delineation is based on a truly integrative approach. Further, a short account on the degree of freshwater planarian endemicity in the Ohrid region is provided. PMID:23840163

  3. 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

  4. 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

  5. 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. PMID:23721474

  6. Comparative transcriptome analysis between planarian Dugesia japonica and other platyhelminth species

    PubMed Central

    2012-01-01

    Background Planarians are considered to be among the extant animals close to one of the earliest groups of organisms that acquired a central nervous system (CNS) during evolution. Planarians have a bilobed brain with nine lateral branches from which a variety of external signals are projected into different portions of the main lobes. Various interneurons process different signals to regulate behavior and learning/memory. Furthermore, planarians have robust regenerative ability and are attracting attention as a new model organism for the study of regeneration. Here we conducted large-scale EST analysis of the head region of the planarian Dugesia japonica to construct a database of the head-region transcriptome, and then performed comparative analyses among related species. Results A total of 54,752 high-quality EST reads were obtained from a head library of the planarian Dugesia japonica, and 13,167 unigene sequences were produced by de novo assembly. A new method devised here revealed that proteins related to metabolism and defense mechanisms have high flexibility of amino-acid substitutions within the planarian family. Eight-two CNS-development genes were found in the planarian (cf. C. elegans 3; chicken 129). Comparative analysis revealed that 91% of the planarian CNS-development genes could be mapped onto the schistosome genome, but one-third of these shared genes were not expressed in the schistosome. Conclusions We constructed a database that is a useful resource for comparative planarian transcriptome studies. Analysis comparing homologous genes between two planarian species showed that the potential of genes is important for accumulation of amino-acid substitutions. The presence of many CNS-development genes in our database supports the notion that the planarian has a fundamental brain with regard to evolution and development at not only the morphological/functional, but also the genomic, level. In addition, our results indicate that the planarian CNS-development genes already existed before the divergence of planarians and schistosomes from their common ancestor. PMID:22747887

  7. [Interspecific variability of telomeric DNA length in some Siberian and endemic Ba?kal planarians (Plathelminthes, Tricladida)].

    PubMed

    Koroleva, A G; Kiril'chik, S V; Timoshkin, O A

    2010-09-01

    The length of the telomeric DNA in nine species of planarians inhabiting Lake Baikal and one Siberian species from Baikal rivers was determined using Southern hybridization. According to preliminary estimations, it varied in the range of 25-30 kb (Rimacephalus arecepta, Rimacephalus pulvinar, Sorocelis hepatizon, Sorocelis nigrofasciata, Protocotylus sp., Baikalobia guttata, Bdellocephala baikalensis, Phagocata sibirica) and 50 kb (Baikaloplana valida, Baikalobia copulatrix). It is the first estimation of the values of telomeric region lengths for Baikal free-living flat worms. PMID:21061625

  8. 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

  9. [Regeneration of planarians: experimental object].

    PubMed

    She?man, I M; Kreshchenko, I D

    2015-01-01

    We discuss the expediency of using invertebrates, such as flatworms and planarians, as experimental objects. Free-living planarian flatworms (phylum Platyhelminthes, class Turbellaria) are invertebrate animals in which a bilateral symmetry appears for the first time in evolution and organs and tissues form. As the highest ecological link of the food chain--predators--these animals are characterized by a set of behavioral reactions controlled by a differentiated central nervous system. Planarians have unsurpassed ability to regenerate lost or damaged body parts. Owing to the ease of their breeding and their convenience for manipulations, these animals are used to study the influence of chemical and physical factors on the processes of life, growth, and reproduction. Currently, planarians are recognized as a model for biological research in the field of regeneration, stem cell biology, study of their proliferation and differentiation, as well as the regulatory mechanisms of morphogenetic processes. The genome of the planarian Schmidtea mediterranea was fully sequenced, which opened up the opportunity to work with this object at the molecular biological level. Furthermore, planarians are used in neurobiological and toxicological studies, in studying the evolutionary aspects of centralization of the nervous system, mechanisms of muscle contraction, and in the development of new antiparasitic drugs. This review aims to demonstrate the relevance and diversity of research conducted on simple biological objects--planarians--to awider audience to show the historical continuity of these studies and their wide geographical distribution and to focus on the studies carried out in Russia, which, as a rule, are not included in the foreign reviews on planarian regeneration. PMID:25898529

  10. Autophagy and apoptosis in planarians

    Microsoft Academic Search

    Cristina Gonzalez-EstevezEmili; Emili Saló

    2010-01-01

    Adult planarians are capable of undergoing regeneration and body remodelling in order to adapt to physical damage or extreme\\u000a environmental conditions. Moreover, most planarians can tolerate long periods of starvation and during this time, they shrink\\u000a from an adult size to, and sometimes beyond, the initial size at hatching. Indeed, these properties have made them a classic\\u000a model to study

  11. A quantitative metabolomics peek into planarian regeneration.

    PubMed

    Natarajan, Nivedita; Ramakrishnan, Padma; Lakshmanan, Vairavan; Palakodeti, Dasaradhi; Rangiah, Kannan

    2015-05-21

    The fresh water planarian species Schmidtea mediterranea is an emerging stem cell model because of its capability to regenerate a whole animal from a small piece of tissue. It is one of the best model systems to address the basic mechanisms essential for regeneration. Here, we are interested in studying the roles of various amines, thiols and nucleotides in planarian regeneration, stem cell function and growth. We developed mass spectrometry based quantitative methods and validated the differential enrichment of 35 amines, 7 thiol metabolites and 4 nucleotides from both intact and regenerating planarians. Among the amines, alanine in sexual and asparagine in asexual are the highest (>1000 ng/mg) in the intact planarians. The levels of thiols such as cysteine and GSH are 651 and 1107 ng mg(-1) in planarians. Among the nucleotides, the level of cGMP is the lowest (0.03 ng mg(-1)) and the level of AMP is the highest (187 ng mg(-1)) in both of the planarian strains. We also noticed increasing levels of amines in both anterior and posterior regenerating planarians. The blastema from day 3 regenerating planarians also showed higher amounts of many amines. Interestingly, the thiol (cysteine and GSH) levels are well maintained during planarian regeneration. This suggests an inherent and effective mechanism to control induced oxidative stress because of the robust regeneration and stem cell proliferation. Like in intact planarians, the level of cGMP is also very low in regenerating planarians. Surprisingly, the levels of amines and thiols in head regenerating blastemas are ?3 times higher compared to those for tail regenerating blastemas. Thus our results strongly indicate the potential roles of amines, thiols and nucleotides in planarian regeneration. PMID:25815385

  12. Muscle Cells Provide Instructions for Planarian Regeneration

    E-print Network

    Witchley, Jessica N.

    Regeneration requires both potential and instructions for tissue replacement. In planarians, pluripotent stem cells have the potential to produce all new tissue. The identities of the cells that provide regeneration ...

  13. Bromodeoxyuridine Specifically Labels the Regenerative Stem Cells of Planarians

    E-print Network

    Alvarado, Alejandro Sánchez

    Bromodeoxyuridine Specifically Labels the Regenerative Stem Cells of Planarians Phillip A. Newmark1 University Parkway, Baltimore, Maryland 21210 The singular regenerative abilities of planarians require to label specifically the regenerative stem cells, combined with the recently described use of double

  14. Planarian Phototactic Assay Reveals Differential Behavioral Responses Based on Wavelength

    PubMed Central

    Paskin, Taylor R.; Jellies, John; Bacher, Jessica; Beane, Wendy S.

    2014-01-01

    Planarians are free-living aquatic flatworms that possess a well-documented photophobic response to light. With a true central nervous system and simple cerebral eyes (ocelli), planarians are an emerging model for regenerative eye research. However, comparatively little is known about the physiology of their photoreception or how their behavior is affected by various wavelengths. Most phototactic studies have examined planarian behavior using white light. Here, we describe a novel planarian behavioral assay to test responses to small ranges of visible wavelengths (red, blue, green), as well as ultraviolet (UV) and infrared (IR) which have not previously been examined. Our data show that planarians display behavioral responses across a range of wavelengths. These responses occur in a hierarchy, with the shortest wavelengths (UV) causing the most intense photophobic responses while longer wavelengths produce no effect (red) or an apparent attraction (IR). In addition, our data reveals that planarian photophobia is comprised of both a general photophobic response (that drives planarians to escape the light source regardless of wavelength) and wavelength-specific responses that encompass specific behavioral reactions to individual wavelengths. Our results serve to improve the understanding of planarian phototaxis and suggest that behavioral studies performed with white light mask a complex behavioral interaction with the environment. PMID:25493551

  15. Bromodeoxyuridine Specifically Labels the Regenerative Stem Cells of Planarians

    Microsoft Academic Search

    Phillip A. Newmark; Alejandro Sánchez Alvarado

    2000-01-01

    The singular regenerative abilities of planarians require a population of stem cells known as neoblasts. In response to wounding, or during the course of cell turnover, neoblasts are signaled to divide and\\/or differentiate, thereby replacing lost cell types. The study of these pluripotent stem cells and their role in planarian regeneration has been severely hampered by the reported inability of

  16. Recent identification of an ERK signal gradient governing planarian regeneration.

    PubMed

    Agata, Kiyokazu; Tasaki, Junichi; Nakajima, Elizabeth; Umesono, Yoshihiko

    2014-06-01

    Planarians have strong regenerative abilities derived from their adult pluripotent stem cell (neoblast) system. However, the molecular mechanisms involved in planarian regeneration have long remained a mystery. In particular, no anterior-specifying factor(s) could be found, although Wnt family proteins had been successfully identified as posterior-specifying factors during planarian regeneration (Gurley et al., 2008; Petersen and Reddien, 2008). A recent textbook of developmental biology therefore proposes a Wnt antagonist as a putative anterior factor (Gilbert, 2013). That is, planarian regeneration was supposed to be explained by a single decreasing gradient of the ?-catenin signal from tail to head. However, recently we succeeded in demonstrating that in fact the extracellular-signal regulated kinases (ERK) form a decreasing gradient from head to tail to direct the reorganization of planarian body regionality after amputation (Umesono et al., 2013). PMID:24854393

  17. On-chip immobilization of planarians for in vivo imaging

    PubMed Central

    Dexter, Joseph P.; Tamme, Mary B.; Lind, Christine H.; Collins, Eva-Maria S.

    2014-01-01

    Planarians are an important model organism for regeneration and stem cell research. A complete understanding of stem cell and regeneration dynamics in these animals requires time-lapse imaging in vivo, which has been difficult to achieve due to a lack of tissue-specific markers and the strong negative phototaxis of planarians. We have developed the Planarian Immobilization Chip (PIC) for rapid, stable immobilization of planarians for in vivo imaging without injury or biochemical alteration. The chip is easy and inexpensive to fabricate, and worms can be mounted for and removed after imaging within minutes. We show that the PIC enables significantly higher-stability immobilization than can be achieved with standard techniques, allowing for imaging of planarians at sub-cellular resolution in vivo using brightfield and fluorescence microscopy. We validate the performance of the PIC by performing time-lapse imaging of planarian wound closure and sequential imaging over days of head regeneration. We further show that the device can be used to immobilize Hydra, another photophobic regenerative model organism. The simple fabrication, low cost, ease of use, and enhanced specimen stability of the PIC should enable its broad application to in vivo studies of stem cell and regeneration dynamics in planarians and Hydra. PMID:25227263

  18. Regeneration and maintenance of the planarian nervous system

    E-print Network

    Lapan, Sylvain William

    2012-01-01

    Planarians can regenerate all tissues, including the central nervous system and the eyes. This process depends on a population of cells in the adult, the neoblasts, that includes pluripotent stem cells. Whether the neoblast ...

  19. Berberine exposure triggers developmental effects on planarian regeneration.

    PubMed

    Balestrini, Linda; Isolani, Maria Emilia; Pietra, Daniele; Borghini, Alice; Bianucci, Anna Maria; Deri, Paolo; Batistoni, Renata

    2014-01-01

    The mechanisms of action underlying the pharmacological properties of the natural alkaloid berberine still need investigation. Planarian regeneration is instrumental in deciphering developmental responses following drug exposure. Here we report the effects of berberine on regeneration in the planarian Dugesia japonica. Our findings demonstrate that this compound perturbs the regenerative pattern. By real-time PCR screening for the effects of berberine exposure on gene expression, we identified alterations in the transcriptional profile of genes representative of different tissues, as well as of genes involved in extracellular matrix (ECM) remodeling. Although berberine does not influence cell proliferation/apoptosis, our experiments prove that this compound causes abnormal regeneration of the planarian visual system. Potential berberine-induced cytotoxic effects were noticed in the intestine. Although we were unable to detect abnormalities in other structures, our findings, sustained by RNAi-based investigations, support the possibility that berberine effects are critically linked to anomalous ECM remodeling in treated planarians. PMID:24810466

  20. Planarians in pharmacology: parthenolide is a specific behavioral antagonist of cocaine in the planarian Girardia tigrina.

    PubMed

    Pagán, Oné R; Baker, Debra; Deats, Sean; Montgomery, Erica; Tenaglia, Matthew; Randolph, Clinita; Kotturu, Dharini; Tallarida, Christopher; Bach, Daniel; Wilk, Galia; Rawls, Scott; Raffa, Robert B

    2012-01-01

    Planarians are traditional animal models in developmental and regeneration biology. Recently, these organisms are arising as vertebrate-relevant animal models in neuropharmacology. Using an adaptation of published behavioral protocols, we have described the alleviation of cocaine-induced planarian seizure-like movements (pSLM) by a naturally-occurring sesquiterpene lactone, parthenolide. Interestingly, parthenolide does not prevent the expression of pSLM induced by amphetamines; in vertebrates, amphetamines interact with the same protein target as cocaine. Parthenolide is also unable to prevent pSLM elicited by the cholinergic com-pounds nicotine and cytisine or by the glutamatergic agents L- or D- glutamic acid or NMDA. Thus, we conclude that parthenolide is a specific anti-cocaine agent in this experimental organism. PMID:22451007

  1. Comparative Analysis of Cystatin Superfamily in Platyhelminths

    PubMed Central

    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 ?-helix, a five stranded ?-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. PMID:25853513

  2. Pharmacological assessment of methamphetamine-induced behavioral hyperactivity mediated by dopaminergic transmission in planarian Dugesia japonica.

    PubMed

    Tashiro, Natsuka; Nishimura, Kaneyasu; Daido, Kanako; Oka, Tomoe; Todo, Mio; Toshikawa, Asami; Tsushima, Jun; Takata, Kazuyuki; Ashihara, Eishi; Yoshimoto, Kanji; Agata, Kiyokazu; Kitamura, Yoshihisa

    2014-07-11

    The freshwater planarian Dugesia japonica has a simple central nervous system (CNS) and can regenerate complete organs, even a functional brain. Recent studies demonstrated that there is a great variety of neuronal-related genes, specifically expressed in several domains of the planarian brain. We identified a planarian dat gene, named it D. japonica dopamine transporter (Djdat), and analyzed its expression and function. Both in situ hybridization and immunofluorescence revealed that localization of Djdat mRNA and protein was the same as that of D. japonica tyrosine hydroxylase (DjTH). Although, dopamine (DA) content in Djdat(RNAi) planarians was not altered, Djdat(RNAi) planarians showed increased spontaneous locomotion. The hyperactivity in the Djdat(RNAi) planarians was significantly suppressed by SCH23390 or sulpiride pretreatment, which are D1 or D2 receptor antagonists, respectively. These results suggest that planarians have a Djdat ortholog and the ability to regulate dopaminergic neurotransmission and association with spontaneous locomotion. PMID:24858686

  3. Planarian regeneration under micro- and hyper-gravity simulated contexts

    NASA Astrophysics Data System (ADS)

    Auletta, Gennaro; Van Loon, ing.. Jack J. W. A.; Adell, Teresa; Salo, Emili

    Planarians are non-parasitic flatworms of the Turbellaria class, some of which show the striking ability to regenerate any part of their body, even the head, in few days. Planarians are common to many parts of the world, living in both saltwater and freshwater, as well as in terrestrial areas. Due to their plasticity Planarians have been a classical model for the study of the mechanisms of regeneration. Currently, their cheap and easy maintenance, as well as the establishment of robust genetic tools, have converted them into an essential system in the field of stem cells and regenerative medicine. The aim of our project is to study the effect that micro- and hyper- gravity could exert during the process of planarians regeneration. The reason for planarians extreme regenerative capability is the maintenance until adulthood of a population of totipotent stem cells as well as the continuous activation of the cell-cell communication molecular pathways. Our prediction is that the alteration of the forces could affect planarians regeneration at different levels: 1) To regenerate, planarians must activate both proliferative and apoptotic responses, in order to create new tissue and to remodel the pre-existing one, respectively. Both cellular processes have been reported to be altered in several models under differential gravitational forces; 2) In planarians, the main intercellular signalling pathways (Wnt, TGFb, BMP, Hh, EGF) must control the process of differentiation and determination of each cell. For instances, it has been demonstrated that the differential activity of the wnt/beta-catenin pathway specifies the posterior (tail) versus the anterior (head) identity. Those pathways rely on the distance that secreted molecules (morphogens) are able to reach. Either this mechanism consist in a passive diffusion or an active transport through phyllopodia, it could sense the magnitude of the gravitational force; 3) The epidermis of planarians is covered by cilia, which beat collectively and in synchrony to propel the mucus and allow the locomotion. The assembly of ciliary structures could be affected by gravity changes. Our strategy consists in the histological, immunological and transcriptomic analysis of planarians that have completely regenerated head and tail structures under different gravity conditions: earth gravity (1g), micro-gravity (in the random positioning machine) and hyper-gravity (in a large diameter centrifuge, at 4g and 8g). Our data shows that planarians regenerate properly head and tail structures, including the eyes and the brain, in all those conditions. However some differences between the groups could be detected: 1) a slight decrease in the number of mitotic cells is observed in hyper-gravity conditions with respect to normal and micro- gravity conditions; 2) an increase in the number of animals that fissioned the tail, which is a mechanism to reproduce asexually for planarians, was observed in hyper-gravity conditions with respect to the rest; 3) although trunk fragments regenerate head and tail properly, smaller fragments, that is, head or tail pieces, could not regenerate the missing tissues under 8g conditions, and they died. Under 4g conditions they could regenerate but not properly; 4) defects in the density and length of the cilia were observed under micro- and hyper- gravity. A transcriptomic analysis is being conducted with samples from all the groups, with the aim to detect gene categories differentially regulated under micro- and hyper- gravity contexts.

  4. Distribution of the stem cells (neoblasts) in the planarian Dugesia japonica

    Microsoft Academic Search

    Hidefumi Orii; Takashige Sakurai; Kenji Watanabe

    2005-01-01

    It has been postulated that the high regeneration ability of planarians is supported by totipotent stem cells, called neoblasts. There have been a few reports showing the distribution of neoblasts in planarians. However, the findings were not completely consistent. To determine the distribution of neoblasts, we focused on proliferating cell nuclear antigen (PCNA), which is present in proliferative cells. We

  5. Recording and spectrum analysis of the planarian electroencephalogram.

    PubMed

    Aoki, R; Wake, H; Sasaki, H; Agata, K

    2009-03-17

    Many animals produce continuous brainwaves, known as the electroencephalogram (EEG), but it is not known at what point in evolution the EEG developed. Planarians possess the most primitive form of brain, but still exhibit learning and memory behaviors. Here, we observed and characterized the EEG waveform of the planarian. We inserted a monopole electrode into the head of a planarian on a cold stage, and were able to observe the EEG at sub-microvolt amplitudes. The EEG had a continuous waveform, similar to that of evolutionarily advanced animals with more developed brains. Occasional myogenic potential spikes were observed in the EEG due to sticking of the electrode, but this was markedly diminished by cooling the sample, which enabled us to investigate the intrinsic character of the continuous EEG waveform. The frequency spectrum of the EEG was observed in the range of 0.1-5 Hz, showing a broad rise below 0.5 Hz and a monotonic decrease above 1 Hz, apparently following the 1/f law. The intensity of the total EEG diminished during anesthesia by cooling to 2-3 degrees C, and recovered when the sample was warmed to about 10 degrees C. The EEG signal was sustained for 30-40 min, and gradually weakened as the animal died. Stimulation of the planarian with water vibration at 0.5-2 Hz induced chaotic resonance with a broad peak spectrum of around the stimulation frequency. Strong illumination suppressed the EEG signals for several minutes, with the degree of suppression positively correlating with the intensity of the light. This provides evidence that the EEG responds to optical signals, although there were no synchronous reactions to light flashes. The continuous EEG waveform suggests the existence of feedback loop circuits in the neural network of the planarian, which was supposed in electric shock memory experiments [McConnell JV, Cornwell P, Clay M (1960) An apparatus for conditioning planaria. Am J Psychol 73:618-622]. However, because of the broad band character of chaotic resonance observed, these loops appear to be loose couplings between ganglia. PMID:19063945

  6. Molecular mechanisms of regeneration initiation and dorsal-ventral patterning in planarians

    E-print Network

    Gaviño, Michael A. (Michael Alexander)

    2013-01-01

    Regeneration is widespread among animals, yet very little is known about the molecular mechanisms that govern regenerative processes. Planarians have emerged in recent years as a powerful model for studying regeneration ...

  7. Identification of pluripotent stem cells and characterization of glia in the planarian Schmidtea mediterranea

    E-print Network

    Wang, Irving E

    2014-01-01

    Given their regenerative capacity, the planarian Schmidtea mediterranea has emerged as a model system for the study of stem cell biology, tissue specification, and axis formation. Many aspects of the regenerative machinery ...

  8. Transcriptome Analysis of the Planarian Eye Identifies ovo as a Specific Regulator of Eye Regeneration

    E-print Network

    Lapan, Sylvain W.

    Among the millions of invertebrate species with visual systems, the genetic basis of eye development and function is well understood only in Drosophila melanogaster. We describe an eye transcriptome for the planarian ...

  9. SMG1 and mTORC1 Act Antagonistically to Regulate Response to Injury and Growth in Planarians

    Microsoft Academic Search

    Cristina González-Estévez; Daniel A. Felix; Matthew D. Smith; Jordi Paps; Simon J. Morley; Victoria James; Tyson V. Sharp; A. Aziz Aboobaker

    2012-01-01

    Planarian flatworms are able to both regenerate their whole bodies and continuously adapt their size to nutrient status. Tight control of stem cell proliferation and differentiation during these processes is the key feature of planarian biology. Here we show that the planarian homolog of the phosphoinositide 3-kinase-related kinase (PIKK) family member SMG-1 and mTOR complex 1 components are required for

  10. iTRAQ-Based Quantitative Proteomic Analysis of the Initiation of Head Regeneration in Planarians

    PubMed Central

    Geng, Xiaofang; Wang, Gaiping; Qin, Yanli; Zang, Xiayan; Li, Pengfei; Geng, Zhi; Xue, Deming; Dong, Zimei; Ma, Kexue; Chen, Guangwen; Xu, Cunshuan

    2015-01-01

    The planarian Dugesia japonica has amazing ability to regenerate a head from the anterior ends of the amputated stump with maintenance of the original anterior-posterior polarity. Although planarians present an attractive system for molecular investigation of regeneration and research has focused on clarifying the molecular mechanism of regeneration initiation in planarians at transcriptional level, but the initiation mechanism of planarian head regeneration (PHR) remains unclear at the protein level. Here, a global analysis of proteome dynamics during the early stage of PHR was performed using isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics strategy, and our data are available via ProteomeXchange with identifier PXD002100. The results showed that 162 proteins were differentially expressed at 2 h and 6 h following amputation. Furthermore, the analysis of expression patterns and functional enrichment of the differentially expressed proteins showed that proteins involved in muscle contraction, oxidation reduction and protein synthesis were up-regulated in the initiation of PHR. Moreover, ingenuity pathway analysis showed that predominant signaling pathways such as ILK, calcium, EIF2 and mTOR signaling which were associated with cell migration, cell proliferation and protein synthesis were likely to be involved in the initiation of PHR. The results for the first time demonstrated that muscle contraction and ILK signaling might played important roles in the initiation of PHR at the global protein level. The findings of this research provide a molecular basis for further unraveling the mechanism of head regeneration initiation in planarians. PMID:26131905

  11. The molecular logic for planarian regeneration along the anterior-posterior axis.

    PubMed

    Umesono, Yoshihiko; Tasaki, Junichi; Nishimura, Yui; Hrouda, Martina; Kawaguchi, Eri; Yazawa, Shigenobu; Nishimura, Osamu; Hosoda, Kazutaka; Inoue, Takeshi; Agata, Kiyokazu

    2013-08-01

    The planarian Dugesia japonica can regenerate a complete individual from a head, trunk or tail fragment via activation of somatic pluripotent stem cells. About a century ago, Thomas Hunt Morgan attempted to explain the extraordinary regenerative ability of planarians by positing two opposing morphogenetic gradients of formative "head stuff" and "tail stuff" along the anterior-posterior axis. However, Morgan's hypothesis remains open to debate. Here we show that extracellular signal-related kinase (ERK) and Wnt/?-catenin signalling pathways establish a solid framework for planarian regeneration. Our data suggest that ERK signalling forms a spatial gradient in the anterior region during regeneration. The fibroblast growth factor receptor-like gene nou-darake (which serves as an output of ERK signalling in the differentiating head) and posteriorly biased ?-catenin activity negatively regulate ERK signalling along the anterior-posterior axis in distinct manners, and thereby posteriorize regenerating tissues outside the head region to reconstruct a complete head-to-tail axis. On the basis of this knowledge about D. japonica, we proposed that ?-catenin signalling is responsible for the lack of head-regenerative ability of tail fragments in the planarian Phagocata kawakatsui, and our confirmation thereof supports the notion that posterior ?-catenin signalling negatively modulates the ERK signalling involved in anteriorization across planarian species. These findings suggest that ERK signalling has a pivotal role in triggering globally dynamic differentiation of stem cells in a head-to-tail sequence through a default program that promotes head tissue specification in the absence of posteriorizing signals. Thus, we have confirmed the broad outline of Morgan's hypothesis, and refined it on the basis of our proposed default property of planarian stem cells. PMID:23883928

  12. Making Heads or Tails: Planarian Stem Cells in the Classroom†

    PubMed Central

    Srougi, Melissa C.; Thomas-Swanik, Jackie; Chan, John D.; Marchant, Jonathan S.; Carson, Susan

    2014-01-01

    Stem cells hold great promise in the treatment of diseases ranging from cancer to dementia. However, as rapidly as the field of stem cell biology has emerged, heated political debate has followed, scrutinizing the ethical implications of stem cell use. It is therefore imperative to promote scientific literacy by educating students about stem cell biology. Yet, there is a definite lack of material to engage students in this subject at the basic science level. Therefore, we have developed and implemented a hands-on introductory laboratory module that introduces students to stem cell biology and can be easily incorporated into existing curricula. Students learn about stem cell biology using an in vivo planarian model system in which they down-regulate two genes important in stem cell differentiation using RNA interference and then observe the regenerative phenotype. The module was piloted at the high school, community college, and university levels. Here, we report that introductory biology students enrolled at a community college were able to demonstrate gains in learning after completion of a one-hour lecture and four 45-minute laboratory sessions over the course of three weeks. These gains in learning outcomes were objectively evaluated both before and after its execution using a student quiz and experimental results. Furthermore, students’ self-assessments revealed increases in perceived knowledge as well as a general interest in stem cells. Therefore, these data suggest that this module is a simple, useful way to engage and to teach students about stem cell biology. PMID:24839511

  13. PRMT5 and the role of symmetrical dimethylarginine in chromatoid bodies of planarian stem cells.

    PubMed

    Rouhana, Labib; Vieira, Ana P; Roberts-Galbraith, Rachel H; Newmark, Phillip A

    2012-03-01

    Planarian flatworms contain a population of adult stem cells (neoblasts) that proliferate and generate cells of all tissues during growth, regeneration and tissue homeostasis. A characteristic feature of neoblasts is the presence of chromatoid bodies, large cytoplasmic ribonucleoprotein (RNP) granules morphologically similar to structures present in the germline of many organisms. This study aims to reveal the function, and identify additional components, of planarian chromatoid bodies. We uncover the presence of symmetrical dimethylarginine (sDMA) on chromatoid body components and identify the ortholog of protein arginine methyltransferase PRMT5 as the enzyme responsible for sDMA modification in these proteins. RNA interference-mediated depletion of planarian PRMT5 results in defects in homeostasis and regeneration, reduced animal size, reduced number of neoblasts, fewer chromatoid bodies and increased levels of transposon and repetitive-element transcripts. Our results suggest that PIWI family member SMEDWI-3 is one sDMA-containing chromatoid body protein for which methylation depends on PRMT5. Additionally, we discover an RNA localized to chromatoid bodies, germinal histone H4. Our results reveal new components of chromatoid bodies and their function in planarian stem cells, and also support emerging studies indicative of sDMA function in stabilization of RNP granules and the Piwi-interacting RNA pathway. PMID:22318224

  14. Multicellularity, stem cells, and the neoblasts of the planarian Schmidtea mediterranea

    E-print Network

    Alvarado, Alejandro Sánchez

    Review Multicellularity, stem cells, and the neoblasts of the planarian Schmidtea mediterranea Available online 25 April 2005 Abstract All multicellular organisms depend on stem cells for their survival of stem cells may have been a prerequisite in the evolution of multicellular organisms. We present

  15. Memory and obesity affect the population dynamics of asexual freshwater planarians

    NASA Astrophysics Data System (ADS)

    Dunkel, Jörn; Talbot, Jared; Schötz, Eva-Maria

    2011-04-01

    Asexual reproduction in multicellular organisms is a complex biophysical process that is not yet well understood quantitatively. Here, we report a detailed population study for the asexual freshwater planarian Schmidtea mediterranea, which can reproduce via transverse fission due to a large stem cell contingent. Our long-term observations of isolated non-interacting planarian populations reveal that the characteristic fission waiting time distributions for head and tail fragments differ significantly from each other. The stochastic fission dynamics of tail fragments exhibits non-negligible memory effects, implying that an accurate mathematical description of future data should be based on non-Markovian tree models. By comparing the effective growth of non-interacting planarian populations with those of self-interacting populations, we are able to quantify the influence of interactions between flatworms and physical conditions on the population growth. A surprising result is the non-monotonic relationship between effective population growth rate and nutrient supply: planarians exhibit a tendency to become 'obese' if the feeding frequency exceeds a critical level, resulting in a decreased reproduction activity. This suggests that these flatworms, which possess many genes homologous to those of humans, could become a new model system for studying dietary effects on reproduction and regeneration in multicellular organisms.

  16. The expression of planarian brain factor homologs, DjFoxG and DjFoxD

    Microsoft Academic Search

    Satoshi Koinuma; Yoshihiko Umesono; Kenji Watanabe; Kiyokazu Agata

    2003-01-01

    Recent accumulating evidence revealed that planarian central nervous system (CNS) has numerous functional domains distinguished by a large number of neural markers, suggesting that primitive animals which developed CNS already had the framework of the brain development. It is of interest to investigate genes which have been acquired at an early stage of evolution for brain pattern formation. One such

  17. Effects of nonionic and ionic surfactants on survival, oxidative stress, and cholinesterase activity of planarian

    Microsoft Academic Search

    Mei-Hui Li

    2008-01-01

    Eight widely used surfactants (cetyltrimethylammonium bromide; CTAB, benzethonium chloride; Hyamine 1622, 4-nonylphenol; NP, octylphenol ethoxylate; Triton X-100, dodecylbenzene sulfonate; LAS, lauryl sulfate; SDS, pentadecafluorooctanoic acid; PFOA, and perfluorooctane sulfonate; PFOS) were selected to examine their acute toxicities and effects on oxidative stress and cholinesterase (ChE) activities in Dugesia japonica. The differences in acute toxicity among eight surfactants to planarians were

  18. A forkhead Transcription Factor Is Wound-Induced at the Planarian Midline and Required for Anterior Pole Regeneration

    E-print Network

    Scimone, M. Lucila

    Planarian regeneration requires positional information to specify the identity of tissues to be replaced as well as pluripotent neoblasts capable of differentiating into new cell types. We found that wounding elicits rapid ...

  19. Protein expression profiling in head fragments during planarian regeneration after amputation.

    PubMed

    Chen, Xiaoguang; Xu, Cunshuan

    2015-04-01

    Following amputation, a planarian tail fragment can regrow into a complete organism including a well-organized brain within about 2-3 weeks, thus restoring the structure and function to presurgical levels. Despite the enormous potential of these animals for regenerative medicine, our understanding of the exact mechanism of planarian regeneration is incomplete. To better understand the molecular nature of planarian head regeneration, we applied two-dimensional electrophoresis (2-DE)/matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF)/time-of-flight mass spectrometry (TOF MS) technique to analyze the dynamic proteomic expression profiles over the course of 6 to 168 h post-decapitation. This approach identified a total of 141 differentially expressed proteins, 47 of which exhibited exceptionally high fold changes (?3-fold change). Of these, Rx protein, an important regulator of head and brain development, was considered to be closely related to planarian head regeneration because of its exceptional high expression almost throughout the time course of regeneration process. Functional annotation analysis classified the 141 proteins into eight categories: (1) signaling, (2) Ca(2+) binding and translocation, (3) transcription and translation, (4) cytoskeleton, (5) metabolism, (6) cell protection, (7) tissue differentiation, and (8) cell cycle. Signaling pathway analysis indicated that Wnt1/Ca(2+) signaling pathway was activated during head regeneration. Integrating the analyses of proteome expression profiling, functional annotation, and signaling pathway, amputation-induced head reformation requires some mechanisms to promote cell proliferation and differentiation, including differential regulation of proapoptotic and antiapoptotic proteins, and the regulation of proliferation and differentiation-related proteins. Importantly, Wnt1/Ca(2+) signaling pathway upregulates Rx expression, finally facilitating the differentiation of neoblasts into various cell types. Taken together, our study demonstrated that proteomic analysis approach used by us is a powerful tool in understanding molecular process related to head regeneration of planarian. PMID:25697422

  20. Survival, mobility, and membrane-bound enzyme activities of freshwater planarian, Dugesia japonica, exposed to synthetic and natural surfactants.

    PubMed

    Li, Mei-Hui

    2012-04-01

    Surfactants are a major class of emerging pollutants widely used in large quantities in everyday life and commonly found in surface waters worldwide. Freshwater planarian was selected to examine the effects of different surfactants by measuring mortality, mobility, and membrane-bound enzyme activities. Among the 10 surfactants tested, the acute toxicities of betaine and polyethylene glycol (PEG-200) to planarians were relatively low, with a median lethal concentration (LC50) greater than 10,000 mg/L. The toxicity to planarians of the other eight surfactants based on 48-h LC50 could be arranged in the descending order of cetylpyridinum chloride (CPC)?>?4-tert-octylphenol (4-tert-OP)?>?ammonium lauryl sulfate?>?benzalkonium chloride?>?saponin?>?sodium lauroylsarcosinate?>?dioctyl sulfosuccinate?>?dodecyl trimethyl ammonium bromide (DTAB). Both CPC and 4-tert-OP were very toxic to planarians, with 48-h LC50 values <1 mg/L. The median effective concentrations (EC50s) of planarian mobility were in the 0.1 to 50 mg/L range and were in the same range as the 24-h LC50 of planarians exposed to different surfactants, except for DTAB. In addition, significant inhibition of cholinesterase activity activities was found in planarians exposed to 4-tert-OP at 2.5 and 5 mg/L and to saponin at 10 mg/L after 2-h treatments. This result suggests that planarian mobility responses can be used as an alternative indicator for acute toxicity of surfactants after a very short exposure period. PMID:22278771

  1. Double-stranded RNA specifically disrupts gene expression during planarian regeneration

    PubMed Central

    Sánchez Alvarado, Alejandro; Newmark, Phillip A.

    1999-01-01

    Metazoan regeneration is one of the least understood fundamental problems of biology. The lack of progress in understanding this phenomenon at the molecular level has been due to the poor regenerative abilities of the genetic organisms used for developmental studies, as well as the difficulties encountered with molecular and genetic manipulations of the commonly studied vertebrate models (the urodele amphibians). Here, we demonstrate that introduction of double-stranded RNA selectively abrogates gene function in planarians, a classic model of regeneration. The ability to eliminate gene function in a regenerating organism such as the planarian overcomes previous experimental limitations and opens the study of animal regeneration to unprecedented levels of molecular detail. PMID:10220416

  2. Evolutionary Analysis of Mitogenomes from Parasitic and Free-Living Flatworms

    PubMed Central

    Frías-López, Cristina; Littlewood, D. Timothy J.; Rozas, Julio; Riutort, Marta

    2015-01-01

    Mitochondrial genomes (mitogenomes) are useful and relatively accessible sources of molecular data to explore and understand the evolutionary history and relationships of eukaryotic organisms across diverse taxonomic levels. The availability of complete mitogenomes from Platyhelminthes is limited; of the 40 or so published most are from parasitic flatworms (Neodermata). Here, we present the mitogenomes of two free-living flatworms (Tricladida): the complete genome of the freshwater species Crenobia alpina (Planariidae) and a nearly complete genome of the land planarian Obama sp. (Geoplanidae). Moreover, we have reanotated the published mitogenome of the species Dugesia japonica (Dugesiidae). This contribution almost doubles the total number of mtDNAs published for Tricladida, a species-rich group including model organisms and economically important invasive species. We took the opportunity to conduct comparative mitogenomic analyses between available free-living and selected parasitic flatworms in order to gain insights into the putative effect of life cycle on nucleotide composition through mutation and natural selection. Unexpectedly, we did not find any molecular hallmark of a selective relaxation in mitogenomes of parasitic flatworms; on the contrary, three out of the four studied free-living triclad mitogenomes exhibit higher A+T content and selective relaxation levels. Additionally, we provide new and valuable molecular data to develop markers for future phylogenetic studies on planariids and geoplanids. PMID:25793530

  3. Effects of nonionic and ionic surfactants on survival, oxidative stress, and cholinesterase activity of planarian.

    PubMed

    Li, Mei-Hui

    2008-02-01

    Eight widely used surfactants (cetyltrimethylammonium bromide; CTAB, benzethonium chloride; Hyamine 1622, 4-nonylphenol; NP, octylphenol ethoxylate; Triton X-100, dodecylbenzene sulfonate; LAS, lauryl sulfate; SDS, pentadecafluorooctanoic acid; PFOA, and perfluorooctane sulfonate; PFOS) were selected to examine their acute toxicities and effects on oxidative stress and cholinesterase (ChE) activities in Dugesia japonica. The differences in acute toxicity among eight surfactants to planarians were at least in the range of three orders of magnitudes. The toxicity rank of surfactants according to estimated 48-h LC(50) was SDS>NP>LAS>Hyamine 1622>CTAB>Triton X-100>PFOS>PFOA. The toxicity rank of surfactants according to 96-h LC(50) was as follows: SDS>CTAB>NP>LAS>Hyamine 1622>Triton X-100>PFOS>PFOA. There were significant increases in catalase activities in planarians exposed to LAS at nominal concentrations of 0.5 or 1 mgl(-1) and to PFOS at nominal concentrations of 5 or 10 mgl(-1) after 48-h exposure. Inhibitions of ChE activities were found in planarians exposed to Hyamine 1622 at all concentrations tested, to PFOS at nominal concentration of 10 mgl(-1), to PFOA at nominal concentrations of 50 or 100 mgl(-1) and to NP at nominal concentration of 0.5 mgl(-1). A significant increase in ChE activities was also observed in planarian exposed to Triton X-100 at nominal concentration of 5 mgl(-1). The implication of ChE inhibition by NP, PFOS and PFOA on neurological and behavioral effects in aquatic animals requires further investigation. PMID:17905407

  4. Guarana provides additional stimulation over caffeine alone in the planarian model.

    PubMed

    Moustakas, Dimitrios; Mezzio, Michael; Rodriguez, Branden R; Constable, Mic Andre; Mulligan, Margaret E; Voura, Evelyn B

    2015-01-01

    The stimulant effect of energy drinks is primarily attributed to the caffeine they contain. Many energy drinks also contain other ingredients that might enhance the tonic effects of these caffeinated beverages. One of these additives is guarana. Guarana is a climbing plant native to the Amazon whose seeds contain approximately four times the amount of caffeine found in coffee beans. The mix of other natural chemicals contained in guarana seeds is thought to heighten the stimulant effects of guarana over caffeine alone. Yet, despite the growing use of guarana as an additive in energy drinks, and a burgeoning market for it as a nutritional supplement, the science examining guarana and how it affects other dietary ingredients is lacking. To appreciate the stimulant effects of guarana and other natural products, a straightforward model to investigate their physiological properties is needed. The planarian provides such a system. The locomotor activity and convulsive response of planarians with substance exposure has been shown to provide an excellent system to measure the effects of drug stimulation, addiction and withdrawal. To gauge the stimulant effects of guarana we studied how it altered the locomotor activity of the planarian species Dugesia tigrina. We report evidence that guarana seeds provide additional stimulation over caffeine alone, and document the changes to this stimulation in the context of both caffeine and glucose. PMID:25880065

  5. A Comparative Transcriptomic Analysis Reveals Conserved Features of Stem Cell Pluripotency in Planarians and Mammals

    PubMed Central

    Labbé, Roselyne M.; Irimia, Manuel; Currie, Ko W.; Lin, Alexander; Zhu, Shu Jun; Brown, David D.R.; Ross, Eric J.; Voisin, Veronique; Bader, Gary D.; Blencowe, Benjamin J.; Pearson, Bret J.

    2014-01-01

    Many long-lived species of animals require the function of adult stem cells throughout their lives. However, the transcriptomes of stem cells in invertebrates and vertebrates have not been compared, and consequently, ancestral regulatory circuits that control stem cell populations remain poorly defined. In this study, we have used data from high-throughput RNA sequencing to compare the transcriptomes of pluripotent adult stem cells from planarians with the transcriptomes of human and mouse pluripotent embryonic stem cells. From a stringently defined set of 4,432 orthologs shared between planarians, mice and humans, we identified 123 conserved genes that are ?5-fold differentially expressed in stem cells from all three species. Guided by this gene set, we used RNAi screening in adult planarians to discover novel stem cell regulators, which we found to affect the stem cell-associated functions of tissue homeostasis, regeneration, and stem cell maintenance. Examples of genes that disrupted these processes included the orthologs of TBL3, PSD12, TTC27, and RACK1. From these analyses, we concluded that by comparing stem cell transcriptomes from diverse species, it is possible to uncover conserved factors that function in stem cell biology. These results provide insights into which genes comprised the ancestral circuitry underlying the control of stem cell self-renewal and pluripotency. PMID:22696458

  6. Guarana Provides Additional Stimulation over Caffeine Alone in the Planarian Model

    PubMed Central

    Moustakas, Dimitrios; Mezzio, Michael; Rodriguez, Branden R.; Constable, Mic Andre; Mulligan, Margaret E.; Voura, Evelyn B.

    2015-01-01

    The stimulant effect of energy drinks is primarily attributed to the caffeine they contain. Many energy drinks also contain other ingredients that might enhance the tonic effects of these caffeinated beverages. One of these additives is guarana. Guarana is a climbing plant native to the Amazon whose seeds contain approximately four times the amount of caffeine found in coffee beans. The mix of other natural chemicals contained in guarana seeds is thought to heighten the stimulant effects of guarana over caffeine alone. Yet, despite the growing use of guarana as an additive in energy drinks, and a burgeoning market for it as a nutritional supplement, the science examining guarana and how it affects other dietary ingredients is lacking. To appreciate the stimulant effects of guarana and other natural products, a straightforward model to investigate their physiological properties is needed. The planarian provides such a system. The locomotor activity and convulsive response of planarians with substance exposure has been shown to provide an excellent system to measure the effects of drug stimulation, addiction and withdrawal. To gauge the stimulant effects of guarana we studied how it altered the locomotor activity of the planarian species Dugesia tigrina. We report evidence that guarana seeds provide additional stimulation over caffeine alone, and document the changes to this stimulation in the context of both caffeine and glucose. PMID:25880065

  7. Tryptophan hydroxylase Is Required for Eye Melanogenesis in the Planarian Schmidtea mediterranea

    PubMed Central

    Lambrus, Bramwell G.; Cochet-Escartin, Olivier; Gao, Jiarong; Newmark, Phillip A.; Collins, Eva-Maria S.; Collins, James J.

    2015-01-01

    Melanins are ubiquitous and biologically important pigments, yet the molecular mechanisms that regulate their synthesis and biochemical composition are not fully understood. Here we present a study that supports a role for serotonin in melanin synthesis in the planarian Schmidtea mediterranea. We characterize the tryptophan hydroxylase (tph) gene, which encodes the rate-limiting enzyme in serotonin synthesis, and demonstrate by RNA interference that tph is essential for melanin production in the pigment cups of the planarian photoreceptors. We exploit this phenotype to investigate the biological function of pigment cups using a quantitative light-avoidance behavioral assay. Planarians lacking eye pigment remain phototactic, indicating that eye pigmentation is not essential for light avoidance in S. mediterranea, though it improves the efficiency of the photophobic response. Finally, we show that the eye pigmentation defect observed in tph knockdown animals can be rescued by injection of either the product of TPH, 5-hydroxytryptophan (5-HTP), or serotonin. Together, these results highlight a role for serotonin in melanogenesis, perhaps as a regulatory signal or as a pigment substrate. To our knowledge, this is the first example of this relationship to be reported outside of mammalian systems. PMID:26017970

  8. Smed-dynA-1 is a planarian nervous system specific dynamin 1 homolog required for normal locomotion

    PubMed Central

    Talbot, Jared A.; Currie, Ko W.; Pearson, Bret J.; Collins, Eva-Maria S.

    2014-01-01

    ABSTRACT Dynamins are GTPases that are required for separation of vesicles from the plasma membrane and thus are key regulators of endocytosis in eukaryotic cells. This role for dynamin proteins is especially crucial for the proper function of neurons, where they ensure that synaptic vesicles and their neurotransmitter cargo are recycled in the presynaptic cell. Here we have characterized the dynamin protein family in the freshwater planarian Schmidtea mediterranea and showed that it possesses six dynamins with tissue specific expression profiles. Of these six planarian homologs, two are necessary for normal tissue homeostasis, and the loss of another, Smed-dynA-1, leads to an abnormal behavioral phenotype, which we have quantified using automated center of mass tracking. Smed-dynA-1 is primarily expressed in the planarian nervous system and is a functional homolog of the mammalian Dynamin I. The distinct expression profiles of the six dynamin genes makes planarians an interesting new system to reveal novel dynamin functions, which may be determined by their differential tissue localization. The observed complexity of neurotransmitter regulation combined with the tools of quantitative behavioral assays as a functional readout for neuronal activity, renders planarians an ideal system for studying how the nervous system controls behavior. PMID:24950970

  9. Inferring Regulatory Networks from Experimental Morphological Phenotypes: A Computational Method Reverse-Engineers Planarian Regeneration

    PubMed Central

    Lobo, Daniel; Levin, Michael

    2015-01-01

    Transformative applications in biomedicine require the discovery of complex regulatory networks that explain the development and regeneration of anatomical structures, and reveal what external signals will trigger desired changes of large-scale pattern. Despite recent advances in bioinformatics, extracting mechanistic pathway models from experimental morphological data is a key open challenge that has resisted automation. The fundamental difficulty of manually predicting emergent behavior of even simple networks has limited the models invented by human scientists to pathway diagrams that show necessary subunit interactions but do not reveal the dynamics that are sufficient for complex, self-regulating pattern to emerge. To finally bridge the gap between high-resolution genetic data and the ability to understand and control patterning, it is critical to develop computational tools to efficiently extract regulatory pathways from the resultant experimental shape phenotypes. For example, planarian regeneration has been studied for over a century, but despite increasing insight into the pathways that control its stem cells, no constructive, mechanistic model has yet been found by human scientists that explains more than one or two key features of its remarkable ability to regenerate its correct anatomical pattern after drastic perturbations. We present a method to infer the molecular products, topology, and spatial and temporal non-linear dynamics of regulatory networks recapitulating in silico the rich dataset of morphological phenotypes resulting from genetic, surgical, and pharmacological experiments. We demonstrated our approach by inferring complete regulatory networks explaining the outcomes of the main functional regeneration experiments in the planarian literature; By analyzing all the datasets together, our system inferred the first systems-biology comprehensive dynamical model explaining patterning in planarian regeneration. This method provides an automated, highly generalizable framework for identifying the underlying control mechanisms responsible for the dynamic regulation of growth and form. PMID:26042810

  10. Insights into the origin and distribution of biodiversity in the Brazilian Atlantic forest hot spot: a statistical phylogeographic study using a low-dispersal organism

    PubMed Central

    Álvarez-Presas, M; Sánchez-Gracia, A; Carbayo, F; Rozas, J; Riutort, M

    2014-01-01

    The relative importance of the processes that generate and maintain biodiversity is a major and controversial topic in evolutionary biology with large implications for conservation management. The Atlantic Forest of Brazil, one of the world's richest biodiversity hot spots, is severely damaged by human activities. To formulate an efficient conservation policy, a good understanding of spatial and temporal biodiversity patterns and their underlying evolutionary mechanisms is required. With this aim, we performed a comprehensive phylogeographic study using a low-dispersal organism, the land planarian species Cephaloflexa bergi (Platyhelminthes, Tricladida). Analysing multi-locus DNA sequence variation under the Approximate Bayesian Computation framework, we evaluated two scenarios proposed to explain the diversity of Southern Atlantic Forest (SAF) region. We found that most sampled localities harbour high levels of genetic diversity, with lineages sharing common ancestors that predate the Pleistocene. Remarkably, we detected the molecular hallmark of the isolation-by-distance effect and little evidence of a recent colonization of SAF localities; nevertheless, some populations might result from very recent secondary contacts. We conclude that extant SAF biodiversity originated and has been shaped by complex interactions between ancient geological events and more recent evolutionary processes, whereas Pleistocene climate changes had a minor influence in generating present-day diversity. We also demonstrate that land planarians are an advantageous biological model for making phylogeographic and, particularly, fine-scale evolutionary inferences, and propose appropriate conservation policies. PMID:24549112

  11. The freshwater planarian Polycelis felina as a sensitive species to assess the long-term toxicity of ammonia.

    PubMed

    Alonso, Alvaro; Camargo, Julio A

    2011-07-01

    Behavioural endpoints are a good link between physiological and ecological effects. However long-term behavioural endpoints are not uniformly studied over all different organism groups. For example behaviour has been scarcely studied in planarians. Unionized ammonia (NH(3)) is one of the most widespread pollutants in developed countries, and is known to alter animal behaviour. In this study a long-term (30 d) bioassay was conducted to assess the effect of this pollutant on survival and behavioural activity (e.g. locomotion activity) of the freshwater planarian Polycelis felina. One control and three environmentally-realistic concentrations of unionized ammonia (treatments of 0.02, 0.05, and 0.09 mg N-NH(3) L(-1)) were used in quintuplicate. The behaviour of planarians was measured after 0, 10, 20 and 30 d of ammonia exposure. Mortality was recorded every 2 d. Unionized ammonia increased mortality in the two highest NH(3) concentrations and the locomotory activity was depressed in all treatments after 20 d of exposure. Behavioural effect was observed at concentrations 20 times lower than the short-term LC50 for this species. Previous studies proposed safe concentrations of unionized ammonia of 0.01-0.10 mg N-NH(3) L(-1) to aquatic ecosystems, but our study has shown that these concentrations will affect planarians. Because planarians play a key role in streams (as predator/scavenger), safe concentrations should be below 0.02 mg N-NH(3) L(-1) to protect this species in the freshwater community. Our results can contribute to improve the knowledge about ammonia toxicity to freshwater ecosystems, we recommend that safe concentrations of unionized ammonia should be based on very sensitive species. PMID:21546058

  12. Identification of neoblast- and regeneration-specific miRNAs in the planarian Schmidtea mediterranea.

    PubMed

    Sasidharan, Vidyanand; Lu, Yi-Chien; Bansal, Dhiru; Dasari, Pranavi; Poduval, Deepak; Seshasayee, Aswin; Resch, Alissa M; Graveley, Brenton R; Palakodeti, Dasaradhi

    2013-10-01

    In recent years, the planarian Schmidtea mediterranea has emerged as a tractable model system to study stem cell biology and regeneration. MicroRNAs are small RNA species that control gene expression by modulating translational repression and mRNA stability and have been implicated in the regulation of various cellular processes. Though recent studies have identified several miRNAs in S. mediterranea, their expression in neoblast subpopulations and during regeneration has not been examined. Here, we identify several miRNAs whose expression is enriched in different neoblast subpopulations and in regenerating tissue at different time points in S. mediterranea. Some of these miRNAs were enriched within 3 h post-amputation and may, therefore, play a role in wound healing and/or neoblast migration. Our results also revealed miRNAs, such as sme-miR-2d-3p and the sme-miR-124 family, whose expression is enriched in the cephalic ganglia, are also expressed in the brain primordium during CNS regeneration. These results provide new insight into the potential biological functions of miRNAs in neoblasts and regeneration in planarians. PMID:23974438

  13. Identification and expression analysis of a Spsb gene in planarian Dugesia japonica.

    PubMed

    Dong, Zimei; Cheng, Fangfang; Yuwen, Yanqing; Chen, Jing; Li, Xiaoyan; Dou, He; Zhang, Haixia; Chen, Guangwen; Liu, Dezeng

    2015-06-15

    The SPSB family is comprised of four highly conserved proteins, each containing a C-terminal SOCS box motif and a central SPRY domain. Presently, Spsb genes have been found in mammals and in a few invertebrates, however, the specific functions of these genes are still unknown. In this study, we identified a Spsb gene from the planarian Dugesia japonica and termed it DjSpsb. The temporal and spatial expression patterns of DjSpsb were examined in both intact and regenerative animals, and expression levels were also quantified in response to various stressors. The results show that (1) DjSpsb is highly conserved in evolutionary history in metazoans and is at closer relationship to Spsb1, Spsb2 and Spsb4; (2) DjSpsb mRNA is mainly expressed in the head and also throughout head regeneration processes, particularly, its expression up-regulated observably on day 5 after amputation; (3) DjSpsb is also expressed in the testes and yolk glands; (4) DjSpsb expression is induced by high temperature and ethanol but inhibited by high doses of ionic liquids. The date suggests that the DjSpsb gene might be active in central nervous system (CNS) formation and functional recovery during head regeneration, and it is also involved in the development of germ cells and stress responses in the planarians. PMID:25827717

  14. Evolution of brain and CNS from the viewpoint of genome and gene expression profile: What happened in the evolutionary process from planarian to human?

    Microsoft Academic Search

    Takashi Gojobori

    The evolutionary origin of the brain remains a challenging und unsolved problem in evolutionary studies. To understand when and how the structural brain emerged, we analyzed the central nervous system (CNS) of a lower invertebrate, planarian. We determined the nucleotide sequence of more than 9,000 ESTs (expressed sequence tags) from the head portion of planarians, obtaining 3,101 non-redundant EST clones.

  15. The majority of parasitic worms belong to either the Platyhelminthes (flatworms/flukes and tape-worms) or Nematoda (roundworms/nematodes).

    E-print Network

    Jawitz, James W.

    The majority of parasitic worms belong to either the Platyhelminthes (flatworms/flukes and tape- worms) or Nematoda (roundworms/nematodes). Unlike earthworms, nematodes are un becomes capable of reproducing (eggs produced after male worm inseminates female). In some instances

  16. Long-range Neural and Gap Junction Protein-mediated Cues Control Polarity During Planarian Regeneration

    PubMed Central

    Oviedo, Néstor J.; Morokuma, Junji; Walentek, Peter; Kema, Ido P.; Gu, Man Bock; Ahn, Joo-Myung; Hwang, Jung Shan; Gojobori, Takashi; Levin, Michael

    2010-01-01

    SUMMARY Having the ability to coordinate the behavior of stem cells to induce regeneration of specific large-scale structures would have far reaching consequences in the treatment of degenerative diseases, acute injury, and aging. Thus, identifying and learning to manipulate the sequential steps that determine the fate of new tissue within the overall morphogenetic program of the organism is fundamental. We identified novel early signals, mediated by the central nervous system and 3 innexin proteins, which determine the fate and axial polarity of regenerated tissue in planarians. Modulation of gap junction-dependent and neural signals specifically induces ectopic anterior regeneration blastemas in posterior and lateral wounds. These ectopic anterior blastemas differentiate new brains that establish permanent primary axes re-established during subsequent rounds of unperturbed regeneration. These data reveal powerful novel controls of pattern formation and suggest a constructive model linking nervous inputs and polarity determination in early stages of regeneration. PMID:20026026

  17. Cloning of fragments of novel homeobox genes expressed during regeneration in planarians

    SciTech Connect

    Lukyanov, K.A.; Tarabykin, V.S.; Potapov, V.K. [and others

    1994-11-01

    The polymerase chain reaction with degenerate primers corresponding to the most conservative amino acids 16-21 (ELEKEF) and 49-54 (WPQNRR) of the Antennapedia class homeodomains was used for the amplification of cDNA from regenerating planarians (asexual race of Dugesia tigrina). A total of six new Antennapedia-like homeobox sequences, designated Dutarh-1-Dutarh-6 (Dugesia tigrina asexual race homeobox gene), have been identified. Their comparison with other homeobox genes using a Genebee software (the EMBL Data Library) showed that all sequences except Dutarh-6 belong to the Antennapedia class. Dutarh-6 is closely related to a recently described novel homeobox gene subfamily which includes mouse mesodermal homeobox genes Max-1 and Max-2 and rat homeobox gene Gax. 17 refs., 2 figs.

  18. Toxicity profiles and solvent-toxicant interference in the planarian Schmidtea mediterranea after dimethylsulfoxide (DMSO) exposure.

    PubMed

    Stevens, An-Sofie; Pirotte, Nicky; Plusquin, Michelle; Willems, Maxime; Neyens, Thomas; Artois, Tom; Smeets, Karen

    2015-03-01

    To investigate hydrophobic test compounds in toxicological studies, solvents like dimethylsulfoxide (DMSO) are inevitable. However, using these solvents, the interpretation of test compound-induced responses can be biased. DMSO concentration guidelines are available, but are mostly based on acute exposures involving one specific toxicity endpoint. Hence, to avoid solvent-toxicant interference, we use multiple chronic test endpoints for additional interpretation of DMSO concentrations and propose a statistical model to assess possible synergistic, antagonistic or additive effects of test compounds and their solvents. In this study, the effects of both short- (1?day) and long-term (2?weeks) exposures to low DMSO concentrations (up to 1000?µl?l(-1) ) were studied in the planarian Schmidtea mediterranea. We measured different biological levels in both fully developed and developing animals. In a long-term exposure set-up, a concentration of 500?µl?l(-1) DMSO interfered with processes on different biological levels, e.g. behaviour, stem cell proliferation and gene expression profiles. After short exposure times, 500?µl?l(-1) DMSO only affected motility, whereas the most significant changes on different parameters were observed at a concentration of 1000?µl?l(-1) DMSO. As small sensitivity differences exist between biological levels and developmental stages, we advise the use of this solvent in concentrations below 500?µl?l(-1) in this organism. In the second part of our study, we propose a statistical approach to account for solvent-toxicant interactions and discuss full-scale solvent toxicity studies. In conclusion, we reassessed DMSO concentration limits for different experimental endpoints in the planarian S. mediterranea. PMID:24964768

  19. 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. PMID:24260820

  20. Reactive Oxygen Species in Planarian Regeneration: An Upstream Necessity for Correct Patterning and Brain Formation

    PubMed Central

    Pirotte, Nicky; Stevens, An-Sofie; Fraguas, Susanna; Plusquin, Michelle; Van Roten, Andromeda; Van Belleghem, Frank; Paesen, Rik; Ameloot, Marcel; Cebrià, Francesc; Artois, Tom; Smeets, Karen

    2015-01-01

    Recent research highlighted the impact of ROS as upstream regulators of tissue regeneration. We investigated their role and targeted processes during the regeneration of different body structures using the planarian Schmidtea mediterranea, an organism capable of regenerating its entire body, including its brain. The amputation of head and tail compartments induces a ROS burst at the wound site independently of the orientation. Inhibition of ROS production by diphenyleneiodonium (DPI) or apocynin (APO) causes regeneration defaults at both the anterior and posterior wound sites, resulting in reduced regeneration sites (blastemas) and improper tissue homeostasis. ROS signaling is necessary for early differentiation and inhibition of the ROS burst results in defects on the regeneration of the nervous system and on the patterning process. Stem cell proliferation was not affected, as indicated by histone H3-P immunostaining, fluorescence-activated cell sorting (FACS), in situ hybridization of smedwi-1, and transcript levels of proliferation-related genes. We showed for the first time that ROS modulate both anterior and posterior regeneration in a context where regeneration is not limited to certain body structures. Our results indicate that ROS are key players in neuroregeneration through interference with the differentiation and patterning processes. PMID:26180588

  1. A Chemical Genetics Approach Reveals H,K-ATPase-Mediated Membrane Voltage is Required for Planarian Head Regeneration

    PubMed Central

    Beane, Wendy Scott; Morokuma, Junji; Adams, Dany Spencer; Levin, Michael

    2012-01-01

    SUMMARY Biophysical signaling is required for both embryonic polarity and regenerative outgrowth. Exploiting endogenous ion transport for regenerative therapies will require direct regulation of membrane voltage. Here, we develop a pharmacological method to target ion transporters, uncovering a novel role for membrane voltage as a key regulator of anterior polarity in regenerating planaria. Utilizing the highly specific inhibitor, SCH-28080, our data reveal that H+,K+-ATPase-mediated membrane depolarization is essential for anterior gene expression and brain induction. H+,K+-ATPase-independent manipulation of membrane potential with ivermectin confirms that depolarization drives head formation, even at posterior-facing wounds. Using this chemical genetics approach, we demonstrate that membrane voltage controls head-vs.-tail identity during planarian regeneration. Our data suggest well-characterized drugs (already approved for human use) might be exploited to control adult stem cell-driven pattern formation during the regeneration of complex structures. PMID:21276941

  2. The physiological response of the marine platyhelminth Macrostomum lignano to different environmental oxygen concentrations.

    PubMed

    Rivera-Ingraham, G A; Bickmeyer, U; Abele, D

    2013-07-15

    The respiration rate of meiofauna is difficult to measure, and the response to variations in the environmental oxygen concentration has so far been mainly addressed through behavioral investigation. We investigated the effect of different oxygen concentrations on the physiology of the marine platyhelminth Macrostomum lignano. Respiration was measured using batches of 20 animals in a glass microtiter plate equipped with optical oxygen sensor spots. At higher oxygen saturations (>12 kPa), the animals showed a clear oxyconforming behavior. However, below this value, the flatworms kept respiration rates constant at 0.064±0.001 nmol O2 l(-1) h(-1) individual(-1) down to 3 kPa PO2, and this rate was increased by 30% in animals that were reoxygenated after enduring a period of 1.5 h in anoxia. Physiological changes related to tissue oxygenation were assessed using live imaging techniques with different fluorophores in animals maintained in normoxic (21 kPa), hyperoxic (40 kPa) or near-anoxic (~0 kPa) conditions and subjected to anoxia-reoxygenation. The pH-sensitive dyes Ageladine-A and BCECF both indicated that pHi under near-anoxia increases by about 0.07-0.10 units. Mitochondrial membrane potential, ??m, was higher in anoxic and hyperoxic than in normoxic conditions (JC1 dye data). Staining with ROS-sensitive dyes - DHE for detection of superoxide anion (O2•(-)) formation and C-H DFFDA for other ROS species aside from O2•(-) (H2O2, HOO• and ONOO) - showed increased ROS formation following anoxia-reoxygenation treatment. Animals exposed to hyperoxic, normoxic and anoxic treatments displayed no significant differences in O2•(-) formation, whereas mitochondrial ROS formation as detected by C-H2DFFDA was higher after hyperoxic exposure and lowest under near-anoxia conditions compared with the normoxic control group. Macrostomum lignano seems to be a species that is tolerant of a wide range of oxygen concentrations (being able to maintain aerobic metabolism from extremely low PO2 up to hyperoxic conditions), which is an essential prerequisite for successfully dealing with the drastic environmental oxygen variations that occur within intertidal sediments. PMID:23531823

  3. egr-4, a target of EGFR signaling, is required for the formation of the brain primordia and head regeneration in planarians.

    PubMed

    Fraguas, Susanna; Barberán, Sara; Iglesias, Marta; Rodríguez-Esteban, Gustavo; Cebrià, Francesc

    2014-05-01

    During the regeneration of freshwater planarians, polarity and patterning programs play essential roles in determining whether a head or a tail regenerates at anterior or posterior-facing wounds. This decision is made very soon after amputation. The pivotal role of the Wnt/?-catenin and Hh signaling pathways in re-establishing anterior-posterior (AP) polarity has been well documented. However, the mechanisms that control the growth and differentiation of the blastema in accordance with its AP identity are less well understood. Previous studies have described a role of Smed-egfr-3, a planarian epidermal growth factor receptor, in blastema growth and differentiation. Here, we identify Smed-egr-4, a zinc-finger transcription factor belonging to the early growth response gene family, as a putative downstream target of Smed-egfr-3. Smed-egr-4 is mainly expressed in the central nervous system and its silencing inhibits anterior regeneration without affecting the regeneration of posterior regions. Single and combinatorial RNA interference to target different elements of the Wnt/?-catenin pathway, together with expression analysis of brain- and anterior-specific markers, revealed that Smed-egr-4: (1) is expressed in two phases - an early Smed-egfr-3-independent phase and a late Smed-egfr-3-dependent phase; (2) is necessary for the differentiation of the brain primordia in the early stages of regeneration; and (3) that it appears to antagonize the activity of the Wnt/?-catenin pathway to allow head regeneration. These results suggest that a conserved EGFR/egr pathway plays an important role in cell differentiation during planarian regeneration and indicate an association between early brain differentiation and the proper progression of head regeneration. PMID:24700819

  4. 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

  5. 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

  6. 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

    2014-01-01

    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.  PMID:25544234

  7. High multiple paternity and low last-male sperm precedence in a hermaphroditic planarian flatworm: consequences for reciprocity patterns.

    PubMed

    Pongratz, N; Michiels, N K

    2003-06-01

    It is difficult to predict a priori how mating success translates into fertilization success in simultaneous hermaphrodites with internal fertilization. Whereas insemination decisions will be determined by male interests, fertilization will depend on female interests, possibly leading to discrepancies between insemination and fertilization patterns. The planarian flatworm Schmidtea polychroa, a simultaneous hermaphrodite in which mating partners trade sperm was studied. Sperm can be stored for months yet individuals mate frequently. Using microsatellites, maternity and paternity data were obtained from 748 offspring produced in six groups of 10 individuals during four weeks. Adults produced young from four mates on average. Reciprocal fertilization between two mates was found in only 41 out of 110 registered mate combinations, which is clearly less than what is predicted from insemination patterns. Multiple paternity was high: > 80% of all cocoons had two to five fathers for only three to five offspring per cocoon. Because animals were collected from a natural population, 28% of all hatchlings were sired by unknown sperm donors in the field, despite a 10-day period of acclimatization and within-group mating. This percentage decreased only moderately throughout the experiment, showing that sperm can be stored and used for at least a month, despite frequent mating and sperm digestion. The immediate paternity a sperm donor could expect to obtain was only about 25%. Male reproductive success increased linearly with the number of female partners, providing support for Bateman's principle in hermaphrodites. Our results suggest that hermaphrodites do not trade fertilizations when trading sperm during insemination, lending support to the view that such conditional sperm exchange is driven by exchange of resources. PMID:12755872

  8. 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. PMID:25548426

  9. 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

  10. Toxicity of selenium (Na sub 2 SeO sub 3 ) and mercury (HgCl sub 2 ) on the planarian Dugesia gonocephala

    SciTech Connect

    Congiu, A.M.; Casu, S.; Ugazio, G. (Istituto di Genetica (Italy))

    1989-10-01

    The toxicity of selenium (Na{sub 2}SeO{sub 3}) and mercury (HgCl{sub 2}) was determined by using a freshwater planarian which is particularly sensitive to pollution, and belongs to a fissiparous breed of Dugesia gonocephala. The mortality and fissiparity frequency of the subjects were studied. They were exposed to intense treatments (48 hours) or for medium to long periods of time (21 days) to either the single compounds or a combination of both, and were fed or fasting. The lethal effect of sodium selenite is correlated to the food intake, whereas the toxicity of mercurous chloride is probably the result of a fixative effect which does not depend on feeding. The 21-day treatment with the first compound has a non-negligible lethal effect which is probably due to an accumulation phenomenon. At doses where an antioxidant effect prevails, fissiparity is stimulated. On the other hand, the second compound reduces reproduction frequency to half the base values. Compared to the Paracentrotus lividus, the Dugesia gonocephala offers various advantages concerning toxicological experiments; besides being easier to handle in the laboratory, it is available all year round and is not subject to seasonal cycles. It is also more susceptible to the toxic effect of mercury, which is a common and highly toxic pollutant, than the sea urchin.

  11. 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. PMID:26090388

  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.

  13. Protostomia: Lophotrochozoa: Annelida Platyhelminthes

    E-print Network

    worms · Marine, freshwater, damp terrestrial · Coelom · Closed circulatory system · Complete gut with segmental ganglia Circulatory system vessels Subpharyngeal ganglion Mouth Cerebral ganglia Anus #12;Annelida with anus · Well-developed nervous system · Metanephridia · Paired, segmental setae/chaetae · Well developed

  14. 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 addition of a vertebrate definitive host. Additional evidence is required from monopisthocotylean monogeneans in order to confirm the monophyly of the group. PMID:17270057

  15. 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 and temperatures shows its potential to readily adapt to several environmental conditions. These findings, together with the fact that A. fasciatus is a protected species and is considered as a biological control organism, necessitate further studies on the ecology and virulence of G. salinae n. sp. PMID:21658217

  16. Schmidtea mediterranea phylogeography: an old species surviving on a few Mediterranean islands?

    PubMed Central

    2011-01-01

    Background Schmidtea mediterranea (Platyhelminthes, Tricladida, Continenticola) is found in scattered localities on a few islands and in coastal areas of the western Mediterranean. Although S. mediterranea is the object of many regeneration studies, little is known about its evolutionary history. Its present distribution has been proposed to stem from the fragmentation and migration of the Corsica-Sardinia microplate during the formation of the western Mediterranean basin, which implies an ancient origin for the species. To test this hypothesis, we obtained a large number of samples from across its distribution area. Using known and new molecular markers and, for the first time in planarians, a molecular clock, we analysed the genetic variability and demographic parameters within the species and between its sexual and asexual populations to estimate when they diverged. Results A total of 2 kb from three markers (COI, CYB and a nuclear intron N13) was amplified from ~200 specimens. Molecular data clustered the studied populations into three groups that correspond to the west, central and southeastern geographical locations of the current distribution of S. mediterranea. Mitochondrial genes show low haplotype and nucleotide diversity within populations but demonstrate higher values when all individuals are considered. The nuclear marker shows higher values of genetic diversity than the mitochondrial genes at the population level, but asexual populations present lower variability than the sexual ones. Neutrality tests are significant for some populations. Phylogenetic and dating analyses show the three groups to be monophyletic, with the west group being the basal group. The time when the diversification of the species occurred is between ~20 and ~4 mya, although the asexual nature of the western populations could have affected the dating analyses. Conclusions S. mediterranea is an old species that is sparsely distributed in a harsh habitat, which is probably the consequence of the migration of the Corsica-Sardinia block. This species probably adapted to temperate climates in the middle of a changing Mediterranean climate that eventually became dry and hot. These data also suggest that in the mainland localities of Europe and Africa, sexual individuals of S. mediterranea are being replaced by asexual individuals that are either conspecific or are from other species that are better adapted to the Mediterranean climate. PMID:21943163

  17. Adhesive secretions in the platyhelminthes

    Microsoft Academic Search

    Ian D. Whittington; Bronwen W. Cribb

    2001-01-01

    This review is the first to draw together knowledge about bioadhesives secreted by a group of parasites. Mechanisms of mechanical attachment are well known among parasites, but some can also attach to host surfaces by chemical means using a thin layer of adhesive material secreted at the parasite-host interface. Attachment by adhesives to living surfaces has not been studied in

  18. Occurrence of Echeneibothrium (Platyhelminthes, Cestoda) in the

    E-print Network

    . Nu- merous macrophagous hemocytes (M) surround the connective tissue capsule (eT) and nearby tissue of the cestode Echeneibothrium sp., were found within the connective tissue of the gonads in calico scallops by a connective tissue capsule of host ori- gin and were located immediately subjacent to the wall ofthe gut. Each

  19. Diversity of introduced terrestrial flatworms in the Iberian Peninsula: a cautionary tale

    PubMed Central

    Álvarez-Presas, Marta; Tudó, Àngels; Jones, Hugh; Riutort, Marta

    2014-01-01

    Many tropical terrestrial planarians (Platyhelminthes, Geoplanidae) have been introduced around the globe. One of these species is known to cause significant decline in earthworm populations, resulting in a reduction of ecological functions that earthworms provide. Flatworms, additionally, are a potential risk to other species that have the same dietary needs. Hence, the planarian invasion might cause significant economic losses in agriculture and damage to the ecosystem. In the Iberian Peninsula only Bipalium kewense Moseley, 1878 had been cited till 2007. From that year on, four more species have been cited, and several reports of the presence of these animals in particular gardens have been received. In the present study we have: (1) analyzed the animals sent by non-specialists and also the presence of terrestrial planarians in plant nurseries and garden centers; (2) identified their species through morphological and phylogenetic molecular analyses, including representatives of their areas of origin; (3) revised their dietary sources and (4) used Species Distribution Modeling (SDM) for one species to evaluate the risk of its introduction to natural areas. The results have shown the presence of at least ten species of alien terrestrial planarians, from all its phylogenetic range. International plant trade is the source of these animals, and many garden centers are acting as reservoirs. Also, landscape restoration to reintroduce autochthonous plants has facilitated their introduction close to natural forests and agricultural fields. In conclusion, there is a need to take measures on plant trade and to have special care in the treatment of restored habitats. PMID:24949245

  20. Ca2+ channels and Praziquantel: a view from the free world

    PubMed Central

    Chan, John D.; Zarowiecki, Magdalena; Marchant, Jonathan S.

    2012-01-01

    Targeting the cellular Ca2+ channels and pumps that underpin parasite Ca2+ homeostasis may realize novel antihelmintic agents. Indeed, the antischistosomal drug praziquantel (PZQ) is a key clinical agent that has been proposed to work in this manner. Heterologous expression data has implicated an action of PZQ on voltage-operated Ca2+ channels, although the relevant in vivo target of this drug has remained undefined over three decades of clinical use. The purpose of this review is to bring new perspective to this issue by discussing the potential utility of free-living planarian flatworms for providing new insight into the mechanism of PZQ action. First, we discuss in vivo functional genetic data from the planarian system that broadly supports the molecular data collected in heterologous systems and the ‘Ca2+ hypothesis’ of PZQ action. On the basis of these similarities we highlight our current knowledge of platyhelminth voltage operated Ca2+ channels, their unique molecular pharmacology and the downstream functional PZQ interactome engaged by dysregulation of Ca2+ influx that has potential to yield novel antischistosomal targets. Overall the broad dataset underscore a common theme of PZQ-evoked disruptions of Ca2+ homeostasis in trematodes, cestodes and turbellarians, and showcase the utility of the planarian model for deriving insight into drug action and targets in parasitic flatworms. PMID:23246536

  1. RESPONSE OF THE PLANARIAN, DUGESIA, TO VERY WEAK

    Microsoft Academic Search

    HORIZONTAL ELECTROSTATIC; FRANK A. BROWN

    A deep-seated, persistent, rhythmic nature, with periods identical with or close to the major natural geophysical ones, appears increasingly to be a universal bio logical property. Striking published correlations of activity of hermetically sealed organisms with unpredictable weather-associated atmospheric temperature and pressure changes, and with day to day irregularities in the variations in primary cosmic and general background radiations, compel

  2. New primers for DNA barcoding of digeneans and cestodes (Platyhelminthes).

    PubMed

    Van Steenkiste, Niels; Locke, Sean A; Castelin, Magalie; Marcogliese, David J; Abbott, Cathryn L

    2015-07-01

    Digeneans and cestodes are species-rich taxa and can seriously impact human health, fisheries, aqua- and agriculture, and wildlife conservation and management. DNA barcoding using the COI Folmer region could be applied for species detection and identification, but both 'universal' and taxon-specific COI primers fail to amplify in many flatworm taxa. We found that high levels of nucleotide variation at priming sites made it unrealistic to design primers targeting all flatworms. We developed new degenerate primers that enabled acquisition of the COI barcode region from 100% of specimens tested (n = 46), representing 23 families of digeneans and 6 orders of cestodes. This high success rate represents an improvement over existing methods. Primers and methods provided here are critical pieces towards redressing the current paucity of COI barcodes for these taxa in public databases. PMID:25490869

  3. [Ecological approach to the problem of monophyly of Neodermata (Platyhelminthes)].

    PubMed

    Timofeeva, T A

    2005-01-01

    The ecological scenario of the evolution of main branches of Neodermata is described. The first neodermateans (= promonogeneans) were parasites of the gill lamellae of Paleozoic jawless vertebrates, which were microphagous suspension-feeding animals. The main apomorphic characters of the primary neodermateans are neodermis, cercomer (posterior hooked attachment organ) and swimming infective larva. All subsequent evolution of Neodermata was related with their acquisition new niches in hosts, which were intensively diverging in that time adapting to new food types and conquering new ecological niches. The acquisition of new microhabitats was accompanied by the development of morphological diversity in Neodermata especially in a structure of attachment and genital organs. Trematoda, Cestoda and Polyopisthocotylea comprise specialized evolutionary lineages and Monopisthocotylea is a basal taxon. Polyopisthocotylea is specialized to the blood feeding on fish gills. The common ancestors of the Trematoda and Cestoda inhabited walls of gills and pharyngeal cavities, from where they penetrated the digestive tract. The aspidogastridean multiloculate hold fast appears to be a highly specialized attachment organ of the monogenean ancestor, which inhabited muscular pharyngeal walls of Paleozoic vertebrates. The loss of cercomer hooks probably took place when mollusk-hosts have been involved in the aspidogastridean life cycle. The extinction of many chondrichthiean groups and progress of small plankton fishes (Teleostei) has led to the appearance Digenea. New vertebrate hosts needed a new infestation type and the cercaria appeared. Parthenogenesis has been developed in stages living in mollusks to counterbalance the loss of individuals at two transmission stages in the digenean cycle; this was resulted in a strong specificity to mollusk-host. Evolutionary tendencies of Trematoda and Cestoda show noticeable similarities. PMID:15907023

  4. RESPONSES OF THE PLANARIAN, DUGESIA, AND THE PROTOZOAN, PARAMECIUM, TO VERY WEAK HORIZONTAL MAGNETIC FIELDS

    Microsoft Academic Search

    FRANK A. BROWN

    The question of whether living things are sensitive to terrestrial magnetism has undoubtedly fleeted through the minds of innumerable persons since this geophysical factor first became known. But neither the naturalist, observing the behavior of organisms in the field during their continuing responses to the myriads of more obvious physical factors, nor the experimental biologist, casually testing the response of

  5. Planarian regeneration involves distinct stem cell responses to wounds and tissue absence

    E-print Network

    Wenemoser, Danielle

    Regeneration requires signaling from a wound site for detection of the wound and a mechanism that determines the nature of the injury to specify the appropriate regenerative response. Wound signals and tissue responses to ...

  6. Architectonics of the central nervous system of Acoela, Platyhelminthes, and Rotifera

    Microsoft Academic Search

    E. A. Kotikova; O. I. Raikova

    2008-01-01

    Based on the literature and own data, consecutive stages of development of the central nervous system (CNS) in the lower Bilateria\\u000a are considered-separation of brain from parenchyma, formation of its own envelopes, and development of the trunk and orthogonal\\u000a nervous system. Results of histochemical (cholinergic and catecholaminergic) and immunocytochemical (5-HT-and FMRF-amid immunoreactive)\\u000a studies of the CNS in representatives of Acoela,

  7. 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

  8. Contributions to the systematics, comparative morphology, and interrelationships of selected lecanicephalidean tapeworms (Platyhelminthes: Cestoda: Lecanicephalidea)

    E-print Network

    Cielocha, Joanna J.

    2013-05-31

    and Cephalobothrium pteroplateae Zaidi & Khan, 1976 from a species of butterfly ray from Pakistan transferred to Hexacanalis. The new species Hexacanalis folifer n. sp. is described from the zonetail butterfly ray Gymnura zonura (Bleeker) from Borneo. Two new genera...

  9. 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. PMID:24732282

  10. 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

  11. 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 Žit?an, 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. PMID:24998346

  12. 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. PMID:18844436

  13. 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. PMID:26080029

  14. Identification of thyroid hormone receptor homologs in the fluke Opisthorchis felineus (Platyhelminthes).

    PubMed

    Pakharukova, Maria Y; Ershov, Nikita I; Vorontsova, Elena V; Shilov, Alexander G; Merkulova, Tatyana I; Mordvinov, Viatcheslav A

    2014-01-01

    The liver fluke, Opisthorchis felineus of the Opisthorchiidae family, is a well-known causative agent of opisthorchiasis in Russia and Europe. The aim of this work was to identify genes encoding thyroid hormone receptors in O. felineus, and to analyze the expression of possible target genes in response to treatment with exogenous thyroid hormones. We identified two genes encoding thyroid hormone receptors in the O. felineus genome, THRA and THRB. The genes were differentially expressed through the life cycle. The maximal level of mRNA expression of THRA1 and THRB was observed in adult worms. Treatment of the worms with triiodothyronine and thyroxine resulted in an increase in glucose 6-phosphatase mRNA expression and a decrease in malate dehydrogenase mRNA expression, potential gene targets of thyroid hormones. These data indicate that thyroid hormone receptors may perform essential roles in physiological processes in adult O. felineus. PMID:24798031

  15. 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

  16. THE “9 + 1” PATTERN OF MICROTUBULES IN SPERMATOZOA OF Mesostoma (PLATYHELMINTHES, TURBELLARIA)*

    PubMed Central

    Henley, Catherine; Costello, D. P.; Thomas, Mary Beth; Newton, W. D.

    1969-01-01

    The living spermatozoa of the flatworm Mesostoma georgianum have a sperm body about 100 ? long and 0.5 ? wide, and two motile free flagella, ca. 200 ? long. In sections examined with the electron microscope, these flagella have the usual nine pairs of peripheral doublet microtubules and have a single central core unit which is connected to the A members of the doublets by spokelike structures. There are also short connections between the doublets and the flagellar membrane. In material negatively stained with phosphotungstic acid, the doublet microtubules seem to have very different elastic properties than the core; they tend to fall on the copper grids in coils of rather uniform diameter (2-4 ?), while the core is much more rigid and is often found extending alone, along a relatively straight course, for very long distances (up to 73 ?). After negative staining, the core has a striking appearance with a dense center around which are wound two hollow structures in a double helix of 45° pitch. The center-to-center distance of each gyre is approximately 650 Å, and the hollow structures are ca. 180 Å in diameter. Images PMID:4190073

  17. 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

    2014-01-01

    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.  PMID:24869820

  18. A Reevaluation of the Taxonomy of the Mesocoelium monas Complex (Platyhelminthes: Digenea: Mesoceliidae) 

    E-print Network

    Calhoun, Dana Marie

    2012-07-16

    available worldwide and based on the presence or absence of tegumental spines, the ratio of the width of the ventral sucker to the width of the oral sucker, egg length and width, and the posterior extent of the uterus recognized only 7 species..., 1964 body type (where the ceca do not surpass the ovary posteriorly and the genital pore is prebifurcal); the Mesocoelium zhejiangensis body type (where the ceca do not surpass the ovary posteriorly and the genital pore is bifurcal); the Mesocoelium...

  19. The Slipper Snail, Crepidula: An Emerging Lophotrochozoan Model System

    E-print Network

    Collin, Rachel

    stricto of Paps et al., 2009) includes molluscs, anne- lids, nemertines, the lophophorates, platyhelminths], Gnatho- stomulida, Nemertea, dicyemid Mesozoa, Entoprocta, and some Platyhelminthes [including polyclad

  20. Transparency Master: Planaria in the Classroom.

    ERIC Educational Resources Information Center

    Jensen, Lauritz A.; Allen, A. Lester

    1983-01-01

    Background information on the morphology and physiology of planarians and uses of the organism in schools is provided. Also provided is a transparency master demonstrating a planarian with an everted proboscis, two-headed/two-tailed planarians, and a planarian demonstrating the digestive tract. (JN)

  1. The ?-lactam antibiotic ceftriaxone inhibits physical dependence and abstinence-induced withdrawal from cocaine, amphetamine, methamphetamine, and clorazepate in planarians

    Microsoft Academic Search

    Scott M. Rawls; Federica Cavallo; Anna Capasso; Zhe Ding; Robert B. Raffa

    2008-01-01

    Ceftriaxone (a ?-lactam antibiotic) has recently been identified as having the rare ability to increase the expression and functional activity of the glutamate transporter subtype 1 (GLT-1) in rat spinal cord cultures. GLT-1 has been implicated in diverse neurological disorders and in opioid dependence and withdrawal. It has been speculated that it might also be involved in the physical dependence

  2. Development of mitochondrial loop-mediated isothermal amplification for detection of the small liver fluke Opisthorchis viverrini (Opisthorchiidae; Trematoda; Platyhelminthes).

    PubMed

    Le, Thanh Hoa; Nguyen, Nga Thi Bich; Truong, Nam Hai; De, Nguyen Van

    2012-04-01

    Mitochondrial DNA sequences offer major advantages over the more usual nuclear targets for loop-mediated isothermal amplification approaches (mito-LAMP) because multiple copies occur in every cell. Four LAMP primers [F3, FIP(F1c+F2), BIP(B1c+B2), and B3] were designed based on the mitochondrial nad1 sequence of Opisthorchis viverrini and used for a highly specific assay (mito-OvLAMP) to distinguish DNA of O. viverrini from that of another opisthorchiid (Clonorchis sinensis) and other trematodes (Haplorchis pumilio, Haplorchis taichui, Fasciola hepatica, and Fasciola gigantica). Conventional PCR was applied using F3/B3 primer pairs to verify the specificity of the primers for O. viverrini DNA templates. All LAMP-positive samples could be detected with the naked eye in sunlight, by gel electrophoresis (stained with ethidium bromide), and by addition of SYBR green I to the product in sunlight or under UV light. Only DNA from O. viverrini yielded amplification products by LAMP (and by PCR verification), and the LAMP limit of detection was as little as 100 fg (10(-4) ng DNA), indicating that this assay is 10 to 100 times more sensitive than PCR. Field testing was done using representative egg and metacercarial samples collected from localities where the fluke is endemic. With the advantages of simplicity, rapidity, sensitivity, and cost effectiveness, mito-OvLAMP is a good tool for molecular detection and epidemiology studies in regions or countries where O. viverrini is endemic, which can lead to more effective control of opisthorchiasis and trematodiasis. PMID:22322346

  3. Phylogenetic relationships of the Gorgoderidae (Platyhelminthes: Trematoda), including the proposal of a new subfamily (Degeneriinae n. subfam.).

    PubMed

    Cutmore, Scott C; Miller, Terrence L; Curran, Stephen S; Bennett, Michael B; Cribb, Thomas H

    2013-08-01

    Phylogenetic analyses of a range of gorgoderid trematodes based on ITS2 and partial 28S rDNA data lead us to propose the Degeneriinae n. subfam. for the genus Degeneria in recognition of its phylogenetic isolation and distinctive morphology and biology. The current concepts of the subfamilies Anaporrhutinae and Gorgoderinae were supported. Within the Gorgoderinae, the large genus Phyllodistomum is shown to be paraphyletic relative to Pseudophyllodistomum and Xystretrum. Notably, the clade of marine Phyllodistomum does not form a clade with the other marine genus, Xystretrum. Distinct clades within the Gorgoderinae correspond variously to identity of first intermediate host, form of cercaria and their marine or freshwater habitat. We are not yet in a position to propose separate genera for these clades. PMID:23760874

  4. 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. PMID:21110724

  5. A Comprehensive Molecular Phylogeny of Dalytyphloplanida (Platyhelminthes: Rhabdocoela) Reveals Multiple Escapes from the Marine Environment and Origins of Symbiotic Relationships

    PubMed Central

    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. PMID:23536894

  6. Ribosomal DNA as molecular markers and their applications in the identification of fish parasites (Platyhelminthes: Monogenea) from India

    PubMed Central

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

    2014-01-01

    The development of molecular techniques for taxonomic analysis of monogenean parasites has led to a great increase for proper identification and factualness. These molecular techniques, in particular the use of molecular markers, have been used to identify and validate the monogenean parasites. Although, improvements in marker detection systems particularly of elements of rDNA like 18S, ITS and 28S used in monogeneans parasites have enabled great advances to be made in recent years in India. However, the molecular sequence analysis and phylogenetic relationships among the parasitic helminthes is unconventional in India. Many workers have been always questioned the validity of Indian species of monogeneans and emphasized the need to ascertain the status of species from Indian fish. Here we would like to provide additional resolution for the interpretation of use of molecular markers in study of monogeneans in India. This review provides an overview of current stage of studies in India that have been used in applying molecular techniques to monogenean.

  7. Genetic differentiation among populations of Minona ileanae (Platyhelminthes: Proseriata) from the Red Sea and the Suez Canal

    Microsoft Academic Search

    Tiziana Lai; Marco Curini-Galletti; Marco Casu

    2008-01-01

    The phenomenon of Lessepsian migration has stimulated the interest of biologists ever since the opening of the Suez Canal in 1869, concerning, in particular, the possible effects of migrants on Mediterranean autochthonous communities. So far, most attention has been devoted to macrofaunal taxa – yet, the nature of the sandy shores of the Canal may constitute an ideal habitat for

  8. 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.

  9. Light and electron microscopy observations of embryogenesis and egg development in the human liver fluke, Opisthorchis viverrini (Platyhelminthes, Digenea)

    Microsoft Academic Search

    Panita Khampoosa; Malcolm K. Jones; Erica M. Lovas; Tuanchai Srisawangwong; Thewarach Laha; Supawadee Piratae; Chalida Thammasiri; Apiporn Suwannatrai; Bungorn Sripanidkulchai; Veerachai Eursitthichai; Smarn Tesana

    Eggs of most species digenean flukes hatch in the external environment to liberate larvae that seek and penetrate a snail\\u000a intermediate host. Those of the human liver flukes, Opisthorchis viverrini, hatch within the gastrointestinal canal of their snail hosts. While adult parasites are primarily responsible for the pathology\\u000a in cases of human opisthorchiasis, their eggs also contribute by inducing granulomata

  10. 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.

  11. Intermediate filaments in muscle and epithelial cells of nematodes

    PubMed Central

    1986-01-01

    Current concepts of the developmentally controlled multigene family of intermediate filament (IF) proteins expect the origin of their complexity in evolutionary precursors preceding all vertebrate classes. Among invertebrates, however, firm ultrastructural as well as molecular documentation of IFs is restricted to some giant axons and to epithelia of a few molluscs and annelids. As Ascaris lumbricoides is easily dissected into clean tissues, IF expression in this large nematode was analyzed by electron microscopic and biochemical procedures and a monoclonal antibody reacting with all mammalian IF proteins. We document for the first time the presence of IFs in muscle cells of an invertebrate. They occur in three muscle types (irregular striated pharynx muscle, obliquely striated body muscle, uterus smooth muscle). IFs are also found in the epithelia studied (syncytial epidermis, intestine, ovary, testis). Immunoblots on muscles, pharynx, intestine, uterus, and epidermis identify a pair of polypeptides (with apparent molecular masses of 71 and 63 kD) as IF constituents. In vitro reconstitution of filaments was obtained with the proteins purified from body muscle. In the small nematode Caenorhabditis elegans IF proteins are so far found only in the massive desmosome-anchored tonofilament bundles which traverse a special epithelial cell type, the marginal cells of the pharynx. We speculate that IFs may occur in most but perhaps not all invertebrates and that they may not occur in all cells in large amounts. As electron micrographs of the epidermis of a planarian--a member of the Platyhelminthes--reveal IFs, the evolutionary origin of this cytoplasmic structure can be expected either among the lowest metazoa or already in some unicellular eukaryotes. PMID:3519620

  12. Bioassays for testing effects of Al, Cr and Cd using development in the amphibian Pleurodeles waltl and regeneration in the planarian Dugesia etrusca

    Microsoft Academic Search

    F Calevro; S Campani; C Filippi; R Batistoni; P Deri; S Bucci; M Ragghianti; G Mancino

    1999-01-01

    Historically, water quality studies have been directed toward obtaining physical and chemical measurements on toxicants occurring in the aquatic environment. At present, bioassays are increasingly used as sensitive indicators of pollutant toxicity, since they are rapid, inexpensive, applicable to a variety of toxicants and allow several acute and chronic endpoints to be assessed simultaneously. The analysis of the potential toxicity

  13. 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. PMID:25651695

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

    Microsoft Academic Search

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

    2006-01-01

    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

  15. 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

  16. 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. PMID:20946697

  17. A serological study of the diet of British, lake-dwelling Glossiphonia complanata (L.) (Hirudinea: Glossiphoniidae)

    Microsoft Academic Search

    Johnstone O. Young

    1981-01-01

    Monthly or two-monthly samples of G. complanata were taken from the stony littoral of five unproductive lakes in N. Wales and seven productive lakes in Cheshire and Shropshire, England, over two years. Satisfactory antisera were produced against ten potential prey groups, viz. Tricladida, Oligochaeta, Mollusca, Cladocera, Asellus, Amphipoda, Chironomidae, Ephemeroptera, Plecoptera and Trichoptera. These were used in the precipitin test

  18. Molecular and Biochemical Parasitology 90 (1997) 395397 Erratum to ``Surprising diversity and distribution of spliced

    E-print Network

    Davis, Richard E.

    1997-01-01

    ,enolasetrans-splicing,andidentificationofflatwormSLRNAs/genes Hostandsourceb Organisma ClassificationEnolasetrans-splicingc SLRNAandGened PhylumHermitcrabshells(Woods+Polycladida(Order)+ Hole,MA) Free-living(HalfMoonBay,Polycladida(Order)NDh +Notoplanaspp. CA) Free-living(WoodsHole,MA) Free-living(CarolinaBiologi-Phagocatamorgani-Tricladida(Order)ND cals) PolychoeruscarmalensisFree-living

  19. SmedGD: the Schmidtea mediterranea genome database

    Microsoft Academic Search

    Sofia M. C. Robb; Eric Ross; Alejandro Sánchez Alvarado

    2008-01-01

    The planarian Schmidtea mediterranea is rapidly emerging as a model organism for the study of regeneration, tissue homeostasis and stem cell biology. The recent sequencing, assembly and annotation of its genome are expected to further buoy the biomedical importance of this organism. In order to make the extensive data associated with the genome sequence accessible to the biomedical and planarian

  20. [The determination of the species classification of Baikal planarian cocoons found in the stomach of the black grayling (Thymallus arcticus baicalensis) by a comparative analysis of the nucleotide sequences of the ribosomal RNA gene].

    PubMed

    Kuznedelov, K D; Dziuba, E V

    1999-01-01

    Comparative analysis of nucleotide sequences of gene 18S of ribosome RNA was carried out. The results show that the genetic sequences of the given locus could be used as a molecular marker to identify the species of planaria irrespective of ontogenetic stage. The articles deals with problem of specific determination of cocoons of Baikal planaria from the stomach of Baikal black grayling using comparative analysis of nucleotide sequences of ribosome RNA fragments with known sequences determined earlier for Baikal planaria. The cocoons belong to two species of Rimacephalus. The authors discuss also the importance of feeding relationships of planaria and benthophage fish to investigate the biotic factors that influence the evolution of Baikal planaria. PMID:10520297

  1. Dactylogyrids (Platyhelminthes: Monogenoidea) parasitizing butterfly fishes (Teleostei: Chaetodontidae) from the coral reefs of Palau, Moorea, Wallis, New Caledonia, and Australia: species of Euryhaliotrematoides n. gen. and Aliatrema n. gen.

    PubMed

    Plaisance, Laetitia; Kritsky, Delane C

    2004-04-01

    Seven species of Euryhaliotrematoides n. gen. and 1 species of Aliatrema n. gen. (Monogenoidea; Dactylogyridae) are described and reported from the gills of 15 species of butterfly fishes (Chaetodontidae) from the coral reefs of Moorea (French Polynesia), Wallis (Wallis and Futuna), Heron and Lizard (Australia), Palau (Micronesia), and New Caledonia: Aliatrema cribbi n. sp. from Chaetodon auriga, Chaetodon lunula, Chaetodon trifasciatus, Chaetodon ulietensis, Chaetodon vagabundus, Forcipiger flavisissimus, and Heniochus chrysostomus; Euryhaliotrematoides annulocirrus n. comb. from C. auriga, C. lunula, and C. vagabundus; Euryhaliotrematoides aspistis n. sp. from C. auriga, Chaetodon citrinellus, C. lunula, Chaetodon reticulatus, C. ulietensis, and C. vagabundus; Euryhaliotrematoides berenguelae n. sp. from C. citrinellus, Chaetodon ornatissimus, and F. flavisissimus; Euryhaliotrematoides grandis n. comb. from C. auriga, C. citrinellus, Chaetodon ephippium, Chaetodon kleinii, Chaetodon lineolatus, C. lunula, C. ornatissimus, C. trifasciatus, C. vagabundus, and H. chrysostomus; Euryhaliotrematoides microphallus n. comb. from C. auriga, C. citrinellus, C. ephippium, C. kleinii, C. lunula, C. ornatissimus, C. reticulatus, Chaetodon trifascialis, C. trifasciatus, C. vagabundus, F. flavisissimus, and H. chrysostomus; Euryhaliotrematoides pirulum n. sp. from C. auriga, C. citrinellus, C. lunula, C. trifasciatus, and C. vagabundus; and Euryhaliotrematoides triangulovagina n. comb. from C. auriga, C. citrinellus, C. kleinii, C. lunula, C. ornatissimus, C. vagabundus, F. flavisissimus, H. chrysostomus, and Hemitaurichthys polylepis. All reports of previously described species are new locality records. With exceptions of E. grandis and E. annulocirrus on C. auriga and C. lunula and E. triangulovagina and E. microphallus on C. auriga, all reports are new host records. Haliotrema hainanensis and H. affinis are considered junior subjective synonyms of E. triangulovagina and E. annulocirrus, respectively. Aliatrema n. gen. is characterized by marine dactylogyrids with tandem gonads (germarium pretesticular), haptoral hooks with upright acute thumbs, a coiled copulatory organ with counterclockwise rings and funnel-shaped base but lacking an accessory piece, and a dextral vaginal pore. Euryhaliotrematoides n. gen. is characterized by marine dactylogyrids having tandem gonads (germarium pretesticular), haptoral hooks with upright acute thumbs, a coiled copulatory organ with counterclockwise rings and funnel-shaped base, a vas deferens looping the left intestinal cecum, and a dextral vaginal pore. PMID:15165056

  2. Tissue absence initiates regeneration through Follistatin-mediated inhibition of Activin signaling

    E-print Network

    Gavino, Michael A.

    Regeneration is widespread, but mechanisms that activate regeneration remain mysterious. Planarians are capable of whole-body regeneration and mount distinct molecular responses to wounds that result in tissue absence and ...

  3. dlx and sp6-9 Control Optic Cup Regeneration in a Prototypic Eye

    E-print Network

    Lapan, Sylvain William

    Optic cups are a structural feature of diverse eyes, from simple pit eyes to camera eyes of vertebrates and cephalopods. We used the planarian prototypic eye as a model to study the genetic control of optic cup formation ...

  4. SmCL3, a Gastrodermal Cysteine Protease of the Human Blood Fluke Schistosoma mansoni

    E-print Network

    Craik, Charles S.

    : Blood flukes of the genus Schistosoma are platyhelminth parasites that infect 200 million people with a molecular model that shows a large and deep S2 pocket. A sequence similarity network (SSN) view clusters Sm

  5. Dynamics of asexual reproduction in flatworms

    Microsoft Academic Search

    Eva-Maria Schoetz; Jared Talbot; Joern Dunkel

    2010-01-01

    Planarians (flatworms) are one of the simplest bilaterally symmetric organisms and famous for their extraordinary regenerative capabilities. One can cut a worm in 100 pieces and after a few weeks one obtains 100 new worms that have reconstructed their entire body, including a central nervous system. This amazing regenerative capability is due to a population of stem cells distributed throughout

  6. MFR PAPER 1205 A Review of the Histopathological Effects

    E-print Network

    days during the first study and 180 days during a second study in which all oysters were irradiated Oyster, Crassostrea gigas MICHAEL C. MIX It has long been known that ionizing radiation causes studies of the effects on planarian regeneration. and those as- sociated with "sterile male" techniques

  7. RESEARCH NOTES 413 1993. Type I repressors of P Element Mobility. Genetics 135: 81

    E-print Network

    Schall, Joseph J.

    species. Journal of Parasitology 89: 1206­1211. ------, D. R. BROOKS, AND G. PEREZ-PONCE DE LEO´ N. 1999): Molecular and morphological evidence. Journal of Parasitology 85: 935­946. MORAVEC, F. 1992. Observations and classification of the Digenea (Platyhelminthes: Trematoda). International Journal of Parasitology 33: 733

  8. Using parasites to infer host population history: a new rationale for parasite conservation

    Microsoft Academic Search

    Noah Kerness Whiteman; Patricia G. Parker

    2005-01-01

    Only one of the 5000 extant louse species (Phthiraptera) and no species of flea (Siphonaptera), parasitic helminth (Platyhelminthes), parasitic nematode (Nemata), mite, or tick (Acari) is listed as threatened by the IUCN, despite impassioned pleas for parasite conservation beginning more than a decade ago. Although they should be conserved for their own sake, past arguments, highlighting the intrinsic and utilitarian

  9. Asexual reproduction and the turbellarian archetype

    Microsoft Academic Search

    Reinhard M. Rieger

    1986-01-01

    The turbellarian archetype is widely believed to have been a hermaphrodite lacking asexual reproduction, and such asexual reproduction as is now seen in the Turbellaria (as paratomy and architomy) is generally assumed to have arisen secondarily several times independently. Asexual reproduction clearly prevails among the most primitive metazoans such as the placozoans, sponges, and radiates, however, and if the Platyhelminthes

  10. Trematode parasites of Otago Harbour (New Zealand) soft?sediment intertidal ecosystems: Life cycles, ecological roles and DNA barcodes

    Microsoft Academic Search

    Tommy L. F. Leung; Kirsten M. Donald; Devon B. Keeney; Anson V. Koehler; Robert C. Peoples; Robert Poulin

    2009-01-01

    Parasites, in particular trematodes (Platyhelminthes: Digenea), play major roles in the population dynamics and community structure of invertebrates on soft?sediment mudflats. Here, we provide a list of the 20 trematode species currently known to infect molluscs, crustaceans and polychaetes from Otago Harbour (New Zealand) soft?sediment intertidal areas, as well as information on their transmission modes, life cycles, andknown ecological impacts.

  11. 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

  12. Back in time: a new systematic proposal for the Bilateria

    Microsoft Academic Search

    Pere Martinez; Jordi Paps; Marta Riutort

    2009-01-01

    Conventional wisdom suggests that bilateral organisms arose from ancestors that were radially, rather than bilaterally, symmetrical and, therefore, had a single body axis and no mesoderm. The two main hypotheses on how this transformation took place consider either a simple organism akin to the planula larva of extant cnidarians or the acoel Platyhelminthes (planuloid-acoeloid theory), or a rather complex organism

  13. Bell Pettigrew Museum of Natural History

    E-print Network

    Brierley, Andrew

    . The lack of a circulatory system to distribute respiratory gases has required the flatworms to adopt. Platyhelminths have no circulatory system to move oxygen around the body and many species have become long (up that lack a body cavity, lack a blood system, lack a through gut and lack any distinguishing features

  14. Conservation and Diversification of Msx Protein in Metazoan Evolution

    Microsoft Academic Search

    Hirokazu Takahashi; Akiko Kamiya; Akira Ishiguro; Atsushi C. Suzuki; Naruya Saitou; Atsushi Toyoda; Jun Aruga

    2007-01-01

    Msx (\\/msh) family genes encode homeodomain (HD) proteins that control ontogeny in many animal species. We compared the structures of Msx genes from a wide range of Metazoa (Porifera, Cnidaria, Nematoda, Arthropoda, Tardigrada, Platyhelminthes, Mollusca, Brachiopoda, Annelida, Echiura, Echinodermata, Hemichordata, and Chordata) to gain an understanding of the role of these genes in phylogeny. Exon-intron boundary analysis suggested that the

  15. 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

  16. Substantial loss of conserved and gain of novel MicroRNA families in flatworms.

    PubMed

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

    2013-12-01

    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

  17. Regeneration across metazoan phylogeny: lessons from model organisms.

    PubMed

    Li, Qiao; Yang, Hao; Zhong, Tao P

    2015-02-20

    Comprehending the diversity of the regenerative potential across metazoan phylogeny represents a fundamental challenge in biology. Invertebrates like Hydra and planarians exhibit amazing feats of regeneration, in which an entire organism can be restored from minute body segments. Vertebrates like teleost fish and amphibians can also regrow large sections of the body. While this regenerative capacity is greatly attenuated in mammals, there are portions of major organs that remain regenerative. Regardless of the extent, there are common basic strategies to regeneration, including activation of adult stem cells and proliferation of differentiated cells. Here, we discuss the cellular features and molecular mechanisms that are involved in regeneration in different model organisms, including Hydra, planarians, zebrafish and newts as well as in several mammalian organs. PMID:25697100

  18. THE URBILATERIAN BRAIN REVISITED: NOVEL INSIGHTS INTO OLD QUESTIONS FROM NEW FLATWORM CLADES

    PubMed Central

    Bailly, Xavier; Reichert, Heinrich; Hartenstein, Volker

    2012-01-01

    SUMMARY Flatworms are classically considered to represent the simplest organizational form of all living bilaterians with a true central nervous system. Based on their simple body plans, all flatworms have been traditionally grouped together in a single phylum at the base of the bilaterians. Current molecular phylogenomic studies now split the flatworms into two widely separated clades, the acoelomorph flatworms and the platyhelminth flatworms, such that the last common ancestor of both clades corresponds to the urbilaterian ancestor of all bilaterian animals. Remarkably, recent comparative neuroanatomical analyses of acoelomorphs and platyhelminths show that both of these flatworm groups have complex anterior brains with surprisingly similar basic neuroarchitectures. Taken together, these findings imply that fundamental neuroanatomical features of the brain in the two separate flatworm groups are likely to be primitive and derived from the urbilaterian brain. PMID:23143292

  19. The Acoela: on their kind and kinships, especially with nemertodermatids and xenoturbellids (Bilateria incertae sedis).

    PubMed

    Achatz, Johannes G; Chiodin, Marta; Salvenmoser, Willi; Tyler, Seth; Martinez, Pedro

    2013-06-01

    Acoels are among the simplest worms and therefore have often been pivotal in discussions of the origin of the Bilateria. Initially thought primitive because of their "planula-like" morphology, including their lumenless digestive system, they were subsequently dismissed by many morphologists as a specialized clade of the Platyhelminthes. However, since molecular phylogenies placed them outside the Platyhelminthes and outside all other phyla at the base of the Bilateria, they became the focus of renewed debate and research. We review what is currently known of acoels, including information regarding their morphology, development, systematics, and phylogenetic relationships, and put some of these topics in a historical perspective to show how the application of new methods contributed to the progress in understanding these animals. Taking all available data into consideration, clear-cut conclusions cannot be made; however, in our view it becomes successively clearer that acoelomorphs are a "basal" but "divergent" branch of the Bilateria. PMID:24098090

  20. [Symbionts of Mytilus edulis in the littoral and sublittoral zones of the Kandalaksha and Onega Gulfs of the White Sea].

    PubMed

    Krapivin, V A

    2012-01-01

    Composition of the fauna of organisms associated with Mytilus edulis in the Kandalaksha and Onega Gulfs of the White Sea has been examined. The following 8 symbiotic species were revealed: Choricystis sp. (Chloro[hyceae), Peniculistoma mytili, Ancistrum mytili (Ciliata, Oligohymenophorea), Urastoma cyprinae, Paravortex sp. (Platyhelminthes, Rhabditophora), and metacercaria of Cercaria parvicaudata, Himasthla sp., and Gymnophallus sp. (Platyhelminthes, Trematoda). Besides, different free-living organisms were found in the mantle cavity; 6 species of nematodes, the planktonic copepod Microsetella norvegica, undetermined copepods, isopod Jaera sp., sea mites of the family Halacaridae, and chironomid larvae. Parameters of infestation and places of localization in the host are given for each group of organisms. Some regularities in the horizontal and vertical distribution of organisms associated with M. edulis are noted. PMID:23082497

  1. The More the Merrier?

    Microsoft Academic Search

    Sofia Quinodoz; Michael A. Thomas; Jörn Dunkel; Eva-Maria Schötz

    2011-01-01

    The trade-off between traits in life-history strategies has been widely studied for sexual and parthenogenetic organisms,\\u000a but relatively little is known about the reproduction strategies of asexual animals. Here, we investigate clonal reproduction\\u000a in the freshwater planarian Schmidtea mediterranea, an important model organism for regeneration and stem cell research. We find that these flatworms adopt a randomized reproduction\\u000a strategy that

  2. Galantamine reverses scopolamine-induced behavioral alterations in Dugesia tigrina.

    PubMed

    Ramakrishnan, Latha; Amatya, Christina; DeSaer, Cassie J; Dalhoff, Zachary; Eggerichs, Michael R

    2014-09-01

    In planaria (Dugesia tigrina), scopolamine, a nonselective muscarinic receptor antagonist, induced distinct behaviors of attenuated motility and C-like hyperactivity. Planarian locomotor velocity (pLMV) displayed a dose-dependent negative correlation with scopolamine concentrations from 0.001 to 1.0 mM, and a further increase in scopolamine concentration to 2.25 mM did not further decrease pLMV. Planarian hyperactivity counts was dose-dependently increased following pretreatment with scopolamine concentrations from 0.001 to 0.5 mM and then decreased for scopolamine concentrations ? 1 mM. Planarian learning and memory investigated using classical Pavlovian conditioning experiments demonstrated that scopolamine (1 mM) negatively influenced associative learning indicated by a significant decrease in % positive behaviors from 86 % (control) to 14 % (1 mM scopolamine) and similarly altered memory retention, which is indicated by a decrease in % positive behaviors from 69 % (control) to 27 % (1 mM scopolamine). Galantamine demonstrated a complex behavior in planarian motility experiments since co-application of low concentrations of galantamine (0.001 and 0.01 mM) protected planaria against 1 mM scopolamine-induced motility impairments; however, pLMV was significantly decreased when planaria were tested in the presence of 0.1 mM galantamine alone. Effects of co-treatment of scopolamine and galantamine on memory retention in planaria via classical Pavlovian conditioning experiments showed that galantamine (0.01 mM) partially reversed scopolamine (1 mM)-induced memory deficits in planaria as the % positive behaviors increased from 27 to 63 %. The results demonstrate, for the first time in planaria, scopolamine's effects in causing learning and memory impairments and galantamine's ability in reversing scopolamine-induced memory impairments. PMID:24402079

  3. Global Expression Analysis Revealed Novel Gender-Specific Gene Expression Features in the Blood Fluke Parasite Schistosoma japonicum

    Microsoft Academic Search

    Xianyu Piao; Pengfei Cai; Shuai Liu; Nan Hou; Lili Hao; Fan Yang; Heng Wang; Jianwei Wang; Qi Jin; Qijun Chen; Erika Martins Braga

    2011-01-01

    BackgroundSchistosoma japonicum is one of the remarkable Platyhelminths that are endemic in China and Southeast Asian countries. The parasite is dioecious and can reside inside the host for many years. Rapid reproduction by producing large number of eggs and count-react host anti-parasite responses are the strategies that benefit long term survival of the parasite. Praziquantel is currently the only drug

  4. Characterisation of Fasciola species from Mainland China by ITS2 ribosomal DNA sequence

    Microsoft Academic Search

    W. Y Huang; B He; C. R Wang; X. Q Zhu

    2004-01-01

    Isolates of Fasciola (Platyhelminthes: Trematoda: Digenea) from different host species and geographical locations in Mainland China were characterised genetically. The second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA (rDNA) was amplified from individual trematodes by polymerase chain reaction (PCR), and the representative amplicons were cloned and sequenced. The length of the ITS-2 sequences was 361–362bp for all Chinese Fasciola

  5. Neuroschistosomiasis

    Microsoft Academic Search

    Allen G. RossDonald; Donald P. McManus; Jeremy Farrar; Richard J. Hunstman; Darren J. Gray; Yue-Sheng Li

    Schistosomiasis (bilharzia) is a neglected tropical disease caused by digenetic trematode platyhelminths of the genus Schistosoma. Neuroschistosomiasis is one of the most severe clinical outcomes associated with schistosome infection. Neurological complications\\u000a early during the course of infection are thought to occur through in situ egg deposition following aberrant migration of adult\\u000a worms to the brain or spinal cord. The presence

  6. SmCL3, a Gastrodermal Cysteine Protease of the Human Blood Fluke Schistosoma mansoni

    Microsoft Academic Search

    Jan Dvo?ák; Susan T. Mashiyama; Mohammed Sajid; Simon Braschi; Melaine Delcroix; Eric L. Schneider; Wilson H. McKerrow; Mahmoud Bahgat; Elizabeth Hansell; Patricia C. Babbitt; Charles S. Craik; James H. McKerrow; Conor R. Caffrey

    2009-01-01

    BackgroundBlood flukes of the genus Schistosoma are platyhelminth parasites that infect 200 million people worldwide. Digestion of nutrients from the host bloodstream is essential for parasite development and reproduction. A network of proteolytic enzymes (proteases) facilitates hydrolysis of host hemoglobin and serum proteins.Methodology\\/Principal FindingsWe identified a new cathepsin L termed SmCL3 using PCR strategies based on S. mansoni EST sequence

  7. Characterization of a flatworm inositol (1,4,5) trisphosphate receptor (IP3R) reveals a role in reproductive physiology

    PubMed Central

    Zhang, Dan; Liu, Xiaolong; Chan, John D.; Marchant, Jonathan S.

    2013-01-01

    Inositol 1,4,5-trisphosphate receptors (IP3Rs) are intracellular Ca2+channels that elevate cytoplasmic Ca2+ in response to the second messenger IP3. Here, we describe the identification and in vivo functional characterization of the planarian IP3R, the first intracellular Ca2+ channel to be defined in flatworms. A single IP3R gene in Dugesia japonica encoded a 2666 amino acid protein (Dj.IP3R) that shared well conserved structural features with vertebrate IP3R counterparts. Expression of an NH2-terminal Dj.IP3R region (amino acid residues 223–585) recovered high affinity 3H-IP3 binding (0.9 ± 0.1 nM) which was abolished by a single point mutation of an arginine residue (R495L) important for IP3 coordination. In situ hybridization revealed that Dj.IP3R mRNA was most strongly expressed in the pharynx and optical nerve system as well as the reproductive system in sexualized planarians. Consistent with this observed tissue distribution, in vivo RNAi of Dj.IP3R resulted in a decreased egg-laying behavior suggesting Dj.IP3R plays an upstream role in planarian reproductive physiology. PMID:23481272

  8. Behavioral characterization of serotonergic activation in the flatworm Planaria.

    PubMed

    Farrell, Martilias S; Gilmore, Kirsti; Raffa, Robert B; Walker, Ellen A

    2008-05-01

    Serotonin (5-hydroxytryptamine, 5-HT) receptors have been identified in Planaria, a model used for studying the pharmacology of behavioral phenomena. This study characterized the behavioral and locomotor effects of 5-HT, a 5-HT1A agonist, a 5-HT1B/2C agonist, and a 5-HT1A antagonist to examine the role of 5-HT receptor activation in this species. Planarians were video recorded individually in a clear plastic cube containing drug solution or vehicle. To quantify locomotor velocity (pLMV), planarians were placed individually into a dish containing drug solution or vehicle and the rate of gridline crossings was recorded. For the antagonist experiments, four conditions were studied: water alone, agonist alone, antagonist alone, and agonist plus antagonist. The decrease in pLMV induced by the5-HT1A agonist (8-OH-DPAT), and the 5-HT1B/2C agonist (mCPP), was antagonized by pretreatment with the 5-HT1A antagonist (WAY-100635) at a dose that had no effect of its own on pLMV. At a higher concentration of WAY-100635, further decreases in pLMV induced by 8-OH-DPAT were observed. Each agonist produced increased occurrences of 'C-like position' and 'screw-like hyperkinesia', 5-HT and mCPP produced 'writhing', and only mCPP produced a significant increase in duration of 'headswing' behavior. The results demonstrate that the 5-HT1A receptor identified in Planaria mediates behavioral responses to 5-HT receptor ligands, supporting the notion that planarians possess functional 5-HT receptors and might serve as a simple model for their study. PMID:18469535

  9. Wnt Signaling in Axial Patterning and Regeneration: Lessons from Planaria

    NSDL National Science Digital Library

    Edward M. De Robertis (Los Angeles; University of California REV)

    2010-06-22

    Wnt signal transduction plays a crucial role in stem cell proliferation and regeneration. When canonical Wnt signaling is low, heads develop, and when it is high, tails are formed. In planarians, Wnt transcription is activated by wounding in a ?-catenin?independent way. Hedgehog is one of the signals involved, because it induces regeneration of tails (instead of heads) through the activation of Wnt transcription. Depletion of Smad4 blocks regeneration entirely, which suggests that the bone morphogenetic protein signaling pathway and the Wnt pathway are required for regeneration and body patterning.

  10. Combined effect of invertebrate predation and sublethal pesticide exposure on the behavior and survival of Asellus aquaticus (Crustacea; Isopoda).

    PubMed

    Bundschuh, Mirco; Appeltauer, Andreas; Dabrunz, André; Schulz, Ralf

    2012-07-01

    Invertebrate communities of lentic habitats comprise, amongst others, the crustacean Asellus aquaticus (Isopoda) and the turbellarian Dendrocoelum lacteum (Tricladida). Because D. lacteum preferentially preys on A. aquaticus, contaminants introduced into the aquatic environment may affect this predator-prey interaction, finally influencing the performance of the predator. However, no studies investigating implications of organic pollutants on this food web subsystem currently exist. Hence, the present study assessed short-term implications of pesticides with different modes of action, namely, the triazole fungicide tebuconazole and the pyrethroid insecticide lambda-cyhalothrin, during a 72 h trial. The experiments for tebuconazole showed a statistically significant decrease in predatory success of D. lacteum. Lambda-cyhalothrin, in contrast, increased predation success by 40%, which is, however, not statistically significant. Both the decrease and the increase in predation seemed to be primarily driven by an altered activity of the prey A. aquaticus. This may be hypothesized because any shift in the prey's activity influenced its probability to stick to mucus, a viscous substance released by D. lacteum, or to encounter the predator directly. PMID:22223070

  11. Mephedrone ("bath salt") pharmacology: insights from invertebrates.

    PubMed

    Ramoz, L; Lodi, S; Bhatt, P; Reitz, A B; Tallarida, C; Tallarida, R J; Raffa, R B; Rawls, S M

    2012-04-19

    Psychoactive bath salts (also called meph, drone, meow meow, m-CAT, bounce, bubbles, mad cow, etc.) contain a substance called mephedrone (4-methylcathinone) that may share psychostimulant properties with amphetamine and cocaine. However, there are only limited studies of the neuropharmacological profile of mephedrone. The present study used an established invertebrate (planarian) assay to test the hypothesis that acute and repeated mephedrone exposure produces psychostimulant-like behavioral effects. Acute mephedrone administration (50-1000 ?M) produced stereotyped movements that were attenuated by a dopamine receptor antagonist (SCH 23390) (0.3 ?M). Spontaneous discontinuation of mephedrone exposure (1, 10 ?M) (60 min) resulted in an abstinence-induced withdrawal response (i.e. reduced motility). In place conditioning experiments, planarians in which mephedrone (100, 500 ?M) was paired with the non-preferred environment during conditioning displayed a shift in preference upon subsequent testing. These results suggest that mephedrone produces three behavioral effects associated with psychostimulant drugs, namely dopamine-sensitive stereotyped movements, abstinence-induced withdrawal, and environmental place conditioning. PMID:22300981

  12. Selective amputation of the pharynx identifies a FoxA-dependent regeneration program in planaria

    PubMed Central

    Adler, Carolyn E; Seidel, Chris W; McKinney, Sean A; Sánchez Alvarado, Alejandro

    2014-01-01

    Planarian flatworms regenerate every organ after amputation. Adult pluripotent stem cells drive this ability, but how injury activates and directs stem cells into the appropriate lineages is unclear. Here we describe a single-organ regeneration assay in which ejection of the planarian pharynx is selectively induced by brief exposure of animals to sodium azide. To identify genes required for pharynx regeneration, we performed an RNAi screen of 356 genes upregulated after amputation, using successful feeding as a proxy for regeneration. We found that knockdown of 20 genes caused a wide range of regeneration phenotypes and that RNAi of the forkhead transcription factor FoxA, which is expressed in a subpopulation of stem cells, specifically inhibited regrowth of the pharynx. Selective amputation of the pharynx therefore permits the identification of genes required for organ-specific regeneration and suggests an ancient function for FoxA-dependent transcriptional programs in driving regeneration. DOI: http://dx.doi.org/10.7554/eLife.02238.001 PMID:24737865

  13. ?-lactamase inhibitors display anti-seizure properties in an invertebrate assay

    PubMed Central

    Rawls, Scott M.; Karaca, Fatma; Madhani, Isha; Bhojani, Vineeta; Martinez, Rogelilo L.; Abou-Gharbia, Magid; Raffa, Robert B.

    2010-01-01

    Summary Antibiotics containing a ?-lactam ring (e.g., ceftriaxone) display anti-glutamate effects that underlie their efficacy in animal models of CNS diseases (Rothstein et al., 2005). We hypothesized that the structurally related ?-lactamase inhibitors (clavulanic acid, tazobactam)- which also contain a ?-lactam ring - will mimic ceftriaxone efficacy in an invertebrate (planarian) assay designed to screen for anti-seizure activity (Rawls et al., 2009). Glutamate or cocaine administration produced planarian seizure-like activity (pSLA). Glutamate- or cocaine-induced pSLA was inhibited by ceftriaxone, clavulanic acid, or tazobactam, but not by the non-?-lactam antibiotic vancomyocin. The present findings indicate ?-lactamase inhibitors display efficacy, and mimic ceftriaxone activity, in an invertebrate anti-seizure screen. These results suggest ?-lactamase inhibitors particularly ones such as clavulanic acid that display enhanced brain penetrability, oral bioavailability, and negligible anti-bacterial activity might offer an attractive alternative to direct antibiotic therapy for managing CNS diseases caused by increased glutamate transmission and provide a solution to the growing concern that ceftriaxone will be of only limited utility as a CNS-active therapeutic because of its intolerable side effects. PMID:20600649

  14. The characteristics of sox gene in Dugesia japonica.

    PubMed

    Dong, Zimei; Shi, Changying; Zhang, Haixia; Dou, He; Cheng, Fangfang; Chen, Guangwen; Liu, Dezeng

    2014-07-10

    Sox genes play important roles in animal developmental processes, including embryogenesis, neural cell stemness, neurogenesis, sex determination, among others. Here, the full length sox gene in planarian Dugesia japonica, named DjsoxB, was cloned using rapid amplification of cDNA ends (RACE). Phylogenetic analysis demonstrates that DjsoxB is highly conserved evolutionarily in metazoans. Whole-mount in situ hybridization found DjsoxB mRNA to be mainly expressed in the head, intestine and mouth in both sexually mature and immature planarians. Moreover, DjsoxB transcripts were detected in the blastema after amputation and throughout the head regeneration processes. The data from real-time PCR showed that the mRNA expression levels of DjsoxB were distinctly up-regulated from 3 to 7days after amputation. These results suggest that DjsoxB gene might be active in CNS formation and functional recovery during head regeneration, maintenance of adult CNS function and the development of other tissues (e.g. intestine) in D. japonica. PMID:24768739

  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. [Phylogenetic analysis of tyrosinase gene family in the Pacific oyster (Crassostrea gigas Thunberg)].

    PubMed

    Yu, Xue; Yu, Hong; Kong, Lingfeng; Li, Qi

    2014-02-01

    The deduced amino acid sequence characteristics, classification and phylogeny of tyrosinase gene family in the Pacific oyster (Crassostrea gigas Thunberg) were analyzed using bioinformatics methods. The results showed that gene duplication was the major cause of tyrosinase gene expansion in the Pacific oyster. The tyrosinase gene family in the Pacific oyster can be further classified into three types: secreted form (Type A), cytosolic form (Type B) and membrane-bound form (Type C). Based on the topology of the phylogenetic tree of the Pacific oyster tyrosinases, among Type A isoforms, tyr18 seemed divergent from other Type A tyrosinases early, while tyr2 and tyr9 appeared divergent early in Type B. In Type C tyrosinses, tyr8 was divergent early. The cluster of the Pacific oyster tyrosinasesis determined by their classifications and positions in the scaffolds. Further analysis suggested that Type A tyrosinases of C. gigas clustered with those from cephalopods and then with nematodes and cnidarians. Type B tyrosinases were generally clustered with the same type of tyrosinases from molluscas and nematodes, and then with those from platyhelminths, cnidarians and chordates. Type A tyrosinases in the Pacific oyster and the Pearl oyster expanded independently and were divergent from membrane-bound form of tyrosinases in chordata, platyhelminthes and annelida. These observations suggested that Type C tyrosinases in the bivalve had a distinct evolution direction. PMID:24846942

  17. The European eel may tolerate multiple infections at a low biological cost.

    PubMed

    Mayo-Hernández, Elvira; Serrano, Emmanuel; Peñalver, Jose; García-Ayala, Alfonsa; Ruiz DE Ybáñez, Rocío; Muñoz, Pilar

    2015-06-01

    Most animals are concurrently infected with multiple parasites, and interactions among them may influence both disease dynamics and host fitness. However, the sublethal costs of parasite infections are difficult to measure and the effects of concomitant infections with multiple parasite species on individual physiology and fitness are poorly described for wild hosts. To understand the costs of co-infection, we investigated the relationships among 189 European eel (Anguilla anguilla) from Mar Menor, parasites (richness and intensity) and eel's 'health status' (fluctuant asymmetry, splenic somatic index and the scaled mass index) by partial least squares regression. We found a positive relationship with 44% of the health status variance explained by parasites. Contracaecum sp. (Nematoda: Anisakidae) was the strongest predictor variable (44·72%) followed by Bucephalus anguillae (Platyhelminthes: Bucephalidae), (29·26%), considered the two most relevant parasites in the analysis. Subsequently, 15·67 and 12·01% of the response variables block were explained by parasite richness and Deropristis inflata (Platyhelminthes: Deropristiidae), respectively. Thus, the presence of multiple parasitic exposures with little effect on condition, strongly suggests that eels from Mar Menor tolerate multiparasitism. PMID:25711727

  18. Design of a flexible component gathering algorithm for converting cell-based models to graph representations for use in evolutionary search

    PubMed Central

    2014-01-01

    Background The ability of science to produce experimental data has outpaced the ability to effectively visualize and integrate the data into a conceptual framework that can further higher order understanding. Multidimensional and shape-based observational data of regenerative biology presents a particularly daunting challenge in this regard. Large amounts of data are available in regenerative biology, but little progress has been made in understanding how organisms such as planaria robustly achieve and maintain body form. An example of this kind of data can be found in a new repository (PlanformDB) that encodes descriptions of planaria experiments and morphological outcomes using a graph formalism. Results We are developing a model discovery framework that uses a cell-based modeling platform combined with evolutionary search to automatically search for and identify plausible mechanisms for the biological behavior described in PlanformDB. To automate the evolutionary search we developed a way to compare the output of the modeling platform to the morphological descriptions stored in PlanformDB. We used a flexible connected component algorithm to create a graph representation of the virtual worm from the robust, cell-based simulation data. These graphs can then be validated and compared with target data from PlanformDB using the well-known graph-edit distance calculation, which provides a quantitative metric of similarity between graphs. The graph edit distance calculation was integrated into a fitness function that was able to guide automated searches for unbiased models of planarian regeneration. We present a cell-based model of planarian that can regenerate anatomical regions following bisection of the organism, and show that the automated model discovery framework is capable of searching for and finding models of planarian regeneration that match experimental data stored in PlanformDB. Conclusion The work presented here, including our algorithm for converting cell-based models into graphs for comparison with data stored in an external data repository, has made feasible the automated development, training, and validation of computational models using morphology-based data. This work is part of an ongoing project to automate the search process, which will greatly expand our ability to identify, consider, and test biological mechanisms in the field of regenerative biology. PMID:24917489

  19. A Transcriptomic Analysis of Echinococcus granulosus Larval Stages: Implications for Parasite Biology and Host Adaptation

    PubMed Central

    Parkinson, John; Wasmuth, James D.; Salinas, Gustavo; Bizarro, Cristiano V.; Sanford, Chris; Berriman, Matthew; Ferreira, Henrique B.; Zaha, Arnaldo; Blaxter, Mark L.; Maizels, Rick M.; Fernández, Cecilia

    2012-01-01

    Background The cestode Echinococcus granulosus - the agent of cystic echinococcosis, a zoonosis affecting humans and domestic animals worldwide - is an excellent model for the study of host-parasite cross-talk that interfaces with two mammalian hosts. To develop the molecular analysis of these interactions, we carried out an EST survey of E. granulosus larval stages. We report the salient features of this study with a focus on genes reflecting physiological adaptations of different parasite stages. Methodology/Principal Findings We generated ?10,000 ESTs from two sets of full-length enriched libraries (derived from oligo-capped and trans-spliced cDNAs) prepared with three parasite materials: hydatid cyst wall, larval worms (protoscoleces), and pepsin/H+-activated protoscoleces. The ESTs were clustered into 2700 distinct gene products. In the context of the biology of E. granulosus, our analyses reveal: (i) a diverse group of abundant long non-protein coding transcripts showing homology to a middle repetitive element (EgBRep) that could either be active molecular species or represent precursors of small RNAs (like piRNAs); (ii) an up-regulation of fermentative pathways in the tissue of the cyst wall; (iii) highly expressed thiol- and selenol-dependent antioxidant enzyme targets of thioredoxin glutathione reductase, the functional hub of redox metabolism in parasitic flatworms; (iv) candidate apomucins for the external layer of the tissue-dwelling hydatid cyst, a mucin-rich structure that is critical for survival in the intermediate host; (v) a set of tetraspanins, a protein family that appears to have expanded in the cestode lineage; and (vi) a set of platyhelminth-specific gene products that may offer targets for novel pan-platyhelminth drug development. Conclusions/Significance This survey has greatly increased the quality and the quantity of the molecular information on E. granulosus and constitutes a valuable resource for gene prediction on the parasite genome and for further genomic and proteomic analyses focused on cestodes and platyhelminths. PMID:23209850

  20. Opening the genetic toolbox of niche model organisms with high throughput techniques: novel proteins in regeneration as a case study.

    PubMed

    Looso, Mario

    2014-04-01

    Understanding in vivo regeneration of complex structures offers a fascinating perspective for translation into medical applications. Unfortunately, mammals in general lack large-scale regenerative capacity, whereas planarians, newts or Hydra can regenerate complete body parts. Such organisms are, however, poorly annotated because of the lack of sequence information. This leads to limited access for molecular biological investigations. In the last decade, high throughput technologies and new methods enabling the effective generation of transgenic animals have rapidly evolved. These developments have allowed the extensive use of niche model organisms as part of a trend towards the accessibility of a greater panel of model species for scientific research. The case study that follows provides an insight into the impact of high throughput techniques on the landscape of models of regeneration. The cases presented here give evidence of alternative stem cell maintenance pathways, the identification of new protein families and new stem cell markers. PMID:24741707

  1. SAPling: a Scan-Add-Print barcoding database system to label and track asexual organisms

    PubMed Central

    Thomas, Michael A.; Schötz, Eva-Maria

    2011-01-01

    SUMMARY We have developed a ‘Scan-Add-Print’ database system, SAPling, to track and monitor asexually reproducing organisms. Using barcodes to uniquely identify each animal, we can record information on the life of the individual in a computerized database containing its entire family tree. SAPling has enabled us to carry out large-scale population dynamics experiments with thousands of planarians and keep track of each individual. The database stores information such as family connections, birth date, division date and generation. We show that SAPling can be easily adapted to other asexually reproducing organisms and has a strong potential for use in large-scale and/or long-term population and senescence studies as well as studies of clonal diversity. The software is platform-independent, designed for reliability and ease of use, and provided open source from our webpage to allow project-specific customization. PMID:21993779

  2. Evolution of multicellular animals as deduced from 5S rRNA sequences: a possible early emergence of the Mesozoa.

    PubMed Central

    Ohama, T; Kumazaki, T; Hori, H; Osawa, S

    1984-01-01

    The nucleotide sequences of 5S rRNA from a mesozoan Dicyema misakiense and three metazoan species, i.e., an acorn-worm Saccoglossus kowalevskii, a moss-animal Bugula neritina, and an octopus Octopus vulgaris have been determined. A phylogenic tree of multicellular animals has been constructed from 73 5S rRNA sequences available at present including those from the above four sequences. The tree suggests that the mesozoan is the most ancient multicellular animal identified so far, its emergence time being almost the same as that of flagellated or ciliated protozoans. The branching points of planarians and nematodes are a little later than that of the mesozoan but are clearly earlier than other metazoan groups including sponges and jellyfishes. Many metazoan groups seem to have diverged within a relatively short period. PMID:6539911

  3. Evolution of multicellular animals as deduced from 5S rRNA sequences: a possible early emergence of the Mesozoa.

    PubMed

    Ohama, T; Kumazaki, T; Hori, H; Osawa, S

    1984-06-25

    The nucleotide sequences of 5S rRNA from a mesozoan Dicyema misakiense and three metazoan species, i.e., an acorn-worm Saccoglossus kowalevskii, a moss-animal Bugula neritina, and an octopus Octopus vulgaris have been determined. A phylogenic tree of multicellular animals has been constructed from 73 5S rRNA sequences available at present including those from the above four sequences. The tree suggests that the mesozoan is the most ancient multicellular animal identified so far, its emergence time being almost the same as that of flagellated or ciliated protozoans. The branching points of planarians and nematodes are a little later than that of the mesozoan but are clearly earlier than other metazoan groups including sponges and jellyfishes. Many metazoan groups seem to have diverged within a relatively short period. PMID:6539911

  4. An In Vivo Requirement for the Mediator Subunit Med14 in the Maintenance of Stem Cell Populations

    PubMed Central

    Burrows, Jeffrey T.A.; Pearson, Bret J.; Scott, Ian C.

    2015-01-01

    Summary The Mediator complex has recently been shown to be a key player in the maintenance of embryonic and induced pluripotent stem cells. However, the in vivo consequences of loss of many Mediator subunits are unknown. We identified med14 as the gene affected in the zebrafish logelei (log) mutant, which displayed a morphological arrest by 2 days of development. Surprisingly, microarray analysis showed that transcription was not broadly affected in log mutants. Indeed, log cells transplanted into a wild-type environment were able to survive into adulthood. In planarians, RNAi knockdown demonstrated a requirement for med14 and many other Mediator components in adult stem cell maintenance and regeneration. Multiple stem/progenitor cell populations were observed to be reduced or absent in zebrafish med14 mutant embryos. Taken together, our results show a critical, evolutionarily conserved, in vivo function for Med14 (and Mediator) in stem cell maintenance, distinct from a general role in transcription. PMID:25772472

  5. Malacological assessment and natural infestation of Biomphalaria straminea (Dunker, 1848) by Schistosoma mansoni (Sambon, 1907) And Chaetogaster limnaei (K. Von Baer, 1827) in an urban eutrophic watershed.

    PubMed

    Callisto, M; Moreno, P; Gonçalves, J F; Ferreira, W R; Gomes, C L Z

    2005-05-01

    The objective of this study was to perform a malacological assessment at the Ibirité reservoir watershed in the metropolitan region of Belo Horizonte (Minas Gerais) and to evaluate the natural infestation rate of Biomphalaria straminea (Gastropoda: Planorbidae) by Schistosoma mansoni (Platyhelminthes: Trematoda) and Chaetogaster limnaei (Oligochaeta: Naididae). The samples were collected from July to August 2002. The B. straminea individuals collected were kept in the laboratory; the natural infestation rate by S. mansoni and C. limnaei was assessed weekly. The malacological assessment identified five mollusk species present in the Ibirité reservoir watershed: B. straminea, Physa marmorata, Lymnea sp., Melanoides tuberculatus, and Pomacea austrum. Laboratory observations showed that the B. straminea individuals were infected by C. limnaei rather than S. mansoni. Although there was no infection of B. straminea by S. mansoni, presence of B. straminea in itself merits close attention due to possible risk of human schistosomiasis by the local population. PMID:16097724

  6. 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

  7. Calcium channels of schistosomes: unresolved questions and unexpected answers

    PubMed Central

    Salvador-Recatalà, Vicenta; Greenberg, Robert M.

    2011-01-01

    Parasitic flatworms of the genus Schistosoma are the causative agents of schistosomiasis, a highly prevalent, neglected tropical disease that causes significant morbidity in hundreds of millions of people worldwide. The current treatment of choice against schistosomiasis is praziquantel (PZQ), which is known to affect Ca2+ homeostasis in schistosomes, but which has an undefined molecular target and mode of action. PZQ is the only available antischistosomal drug in most parts of the world, making reports of PZQ resistance particularly troubling. Voltage-gated Ca2+ (Cav) channels have been proposed as possible targets for PZQ, and, given their central role in the neuromuscular system, may also serve as targets for new anthelmintic therapeutics. Indeed, ion channels constitute the majority of targets for current anthelmintics. Cav channel subunits from schistosomes and other platyhelminths have several unique properties that make them attractive as potential drug targets, and that could also provide insights into structure-function relationships in, and evolution of, Cav channels. PMID:22347719

  8. Cytosine methylation regulates oviposition in the pathogenic blood fluke Schistosoma mansoni

    PubMed Central

    Geyer, Kathrin K.; Rodríguez López, Carlos M.; Chalmers, Iain W.; Munshi, Sabrina E.; Truscott, Martha; Heald, James; Wilkinson, Mike J.; Hoffmann, Karl F.

    2011-01-01

    Similar to other metazoan pathogens, Schistosoma mansoni undergoes transcriptional and developmental regulation during its complex lifecycle and host interactions. DNA methylation as a mechanism to control these processes has, to date, been discounted in this parasite. Here we show the first evidence for cytosine methylation in the S. mansoni genome. Transcriptional coregulation of novel DNA methyltransferase (SmDnmt2) and methyl-CpG-binding domain proteins mirrors the detection of cytosine methylation abundance and implicates the presence of a functional DNA methylation machinery. Genome losses in cytosine methylation upon SmDnmt2 silencing and the identification of a hypermethylated, repetitive intron within a predicted forkhead gene confirm this assertion. Importantly, disruption of egg production and egg maturation by 5-azacytidine establishes an essential role for 5-methylcytosine in this parasite. These findings provide the first functional confirmation for this epigenetic modification in any worm species and link the cytosine methylation machinery to platyhelminth oviposition processes. PMID:21829186

  9. ?-lactamase inhibitors display anti-seizure properties in an invertebrate assay.

    PubMed

    Rawls, S M; Karaca, F; Madhani, I; Bhojani, V; Martinez, R L; Abou-Gharbia, M; Raffa, R B

    2010-09-15

    Antibiotics containing a beta-lactam ring (e.g. ceftriaxone) display anti-glutamate effects that underlie their efficacy in animal models of central nervous system (CNS) diseases [Rothstein JD, Patel S, Regan MR, Haenggeli C, Huang YH, Bergles DE, Jin L, Dykes Hoberg M, Vidensky S, Chung DS, Toan SV, Bruijn LI, Su ZZ, Gupta P, Fisher PB (2005) Nature 433:73-77]. We hypothesized that the structurally related beta-lactamase inhibitors (clavulanic acid, tazobactam)--which also contain a beta-lactam ring--will mimic ceftriaxone efficacy in an invertebrate (planarian) assay designed to screen for anti-seizure activity [Rawls SM, Thomas T, Adeola M, Patil T, Raymondi N, Poles A, Loo M, Raffa RB (2009) Pharmacol Biochem Behav 93:363-367]. Glutamate or cocaine administration produced planarian seizure-like activity (pSLA). Glutamate- or cocaine-induced pSLA was inhibited by ceftriaxone, clavulanic acid, or tazobactam, but not by the non-beta-lactam antibiotic vancomyocin. The present findings indicate beta-lactamase inhibitors display efficacy, and mimic ceftriaxone activity, in an invertebrate anti-seizure screen. These results suggest beta-lactamase inhibitors--particularly ones such as clavulanic acid that display enhanced brain penetrability, oral bioavailability, and negligible anti-bacterial activity--might offer an attractive alternative to direct antibiotic therapy for managing CNS diseases caused by increased glutamate transmission and provide a solution to the growing concern that ceftriaxone will be of only limited utility as a CNS-active therapeutic because of its intolerable side effects. PMID:20600649

  10. Characterization of the stem cell system of the acoel Isodiametra pulchra

    PubMed Central

    2009-01-01

    Background Tissue plasticity and a substantial regeneration capacity based on stem cells are the hallmark of several invertebrate groups such as sponges, cnidarians and Platyhelminthes. Traditionally, Acoela were seen as an early branching clade within the Platyhelminthes, but became recently positioned at the base of the Bilateria. However, little is known on how the stem cell system in this new phylum is organized. In this study, we wanted to examine if Acoela possess a neoblast-like stem cell system that is responsible for development, growth, homeostasis and regeneration. Results We established enduring laboratory cultures of the acoel Isodiametra pulchra (Acoela, Acoelomorpha) and implemented in situ hybridization and RNA interference (RNAi) for this species. We used BrdU labelling, morphology, ultrastructure and molecular tools to illuminate the morphology, distribution and plasticity of acoel stem cells under different developmental conditions. We demonstrate that neoblasts are the only proliferating cells which are solely mesodermally located within the organism. By means of in situ hybridisation and protein localisation we could demonstrate that the piwi-like gene ipiwi1 is expressed in testes, ovaries as well as in a subpopulation of somatic stem cells. In addition, we show that germ cell progenitors are present in freshly hatched worms, suggesting an embryonic formation of the germline. We identified a potent stem cell system that is responsible for development, homeostasis, regeneration and regrowth upon starvation. Conclusions We introduce the acoel Isodiametra pulchra as potential new model organism, suitable to address developmental questions in this understudied phylum. We show that neoblasts in I. pulchra are crucial for tissue homeostasis, development and regeneration. Notably, epidermal cells were found to be renewed exclusively from parenchymally located stem cells, a situation known only from rhabditophoran flatworms so far. For further comparison, it will be important to analyse the stem cell systems of other key-positioned understudied taxa. PMID:20017953

  11. 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

  12. 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-intron remodeling. The differentiated enzymatic properties might be acquired by the evolutionary relaxation of selection pressure and/or biochemical adaptation to the acting environments. Our present study would be beneficial to get detailed insights into the complex GPx evolution, and to understand the molecular basis of the specialized physiological implications of this antioxidant system in their respective donor organisms. PMID:19344533

  13. 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 measures to prevent further spread of the flatworm to and from this site, identifying if possible the likely primary source of the flatworm, and tracing other possible incursions that may have resulted from accidental dispersal of plants and soil from the site. PMID:24688873

  14. RNA interference can target pre-mRNA: consequences for gene expression in a Caenorhabditis elegans operon.

    PubMed Central

    Bosher, J M; Dufourcq, P; Sookhareea, S; Labouesse, M

    1999-01-01

    In nematodes, flies, trypanosomes, and planarians, introduction of double-stranded RNA results in sequence-specific inactivation of gene function, a process termed RNA interference (RNAi). We demonstrate that RNAi against the Caenorhabditis elegans gene lir-1, which is part of the lir-1/lin-26 operon, induced phenotypes very different from a newly isolated lir-1 null mutation. Specifically, lir-1(RNAi) induced embryonic lethality reminiscent of moderately strong lin-26 alleles, whereas the lir-1 null mutant was viable. We show that the lir-1(RNAi) phenotypes resulted from a severe loss of lin-26 gene expression. In addition, we found that RNAi directed against lir-1 or lin-26 introns induced similar phenotypes, so we conclude that lir-1(RNAi) targets the lir-1/lin-26 pre-mRNA. This provides direct evidence that RNA interference can prevent gene expression by targeting nuclear transcripts. Our results highlight that caution may be necessary when interpreting RNA interference without the benefit of mutant alleles. PMID:10545456

  15. Charles Manning Child (1869-1954): the past, present, and future of metabolic signaling.

    PubMed

    Blackstone, Neil W

    2006-01-15

    Charles Manning Child's work focused on metabolic gradients and their influence on organismal development. Early in the 20th century, his work had considerable currency, but by the second half of the century he had become little more than a historical footnote. Yet today Child's ideas are once again topical. While there were issues of cause and effect that Child and his students were never able to address adequately, in hindsight the extent of his eclipse hardly seems warranted. In fact, the demise of Child's theories may have resulted from larger changes in the nature of biology in the early 20th century. Child frequently studied planarians, hydroids, and other animals that are capable of asexual, agametic reproduction, and his theories most clearly apply to such organisms. In contrast, Thomas Hunt Morgan, initially one of Child's competitors in studies of regeneration, later developed the field of transmission genetics based on fruit flies, which can only reproduce via gametes. Child's theories and model systems were largely casualties of the success of Morgan's mechanistic paradigm. Nevertheless, in modern biology metabolic gradients, recast in terms of redox signaling, have become central to understanding both normal and pathological development. PMID:16353198

  16. Variation in spiralian development: insights from polychaetes.

    PubMed

    Seaver, Elaine C

    2014-01-01

    Spiralian development is characterized by the conservation of spindle orientation and cell geometry during early cleavage stages, as well as features of the ultimate fates of identified cells. This complex set of characters is shared by a number of animal lineages including nemerteans, polyclad platyhelminthes, annelids and mollusks. How a similar, highly stereotypical cleavage program can give rise to such diversity of larval and adult forms has intrigued researchers for many years. This review summarizes recent data from polychaete annelids, and highlights both conservation and variation in the cellular and molecular mechanisms that guide the spiral cleavage developmental program. There is a specific focus on comparisons of fate maps, patterns of cleavage, mechanisms of cell fate specification, organizing activity, and differences in molecular patterning. Some of the differences in early development represent intra-clade variation within annelids, and others hint at differences between annelids and other taxa. Because much of the classic work on spiralians has focused on mollusks, these new data from annelids have expanded our knowledge about the evolutionary flexibility in spiralian development and potentially its role in body plan evolution. PMID:25690962

  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. (?(2) = 6.02, P = 0.01), while individuals harboring Chilomastix sp. were less likely to have Capillaria sp. present (?(2) = 4.03, P = 0.04). PMID:25686475

  18. Egg-specific expression of protein with DNA methyltransferase activity in the biocarcinogenic liver fluke Clonorchis sinensis.

    PubMed

    Kim, Seon-Hee; Cho, Hye-Jeong; Sohn, Woon-Mok; Ahn, Chun-Seob; Kong, Yoon; Yang, Hyun-Jong; Bae, Young-An

    2015-08-01

    Despite recent reports regarding the biology of cytosine methylation in Schistosoma mansoni, the impact of the regulatory machinery remains unclear in diverse platyhelminthes. This ambiguity is reinforced by discoveries of DNA methyltransferase 2 (DNMT2)-only organisms and the substrate specificity of DNMT2 preferential to RNA molecules. Here, we characterized a novel DNA methyltransferase, named CsDNMT2, in a liver fluke Clonorchis sinensis. The protein exhibited structural properties conserved in other members of the DNMT2 family. The native and recombinant CsDNMT2 exhibited considerable enzymatic activity on DNA. The spatiotemporal expression of CsDNMT2 mirrored that of 5-methylcytosine (5 mC), both of which were elevated in the C. sinensis eggs. However, CsDNMT2 and 5 mC were marginally detected in other histological regions of C. sinensis adults including ovaries and seminal receptacle. The methylation site seemed not related to genomic loci occupied by progenies of an active long-terminal-repeat retrotransposon. Taken together, our data strongly suggest that C. sinensis has preserved the functional DNA methylation machinery and that DNMT2 acts as a genuine alternative to DNMT1/DNMT3 to methylate DNA in the DNMT2-only organism. The epigenetic regulation would target functional genes primarily involved in the formation and/or maturation of eggs, rather than retrotransposons. PMID:26036304

  19. Presence of galactosylated core fucose on N-glycans in the planaria Dugesia japonica

    PubMed Central

    Paschinger, Katharina; Razzazi-Fazeli, Ebrahim; Furukawa, Kiyoshi; Wilson, Iain BH

    2011-01-01

    Planarial species are of especial interest to biologists due to the phenomenon of pluripotency and, in comparison to other developmental processes, it can be hypothesised that glycan–lectin interactions may play a role. In order to examine the N-glycans of one of these organisms, Dugesia japonica, peptide:N-glycosidase A was employed and the released glycans were subject to pyridylamination, HPLC and mass spectrometric analysis. A range of oligomannosidic glycans was observed with a trimethylated Man5GlcNAc2 structure being the dominant species. Three glycans were also observed to contain deoxyhexose; in particular, a glycan with the composition Hex4HexNAc2Fuc1Me2 was revealed by exoglycosidase digestion, in combination with MS/MS, to contain a galactosylated core ?1,6-fucose residue, whereas this core modification was found to be capped with a methylhexose residue in the case of a Hex5HexNAc2Fuc1Me3 structure. This is the first report of these types of structures in a platyhelminth and indicates that the ‘GalFuc’ modification of N-glycans is not just restricted to molluscs and nematodes. Copyright © 2011 John Wiley & Sons, Ltd. PMID:21630384

  20. Comparative analyses of the neuropeptide F (NPF)- and FMRFamide-related peptide (FaRP)-immunoreactivities in Fasciola hepatica and Schistosoma spp.

    PubMed

    Marks, N J; Halton, D W; Maule, A G; Brennan, G P; Shaw, C; Southgate, V R; Johnston, C F

    1995-05-01

    Immunochemical techniques were used to determine the distribution, chemical characteristics and relative abundance of immunoreactivity (IR) to two native platyhelminth neuropeptides, neuropeptide F (NPF) (Moniezia expansa) and the FMRFamide-related peptide (FaRP), GNFFRFamide, in the trematodes, Fasciola hepatica and Schistosoma mansoni; the larger S. margrebowiei was used in the chemical analysis. Extensive immunostaining for the two peptides was demonstrated throughout the nervous systems of both F. hepatica and S. mansoni, with strong IR also in the innervation of muscular structures, including those associated with the egg-forming apparatus. The patterns of immunostaining were similar to those previously described for the vertebrate neuropeptide Y superfamily of peptides and for FMRFamide. Ultrastructurally, gold labelling of NPF- and GNFFRFamide-IRs was localized exclusively to the contents of secretory vesicles in the axons and somatic cytoplasm of neurones. Double-labelling experiments showed an apparent homogeneity of antigenic sites, in all probability due to the demonstrated cross-reactivity of the FaRP antiserum with NPF. Radioimmunoassay of acid-ethanol extracts of the worms detected 8.3 pmol/g and 4.7 pmol/g equivalents of NPF- and FMRFamide-IRs, respectively, for F. hepatica, and corresponding values of 4.9 pmol/g and 4.3 pmol/g equivalents for S. margrebowiei. Gel-permeation chromatography resolved IR to both peptides in discrete peaks and these eluted in similar positions to synthetic NPF (M. expansa) and GNFFRFamide, respectively. PMID:7753578

  1. The Opisthorchis felineus paramyosin: cDNA sequence and characterization of its recombinant fragment.

    PubMed

    Shustov, A V; Kotelkin, A T; Sorokin, A V; Ternovoi, V A; Loktev, V B

    2002-08-01

    The cDNA sequence of Opisthorchis felineus paramyosin (PM) was determined and shown to have 66-70% homology with two schistosomes and two cestodes. Phylogenetic analysis revealed an almost equal distance between O. felineus and these distinct clades. Because of its relatively low conservation, the PM gene may be a convenient genetic marker for studying phylogenetic relationships among platyhelminthes.A 25-kDa recombinant polypeptide corresponding to the central part of the full-length PM was produced. In Western blot analysis, murine hyperimmune serum against recombinant PM (recPM) detected 100-kDa polypeptides in the O. felineusegg and somatic antigens. Interactions of recPM with polyclonal anti-parasite antibodies and anti-recPM sera in ELISA with native antigens demonstrated that recPM carries a B cell epitope identical to the O. felineusnative antigen. Our sequence and immunologic data may be helpful in developing new diagnostic tools and candidate vaccines for O. felineus infection. PMID:12122429

  2. Complete Mitochondrial Genome of Haplorchis taichui and Comparative Analysis with Other Trematodes

    PubMed Central

    Lee, Dongmin; Choe, Seongjun; Park, Hansol; Jeon, Hyeong-Kyu; Chai, Jong-Yil; Sohn, Woon-Mok; Yong, Tai-Soon; Min, Duk-Young; Rim, Han-Jong

    2013-01-01

    Mitochondrial genomes have been extensively studied for phylogenetic purposes and to investigate intra- and interspecific genetic variations. In recent years, numerous groups have undertaken sequencing of platyhelminth mitochondrial genomes. Haplorchis taichui (family Heterophyidae) is a trematode that infects humans and animals mainly in Asia, including the Mekong River basin. We sequenced and determined the organization of the complete mitochondrial genome of H. taichui. The mitochondrial genome is 15,130 bp long, containing 12 protein-coding genes, 2 ribosomal RNAs (rRNAs, a small and a large subunit), and 22 transfer RNAs (tRNAs). Like other trematodes, it does not encode the atp8 gene. All genes are transcribed from the same strand. The ATG initiation codon is used for 9 protein-coding genes, and GTG for the remaining 3 (nad1, nad4, and nad5). The mitochondrial genome of H. taichui has a single long non-coding region between trnE and trnG. H. taichui has evolved as being more closely related to Opisthorchiidae than other trematode groups with maximal support in the phylogenetic analysis. Our results could provide a resource for the comparative mitochondrial genome analysis of trematodes, and may yield genetic markers for molecular epidemiological investigations into intestinal flukes. PMID:24516279

  3. Enhanced primers for amplification of DNA barcodes from a broad range of marine metazoans

    PubMed Central

    2013-01-01

    Background Building reference libraries of DNA barcodes is relatively straightforward when specifically designed primers are available to amplify the COI-5P region from a relatively narrow taxonomic group (e.g. single class or single order). DNA barcoding marine communities have been comparatively harder to accomplish due to the broad taxonomic diversity and lack of consistently efficient primers. Although some of the so-called “universal” primers have been relatively successful, they still fail to amplify COI-5P of many marine animal groups, while displaying random success even among species within each group. Here we propose a new pair of primers designed to enhance amplification of the COI-5P region in a wide range of marine organisms. Results Amplification tests conducted on a wide range of marine animal taxa, rendered possible the first–time sequencing of DNA barcodes from eight separated phyla (Annelida, Arthropoda, Chordata, Cnidaria, Echinodermata, Mollusca, Nemertea and Platyhelminthes), comprising a total of 14 classes, 28 orders, 57 families, 68 genus and 76 species. Conclusions These primers demonstrated to be highly cost-effective, which is of key importance for DNA barcoding procedures, such as for building comprehensive DNA barcode libraries of marine communities, where the processing of a large numbers of specimens from a wide variety of marine taxa is compulsory. PMID:24020880

  4. Invasive species threat: parasite phylogenetics reveals patterns and processes of host-switching between non-native and native captive freshwater turtles.

    PubMed

    Verneau, O; Palacios, C; Platt, T; Alday, M; Billard, E; Allienne, J-F; Basso, C; DU Preez, L H

    2011-11-01

    One of the major threats to biodiversity involves biological invasions with direct consequences on the stability of ecosystems. In this context, the role of parasites is not negligible as it may enhance the success of invaders. The red-eared slider, Trachemys scripta elegans, has been globally considered among the worst invasive species. Since its introduction through the pet trade, T. s. elegans is now widespread and represents a threat for indigenous species. Because T. s. elegans coexists with Emys orbicularis and Mauremys leprosa in Europe, it has been suggested it may compete with the native turtle species and transmit pathogens. We examined parasite transfer from American captive to the two native species that co-exist in artificial pools of a Turtle Farm in France. As model parasite species we used platyhelminth worms of the family Polystomatidae (Monogenea) because polystomes have been described from American turtles in their native range. Phylogenetic relationships among polystomes parasitizing chelonian host species that are geographically widespread show patterns of diversification more complex than expected. Using DNA barcoding to identify species from adult and/or polystome eggs, several cases of host switching from exotic to indigenous individuals were illustrated, corroborating that parasite transmission is important when considering the pet trade and in reintroduction programmes to reinforce wild populations of indigenous species. PMID:21767431

  5. The Global Invertebrate Genomics Alliance (GIGA): Developing Community Resources to Study Diverse Invertebrate Genomes

    PubMed Central

    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. PMID:24336862

  6. Isolation and characterization of species-specific DNA probes from Taenia solium and Taenia saginata and their use in an egg detection assay.

    PubMed Central

    Chapman, A; Vallejo, V; Mossie, K G; Ortiz, D; Agabian, N; Flisser, A

    1995-01-01

    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. PMID:7615742

  7. Parasite neuropeptide biology: Seeding rational drug target selection?

    PubMed Central

    McVeigh, Paul; Atkinson, Louise; Marks, Nikki J.; Mousley, Angela; Dalzell, Johnathan J.; Sluder, Ann; Hammerland, Lance; Maule, Aaron G.

    2011-01-01

    The rationale for identifying drug targets within helminth neuromuscular signalling systems is based on the premise that adequate nerve and muscle function is essential for many of the key behavioural determinants of helminth parasitism, including sensory perception/host location, invasion, locomotion/orientation, attachment, feeding and reproduction. This premise is validated by the tendency of current anthelmintics to act on classical neurotransmitter-gated ion channels present on helminth nerve and/or muscle, yielding therapeutic endpoints associated with paralysis and/or death. Supplementary to classical neurotransmitters, helminth nervous systems are peptide-rich and encompass associated biosynthetic and signal transduction components – putative drug targets that remain to be exploited by anthelmintic chemotherapy. At this time, no neuropeptide system-targeting lead compounds have been reported, and given that our basic knowledge of neuropeptide biology in parasitic helminths remains inadequate, the short-term prospects for such drugs remain poor. Here, we review current knowledge of neuropeptide signalling in Nematoda and Platyhelminthes, and highlight a suite of 19 protein families that yield deleterious phenotypes in helminth reverse genetics screens. We suggest that orthologues of some of these peptidergic signalling components represent appealing therapeutic targets in parasitic helminths. PMID:24533265

  8. Mixed Infections and Hybridisation in Monogenean Parasites

    PubMed Central

    Schelkle, Bettina; Faria, Patricia J.; Johnson, Mireille B.; van Oosterhout, Cock; Cable, Joanne

    2012-01-01

    Theory predicts that sexual reproduction promotes disease invasion by increasing the evolutionary potential of the parasite, whereas asexual reproduction tends to enhance establishment success and population growth rate. Gyrodactylid monogeneans are ubiquitous ectoparasites of teleost fish, and the evolutionary success of the specious Gyrodactylus genus is thought to be partly due to their use of various modes of reproduction. Gyrodactylus turnbulli is a natural parasite of the guppy (Poecilia reticulata), a small, tropical fish used as a model for behavioural, ecological and evolutionary studies. Using experimental infections and a recently developed microsatellite marker, we conclusively show that monogenean parasites reproduce sexually. Conservatively, we estimate that sexual recombination occurs and that between 3.7–10.9% of the parasites in our experimental crosses are hybrid genotypes with ancestors from different laboratory strains of G. turnbulli. We also provide evidence of hybrid vigour and/or inter-strain competition, which appeared to lead to a higher maximum parasite load in mixed infections. Finally, we demonstrate inbreeding avoidance for the first time in platyhelminths which may influence the distribution of parasites within a host and their subsequent exposure to the host's localized immune response. Combined reproductive modes and inbreeding avoidance may explain the extreme evolutionary diversification success of parasites such as Gyrodactylus, where host-parasite coevolution is punctuated by relatively frequent host switching. PMID:22808040

  9. 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

  10. Schistosoma mansoni Polo-like kinases and their function in control of mitosis and parasite reproduction.

    PubMed

    Dissous, Colette; Grevelding, Christoph G; Long, Thavy

    2011-06-01

    Polo-like kinases are important regulators of cell cycle progression and mitosis. They constitute a family of conserved serine/threonine kinases which are highly related in their catalytic domains and contain polo boxes involved in protein-protein interactions and subcellular localization. In mammals, five Plks (Plk 1-5) encompass diverse roles in centrosome dynamics, spindle formation, intra S-phase and G2/M checkpoints and DNA damage response. Plk1 is a key positive regulator of mitosis and is overexpressed in various types of cancers. Plk4 is a divergent member of the Plk family, with essential functions in centriole duplication. Homozygous disruption of Plk1 or Plk4 in mice is lethal in embryos. Two Plk members SmPlk1 and SmSak, homologous to Plk1 and Plk4 respectively, are present in the parasitic platyhelminth Schistosoma mansoni. Structural and functional analyses of SmPlk1 have demonstrated its conserved function in the regulation of cell cycle G2/M transition in Xenopus oocytes. The anti-cancer drug BI 2536 (the most potent and selective Plk1 inhibitor) inhibits specifically the catalytic activity of SmPlk1 and induced profound alterations in schistosome gonads, indicating a role of SmPlk1 in parasite gametogenesis and its potential as a novel chemotherapeutic target against schistosomiasis. Functions of SmSak in cell cycle regulation and schistosome gonad development are currently investigated. PMID:21670883

  11. Diagnostic PCR can be used to illuminate meiofaunal diets and trophic relationships

    PubMed Central

    Maghsoud, Hanna; Weiss, Austin; Smith, Julian P.S.; Litvaitis, Marian K.; Fegley, Stephen R.

    2014-01-01

    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. PMID:25071364

  12. HelmCoP: An Online Resource for Helminth Functional Genomics and Drug and Vaccine Targets Prioritization

    PubMed Central

    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. PMID:21760913

  13. Lessons from parasitic flatworms about evolution and historical biogeography of their vertebrate hosts.

    PubMed

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

    2009-01-01

    Cophylogenetic studies investigate the evolutionary trends within host-parasite associations. Examination of the different levels of fidelity between host and parasite phylogenies provides a powerful tool to inspect patterns and processes of parasite diversification over host evolution and geological times. Within the phylum Platyhelminthes, the monogeneans are mainly fish parasites. The Polystomatidae, however, are known from the sarcopterygian Australian lungfish and tetrapods such as amphibians, freshwater turtles, and the African hippopotamus. Cophylogenetic and biogeographic vicariance analyses, supplemented by molecular calibrations, showed that the Polystomatidae may track the evolutionary history of the first aquatic tetrapods in the Palaeozoic age. Evolutionary lines of the major polystome lineages would also be intimately related to the evolution of their hosts over hundreds of millions years. Since the Mesozoic, evolution of polystomes would have been shaped mainly by plate tectonics during the break-up of Gondwanaland and subsequent dispersal of ancestral neobatrachian host lineages. Therefore the Polystomatidae could serve as a novel model to improve cophylogenetic tools and to inspect a suite of questions about the evolution of vertebrate hosts. PMID:19281948

  14. The neuropeptide complement of the marine annelid Platynereis dumerilii

    PubMed Central

    2013-01-01

    Background The marine annelid Platynereis dumerilii is emerging as a powerful lophotrochozoan experimental model for evolutionary developmental biology (evo-devo) and neurobiology. Recent studies revealed the presence of conserved neuropeptidergic signaling in Platynereis, including vasotocin/neurophysin, myoinhibitory peptide and opioid peptidergic systems. Despite these advances, comprehensive peptidome resources have yet to be reported. Results The present work describes the neuropeptidome of Platynereis. We established a large transcriptome resource, consisting of stage-specific next-generation sequencing datasets and 77,419 expressed sequence tags. Using this information and a combination of bioinformatic searches and mass spectrometry analyses, we increased the known proneuropeptide (pNP) complement of Platynereis to 98. Based on sequence homology to metazoan pNPs, Platynereis pNPs were grouped into ancient eumetazoan, bilaterian, protostome, lophotrochozoan, and annelid families, and pNPs only found in Platynereis. Compared to the planarian Schmidtea mediterranea, the only other lophotrochozoan with a large-scale pNP resource, Platynereis has a remarkably full complement of conserved pNPs, with 53 pNPs belonging to ancient eumetazoan or bilaterian families. Our comprehensive search strategy, combined with analyses of sequence conservation, also allowed us to define several novel lophotrochozoan and annelid pNP families. The stage-specific transcriptome datasets also allowed us to map changes in pNP expression throughout the Platynereis life cycle. Conclusion The large repertoire of conserved pNPs in Platynereis highlights the usefulness of annelids in comparative neuroendocrinology. This work establishes a reference dataset for comparative peptidomics in lophotrochozoans and provides the basis for future studies of Platynereis peptidergic signaling. PMID:24359412

  15. Phylogeography of competing sexual and parthenogenetic forms of a freshwater flatworm: patterns and explanations

    PubMed Central

    Pongratz, Norbert; Storhas, Martin; Carranza, Salvador; Michiels, Nicolaas K

    2003-01-01

    Background Models of the maintenance of sex predict that one reproductive strategy, sexual or parthenogenetic, should outcompete the other. Distribution patterns may reflect the outcome of this competition as well as the effect of chance and historical events. We review the distribution data of sexual and parthenogenetic biotypes of the planarian Schmidtea polychroa. Results S. polychroa lives in allopatry or sympatry across Europe except for Central and North-Western Europe, where sexual individuals have never been reported. A phylogenetic relationship between 36 populations based on a 385 bp fragment of the mitochondrial cytochrome oxidase I gene revealed that haplotypes were often similar over large geographic distances. In North Italian lakes, however, diversity was extreme, with sequence differences of up to 5% within the same lake in both sexuals and parthenogens. Mixed populations showed "endemic" parthenogenetic lineages that presumably originated from coexisting sexuals, and distantly related ones that probably result from colonization by parthenogens independent from sexuals. Conclusions Parthenogens originated repeatedly from sexuals, mainly in Italy, but the same may apply to other Mediterranean regions (Spain, Greece). The degree of divergence between populations suggests that S. polychroa survived the ice ages in separate ice-free areas in Central, Eastern and Southern Europe and re-colonised Europe after the retreat of the major glaciers. Combining these results with those based on nuclear markers, the data suggest that repeated hybridisation between sexuals and parthenogenetic lineages in mixed populations maintains high levels of genetic diversity in parthenogens. This can explain why parthenogens persist in populations that were originally sexual. Exclusive parthenogenesis in central and western populations suggests better colonisation capacity, possibly because of inbreeding costs as well as hybridisation of sexuals with parthenogens. PMID:14622447

  16. Application Of Stable Isotope Analysis To Study Temporal Changes In Foraging Ecology In A Highly Endangered Amphibian

    PubMed Central

    Gillespie, J. Hayley

    2013-01-01

    Background Understanding dietary trends for endangered species may be essential to assessing the effects of ecological disturbances such as habitat modification, species introductions or global climate change. Documenting temporal variation in prey selection may also be crucial for understanding population dynamics. However, the rarity, secretive behaviours and obscure microhabitats of some endangered species can make direct foraging observations difficult or impossible. Furthermore, the lethality or invasiveness of some traditional methods of dietary analysis (e.g. gut contents analysis, gastric lavage) makes them inappropriate for such species. Stable isotope analysis facilitates non-lethal, indirect analysis of animal diet that has unrealized potential in the conservation of endangered organisms, particularly amphibians. Methodology/findings I determined proportional contributions of aquatic macroinvertebrate prey to the diet of an endangered aquatic salamander Eurycea sosorum over a two-year period using stable isotope analysis of 13/12C and 15/14N and the Bayesian stable isotope mixing model SIAR. I calculated Strauss’ dietary electivity indices by comparing these proportions with changing relative abundance of potential prey species through time. Stable isotope analyses revealed that a previously unknown prey item (soft-bodied planarian flatworms in the genus Dugesia) made up the majority of E. sosorum diet. Results also demonstrate that E. sosorum is an opportunistic forager capable of diet switching to include a greater proportion of alternative prey when Dugesia populations decline. There is also evidence of intra-population dietary variation. Conclusions/significance Effective application of stable isotope analysis can help circumvent two key limitations commonly experienced by researchers of endangered species: the inability to directly observe these species in nature and the invasiveness or lethality of traditional methods of dietary analysis. This study illustrates the feasibility of stable isotope analysis in identifying preferred prey species that can be used to guide conservation management of both wild and captive food sources for endangered species. PMID:23341920

  17. Molecular Cloning and Characterization of Growth Factor Receptor Bound-Protein in Clonorchis sinensis

    PubMed Central

    Bai, Xuelian; Lee, Ji-Yun; Kim, Tae Im; Dai, Fuhong; Lee, Tae-Jin; Hong, Sung-Jong

    2014-01-01

    Background Clonorchis sinensis causes clonorchiasis, a potentially serious disease. Growth factor receptor-bound protein 2 (Grb2) is a cytosolic protein conserved among animals and plays roles in cellular functions such as meiosis, organogenesis and energy metabolism. In the present study, we report first molecular characters of growth factor receptor bound-protein (CsGrb2) from C. sinensis as counter part of Grb2 from animals and its possible functions in development and organogenesis of C. sinensis. Methodology/Principal Findings A CsGrb2 cDNA clone retrieved from the C. sinensis transcriptome encoded a polypeptide with a SH3-SH2-SH3 structure. Recombinant CsGrb2 was bacterially produced and purified to homogeneity. Native CsGrb2 with estimated molecular weight was identified from C. sinensis adult extract by western blotting using a mouse immune serum to recombinant CsGrb2. CsGrb2 transcripts was more abundant in the metacercariae than in the adults. Immunohistochemical staining showed that CsGrb2 was localized to the suckers, mesenchymal tissues, sperms in seminal receptacle and ovary in the adults, and abundantly expressed in most organs of the metacercariae. Recombinant CsGrb2 was evaluated to be little useful as a serodiagnostic reagent for C. sinesis human infections. Conclusion Grb2 protein found in C. sinensis was conserved among animals and suggested to play a role in the organogenesis, energy metabolism and mitotic spermatogenesis of C. sinensis. These findings from C. sinensis provide wider understanding on diverse function of Grb2 in lower animals such as platyhelminths. PMID:24454892

  18. Morphology, Molecules, and Monogenean Parasites: An Example of an Integrative Approach to Cichlid Biodiversity

    PubMed Central

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

    2015-01-01

    The unparalleled biodiversity of Lake Tanganyika (Africa) has fascinated biologists for over a century; its unique cichlid communities are a preferred model for evolutionary research. Although species delineation is, in most cases, relatively straightforward, higher-order classifications were shown not to agree with monophyletic groups. Here, traditional morphological methods meet their limitations. A typical example are the tropheine cichlids currently belonging to Simochromis and Pseudosimochromis. The affiliations of these widespread and abundant cichlids are poorly understood. Molecular work suggested that genus and species boundaries should be revised. Moreover, previous morphological results indicated that intraspecific variation should be considered to delineate species in Lake Tanganyika cichlids. We review the genera Simochromis and Pseudosimochromis using an integrative approach. Besides a morphometric study and a barcoding approach, monogenean Cichlidogyrus (Platyhelminthes: Ancyrocephalidae) gill parasites, often highly species-specific, are used as complementary markers. Six new species are described. Cichlidogyrus raeymaekersi sp. nov., C. muterezii sp. nov. and C. banyankimbonai sp. nov. infect S. diagramma. Cichlidogyrus georgesmertensi sp. nov. was found on S. babaulti and S. pleurospilus, C. franswittei sp. nov. on both S. marginatus and P. curvifrons and C. frankwillemsi sp. nov. only on P. curvifrons. As relatedness between Cichlidogyrus species usually reflects relatedness between hosts, we considered Simochromis monotypic because the three Cichlidogyrus species found on S. diagramma belonged to a different morphotype than those found on the other Simochromis. The transfer of S. babaulti, S. marginatus, S. pleurospilus and S. margaretae to Pseudosimochromis was justified by the similarity of their Cichlidogyrus fauna and the intermediate morphology of S. margaretae. Finally parasite data also supported the synonymy between S. pleurospilus and S. babaulti, a species that contains a large amount of geographical morphological variation. PMID:25923665

  19. Recent evidence for evolution of the genetic code

    NASA Technical Reports Server (NTRS)

    Osawa, S.; Jukes, T. H.; Watanabe, K.; Muto, A.

    1992-01-01

    The genetic code, formerly thought to be frozen, is now known to be in a state of evolution. This was first shown in 1979 by Barrell et al. (G. Barrell, A. T. Bankier, and J. Drouin, Nature [London] 282:189-194, 1979), who found that the universal codons AUA (isoleucine) and UGA (stop) coded for methionine and tryptophan, respectively, in human mitochondria. Subsequent studies have shown that UGA codes for tryptophan in Mycoplasma spp. and in all nonplant mitochondria that have been examined. Universal stop codons UAA and UAG code for glutamine in ciliated protozoa (except Euplotes octacarinatus) and in a green alga, Acetabularia. E. octacarinatus uses UAA for stop and UGA for cysteine. Candida species, which are yeasts, use CUG (leucine) for serine. Other departures from the universal code, all in nonplant mitochondria, are CUN (leucine) for threonine (in yeasts), AAA (lysine) for asparagine (in platyhelminths and echinoderms), UAA (stop) for tyrosine (in planaria), and AGR (arginine) for serine (in several animal orders) and for stop (in vertebrates). We propose that the changes are typically preceded by loss of a codon from all coding sequences in an organism or organelle, often as a result of directional mutation pressure, accompanied by loss of the tRNA that translates the codon. The codon reappears later by conversion of another codon and emergence of a tRNA that translates the reappeared codon with a different assignment. Changes in release factors also contribute to these revised assignments. We also discuss the use of UGA (stop) as a selenocysteine codon and the early history of the code.

  20. A revision of Patagifer Dietz, 1909 (Digenea: Echinostomatidae) and a key to its species.

    PubMed

    Faltýnková, Anna; Gibson, David I; Kostadinova, Aneta

    2008-07-01

    Patagifer Dietz, 1909 is revised and a key to the species is presented. P. oweni n. sp. is described from Threskiornis molucca (Cuvier) in the Western Province of Papua New Guinea and distinguished from the related P. chandrapuri Srivastava, 1952 by: the shape of the pair of large angle spines (cudgel-shaped vs sub-rectangular); pointed (vs rod-shaped) marginal spines; a smaller body and internal organs; more anteriorly located testes; and larger eggs. The new species differs from P. brygooi Richard, 1964 in its larger body, head collar, suckers, pharynx and eggs, longer oesophagus and testes, the latter being also more elongate and more anteriorly located, and a different number of collar spines (61-62 vs 59). P. bilobus (Rudolphi, 1819) (the type-species), P. parvispinosus Yamaguti, 1933, P. chandrapuri and P. vioscai Lumsden, 1962 are redescribed on the basis of museum and newly collected material. The variations in the number and size of the collar spines and other metrical characters of P. bilobus are studied in two different host species from Europe, Plegadis falcinellus and Platalea leucorodia. Other species considered valid are: Patagifer consimilis Dietz, 1909, P. acuminatus Johnston, 1917, P. fraternus Johnston, 1917, P. wesleyi Verma, 1936, P. brygooi and P. toki Onda, Imai & Ishii, 1983. P. plegadisi Sakla, Monib & Mandour, 1988 and P. simarai Nigam, 1944 are considered synonyms of P. bilobus, and P. sarai Saksena, 1957 is placed in synonymy with P. chandrapuri. Forms considered dubious are: P. bilobus of Machida et al. (Jpn J Parasitol 15:339, 1966) and Machida (Bull Natl Sci Mus Tokyo 11:157-160, 1968), P. simerai [sic] of Mehra (The fauna of India and adjacent countries. Platyhelminthes, 1980), P. skrjabini Hilmy, 1949 sp. inq. and P. srivastavai Peter, 1954 sp. inq. Lists of the records and hosts of the 11 valid species are included. PMID:18535788

  1. An introduction to loricifera, cycliophora, and micrognathozoa.

    PubMed

    Kristensen, Reinhardt Møbjerg

    2002-07-01

    Loriciferans, cycliophorans and micrognathozoans are amongst the latest groups of animals to be discovered. Other than all being microscopic, they have very different body plans and are not closely related. Loriciferans were originally assigned to the Aschelminthes. However, both new molecular and ultrastructural researches have shown that Aschelminthes consist of two unrelated groups, Cycloneuralia and Gnathifera. Cycloneuralia may be included in the Ecdysozoa, including all molting invertebrates, and Gnathifera are more closely related to Platyhelminthes. The phylum Loricifera shares many apomorphic characters (e.g., scalids on the introvert) with both Priapulida and Kinorhyncha, and can be included in the taxon Scalidophora, a subgroup of Cycloneuralia. Cycliophora was originally allied to the Entoprocta and Ectoprocta (Bryozoa) based on ultrastructual research. Subsequent molecular data show they may be related to Rotifera and Acanthocephala, within the taxon Gnathifera. The phylogenetic position of Cycliophora is therefore not settled, and more ultrastructural and molecular data are needed. Micrognathozoa is the most recent major group of animals to be described. They show strong affinities with both Rotifera and Gnathostomulida (within the taxon Gnathifera), especially in the fine structure of the pharyngeal apparatus, where the jaw elements have cuticular rods with osmiophilic cores. Furthermore the micrognathozoans have two rows of multiciliated cells that form a locomotory organ, similar to that seen in some gastrotrichs and interstitial annelids. This character is never seen in Rotifera or in the monociliated Gnathostomulida. Rotifera and Acanthocephala always have a syncytial epidermis (Syndermata). Micrognathozoa lack this characteristic feature. Therefore, they are postulated to be placed basally in the Gnathifera, either as a sister-group to Gnathostomulida or as a sister-group to Rotifera + Acanthocephala. PMID:21708760

  2. BIOFRAG – a new database for analyzing BIOdiversity responses to forest FRAGmentation

    PubMed Central

    Pfeifer, Marion; Lefebvre, Veronique; Gardner, Toby A; Arroyo-Rodriguez, Victor; Baeten, Lander; Banks-Leite, Cristina; Barlow, Jos; Betts, Matthew G; Brunet, Joerg; Cerezo, Alexis; Cisneros, Laura M; Collard, Stuart; D'Cruze, Neil; da Silva Motta, Catarina; Duguay, Stephanie; Eggermont, Hilde; Eigenbrod, Felix; Hadley, Adam S; Hanson, Thor R; Hawes, Joseph E; Heartsill Scalley, Tamara; Klingbeil, Brian T; Kolb, Annette; Kormann, Urs; Kumar, Sunil; Lachat, Thibault; Lakeman Fraser, Poppy; Lantschner, Victoria; Laurance, William F; Leal, Inara R; Lens, Luc; Marsh, Charles J; Medina-Rangel, Guido F; Melles, Stephanie; Mezger, Dirk; Oldekop, Johan A; Overal, William L; Owen, Charlotte; Peres, Carlos A; Phalan, Ben; Pidgeon, Anna M; Pilia, Oriana; Possingham, Hugh P; Possingham, Max L; Raheem, Dinarzarde C; Ribeiro, Danilo B; Ribeiro Neto, Jose D; Douglas Robinson, W; Robinson, Richard; Rytwinski, Trina; Scherber, Christoph; Slade, Eleanor M; Somarriba, Eduardo; Stouffer, Philip C; Struebig, Matthew J; Tylianakis, Jason M; Tscharntke, Teja; Tyre, Andrew J; Urbina Cardona, Jose N; Vasconcelos, Heraldo L; Wearn, Oliver; Wells, Konstans; Willig, Michael R; Wood, Eric; Young, Richard P; Bradley, Andrew V; Ewers, Robert M

    2014-01-01

    Habitat fragmentation studies have produced complex results that are challenging to synthesize. Inconsistencies among studies may result from variation in the choice of landscape metrics and response variables, which is often compounded by a lack of key statistical or methodological information. Collating primary datasets on biodiversity responses to fragmentation in a consistent and flexible database permits simple data retrieval for subsequent analyses. We present a relational database that links such field data to taxonomic nomenclature, spatial and temporal plot attributes, and environmental characteristics. Field assessments include measurements of the response(s) (e.g., presence, abundance, ground cover) of one or more species linked to plots in fragments within a partially forested landscape. The database currently holds 9830 unique species recorded in plots of 58 unique landscapes in six of eight realms: mammals 315, birds 1286, herptiles 460, insects 4521, spiders 204, other arthropods 85, gastropods 70, annelids 8, platyhelminthes 4, Onychophora 2, vascular plants 2112, nonvascular plants and lichens 320, and fungi 449. Three landscapes were sampled as long-term time series (>10 years). Seven hundred and eleven species are found in two or more landscapes. Consolidating the substantial amount of primary data available on biodiversity responses to fragmentation in the context of land-use change and natural disturbances is an essential part of understanding the effects of increasing anthropogenic pressures on land. The consistent format of this database facilitates testing of generalizations concerning biologic responses to fragmentation across diverse systems and taxa. It also allows the re-examination of existing datasets with alternative landscape metrics and robust statistical methods, for example, helping to address pseudo-replication problems. The database can thus help researchers in producing broad syntheses of the effects of land use. The database is dynamic and inclusive, and contributions from individual and large-scale data-collection efforts are welcome. PMID:24967073

  3. Gene discovery for the carcinogenic human liver fluke, Opisthorchis viverrini

    PubMed Central

    Laha, Thewarach; Pinlaor, Porntip; Mulvenna, Jason; Sripa, Banchob; Sripa, Manop; Smout, Michael J; Gasser, Robin B; Brindley, Paul J; Loukas, Alex

    2007-01-01

    Background Cholangiocarcinoma (CCA) – cancer of the bile ducts – is associated with chronic infection with the liver fluke, Opisthorchis viverrini. Despite being the only eukaryote that is designated as a 'class I carcinogen' by the International Agency for Research on Cancer, little is known about its genome. Results Approximately 5,000 randomly selected cDNAs from the adult stage of O. viverrini were characterized and accounted for 1,932 contigs, representing ~14% of the entire transcriptome, and, presently, the largest sequence dataset for any species of liver fluke. Twenty percent of contigs were assigned GO classifications. Abundantly represented protein families included those involved in physiological functions that are essential to parasitism, such as anaerobic respiration, reproduction, detoxification, surface maintenance and feeding. GO assignments were well conserved in relation to other parasitic flukes, however, some categories were over-represented in O. viverrini, such as structural and motor proteins. An assessment of evolutionary relationships showed that O. viverrini was more similar to other parasitic (Clonorchis sinensis and Schistosoma japonicum) than to free-living (Schmidtea mediterranea) flatworms, and 105 sequences had close homologues in both parasitic species but not in S. mediterranea. A total of 164 O. viverrini contigs contained ORFs with signal sequences, many of which were platyhelminth-specific. Examples of convergent evolution between host and parasite secreted/membrane proteins were identified as were homologues of vaccine antigens from other helminths. Finally, ORFs representing secreted proteins with known roles in tumorigenesis were identified, and these might play roles in the pathogenesis of O. viverrini-induced CCA. Conclusion This gene discovery effort for O. viverrini should expedite molecular studies of cholangiocarcinogenesis and accelerate research focused on developing new interventions, drugs and vaccines, to control O. viverrini and related flukes. PMID:17587442

  4. SmCL3, a Gastrodermal Cysteine Protease of the Human Blood Fluke Schistosoma mansoni

    PubMed Central

    Dvo?ák, Jan; Mashiyama, Susan T.; Sajid, Mohammed; Braschi, Simon; Delcroix, Melaine; Schneider, Eric L.; McKerrow, Wilson H.; Bahgat, Mahmoud; Hansell, Elizabeth; Babbitt, Patricia C.; Craik, Charles S.; McKerrow, James H.; Caffrey, Conor R.

    2009-01-01

    Background Blood flukes of the genus Schistosoma are platyhelminth parasites that infect 200 million people worldwide. Digestion of nutrients from the host bloodstream is essential for parasite development and reproduction. A network of proteolytic enzymes (proteases) facilitates hydrolysis of host hemoglobin and serum proteins. Methodology/Principal Findings We identified a new cathepsin L termed SmCL3 using PCR strategies based on S. mansoni EST sequence data. An ortholog is present in Schistosoma japonicum. SmCL3 was heterologously expressed as an active enzyme in the yeast, Pichia pastoris. Recombinant SmCL3 has a broad pH activity range against peptidyl substrates and is inhibited by Clan CA protease inhibitors. Consistent with a function in degrading host proteins, SmCL3 hydrolyzes serum albumin and hemoglobin, is localized to the adult gastrodermis, and is expressed mainly in those life stages infecting the mammalian host. The predominant form of SmCL3 in the parasite exists as a zymogen, which is unusual for proteases. This zymogen includes an unusually long prodomain with alpha helical secondary structure motifs. The striking specificity of SmCL3 for amino acids with large aromatic side chains (Trp and Tyr) at the P2 substrate position, as determined with positional scanning-synthetic combinatorial library, is consistent with a molecular model that shows a large and deep S2 pocket. A sequence similarity network (SSN) view clusters SmCL3 and other cathepsins L in accordance with previous large-scale phylogenetic analyses that identify six super kingdoms. Conclusions/Significance SmCL3 is a gut-associated cathepsin L that may contribute to the network of proteases involved in degrading host blood proteins as nutrients. Furthermore, this enzyme exhibits some unusual sequence and biophysical features that may result in additional functions. The visualization of network inter-relationships among cathepsins L suggests that these enzymes are suitable ‘marker sequences’ for inclusion in future phylogenetic analyses. PMID:19488406

  5. Genomic linkage map of the human blood fluke Schistosoma mansoni

    PubMed Central

    Criscione, Charles D; Valentim, Claudia LL; Hirai, Hirohisa; LoVerde, Philip T; Anderson, Timothy JC

    2009-01-01

    Background Schistosoma mansoni is a blood fluke that infects approximately 90 million people. The complete life cycle of this parasite can be maintained in the laboratory, making this one of the few experimentally tractable human helminth infections, and a rich literature reveals heritable variation in important biomedical traits such as virulence, host-specificity, transmission and drug resistance. However, there is a current lack of tools needed to study S. mansoni's molecular, quantitative, and population genetics. Our goal was to construct a genetic linkage map for S. mansoni, and thus provide a new resource that will help stimulate research on this neglected pathogen. Results We genotyped grandparents, parents and 88 progeny to construct a 5.6 cM linkage map containing 243 microsatellites positioned on 203 of the largest scaffolds in the genome sequence. The map allows 70% of the estimated 300 Mb genome to be ordered on chromosomes, and highlights where scaffolds have been incorrectly assembled. The markers fall into eight main linkage groups, consistent with seven pairs of autosomes and one pair of sex chromosomes, and we were able to anchor linkage groups to chromosomes using fluorescent in situ hybridization. The genome measures 1,228.6 cM. Marker segregation reveals higher female recombination, confirms ZW inheritance patterns, and identifies recombination hotspots and regions of segregation distortion. Conclusions The genetic linkage map presented here is the first for S. mansoni and the first for a species in the phylum Platyhelminthes. The map provides the critical tool necessary for quantitative genetic analysis, aids genome assembly, and furnishes a framework for comparative flatworm genomics and field-based molecular epidemiological studies. PMID:19566921

  6. Morphology, molecules, and monogenean parasites: an example of an integrative approach to cichlid biodiversity.

    PubMed

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

    2015-01-01

    The unparalleled biodiversity of Lake Tanganyika (Africa) has fascinated biologists for over a century; its unique cichlid communities are a preferred model for evolutionary research. Although species delineation is, in most cases, relatively straightforward, higher-order classifications were shown not to agree with monophyletic groups. Here, traditional morphological methods meet their limitations. A typical example are the tropheine cichlids currently belonging to Simochromis and Pseudosimochromis. The affiliations of these widespread and abundant cichlids are poorly understood. Molecular work suggested that genus and species boundaries should be revised. Moreover, previous morphological results indicated that intraspecific variation should be considered to delineate species in Lake Tanganyika cichlids. We review the genera Simochromis and Pseudosimochromis using an integrative approach. Besides a morphometric study and a barcoding approach, monogenean Cichlidogyrus (Platyhelminthes: Ancyrocephalidae) gill parasites, often highly species-specific, are used as complementary markers. Six new species are described. Cichlidogyrus raeymaekersi sp. nov., C. muterezii sp. nov. and C. banyankimbonai sp. nov. infect S. diagramma. Cichlidogyrus georgesmertensi sp. nov. was found on S. babaulti and S. pleurospilus, C. franswittei sp. nov. on both S. marginatus and P. curvifrons and C. frankwillemsi sp. nov. only on P. curvifrons. As relatedness between Cichlidogyrus species usually reflects relatedness between hosts, we considered Simochromis monotypic because the three Cichlidogyrus species found on S. diagramma belonged to a different morphotype than those found on the other Simochromis. The transfer of S. babaulti, S. marginatus, S. pleurospilus and S. margaretae to Pseudosimochromis was justified by the similarity of their Cichlidogyrus fauna and the intermediate morphology of S. margaretae. Finally parasite data also supported the synonymy between S. pleurospilus and S. babaulti, a species that contains a large amount of geographical morphological variation. PMID:25923665

  7. Expression and immunogenicity of an Echinococcus granulosus fatty acid-binding protein in live attenuated Salmonella vaccine strains.

    PubMed

    Chabalgoity, J A; Harrison, J A; Esteves, A; Demarco de Hormaeche, R; Ehrlich, R; Khan, C M; Hormaeche, C E

    1997-06-01

    Fatty acid-binding proteins (FABPs) are candidate molecules for vaccines against several parasitic platyhelminths. A FABP from the cestode Echinococcus granulosus (EgDf1) was expressed in Salmonella vaccine strains as a C-terminal fusion to fragment C of tetanus toxin (TetC) by using expression vector pTECH. The fusion protein was equally expressed in several attenuated vaccine strains derived from bacteria with different genetic backgrounds and different attenuating mutations. Single-dose immunization experiments with the aroA Salmonella typhimurium strain SL3261 carrying the pTECH-EgDf1 construct were conducted with mice, using both the intravenous and the oral routes. Surprisingly, the antibody response to EgDf1 and the antigen-specific cytokine production in spleen cells were stronger in mice immunized orally. Furthermore, immune mouse sera strongly reacted with fixed sections of the worm's larval stage. Analysis of the isotype distribution of the specific anti-EgDf1 antibodies showed similar production of immunoglobulin G1 (IgG1) and IgG2a together with specific IgA antibodies. In addition, stimulation of spleen cells from mice immunized with the different constructs with either Salmonella lysate, TetC, or EgDf1 showed that, together with Th1-related cytokines (gamma interferon and interleukin 2 [IL-2]), significant levels of a Th2 cytokine (IL-5) were produced specifically, indicating a Th2 component to the response to the Salmonella carrier and to the recombinant antigens. Salmonellae expressing the TetC-rEgDfl fusion are currently under evaluation as potential vaccines against E. granulosus. PMID:9169781

  8. The venus kinase receptor (VKR) family: structure and evolution

    PubMed Central

    2013-01-01

    Background Receptor tyrosine kinases (RTK) form a family of transmembrane proteins widely conserved in Metazoa, with key functions in cell-to-cell communication and control of multiple cellular processes. A new family of RTK named Venus Kinase Receptor (VKR) has been described in invertebrates. The VKR receptor possesses a Venus Fly Trap (VFT) extracellular module, a bilobate structure that binds small ligands to induce receptor kinase activity. VKR was shown to be highly expressed in the larval stages and gonads of several invertebrates, suggesting that it could have functions in development and/or reproduction. Results Analysis of recent genomic data has allowed us to extend the presence of VKR to five bilaterian phyla (Platyhelminthes, Arthropoda, Annelida, Mollusca, Echinodermata) as well as to the Cnidaria phylum. The presence of NveVKR in the early-branching metazoan Nematostella vectensis suggested that VKR arose before the bilaterian radiation. Phylogenetic and gene structure analyses showed that the 40 receptors identified in 36 animal species grouped monophyletically, and likely evolved from a common ancestor. Multiple alignments of tyrosine kinase (TK) and VFT domains indicated their important level of conservation in all VKRs identified up to date. We showed that VKRs had inducible activity upon binding of extracellular amino-acids and molecular modeling of the VFT domain confirmed the structure of the conserved amino-acid binding site. Conclusions This study highlights the presence of VKR in a large number of invertebrates, including primitive metazoans like cnidarians, but also its absence from nematodes and chordates. This little-known RTK family deserves to be further explored in order to determine its evolutionary origin, its possible interest for the emergence and specialization of Metazoa, and to understand its function in invertebrate development and/or reproductive biology. PMID:23721482

  9. Neuroschistosomiasis.

    PubMed

    Ross, Allen G; McManus, Donald P; Farrar, Jeremy; Hunstman, Richard J; Gray, Darren J; Li, Yue-Sheng

    2012-01-01

    Schistosomiasis (bilharzia) is a neglected tropical disease caused by digenetic trematode platyhelminths of the genus Schistosoma. Neuroschistosomiasis is one of the most severe clinical outcomes associated with schistosome infection. Neurological complications early during the course of infection are thought to occur through in situ egg deposition following aberrant migration of adult worms to the brain or spinal cord. The presence of eggs in the CNS induces a cell-mediated Th2-driven periovular granulomatous reaction. The mass effect of thousands of eggs and the large granulomas concentrated within the brain or spinal cord explain the signs and symptoms of increased intracranial pressure, myelopathy, radiculopathy and subsequent clinical sequelae. Myelopathy (acute transverse myelitis and subacute myeloradiculopathy) of the lumbosacral region is the most common neurological manifestation of S. mansoni or S. haematobium infection, whereas acute encephalitis of the cortex, subcortical white matter, basal ganglia or internal capsule is typical of S. japonicum infection. Cerebral complications include encephalopathy with headache, visual impairment, delirium, seizures, motor deficits and ataxia, whereas spinal symptoms include lumbar pain, lower limb radicular pain, muscle weakness, sensory loss and bladder dysfunction. The finding of eggs in the stool or a positive serology, provides supportive but not direct evidence of neuroschistosomiasis. A definitive diagnosis can only be made with histopathological study showing Schistosoma eggs and granulomas. Schistosomicidal drugs (notably praziquantel), steroids and surgery are currently used for the treatment of neuroschistosomiasis. During the 'acute phase' of the disease, neuroschistosomiasis is treated with corticosteroids which are augmented with a course of praziquantel once female worm ovipositioning commences. Surgery should be reserved for special cases such as in those with evidence of medullary compression and in those who deteriorate despite clinical management. PMID:21674195

  10. Phylogenetic Analyses and Characterization of RNase X25 from Drosophila melanogaster Suggest a Conserved Housekeeping Role and Additional Functions for RNase T2 Enzymes in Protostomes

    PubMed Central

    Ambrosio, Linda; Bailey, Ryan; Ding, Jian; MacIntosh, Gustavo C.

    2014-01-01

    Ribonucleases belonging to the RNase T2 family are enzymes associated with the secretory pathway that are almost absolutely conserved in all eukaryotes. Studies in plants and vertebrates suggest they have an important housekeeping function in rRNA recycling. However, little is known about this family of enzymes in protostomes. We characterized RNase X25, the only RNase T2 enzyme in Drosophila melanogaster. We found that RNase X25 is the major contributor of ribonuclease activity in flies as detected by in gel assays, and has an acidic pH preference. Gene expression analyses showed that the RNase X25 transcript is present in all adult tissues and developmental stages. RNase X25 expression is elevated in response to nutritional stresses; consistent with the hypothesis that this enzyme has a housekeeping role in recycling RNA. A correlation between induction of RNase X25 expression and autophagy was observed. Moreover, induction of gene expression was triggered by oxidative stress suggesting that RNase X25 may have additional roles in stress responses. Phylogenetic analyses of this family in protostomes showed that RNase T2 genes have undergone duplication events followed by divergence in several phyla, including the loss of catalytic residues, and suggest that RNase T2 proteins have acquired novel functions. Among those, it is likely that a role in host immunosuppression evolved independently in several groups, including parasitic Platyhelminthes and parasitoid wasps. The presence of only one RNase T2 gene in the D. melanogaster genome, without any other evident secretory RNase activity detected, makes this organism an ideal system to study the cellular functions of RNase T2 proteins associated with RNA recycling and maintenance of cellular homeostasis. On the other hand, the discovery of gene duplications in several protostome genomes also presents interesting new avenues to study additional biological functions of this ancient family of proteins. PMID:25133712

  11. Faunal communities at sites of gas- and oil-bearing fluids in Lake Baikal

    NASA Astrophysics Data System (ADS)

    Zemskaya, Tamara I.; Sitnikova, Tatiana Y.; Kiyashko, Sergei I.; Kalmychkov, Gennady V.; Pogodaeva, Tatiana V.; Mekhanikova, Irina V.; Naumova, Tatiana V.; Shubenkova, Olga V.; Chernitsina, Svetlana M.; Kotsar, Oleg V.; Chernyaev, Evgeny S.; Khlystov, Oleg M.

    2012-12-01

    Macro- and meiofaunal communities were examined at four geomorphologically distinct sites with different gas- and oil-bearing fluid characteristics in the northern, central and southern basins of Lake Baikal. All sites had elevated concentrations of bicarbonate, nitrate, sulphate and chloride ions in pore fluids, with highest values at the Frolikha vent. Elevated levels of iron ions were found in pore waters of the St. Petersburg methane seep and the Gorevoy Utes oil seep. The chemical composition of pore waters at the Malenky mud volcano was similar to that reported in earlier work. Consistent with published data, the Frolikha vent (northern basin) and the St. Petersburg methane seep (central basin) were characterised by methane of mixed genesis (thermogenic + biogenic), whereas the methane source was mainly thermogenic at the Gorevoy Utes oil seep (central basin) and biogenic at the Malenky mud volcano (southern basin). In contrast to marine seep ecosystems, the macrofauna was dominated only by amphipods, giant planarians and oligochaetes, whereas bivalves were absent; the meiofauna was similar to its marine counterpart, being dominated by nematodes, cyclops, harpacticoids and ostracods. A statistically significant positive relationship was revealed between faunal abundance and the availability of bacterial mats on seep sediments. Moreover, ANOVA tests showed significant increases in both meiozoobenthic and macrozoobenthic densities at "hot spot" vent/seep sites relative to discharge-free reference sites. The isotopic composition of carbon and nitrogen at various trophic levels of these benthic vent/seep communities was found to differ markedly from that reported by earlier studies for the pelagic and other benthic food webs in Lake Baikal. As in marine seeps, the macrofauna had variable isotopic signatures. Light ?13C and ?15N values suggest the utilization of chemosynthetically fixed and/or methane-derived organic matter. By contrast, the heavy ?13C signatures of some mobile amphipods likely reflect consumption of photosynthetically derived carbon. These findings would at least partly explain why Lake Baikal is a notable outlier in global temperature-biodiversity patterns, exhibiting the highest biodiversity of any lake worldwide but at an extremely cold average temperature.

  12. [Effects of sewage discharge on abundance and biomass of meiofauna].

    PubMed

    Huang, De-Ming; Liu, Xiao-Shou; Lin, Ming-Xian; Chen, Huai-Pu; Wei, Lian-Ming; Huang, Xin; Zhang, Zhi-Nan

    2014-10-01

    In order to elucidate the effects of sewage discharge on abundance and biomass of meio- fauna, a seasonal survey was carried out on meiofauna at stations with different distances to a sewage outlet in the middle intertidal zone of No. 1 bathing beach in Huiquan Bay, Qingdao in spring (April), summer (August), autumn (October) and winter (December), 2011. The results showed that the annual average meiofaunal abundance was (1859.9 ± 705.1) ind · 10 cm(-2), with higher values of (2444.9 ± 1220.5) ind · 10 cm(-2) at Station S2 (20 m to the sewage outlet) and (2492.2 ± 1839.9) ind · 10 cm(-2) at Station S3 (40 m to the sewage outlet), while the lowest value of (327.9 ± 183.2) ind · 10 cm(-2) was observed at Station S1 (0 m to the sewage outlet) in terms of horizontal distribution. The annual average biomass was (1513.4 ± 372.7) ?g · 10 cm(-2). Meiofaunal abundance and biomass varied seasonally with the highest values in spring and the lowest values in summer. A total of 11 meiofaunal groups were identified, including nematodes, copepods, polychaetes, oligochaetes, tardigrades, halacaroideans, planarians, ostracods, isopods, crustacean nauplii and others. Free-living marine nematodes were the dominant group constituting 83. 1% of the total abundance, followed by benthic copepods, accounting for 12. 8% of the total abundance. In terms of vertical distribution, most of the meiofauna concentrated in the top 0-2 cm, and the meiofauna abundance decreased with increasing the sediment depth. Meiofauna was also noted to migrate deeper into the sediment in the winter. Pearson correlation analysis showed that meiofaunal abundance and biomass had highly significant negative correlations with sediment median particle diameter and organic matter content. In addition, tourism-induced activities affected meiofaunal abundance and distribution. A comparison with historical data from similar studies was carried out, and the applicability of the ratio of abundance of nematodes to copepods in monitoring organic pollution was discussed. PMID:25796915

  13. The Diterpenoid 7-Keto-Sempervirol, Derived from Lycium chinense, Displays Anthelmintic Activity against both Schistosoma mansoni and Fasciola hepatica

    PubMed Central

    Edwards, Jennifer; Brown, Martha; Peak, Emily; Bartholomew, Barbara; Nash, Robert J.; Hoffmann, Karl F.

    2015-01-01

    Background Two platyhelminths of biomedical and commercial significance are Schistosoma mansoni (blood fluke) and Fasciola hepatica (liver fluke). These related trematodes are responsible for the chronic neglected tropical diseases schistosomiasis and fascioliasis, respectively. As no vaccine is currently available for anti-flukicidal immunoprophylaxis, current treatment is mediated by mono-chemical chemotherapy in the form of mass drug administration (MDA) (praziquantel for schistosomiasis) or drenching (triclabendazole for fascioliasis) programmes. This overreliance on single chemotherapeutic classes has dramatically limited the number of novel chemical entities entering anthelmintic drug discovery pipelines, raising significant concerns for the future of sustainable blood and liver fluke control. Methodology/ Principle Findings Here we demonstrate that 7-keto-sempervirol, a diterpenoid isolated from Lycium chinense, has dual anthelmintic activity against related S. mansoni and F. hepatica trematodes. Using a microtiter plate-based helminth fluorescent bioassay (HFB), this activity is specific (Therapeutic index = 4.2, when compared to HepG2 cell lines) and moderately potent (LD50 = 19.1 ?M) against S. mansoni schistosomula cultured in vitro. This anti-schistosomula effect translates into activity against both adult male and female schistosomes cultured in vitro where 7-keto-sempervirol negatively affects motility/behaviour, surface architecture (inducing tegumental holes, tubercle swelling and spine loss/shortening), oviposition rates and egg morphology. As assessed by the HFB and microscopic phenotypic scoring matrices, 7-keto-sempervirol also effectively kills in vitro cultured F. hepatica newly excysted juveniles (NEJs, LD50 = 17.7 ?M). Scanning electron microscopy (SEM) evaluation of adult F. hepatica liver flukes co-cultured in vitro with 7-keto-sempervirol additionally demonstrates phenotypic abnormalities including breaches in tegumental integrity and spine loss. Conclusions/ Significance 7-keto-sempervirol negatively affects the viability and phenotype of two related pathogenic trematodes responsible for significant human and animal infectious diseases. This plant-derived, natural product is also active against both larval and adult developmental forms. As such, the data collectively indicate that 7-keto-sempervirol is an important starting point for anthelmintic drug development. Medicinal chemistry optimisation of more potent 7-keto-sempervirol analogues could lead to the identification of novel chemical entities useful for future combinatorial or replacement anthelmintic control. PMID:25768432

  14. Posterior regeneration in Isodiametra pulchra (Acoela, Acoelomorpha)

    PubMed Central

    2013-01-01

    Introduction Regeneration is a widespread phenomenon in the animal kingdom, but the capacity to restore damaged or missing tissue varies greatly between different phyla and even within the same phylum. However, the distantly related Acoelomorpha and Platyhelminthes share a strikingly similar stem-cell system and regenerative capacity. Therefore, comparing the underlying mechanisms in these two phyla paves the way for an increased understanding of the evolution of this developmental process. To date, Isodiametra pulchra is the most promising candidate as a model for the Acoelomorpha, as it reproduces steadily under laboratory conditions and is amenable to various techniques, including the silencing of gene expression by RNAi. In order to provide an essential framework for future studies, we report the succession of regeneration events via the use of cytochemical, histological and microscopy techniques, and specify the total number of cells in adult individuals. Results Isodiametra pulchra is not capable of regenerating a new head, but completely restores all posterior structures within 10 days. Following amputation, the wound closes via the contraction of local muscle fibres and an extension of the dorsal epidermis. Subsequently, stem cells and differentiating cells invade the wound area and form a loosely delimited blastema. After two days, the posterior end is re-patterned with the male (and occasionally the female) genital primordium being apparent. Successively, these primordia differentiate into complete copulatory organs. The size of the body and also of the male and female copulatory organs, as well as the distance between the copulatory organs, progressively increase and by nine days copulation is possible. Adult individuals with an average length of 670 ?m consist of approximately 8100 cells. Conclusion Isodiametra pulchra regenerates through a combination of morphallactic and epimorphic processes. Existing structures are “re-modelled” and provide a framework onto which newly differentiating cells are added. Growth proceeds through the intercalary addition of structures, mirroring the embryonic and post-embryonic development of various organ systems. The suitability of Isodiametra pulchra for laboratory techniques, the fact that its transcriptome and genome data will soon be available, as well as its small size and low number of cells, make it a prime candidate subject for research into the cellular mechanisms that underlie regeneration in acoelomorphs. PMID:24160844

  15. The Schistosoma mansoni Tegumental-Allergen-Like (TAL) Protein Family: Influence of Developmental Expression on Human IgE Responses

    PubMed Central

    Fitzsimmons, Colin M.; Jones, Frances M.; Stearn, Alex; Chalmers, Iain W.; Hoffmann, Karl F.; Wawrzyniak, Jakub; Wilson, Shona; Kabatereine, Narcis B.; Dunne, David W.

    2012-01-01

    Background A human IgE response to Sm22.6 (a dominant IgE target in Schistosoma mansoni) is associated with the development of partial immunity. Located inside the tegument, the molecule belongs to a family of proteins from parasitic platyhelminths, the Tegument-Allergen-Like proteins (TALs). In addition to containing dynein-light-chain domains, these TALs also contain EF-hand domains similar to those found in numerous EF-hand allergens. Methodology/Principal Findings S. mansoni genome searches revealed 13 members (SmTAL1-13) within the species. Recent microarray data demonstrated they have a wide range of life-cycle transcriptional profiles. We expressed SmTAL1 (Sm22.6), SmTAL2, 3, 4, 5 and 13 as recombinant proteins and measured IgE and IgG4 in 200 infected males (7–60 years) from a schistosomiasis endemic region in Uganda. For SmTAL1 and 3 (transcribed in schistosomula through adult-worms and adult-worms, respectively) and SmTAL5 (transcribed in cercariae through adult-worms), detectable IgE responses were rare in 7–9 year olds, but increased with age. At all ages, IgE to SmTAL2 (expressed constitutively), was rare while anti-SmTAL2 IgG4 was common. Levels of IgE and IgG4 to SmTAL4 and 13 (transcribed predominantly in the cercariae/skin stage) were all low. Conclusions We have not measured SmTAL protein abundance or exposure in live parasites, but the antibody data suggests to us that, in endemic areas, there is priming and boosting of IgE to adult-worm SmTALs by occasional death of long-lived worms, desensitization to egg SmTALs through continuous exposure to dying eggs and low immunogenicity of larval SmTALs due to immunosuppression in the skin by the parasite. Of these, it is the gradual increase in IgE to the worm antigens that parallels age-dependent immunity seen in endemic areas. PMID:22509417

  16. Evolution of a novel nuclear receptor subfamily with emphasis on the member from the Pacific oyster Crassostrea gigas.

    PubMed

    Huang, Wen; Xu, Fei; Li, Juan; Li, Li; Que, Huayong; Zhang, Guofan

    2015-08-10

    Nuclear receptors (NRs) belong to the transcription factor superfamily that regulates development, homeostasis, differentiation, and reproduction in metazoans via control of gene expression. Recently, rapid advances in genome projects on various metazoans have provided new opportunities for studying the evolution and function of NRs. Typically structured NRs are divided into six subfamilies. Here, the gene for a typically structured NR (CgNR8A1) was cloned from the Pacific oyster Crassostrea gigas. However, this novel receptor could not be assigned to a known NR subfamily. By data mining, nine other CgNR8A1 gene homologs were identified in metazoans such as cnidarians, mollusks, annelids, echinoderms, hemichordates, and cephalochordates. Phylogenetic analysis showed that these receptors belonged to a novel NR subfamily, hereafter designated as NR8. Evolutionary analysis revealed that the NR8 subfamily was phylogenetically the third-oldest NR subfamily, and it originated from a common ancestor of Eumetazoa; several gene loss events occurred independently in ancestors of vertebrates, ecdysozoans, and platyhelminths, which do not have NR8 members. Furthermore, the function of CgNR8A1 was investigated to provide an insight into the functions of this novel NR subfamily. A nuclear localization signal peptide, GKHRNKKPRLD, was identified in CgNR8A1, and a recombinant full-length protein of CgNR8A1 was localized in the nuclei of HeLa cells. The mRNA expression profile of CgNR8A1 suggested that it might be involved in the embryogenesis of C. gigas. The electrophoretic mobility shift assay showed that CgNR8A1 binds strongly to conserved DNA core motifs DR0, DR2, and DR4 and weakly to DR1, DR3, DR5, Half, and Pal0. In summary, the novel NR8 subfamily identified in this study improves our understanding of NR evolution, and the functional analysis of CgNR8A1 provided further insights into the functions of NR8A1s. PMID:25956376

  17. Nearly complete rRNA genes from 371 Animalia: updated structure-based alignment and detailed phylogenetic analysis.

    PubMed

    Mallatt, Jon; Craig, Catherine Waggoner; Yoder, Matthew J

    2012-09-01

    This study presents a manually constructed alignment of nearly complete rRNA genes from most animal clades (371 taxa from ~33 of the ~36 metazoan phyla), expanded from the 197 sequences in a previous study. This thorough, taxon-rich alignment, available at http://www.wsu.edu/~jmallatt/research/rRNAalignment.html and in the Dryad Repository (doi: http://dx.doi.org/10.5061/dryad.1v62kr3q), is based rigidly on the secondary structure of the SSU and LSU rRNA molecules, and is annotated in detail, including labeling of the erroneous sequences (contaminants). The alignment can be used for future studies of the molecular evolution of rRNA. Here, we use it to explore if the larger number of sequences produces an improved phylogenetic tree of animal relationships. Disappointingly, the resolution did not improve, neither when the standard maximum-likelihood method was used, nor with more sophisticated methods that partitioned the rRNA into paired and unpaired sites (stem, loop, bulge, junction), or accounted for the evolution of the paired sites. For example, no doublet model of paired-site substitutions (16-state, 16A and 16B, 7A-F, or 6A-C models) corrected the placement of any rogue taxa or increased resolution. The following findings are from the simplest, standard, ML analysis. The 371-taxon tree only imperfectly supported the bilaterian clades of Lophotrochozoa and Ecdysozoa, and this problem remained after 17 taxa with unstably positioned sequences were omitted from the analysis. The problem seems to stem from base-compositional heterogeneity across taxa and from an overrepresentation of highly divergent sequences among the newly added taxa (e.g., sequences from Cephalopoda, Rotifera, Acoela, and Myxozoa). The rogue taxa continue to concentrate in two locations in the rRNA tree: near the base of Arthropoda and of Bilateria. The approximately uncertain (AU) test refuted the monophyly of Mollusca and of Chordata, probably due to long-branch attraction of the highly divergent cephalopod and urochordate sequences out of those clades. Unlikely to be correct, these refutations show for the first time that rRNA phylogeny can support some 'wrong' clades. Along with its weaknesses, the rRNA tree has strengths: It recovers many clades that are supported by independent evidence (e.g., Metazoa, Bilateria, Hexapoda, Nonoculata, Ambulacraria, Syndermata, and Thecostraca with Malacostraca) and shows good resolution within certain groups (e.g., in Platyhelminthes, Insecta, Cnidaria). As another strength, the newly added rRNA sequences yielded the first rRNA-based support for Carnivora and Cetartiodactyla (dolphin+llama) in Mammalia, for basic subdivisions of Bryozoa ('Gymnolaemata+Stenolaemata' versus Phylactolaemata), and for Oligostraca (ostracods+branchiurans+pentastomids+mystacocarids). Future improvement could come from better sequence-evolution models that account for base-compositional heterogeneity, and from combining rRNA with protein-coding genes in phylogenetic reconstruction. PMID:22641172

  18. Evolution of the trypanorhynch tapeworms: parasite phylogeny supports independent lineages of sharks and rays.

    PubMed

    Olson, Peter D; Caira, Janine N; Jensen, Kirsten; Overstreet, Robin M; Palm, Harry W; Beveridge, Ian

    2010-02-01

    Trypanorhynch tapeworms (Platyhelminthes: Cestoda) are among the most diverse and abundant groups of metazoan parasites of elasmobranchs and are a ubiquitous part of the marine food webs that include these apex predators. Here we present a comprehensive analysis of their phylogeny, character evolution and host associations based on 10years of sampling effort, including representatives of 12 of 15 and 44 of 66 currently recognized trypanorhynch families and genera, respectively. Using a combination of ssrDNA and lsrDNA (Domains 1-3) for 79 and 80 taxa, respectively, we maintain one-to-one correspondence between molecules and morphology by scoring 45 characters from the same specimens used for sequencing, and provide museum vouchers for this material. Host associations are examined through likelihood-based ancestral character state reconstructions (ACSRs) and by estimating dates of divergence using strict and relaxed molecular clock models in a Bayesian context. Maximum parsimony and Bayesian inference analyses of rDNA produced well-resolved and strongly supported trees in which the trypanorhynchs formed two primary lineages and were monophyletic with respect to the diphyllidean outgroup taxa. These lineages showed marked differences in their rates of divergence which in turn resulted in differing support and stability characteristics within the lineages. Mapping of morphological characters onto the tree resulting from combined analysis of rDNA showed most traits to be highly plastic, including some previously considered of key taxonomic importance such as underlying symmetries in tentacular armature. The resulting tree was found to be congruent with the most recent morphologically based superfamily designations in the order, providing support for four proposed superfamilies, but not for the Tentacularioidea and Eutetrarhynchoidea. ACSRs based on the combined analysis of rDNA estimated the original hosts of the two primary parasite lineages to be alternatively rajiform batoids and carcharhiniform sharks. This fundamental split provides independent support for rejecting the notion that rays are derived sharks, and thus supports the most recent molecular phylogenies of the Neoselachii. Beyond the basal split between shark- and ray-inhabiting lineages, no pattern was found to suggest that the trypanorhynchs have closely tracked the evolutionary histories of these host lineages, but instead, it appears that host-switching has been common and that the subsequent evolution of the parasites has been ecologically driven primarily through overlap in the niches of their shark and ray hosts. Using a relaxed molecular clock model calibrated by means of host fossil data, the ray-inhabiting lineage is estimated to have diversified around the Jurassic-Cretaceous boundary, whereas the shark-inhabiting lineage is estimated to have diversified later, in the Middle Cretaceous. Although the large error associated with the estimated divergence dates prevents robust conclusions from being drawn, the dates are nevertheless found to be consistent in a relative sense with the origins of their major hosts groups. The erection and definition of the suborders Trypanobatoida and Trypanoselachoida, for the major clades of trypanorhynchs parasitizing primarily rays and sharks, respectively, is proposed for the two primary lineages recovered here. PMID:19761769