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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1993-11-01

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

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

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

2014-06-01

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.

Environmental Impact Research Program. Ecological Effects of Rubble-Mound Breakwater Construction and Channel Dredging at West Harbor, Ohio (Western Lake Erie).

DTIC Science & Technology

1985-09-01

Harbor, Ohio (August 1981-1983) Taxa* Percent Porifera (Spongil a) 0.01 Cnidaria (Hydra) 0.30 Rhabdocoela 0.35 Tricladida 0.16 Nemertinea 0.14 Nematoda...Breakwaters at West Harbor. Ohio (April 1982-September 1983) Taxa* Percent * Cnidaria (Hydra) 5.98 Rhabdocoela 0.14 Tricladida 0.37 Nemertinea 0.11 Nematoda...3 3.0 OL!GOCHAE1A 23 85 2t 2000 CHIRONOMIDAE 3 8 0 163 CNIDARIA 0 2 0 30 BRYOZDA + + + 4 4.0 OLIGOCHAETA 325 56 148 7836 CHIRONOMIDAE 26 13 21

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2001-01-01

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

High copy number of highly similar mariner-like transposons in planarian (Platyhelminthe): evidence for a trans-phyla horizontal transfer.

PubMed

Garcia-Fernàndez, J; Bayascas-Ramírez, J R; Marfany, G; Muñoz-Mármol, A M; Casali, A; Baguñà, J; Saló, E

1995-05-01

Several DNA sequences similar to the mariner element were isolated and characterized in the platyhelminthe Dugesia (Girardia) tigrina. They were 1,288 bp long, flanked by two 32 bp-inverted repeats, and contained a single 339 amino acid open-reading frame (ORF) encoding the transposase. The number of copies of this element is approximately 8,000 per haploid genome, constituting a member of the middle-repetitive DNA of Dugesia tigrina. Sequence analysis of several elements showed a high percentage of conservation between the different copies. Most of them presented an intact ORF and the standard signals of actively expressed genes, which suggests that some of them are or have recently been functional transposons. The high degree of similarity shared with other mariner elements from some arthropods, together with the fact that this element is undetectable in other planarian species, strongly suggests a case of horizontal transfer between these two distant phyla.

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

PubMed

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

2014-10-20

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

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

PubMed

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

2017-01-01

The second part of the catalogue of type material deposited in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), between 1979 and 2016, is presented, to complement the first list of all types that was published in 1979. This part includes Platyhelminthes other than monogenoids, which were covered in the first part published in September 2016. The present catalogue comprises type material for 104 species, distributed across three classes, 40 families and 75 genera. Species names are listed systematically, followed by type host, infection site, type locality and specimens with their collection numbers and references. The classification and the nomenclature of the species have been updated.

Type material of Platyhelminthes housed in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), Rio de Janeiro, Brazil, from 1979 to 2016 (Rhabditophora, Trematoda and Cestoda)

PubMed Central

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

2017-01-01

Abstract The second part of the catalogue of type material deposited in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), between 1979 and 2016, is presented, to complement the first list of all types that was published in 1979. This part includes Platyhelminthes other than monogenoids, which were covered in the first part published in September 2016. The present catalogue comprises type material for 104 species, distributed across three classes, 40 families and 75 genera. Species names are listed systematically, followed by type host, infection site, type locality and specimens with their collection numbers and references. The classification and the nomenclature of the species have been updated. PMID:28769607

Parasitic peptides! The structure and function of neuropeptides in parasitic worms.

PubMed

Day, T A; Maule, A G

1999-01-01

Parasitic worms come from two very different phyla-Platyhelminthes (flatworms) and Nematoda (roundworms). Although both phyla possess nervous systems with highly developed peptidergic components, there are key differences in the structure and action of native neuropeptides in the two groups. For example, the most abundant neuropeptide known in platyhelminths is the pancreatic polypeptide-like neuropeptide F, whereas the most prevalent neuropeptides in nematodes are FMRFamide-related peptides (FaRPs), which are also present in platyhelminths. With respect to neuropeptide diversity, platyhelminth species possess only one or two distinct FaRPs, whereas nematodes have upwards of 50 unique FaRPs. FaRP bioactivity in platyhelminths appears to be restricted to myoexcitation, whereas both excitatory and inhibitory effects have been reported in nematodes. Recently interest has focused on the peptidergic signaling systems of both phyla because elucidation of these systems will do much to clarify the basic biology of the worms and because the peptidergic systems hold the promise of yielding novel targets for a new generation of antiparasitic drugs.

A Method for Dispensing Planaria (Dugesia dorotocephala) for Mosquito Control

DTIC Science & Technology

1988-12-01

Predation of mosquitoes by the planarian Du- fed 20 fourth instar Aedes aei,3pa fLinn.) per ..esia dorotocephala (Woodworth) (Tricladida: planarian every...the planarian . Du4(.sa dfr,r,i,#- phala I\\Woodworthi. in the presence of (’ul,,x pcu., l.egner. E. F. and R. A. Medved. 1972. Predators Speiser

The Echinococcus canadensis (G7) genome: a key knowledge of parasitic platyhelminth human diseases.

PubMed

Maldonado, Lucas L; Assis, Juliana; Araújo, Flávio M Gomes; Salim, Anna C M; Macchiaroli, Natalia; Cucher, Marcela; Camicia, Federico; Fox, Adolfo; Rosenzvit, Mara; Oliveira, Guilherme; Kamenetzky, Laura

2017-02-27

The parasite Echinococcus canadensis (G7) (phylum Platyhelminthes, class Cestoda) is one of the causative agents of echinococcosis. Echinococcosis is a worldwide chronic zoonosis affecting humans as well as domestic and wild mammals, which has been reported as a prioritized neglected disease by the World Health Organisation. No genomic data, comparative genomic analyses or efficient therapeutic and diagnostic tools are available for this severe disease. The information presented in this study will help to understand the peculiar biological characters and to design species-specific control tools. We sequenced, assembled and annotated the 115-Mb genome of E. canadensis (G7). Comparative genomic analyses using whole genome data of three Echinococcus species not only confirmed the status of E. canadensis (G7) as a separate species but also demonstrated a high nucleotide sequences divergence in relation to E. granulosus (G1). The E. canadensis (G7) genome contains 11,449 genes with a core set of 881 orthologs shared among five cestode species. Comparative genomics revealed that there are more single nucleotide polymorphisms (SNPs) between E. canadensis (G7) and E. granulosus (G1) than between E. canadensis (G7) and E. multilocularis. This result was unexpected since E. canadensis (G7) and E. granulosus (G1) were considered to belong to the species complex E. granulosus sensu lato. We described SNPs in known drug targets and metabolism genes in the E. canadensis (G7) genome. Regarding gene regulation, we analysed three particular features: CpG island distribution along the three Echinococcus genomes, DNA methylation system and small RNA pathway. The results suggest the occurrence of yet unknown gene regulation mechanisms in Echinococcus. This is the first work that addresses Echinococcus comparative genomics. The resources presented here will promote the study of mechanisms of parasite development as well as new tools for drug discovery. The availability of a high

Neuropeptide physiology in helminths.

PubMed

Mousley, Angela; Novozhilova, Ekaterina; Kimber, Michael J; Day, Tim A

2010-01-01

Parasitic worms come from two distinct, distant phyla, Nematoda (roundworms) and Platyhelminthes (flatworms). The nervous systems of worms from both phyla are replete with neuropeptides and there is ample physiological evidence that these neuropeptides control vital aspects of worm biology. In each phyla, the physiological evidence for critical roles for helminth neuropeptides is derived from both parasitic and free-living members. In the nematodes, the intestinal parasite Ascaris suum and the free-living Caenorhabditis elegans have yielded most of the data; in the platyhelminths, the most physiological data has come from the blood fluke Schistosoma mansoni. FMRFamide-like peptides (FLPs) have many varied effects (excitation, relaxation, or a combination) on somatic musculature, reproductive musculature, the pharynx and motor neurons in nematodes. Insulin-like peptides (INSs) play an essential role in nematode dauer formation and other developmental processes. There is also some evidence for a role in somatic muscle control for the somewhat heterogeneous grouping ofpeptides known as neuropeptide-like proteins (NLPs). In platyhelminths, as in nematodes, FLPs have a central role in somatic muscle function. Reports of FLP physiological action in platyhelminths are limited to a potent excitation of the somatic musculature. Platyhelminths are also abundantly endowed with neuropeptide Fs (NPFs), which appear absent from nematodes. There is not yet any data linking platyhelminth NPF to any particular physiological outcome, but this neuropeptide does potently and specifically inhibit cAMP accumulation in schistosomes. In nematodes and platyhelminths, there is an abundance of physiological evidence demonstrating that neuropeptides play critical roles in the biology of both free-living and parasitic helminths. While it is certainly true that there remains a great deal to learn about the biology of neuropeptides in both phyla, physiological evidence presently available points

Behavioural responses of stable flies to cattle manure slurry associated odourants

USDA-ARS?s Scientific Manuscript database

Stable flies (Stomoxys calcitrans [Diptera: Muscidae] L.) are blood-feeding synanthropic pests, which cause significant economic losses in livestock. Stable fly antennae contain olfactory sensilla responsive to host and host environment-associated odours. Field observation indicated that the abundan...

Algal bloom-associated disease outbreaks among users of freshwater lakes-United States, 2009 - 2010

EPA Science Inventory

‘Algal blooms’ are local abundances of phytoplankton – microscopic photosynthesizing aquatic organisms found in surface waters worldwide; blooms are variable temporally and spatially and frequently produce a visible algal scum on the water. Harmful algal blooms (HABs) are abundan...

DINOFLAGELLATE CYST RECORDS AND HUMAN DISTURBANCE IN TWO NEIGHBORING ESTUARIES, NEW BEDFORD HARBOR AND APPONAGANSETT BAY, MASSACHUSETTS, USA

EPA Science Inventory

The dinoflagellate cyst records in sediments from New Bedford Harbor and Apponagansett Bay demonstrate sensitivity to environmental change caused by human activity in the watersheds over the last 500 years. Changes in the species richness, as well as absolute and relative abundan...

A Survey of Golf Courses as a Source of Invasive C3 Grasses

USDA-ARS?s Scientific Manuscript database

Creeping bentgrass (Agrostis stolonifera L.; CBG), Kentucky bluegrass (Poa pratensis L.; KBG), and fine fescue species (Festuca spp.; FF) are commonly used as turf on golf courses. All have been identified as invasive species by governmental or non-governmental groups. We hypothesized that abundan...

Meteorological and management factors influencing weed abundance during 18 years of organic crop rotations

USDA-ARS?s Scientific Manuscript database

Organic crop production is often limited by the inability to control weeds. An 18-year dataset of weed cover in organic crop rotations at the long-term Farming Systems Project at Beltsville, Maryland, provided the opportunity to identify meteorological and management factors influencing weed abundan...

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

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

Nuclear hormone receptors in parasitic helminths

PubMed Central

Wu, Wenjie; LoVerde, Philip T

2010-01-01

Nuclear receptors (NRs) belong to a large protein superfamily that are important transcriptional modulators in metazoans. Parasitic helminths include parasitic worms from the Lophotrochozoa (Platyhelminths) and Ecdysozoa (Nematoda). NRs in parasitic helminths diverged into two different evolutionary lineages. NRs in parasitic Platyhelminths have orthologues in Deuterostomes, in arthropods or both with a feature of extensive gene loss and gene duplication within different gene groups. NRs in parasitic Nematoda follow the nematode evolutionary lineage with a feature of multiple duplication of SupNRs and gene loss. PMID:20600585

To Be or Not to Be a Flatworm: The Acoel Controversy

PubMed Central

Arendt, Detlev; Borgonie, Gaëtan; Funayama, Noriko; Gschwentner, Robert; Hartenstein, Volker; Hobmayer, Bert; Hooge, Matthew; Hrouda, Martina; Ishida, Sachiko; Kobayashi, Chiyoko; Kuales, Georg; Nishimura, Osamu; Pfister, Daniela; Rieger, Reinhard; Salvenmoser, Willi; Smith, Julian; Technau, Ulrich; Tyler, Seth; Agata, Kiyokazu; Salzburger, Walter; Ladurner, Peter

2009-01-01

Since first described, acoels were considered members of the flatworms (Platyhelminthes). However, no clear synapomorphies among the three large flatworm taxa - the Catenulida, the Acoelomorpha and the Rhabditophora - have been characterized to date. Molecular phylogenies, on the other hand, commonly positioned acoels separate from other flatworms. Accordingly, our own multi-locus phylogenetic analysis using 43 genes and 23 animal species places the acoel flatworm Isodiametra pulchra at the base of all Bilateria, distant from other flatworms. By contrast, novel data on the distribution and proliferation of stem cells and the specific mode of epidermal replacement constitute a strong synapomorphy for the Acoela plus the major group of flatworms, the Rhabditophora. The expression of a piwi-like gene not only in gonadal, but also in adult somatic stem cells is another unique feature among bilaterians. These two independent stem-cell-related characters put the Acoela into the Platyhelminthes-Lophotrochozoa clade and account for the most parsimonious evolutionary explanation of epidermal cell renewal in the Bilateria. Most available multigene analyses produce conflicting results regarding the position of the acoels in the tree of life. Given these phylogenomic conflicts and the contradiction of developmental and morphological data with phylogenomic results, the monophyly of the phylum Platyhelminthes and the position of the Acoela remain unresolved. By these data, both the inclusion of Acoela within Platyhelminthes, and their separation from flatworms as basal bilaterians are well-supported alternatives. PMID:19430533

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

PubMed

Paladini, Giuseppe; Huyse, Tine; Shinn, Andrew P

2011-06-09

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. 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). The ability of G. salinae n. sp. to tolerate a wide range of salinities and temperatures shows its

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.

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

PubMed

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

2015-11-01

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

Schistosoma comparative genomics: integrating genome structure, parasite biology and anthelmintic discovery

PubMed Central

Swain, Martin T.; Larkin, Denis M.; Caffrey, Conor R.; Davies, Stephen J.; Loukas, Alex; Skelly, Patrick J.; Hoffmann, Karl F.

2011-01-01

Schistosoma genomes provide a comprehensive resource for identifying the molecular processes that shape parasite evolution and for discovering novel chemotherapeutic or immunoprophylactic targets. Here, we demonstrate how intra- and intergenus comparative genomics can be used to drive these investigations forward, illustrate the advantages and limitations of these approaches and review how post genomic technologies offer complementary strategies for genome characterisation. While sequencing and functional characterisation of other schistosome/platyhelminth genomes continues to expedite anthelmintic discovery, we contend that future priorities should equally focus on improving assembly quality, and chromosomal assignment, of existing schistosome/platyhelminth genomes. PMID:22024648

Evidence for the persistence of the land planarian species Microplana terrestris (Müller, 1774) (Platyhelminthes, Tricladida) in microrefugia during the Last Glacial Maximum in the northern section of the Iberian Peninsula.

PubMed

Álvarez-Presas, Marta; Mateos, Eduardo; Vila-Farré, Miquel; Sluys, Ronald; Riutort, Marta

2012-09-01

The land planarian species Microplana terrestris (Müller, 1774), shows a wide distribution in the north of the Iberian Peninsula, where mature humid forests can be found. Since most terrestrial planarians require the presence and good condition of wet forests to survive, a parallel evolution of the taxon and its habitat might be expected. Performing molecular analyses (mitochondrial cytochrome oxidase I and nuclear ITS-1 genes) we estimated the demography and biogeographic history of the species in that region. Our results show the species to present levels of genetic diversity likely originating before the Pleistocene. However, it presents a genetic structure that presumably resulted from its survival in various refugees during the Pleistocene glacial cycles. The two main genetic groups, present on the Iberian Peninsula, seem to have different origins: the western one being of Iberian origin, while the eastern group may have been the result of a re-colonization from the north. In both cases, their biogeographical history mirrors their habitat range movements, reinforcing the phylogeographical hypothesis put forward for its preferred habitat, i.e. humid forests. Copyright © 2012 Elsevier Inc. All rights reserved.

Ecology and Disease Transmission Potential in the Colombian Amazon Basin.

DTIC Science & Technology

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

Complete mitochondrial genomes and nuclear ribosomal RNA operons of two species of Diplostomum (Platyhelminthes: Trematoda): a molecular resource for taxonomy and molecular epidemiology of important fish pathogens.

PubMed

Brabec, Jan; Kostadinova, Aneta; Scholz, Tomáš; Littlewood, D Timothy J

2015-06-19

The genus Diplostomum (Platyhelminthes: Trematoda: Diplostomidae) is a diverse group of freshwater parasites with complex life-cycles and global distribution. The larval stages are important pathogens causing eye fluke disease implicated in substantial impacts on natural fish populations and losses in aquaculture. However, the problematic species delimitation and difficulties in the identification of larval stages hamper the assessment of the distributional and host ranges of Diplostomum spp. and their transmission ecology. Total genomic DNA was isolated from adult worms and shotgun sequenced using Illumina MiSeq technology. Mitochondrial (mt) genomes and nuclear ribosomal RNA (rRNA) operons were assembled using established bioinformatic tools and fully annotated. Mt protein-coding genes and nuclear rRNA genes were subjected to phylogenetic analysis by maximum likelihood and the resulting topologies compared. We characterised novel complete mt genomes and nuclear rRNA operons of two closely related species, Diplostomum spathaceum and D. pseudospathaceum. Comparative mt genome assessment revealed that the cox1 gene and its 'barcode' region used for molecular identification are the most conserved regions; instead, nad4 and nad5 genes were identified as most promising molecular diagnostic markers. Using the novel data, we provide the first genome wide estimation of the phylogenetic relationships of the order Diplostomida, one of the two fundamental lineages of the Digenea. Analyses of the mitogenomic data invariably recovered the Diplostomidae as a sister lineage of the order Plagiorchiida rather than as a basal lineage of the Diplostomida as inferred in rDNA phylogenies; this was concordant with the mt gene order of Diplostomum spp. exhibiting closer match to the conserved gene order of the Plagiorchiida. Complete sequences of the mt genome and rRNA operon of two species of Diplostomum provide a valuable resource for novel genetic markers for species delineation and

Echinococcus granulosus fatty acid binding proteins subcellular localization.

PubMed

Alvite, Gabriela; Esteves, Adriana

2016-05-01

Two fatty acid binding proteins, EgFABP1 and EgFABP2, were isolated from the parasitic platyhelminth Echinococcus granulosus. These proteins bind fatty acids and have particular relevance in flatworms since de novo fatty acids synthesis is absent. Therefore platyhelminthes depend on the capture and intracellular distribution of host's lipids and fatty acid binding proteins could participate in lipid distribution. To elucidate EgFABP's roles, we investigated their intracellular distribution in the larval stage by a proteomic approach. Our results demonstrated the presence of EgFABP1 isoforms in cytosolic, nuclear, mitochondrial and microsomal fractions, suggesting that these molecules could be involved in several cellular processes. Copyright © 2016 Elsevier Inc. All rights reserved.

An approach for phycoremediation of different wastewaters and biodiesel production using microalgae.

PubMed

Amit; Ghosh, Uttam Kumar

2018-04-28

Four microalgal strains, namely, Tetraselmis indica (T. indica), Scenedesmus abundans (S. abundans), Spirulina sp., and Nostoc muscorum (N. muscorum) were cultivated on four different wastewaters in 1000 ml photobioreactors with 750 ml working volume under 94.5 μmol m -2  s -1 light intensity for 14 days for phycoremediation of wastewaters and sustainable biodiesel production. These microalgal strains attained maximum biomass growth in the secondary treated sewage (STS). Maximum biomass yield (0.6533 g L -1 ) and lipid productivity (25.44 mg L -1  d -1 ) for T. indica were achieved in STS. T. indica removed (63.6-78.24%) of nitrate, (60.90-65.97%) of phosphate, (61.01-80.01%) of ammonical nitrogen, and (71.16-85.70%) of total organic carbon (TOC) in all four wastewaters. The fatty acid methyl ester (FAME) profile of T. indica shows the presence of myristic acid (1.2%) pentadecylic acid (0.28%), palmitic acid (10.32%), oleic acid (34.59%), linoleic acid (12.38%), and eicosanoic acid (14.88%) in STS. This study demonstrates that T. indica is the most suitable microalgal species among the four microalgal strains selected for phycoremediation of wastewaters and higher biomass production for sustainable biodiesel production.

Helminths and Cancers From the Evolutionary Perspective.

PubMed

Scholte, Larissa L S; Pascoal-Xavier, Marcelo A; Nahum, Laila A

2018-01-01

Helminths include free-living and parasitic Platyhelminthes and Nematoda which infect millions of people worldwide. Some Platyhelminthes species of blood flukes ( Schistosoma haematobium, Schistosoma japonicum , and Schistosoma mansoni ) and liver flukes ( Clonorchis sinensis and Opisthorchis viverrini ) are known to be involved in human cancers. Other helminths are likely to be carcinogenic. Our main goals are to summarize the current knowledge of human cancers caused by Platyhelminthes, point out some helminth and human biomarkers identified so far, and highlight the potential contributions of phylogenetics and molecular evolution to cancer research. Human cancers caused by helminth infection include cholangiocarcinoma, colorectal hepatocellular carcinoma, squamous cell carcinoma, and urinary bladder cancer. Chronic inflammation is proposed as a common pathway for cancer initiation and development. Furthermore, different bacteria present in gastric, colorectal, and urogenital microbiomes might be responsible for enlarging inflammatory and fibrotic responses in cancers. Studies have suggested that different biomarkers are involved in helminth infection and human cancer development; although, the detailed mechanisms remain under debate. Different helminth proteins have been studied by different approaches. However, their evolutionary relationships remain unsolved. Here, we illustrate the strengths of homology identification and function prediction of uncharacterized proteins from genome sequencing projects based on an evolutionary framework. Together, these approaches may help identifying new biomarkers for disease diagnostics and intervention measures. This work has potential applications in the field of phylomedicine (evolutionary medicine) and may contribute to parasite and cancer research.

Thioredoxin Glutathione Reductase as a Novel Drug Target: Evidence from Schistosoma japonicum

PubMed Central

Xie, ShuYing; Qian, ChunYan; Wang, Jie; Zhang, Wei; Yin, XuRen; Hua, ZiChun; Yu, ChuanXin

2012-01-01

Background Schistosomiasis remains a major public health concern affecting billions of people around the world. Currently, praziquantel is the only drug of choice for treatment of human schistosomiasis. The emergence of drug resistance to praziquantel in schistosomes makes the development of novel drugs an urgent task. Thioredoxin glutathione reductase (TGR) enzymes in Schistosoma mansoni and some other platyhelminths have been identified as alternative targets. The present study was designed to confirm the existense and the potential value of TGR as a target for development of novel antischistosomal agents in Schistosoma japonicum, a platyhelminth endemic in Asia. Methods and Findings After cloning the S. japonicum TGR (SjTGR) gene, the recombinant SjTGR selenoprotein was purified and characterized in enzymatic assays as a multifunctional enzyme with thioredoxin reductase (TrxR), glutathione reductase (GR) and glutaredoxin (Grx) activities. Immunological and bioinformatic analyses confirmed that instead of having separate TrxR and GR proteins in mammalian, S. japonicum only encodes TGR, which performs the functions of both enzymes and plays a critical role in maintaining the redox balance in this parasite. These results were in good agreement with previous findings in Schistosoma mansoni and some other platyhelminths. Auranofin, a known inhibitor against TGR, caused fatal toxicity in S. japonicum adult worms in vitro and reduced worm and egg burdens in S. japonicum infected mice. Conclusions Collectively, our study confirms that a multifunctional enzyme SjTGR selenoprotein, instead of separate TrxR and GR enzymes, exists in S. japonicum. Furthermore, TGR may be a potential target for development of novel agents against schistosomes. This assumption is strengthened by our demonstration that the SjTGR is an essential enzyme for maintaining the thiol-disulfide redox homeostasis of S. japonicum. PMID:22384025

Put a tiger in your tank: the polyclad flatworm Maritigrella crozieri as a proposed model for evo-devo.

PubMed

Lapraz, François; Rawlinson, Kate A; Girstmair, Johannes; Tomiczek, Bartłomiej; Berger, Jürgen; Jékely, Gáspár; Telford, Maximilian J; Egger, Bernhard

2013-10-09

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.

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

[Evolution of the tegument of Polystoma (Monogenea Polystomatidae) during the cycle. Persistence of the nucleated embryonic epidermis in oncomiracidia (author's transl)].

PubMed

Fournier, A

1979-08-01

The evolution of tegument ultrastructures during development was studied in two Polystome species, Polystoma integerrimum and Polystoma pelobatis. It differs from Monogenea and other Platyhelminths in the presence of nuclei in the tegumentary syncytium of the oncomiracidium and their deferred elimination which occurs in the post-larva attached to the gills of the tadpole. This represents a delay in the loss of embryonic characteristics in Polystoma larvae which may be related to the possibility of neotenic development of these larvae. This delay allows us to follow naturally the considerable cytoplasmic changes which accompany the elimination of embryonic nuclei (disappearance of the ergastoplasm, golgi complexes and ribosomes, and of the vacuoles) and the transfer of control of this "enucleated" cytoplasm to nuclear information from tegumentary parenchymatic cells (appearance of new inclusions in the "annexed" cytoplasmic zone, maintenance of numerous organelles involved in the formation of these inclusions in the deep perinuclear region). The ultrastructual characteristics of ciliated cells and the tegumentary syncytium are discussed from the general point of view of the Platyhelminths and with respect to their adaptative function in the Polystomatidae. The originality of the Polystomatidae among the Monogenea is emphasized.

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

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

PubMed

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

1994-10-01

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

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

DTIC Science & Technology

1982-03-01

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

Structural analysis of the α subunit of Na(+)/K(+) ATPase genes in invertebrates.

PubMed

Thabet, Rahma; Rouault, J-D; Ayadi, Habib; Leignel, Vincent

2016-01-01

The Na(+)/K(+) ATPase is a ubiquitous pump coordinating the transport of Na(+) and K(+) across the membrane of cells and its role is fundamental to cellular functions. It is heteromer in eukaryotes including two or three subunits (α, β and γ which is specific to the vertebrates). The catalytic functions of the enzyme have been attributed to the α subunit. Several complete α protein sequences are available, but only few gene structures were characterized. We identified the genomic sequences coding the α-subunit of the Na(+)/K(+) ATPase, from the whole-genome shotgun contigs (WGS), NCBI Genomes (chromosome), Genomic Survey Sequences (GSS) and High Throughput Genomic Sequences (HTGS) databases across distinct phyla. One copy of the α subunit gene was found in Annelida, Arthropoda, Cnidaria, Echinodermata, Hemichordata, Mollusca, Placozoa, Porifera, Platyhelminthes, Urochordata, but the nematodes seem to possess 2 to 4 copies. The number of introns varied from 0 (Platyhelminthes) to 26 (Porifera); and their localization and length are also highly variable. Molecular phylogenies (Maximum Likelihood and Maximum Parsimony methods) showed some clusters constituted by (Chordata/(Echinodermata/Hemichordata)) or (Plathelminthes/(Annelida/Mollusca)) and a basal position for Porifera. These structural analyses increase our knowledge about the evolutionary events of the α subunit genes in the invertebrates. Copyright © 2016 Elsevier Inc. All rights reserved.

Changes in mitochondrial genetic codes as phylogenetic characters: Two examples from the flatworms

PubMed Central

Telford, Maximilian J.; Herniou, Elisabeth A.; Russell, Robert B.; Littlewood, D. Timothy J.

2000-01-01

Shared molecular genetic characteristics other than DNA and protein sequences can provide excellent sources of phylogenetic information, particularly if they are complex and rare and are consequently unlikely to have arisen by chance convergence. We have used two such characters, arising from changes in mitochondrial genetic code, to define a clade within the Platyhelminthes (flatworms), the Rhabditophora. We have sampled 10 distinct classes within the Rhabditophora and find that all have the codon AAA coding for the amino acid Asn rather than the usual Lys and AUA for Ile rather than the usual Met. We find no evidence to support claims that the codon UAA codes for Tyr in the Platyhelminthes rather than the standard stop codon. The Rhabditophora are a very diverse group comprising the majority of the free-living turbellarian taxa and the parasitic Neodermata. In contrast, three other classes of turbellarian flatworm, the Acoela, Nemertodermatida, and Catenulida, have the standard invertebrate assignments for these codons and so are convincingly excluded from the rhabditophoran clade. We have developed a rapid computerized method for analyzing genetic codes and demonstrate the wide phylogenetic distribution of the standard invertebrate code as well as confirming already known metazoan deviations from it (ascidian, vertebrate, echinoderm/hemichordate). PMID:11027335

[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.

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

PubMed

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

2017-02-01

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

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

PubMed Central

Haukisalmi, Voitto

2015-01-01

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

Codon Usage Patterns of Tyrosinase Genes in Clonorchis sinensis.

PubMed

Bae, Young-An

2017-04-01

Codon usage bias (CUB) is a unique property of genomes and has contributed to the better understanding of the molecular features and the evolution processes of particular gene. In this study, genetic indices associated with CUB, including relative synonymous codon usage and effective numbers of codons, as well as the nucleotide composition, were investigated in the Clonorchis sinensis tyrosinase genes and their platyhelminth orthologs, which play an important role in the eggshell formation. The relative synonymous codon usage patterns substantially differed among tyrosinase genes examined. In a neutrality analysis, the correlation between GC 12 and GC 3 was statistically significant, and the regression line had a relatively gradual slope (0.218). NC-plot, i.e., GC 3 vs effective number of codons (ENC), showed that most of the tyrosinase genes were below the expected curve. The codon adaptation index (CAI) values of the platyhelminth tyrosinases had a narrow distribution between 0.685/0.714 and 0.797/0.837, and were negatively correlated with their ENC. Taken together, these results suggested that CUB in the tyrosinase genes seemed to be basically governed by selection pressures rather than mutational bias, although the latter factor provided an additional force in shaping CUB of the C. sinensis and Opisthorchis viverrini genes. It was also apparent that the equilibrium point between selection pressure and mutational bias is much more inclined to selection pressure in highly expressed C. sinensis genes, than in poorly expressed genes.

In silico analysis of Schmidtea mediterranea TIR domain-containing proteins.

PubMed

Tsoumtsa, Landry Laure; Sougoufora, Seynabou; Torre, Cedric; Lemichez, Emmanuel; Pontarotti, Pierre; Ghigo, Eric

2018-09-01

While genetic evidence points towards an absence of Toll-Like Receptors (TLRs) in Platyhelminthes, the Toll/IL-1 Receptor (TIR)-domains that drive the assembly of signalling complexes downstream TLR are present in these organisms. Here, we undertook the characterisation of the repertoire of TIR-domain containing proteins in Schmidtea mediterranea in order to gain valuable information on TLR evolution in metazoan. We report the presence of twenty proteins containing between one and two TIR domains. In addition, our phylogenetic-based reconstruction approach identified Smed-SARM and Smed-MyD88 as conserved TLR adaptors. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Splenic hydatid cyst. Case report of a pregnant woman].

PubMed

Menéndez-Arzac, Rodrigo; Sanjuán, Alberto; Rebolledo, Gustavo; Márquez, Juan Carlos; Recinos, Elio Germán; Cue, Araceli; Blas, Carolina; Flisser, Ana

2002-01-01

Hydatid disease is caused by larvae of the platyhelminth parasite called Echinococcus; it generally lodges in liver and lung, and less commonly in spleen. In Mexico, hydatid disease has a very low frequency; only few cases of lung disease have been reported. In this paper, case of a 7 weeks pregnant female patient with a simple cyst in spleen identified by ultrasound and tomography is reported. The patient underwent splenectomy. Diagnosis of hydatid cyst was confirmed by histopathology. This case suggests that hydatid disease should be considered as differential diagnosis in every patient with a cystic mass of the spleen.

Neurobehavioral toxicity of cadmium sulfate to the planarian Dugesia dorotocephala

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grebe, E.; Schaeffer, D.J.

1991-05-01

The authors are developing bioassays which use planarians (free-living platyhelminthes) for the rapid determination of various types of toxicity, including acute mortality, tumorigenicity, and short-term neurobehavioral responses. Their motivation for using these animals is due to their importance as components of the aquatic ecology of unpolluted streams their sensitivity to low concentrations of environmental toxicants and the presence of a sensitive neurological system with a true brain which allows for complex social behavior. A previous paper described the results of a neurobehavioral bioassay using phenol in a crossover study. This paper reports a similar crossover study using cadmium sulfate.

Ultrastructure of the gravid uterus of Hymenolepis diminuta (Platyhelminthes: Cestoda).

PubMed

Conn, D B

1993-08-01

The fine structure of the uterus in gravid proglottids of Hymenolepis diminuta was examined by standard techniques for scanning and transmission electron microscopy. The uterus consisted of a syncytial uterine epithelium attached to the medullary parenchyma through a thin extracellular basal matrix. The epithelium contained prominent nuclei in the juxtalumenal cytoplasm. The cytoplasm was dominated by extensive granular endoplasmic reticulum, with dilated cisternae containing an electron-lucent material and widely scattered electron-dense spherical bodies. No Golgi body or other agranular endomembrane component was observed, but the epithelium contained numerous free ribosomes and a few mitochondria. The apical plasma membrane was folded into long microlamellae. Epithelial and epitheliomesenchymal folds and villi resulted in a compartmentalized uterine lumen, with each chamber containing 1 to several eggs. These data suggest a high level of synthetic activity within the uterine epithelium, but the chemical products and functional significance of this activity are not yet known.

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

PubMed

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

2015-08-01

Predatory flatworms belonging to the taxon Kalyptorhynchia are characterized by an anterior muscular proboscis that they use to seize prey. In many cases, the proboscis is armed with hooks, derived either from the extracellular matrix that surrounds the muscles or from intracellular deposits in the epithelium covering the proboscis. Glands associated with the proboscis reportedly are venomous; however, there are few direct tests of this hypothesis. This article reviews the structure and current knowledge of the function of the proboscis in the Kalyptorhynchia, points to areas in which the current understanding of phylogenetic relationships within this taxon is incongruent with our hypothesis of how the proboscis evolved, and addresses areas in need of further research, especially as regards functional morphology and biomechanics. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Effects of Water Quality on Survival and Reproduction of Four Species of Planaria (Turbellaria: Tricladida)

DTIC Science & Technology

1994-01-01

Institute of Research, Washington, DC 20307-5100, USA Received 4 June 1992; Accepted 15 September 1993 Summary In a series of bioassays, four planarian ...Marking All previous research on the physical and chemical and Dawson, 1973) for four water hardness levels of effects on planarian growth and...reproduction has been very soft (10-13mg/I CaCO 3), soft (40-48mg/1 designed to study development of planarian mass CaCO3), hard (160-168 mg/l CaCO 3), and very

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

PubMed

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

2016-03-01

The Echinostomatoidea is a large, cosmopolitan group of digeneans currently including nine families and 105 genera, the vast majority parasitic, as adults, in birds with relatively few taxa parasitising mammals, reptiles and, exceptionally, fish. Despite the complex structure, diverse content and substantial species richness of the group, almost no attempt has been made to elucidate its phylogenetic relationships at the suprageneric level based on molecules due to the lack of data. Herein, we evaluate the consistency of the present morphology-based classification system of the Echinostomatoidea with the phylogenetic relationships of its members based on partial sequences of the nuclear lsrRNA gene for a broad diversity of taxa (80 species, representing eight families and 40 genera), including representatives of five subfamilies of the Echinostomatidae, which currently exhibits the most complex taxonomic structure within the superfamily. This first comprehensive phylogeny for the Echinostomatoidea challenged the current systematic framework based on comparative morphology. A morphology-based evaluation of this new molecular framework resulted in a number of systematic and nomenclatural changes consistent with the phylogenetic estimates of the generic and suprageneric boundaries and a new phylogeny-based classification of the Echinostomatoidea. In the current systematic treatment: (i) the rank of two family level lineages, the former Himasthlinae and Echinochasminae, is elevated to full family status; (ii) Caballerotrema is distinguished at the family level; (iii) the content and diagnosis of the Echinostomatidae (sensu stricto) (s. str.) are revised to reflect its phylogeny, resulting in the abolition of the Nephrostominae and Chaunocephalinae as synonyms of the Echinostomatidae (s. str.); (iv) Artyfechinostomum, Cathaemasia, Rhopalias and Ribeiroia are re-allocated within the Echinostomatidae (s. str.), resulting in the abolition of the Cathaemasiidae, Rhopaliidae and Ribeiroiinae, which become synonyms of the Echinostomatidae (s. str.); and (v) refinements of the generic boundaries within the Echinostomatidae (s. str.), Psilostomidae and Fasciolidae are made. Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

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

PubMed

Nishimura, Osamu; Hirao, Yukako; Tarui, Hiroshi; Agata, Kiyokazu

2012-06-29

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. 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. 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.

Molecular identification of Fasciola spp. (Digenea: Platyhelminthes) in cattle from Vietnam

PubMed Central

Nguyen, S.; Amer, S.; Ichikawa, M.; Itagaki, T.; Fukuda, Y.; Nakai, Y.

2012-01-01

Fasciola spp. were collected from naturally infected cattle at a local abattoir of Khanh Hoa province, Vietnam, for morphological and genetic investigations. Microscopic examination detected no sperm cells in the seminal vesicles, suggesting a parthenogenetic reproduction of the flukes. Analyses of sequences from the first and second internal transcribed spacers (ITS1 and ITS2) of the ribosomal RNA revealed that 13 out of 16 isolates were of Fasciola gigantica type, whereas three isolates presented a hybrid sequence from F. gigantica and Fasciola hepatica. Interestingly, all the mitochondrial sequences (partial COI and NDI) were of F. gigantica type, suggesting that the maternal lineage of the hybrid form is from F. gigantica. No intra-sequence variation was detected. PMID:22314245

TTX-Bearing Planocerid Flatworm (Platyhelminthes: Acotylea) in the Ryukyu Islands, Japan

PubMed Central

Ueda, Hiroyuki; Itoi, Shiro; Sugita, Haruo

2018-01-01

Polyclad flatworms comprise a highly diverse and cosmopolitan group of marine turbellarians. Although some species of the genera Planocera and Stylochoplana are known to be tetrodotoxin (TTX)-bearing, there are few new reports. In this study, planocerid-like flatworm specimens were found in the sea bottom off the waters around the Ryukyu Islands, Japan. The bodies were translucent with brown reticulate mottle, contained two conical tentacles with eye spots clustered at the base, and had a slightly frilled-body margin. Each specimen was subjected to TTX extraction followed by liquid chromatography with tandem mass spectrometry analysis. Mass chromatograms were found to be identical to those of the TTX standards. The TTX amounts in the two flatworm specimens were calculated to be 468 and 3634 μg. Their external morphology was found to be identical to that of Planocera heda. Phylogenetic analysis based on the sequences of the 28S rRNA gene and cytochrome-c oxidase subunit I gene also showed that both specimens clustered with the flatworms of the genus Planocera (Planocera multitentaculata and Planocera reticulata). This fact suggests that there might be other Planocera species that also possess highly concentrated TTX, contributing to the toxification of TTX-bearing organisms, including fish. PMID:29351203

Visualization and 3D Reconstruction of Flame Cells of Taenia solium (Cestoda)

PubMed Central

Valverde-Islas, Laura E.; Arrangoiz, Esteban; Vega, Elio; Robert, Lilia; Villanueva, Rafael; Reynoso-Ducoing, Olivia; Willms, Kaethe; Zepeda-Rodríguez, Armando; Fortoul, Teresa I.; Ambrosio, Javier R.

2011-01-01

Background Flame cells are the terminal cells of protonephridial systems, which are part of the excretory systems of invertebrates. Although the knowledge of their biological role is incomplete, there is a consensus that these cells perform excretion/secretion activities. It has been suggested that the flame cells participate in the maintenance of the osmotic environment that the cestodes require to live inside their hosts. In live Platyhelminthes, by light microscopy, the cells appear beating their flames rapidly and, at the ultrastructural, the cells have a large body enclosing a tuft of cilia. Few studies have been performed to define the localization of the cytoskeletal proteins of these cells, and it is unclear how these proteins are involved in cell function. Methodology/Principal Findings Parasites of two different developmental stages of T. solium were used: cysticerci recovered from naturally infected pigs and intestinal adults obtained from immunosuppressed and experimentally infected golden hamsters. Hamsters were fed viable cysticerci to recover adult parasites after one month of infection. In the present studies focusing on flame cells of cysticerci tissues was performed. Using several methods such as video, confocal and electron microscopy, in addition to computational analysis for reconstruction and modeling, we have provided a 3D visual rendition of the cytoskeletal architecture of Taenia solium flame cells. Conclusions/Significance We consider that visual representations of cells open a new way for understanding the role of these cells in the excretory systems of Platyhelminths. After reconstruction, the observation of high resolution 3D images allowed for virtual observation of the interior composition of cells. A combination of microscopic images, computational reconstructions and 3D modeling of cells appears to be useful for inferring the cellular dynamics of the flame cell cytoskeleton. PMID:21412407

Repurposing pharma assets: an accelerated mechanism for strengthening the schistosomiasis drug development pipeline.

PubMed

Ramamoorthi, Roopa; Graef, Katy M; Dent, Jennifer

2015-01-01

Schistosomiasis, one of 17 diseases deemed to be neglected by the World Health Organization, has received little attention from the biopharmaceutical industry. Due to this, only a handful of drugs have been developed to treat schistosomiasis, with only one, praziquantel, used in most endemic regions. Growing concern over resistance coupled with praziquantel's incomplete efficacy across all stages of the Schistosoma platyhelminth life cycle highlights the urgent need for new drugs. The WIPO Re:Search consortium is a platform whereupon biopharmaceutical company compounds are being repurposed to efficiently and cost-effectively develop new drugs for neglected diseases such as schistosomiasis. This article summarizes recent clinical-stage efforts to identify new antischistosomals and highlights biopharmaceutical company compounds with potential for repurposing to treat schistosomiasis.

[An ultrastructural study of oogenesis in the planarian Schmidtea mediterranea (Platyhelminthe, Paludicola)].

PubMed

Harrath, Abdul Halim; Alwasal, Saleh H; Alhazza, Ibrahim; Zghal, Fathia; Tekaya, Saida

2011-07-01

The ovary of the freshwater planarian Schmidtea mediterranea has been studied for the first time using both light and electron microscopy methods. The ultrastructure of the ovary revealed two types of cells: accessory cells and germinal cells at various stages of differentiation, distributed along a maturation axis. Initially, oogonia underwent cytoplasm growth due to the development of organelles, such as endoplasmic reticulum, Golgi complex, and mitochondria, which are all involved in the production of cytoplasmic inclusions or yolk globules. It is shown that the chromatoid body and fibrogranular aggregates may participate in the synthesis of vitelline inclusions. When completely mature, the oocytes have become larger, due to the accumulation of nutritive inclusions, which are round in shape and have a paracrystalline structure. These inclusions are interpreted as being yolk globules and may represent a kind of nutritive material for the developing embryo. These ultrastructural features of the ovary agree with the available phylogenetic tree, based on morphological and karyological characters that considers Schmidtea group as a genus and not a subgenus. The presence of sperm between the oocytes suggests that fertilization may occur within the ovary, representing an uncommon condition within the Triclads, in which fertilization usually takes places outside of the ovaries. Copyright © 2011 Académie des sciences. Published by Elsevier SAS. All rights reserved.

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

PubMed

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

2015-08-01

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

The invasive New Guinea flatworm Platydemus manokwari in France, the first record for Europe: time for action is now.

PubMed

Justine, Jean-Lou; Winsor, Leigh; Gey, Delphine; Gros, Pierre; Thévenot, Jessica

2014-01-01

Non-indigenous terrestrial flatworms (Platyhelminthes) have been recorded in thirteen European countries. They include Bipalium kewense and Dolichoplana striata that are largely restricted to hothouses and may be regarded as non-invasive species. In addition there are species from the southern hemisphere such as the invasive New Zealand flatworm Arthurdendyus triangulatus in the United Kingdom, Eire and the Faroe Islands, the Australian flatworm Australoplana sanguinea alba in Eire and the United Kingdom, and the Australian Blue Garden flatworm Caenoplana coerulea in France, Menorca and the United Kingdom. The United Kingdom has some twelve or more non-indigenous species most of which are Australian and New Zealand species. These species may move to an invasive stage when optimum environmental and other conditions occur, and the flatworms then have the potential to cause economic or environmental harm. In this paper, we report the identification (from morphology and molecular analysis of COI sequences) of non-indigenous terrestrial flatworms found in a hothouse in Caen (France) as the New Guinea flatworm Platydemus manokwari de Beauchamp, 1963 (Platyhelminthes, Continenticola, Geoplanidae, Rhynchodeminae). Platydemus manokwari is among the "100 World's Worst Invader Alien Species". Lists of World geographic records, prey in the field and prey in laboratories of P. manokwari are provided. This species is considered a threat to native snails wherever it is introduced. The recent discovery of P. manokwari in France represents a significant extension of distribution of this Invasive Alien Species from the Indo-Pacific region to Europe. If it escaped the hothouse, the flatworm might survive winters and become established in temperate countries. The existence of this species in France requires an early warning of this incursion to State and European Union authorities, followed by the eradication of the flatworm in its locality, tightening of internal quarantine measures

Type material of Acanthocephala, Nematoda and other non-helminths phyla (Cnidaria, Annelida, and Arthropoda) housed in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), Rio de Janeiro, Brazil, from 1979 to 2016.

PubMed

Lopes, Daniela A; Gomes, Delir Corrêa; Knoff, Marcelo

2017-01-01

The third part of the catalogue of type material in the Helminthological Collection of the Oswaldo Cruz Institute/FIOCRUZ (CHIOC), comprising types deposited between 1979 and 2016, is presented to complement the first list of all types that was published in 1979. This part encompasses Acanthocephala, Nematoda and the other non-helminth phyla Cnidaria, Annelida, and Arthropoda. Platyhelminthes was covered in the first (Monogenoidea) and second (Rhabditophora Trematoda and Cestoda) parts of the catalogue published in September 2016 and March 2017, respectively. The present catalogue comprises type material for 116 species distributed across five phyla, nine classes, 50 families, and 80 genera. Specific names are listed systematically, followed by type host, infection site, type locality, and specimens with their collection numbers and references. Species classification and nomenclature are updated.

Type material of Acanthocephala, Nematoda and other non-helminths phyla (Cnidaria, Annelida, and Arthropoda) housed in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), Rio de Janeiro, Brazil, from 1979 to 2016

PubMed Central

Lopes, Daniela A.; Gomes, Delir Corrêa; Knoff, Marcelo

2017-01-01

Abstract The third part of the catalogue of type material in the Helminthological Collection of the Oswaldo Cruz Institute/FIOCRUZ (CHIOC), comprising types deposited between 1979 and 2016, is presented to complement the first list of all types that was published in 1979. This part encompasses Acanthocephala, Nematoda and the other non-helminth phyla Cnidaria, Annelida, and Arthropoda. Platyhelminthes was covered in the first (Monogenoidea) and second (Rhabditophora Trematoda and Cestoda) parts of the catalogue published in September 2016 and March 2017, respectively. The present catalogue comprises type material for 116 species distributed across five phyla, nine classes, 50 families, and 80 genera. Specific names are listed systematically, followed by type host, infection site, type locality, and specimens with their collection numbers and references. Species classification and nomenclature are updated. PMID:29134026

Two novel Mesocestoides vogae fatty acid binding proteins--functional and evolutionary implications.

PubMed

Alvite, Gabriela; Canclini, Lucía; Corvo, Ileana; Esteves, Adriana

2008-01-01

This work describes two new fatty acid binding proteins (FABPs) identified in the parasite platyhelminth Mesocestoides vogae (syn. corti). The corresponding polypeptide chains share 62% identical residues and overall 90% similarity according to CLUSTALX default conditions. Compared with Cestoda FABPs, these proteins share the highest similarity score with the Taenia solium protein. M. vogae FABPs are also phylogenetically related to the FABP3/FABP4 mammalian FABP subfamilies. The native proteins were purified by chromatographical procedures, and apparent molecular mass and isoelectric point were determined. Immunolocalization studies determined the localization of the expression of these proteins in the larval form of the parasite. The genomic exon-intron organization of both genes is also reported, and supports new insights on intron evolution. Consensus motifs involved in splicing were identified.

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

PubMed

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

2014-12-01

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

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.

Lophotrochozoan mitochondrial genomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valles, Yvonne; Boore, Jeffrey L.

2005-10-01

Progress in both molecular techniques and phylogeneticmethods has challenged many of the interpretations of traditionaltaxonomy. One example is in the recognition of the animal superphylumLophotrochozoa (annelids, mollusks, echiurans, platyhelminthes,brachiopods, and other phyla), although the relationships within thisgroup and the inclusion of some phyla remain uncertain. While much ofthis progress in phylogenetic reconstruction has been based on comparingsingle gene sequences, we are beginning to see the potential of comparinglarge-scale features of genomes, such as the relative order of genes.Even though tremendous progress is being made on the sequencedetermination of whole nuclear genomes, the dataset of choice forgenome-level characters for many animalsmore » across a broad taxonomic rangeremains mitochondrial genomes. We review here what is known aboutmitochondrial genomes of the lophotrochozoans and discuss the promisethat this dataset will enable insight into theirrelationships.« less

Mini review on chemotherapy of taeniasis and cysticercosis due to Taenia solium in Asia, and a case report with 20 tapeworms in China.

PubMed

Ito, A; Li, T; Chen, X; Long, C; Yanagida, T; Nakao, M; Sako, Y; Okamoto, M; Wu, Y; Raoul, F; Giraudoux, P; Craig, P S

2013-06-01

A 43-year-old Tibetan woman living in northwest Sichuan, China, confirmed to be a taeniasis carrier of Taenia solium was treated with pumpkin seeds combined with Areca nut extract in October 2009. All 20 tapeworms except one without scolex were expelled under good conditions. She was free of secondary cysticercosis within one year follow up. Although the first choice for treatment of taeniasis is still praziquantel, it may often cause serious side effect on asymptomatic cysticercosis cases to suddenly become symptomatic within a half day of the treatment. Therefore, the problems in treatment of taeniasis and/or cysticercosis in Asia are briefly overviewed, since other platyhelminthic diseases including schistosomiasis, opisthorchiasis etc. are more common and praziquantel is strongly recommended for mass treatment of these trematodiases with no idea on the co-infection with eggs of T. solium which cause asymptomatic cysticercosis.

Animal Fascioliasis: Perspectives from high altitudinal regions.

PubMed

Lyngdoh, Damanbha; Sharma, Sunil; Roy, Bishnupada; Tandon, Veena

2016-12-15

The parasitic flukes of the genus Fasciola (Platyhelminthes: Trematoda: Digenea) cause fascioliasis or liver-rot disease in ruminant livestock in tropical and sub-tropical regions of the world. Classically, two species of Fasciola- F. hepatica and F. gigantica, are universally recognized as taxonomically valid species. Our survey studies on ovid and bovid animals including yak and mithun from high altitudinal mountainous regions in Northeast India revealed the occurrence of Fasciola gigantica and also Fasciola sp.- an intermediate form, at altitudes between 5000 and 14,085 feet above sea level (asl). Two morphotypes- F. hepatica - like and F. gigantica - like, of Fasciola species were reported from the high altitudinal areas of Northeast India; most of these locales constitute new-locality and first records for the occurrence of these liver flukes. Copyright © 2016 Elsevier B.V. All rights reserved.

Expansion of TALE homeobox genes and the evolution of spiralian development.

PubMed

Morino, Yoshiaki; Hashimoto, Naoki; Wada, Hiroshi

2017-12-01

Spiralians, including molluscs, annelids and platyhelminths, share a unique development process that includes the typical geometry of early cleavage and early segregation of cell fate in blastomeres along the animal-vegetal axis. However, the molecular mechanisms underlying this early cell fate segregation are largely unknown. Here, we report spiralian-specific expansion of the three-amino-acid loop extension (TALE) class of homeobox genes. During early development, some of these TALE genes are expressed in staggered domains along the animal-vegetal axis in the limpet Nipponacmea fuscoviridis and the polychaete Spirobranchus kraussii. Inhibition or overexpression of these genes alters the developmental fate of blastomeres, as predicted by the gene expression patterns. These results suggest that the expansion of novel TALE genes plays a critical role in the establishment of a novel cell fate segregation mechanism in spiralians.

Multigene analysis of lophophorate and chaetognath phylogenetic relationships.

PubMed

Helmkampf, Martin; Bruchhaus, Iris; Hausdorf, Bernhard

2008-01-01

Maximum likelihood and Bayesian inference analyses of seven concatenated fragments of nuclear-encoded housekeeping genes indicate that Lophotrochozoa is monophyletic, i.e., the lophophorate groups Bryozoa, Brachiopoda and Phoronida are more closely related to molluscs and annelids than to Deuterostomia or Ecdysozoa. Lophophorates themselves, however, form a polyphyletic assemblage. The hypotheses that they are monophyletic and more closely allied to Deuterostomia than to Protostomia can be ruled out with both the approximately unbiased test and the expected likelihood weights test. The existence of Phoronozoa, a putative clade including Brachiopoda and Phoronida, has also been rejected. According to our analyses, phoronids instead share a more recent common ancestor with bryozoans than with brachiopods. Platyhelminthes is the sister group of Lophotrochozoa. Together these two constitute Spiralia. Although Chaetognatha appears as the sister group of Priapulida within Ecdysozoa in our analyses, alternative hypothesis concerning chaetognath relationships could not be rejected.

Diversity and distribution of fish tapeworms of the "Bothriocephalidea" (Eucestoda).

PubMed

Kuchta, R; Scholz, T

2007-09-01

Recent studies have demonstrated the invalidity of the Pseudophyllidea, a long-term recognised order of tapeworms (Platyhelminthes: Cestoda), typical in possessing two dorsoventrally situated attachment organs called bothria. In fact, cestodes parasitic in tetrapods, especially mammals including man, form a relatively basal group called provisionally the "Diphyllobothriidea", whereas tapeworms occurring in freshwater and marine fish, with a few taxa known from amphibians (frogs and newts), belong to a more derived clade, for which the name "Bothriocephalidea" is tentatively proposed. Revision of the "Bothriocephalidea", based on literary data, study of type- and voucher specimens and extensive newly collected material made it possible to critically review the species composition of the group and to prepare a tentative list of its valid species. Out of 305 nominal taxa, only 125 species are considered to be valid. In addition, the spectrum of definitive hosts and geographical distribution of bothriocephalideans are briefly discussed.

Phylogenetic study of the arginine-vasotocin/arginine-vasopressin-like immunoreactive system in invertebrates.

PubMed

Mizuno, J; Takeda, N

1988-01-01

1. A phylogenetic study of arg-vasotocin (AVT)/arg-vasopressin (AVP)-like immunoreactive cells was performed by the PAP method in the central nervous system of invertebrates. 2. The immunoreactivity was detected in the nerve cells of Hydra magnipapillata of the Coelenterata; Neanthes japonica and Pheretima communissima of the Annelida; Pomacea canaliculata, Aplysia kurodai, Oncidium verrucosum, Bradybaena similaris, Achatina fulica, Limax marginatus and Meretrix lamarckii of the Mollusca; Gnorimosphaeroma rayi, Hemigrapsus sanguineus, Gryllus bimaculatus and Baratha brassicae of the Arthropoda; Asterina pectinifera of the Echinodermata; and Halocynthia roretzi of the Protochordata. 3. No immunoreactivity was detected in Bipalium sp. of the Platyhelminthes, or in Procambarus clarkii and Helice tridens of the Arthropoda. 4. From these results, it appears that AVT/AVP is a phylogenetically ancient peptide which is present in a wide variety of invertebrates. 5. The actions of AVT/AVP and its presence in invertebrates are discussed.

Phylogenetic study of the oxytocin-like immunoreactive system in invertebrates.

PubMed

Mizuno, J; Takeda, N

1988-01-01

1. A phylogenetic study of oxytocin (OXT)-like immunoreactive cells was performed by the PAP method in the central nervous system of invertebrates. 2. The immunoreactivity was detected in the nerve cells of Hydra magnipapillata of the Coelenterata; Neanthes japonica and Pheretima communissima of the Annelida; Oncidium verrucosum, Limax marginatus and Meretrix lamarckii of the Mollusca; and Baratha brassica of the Arthropoda. 3. No immunoreactive cells were found in Bipalium sp. of the Platyhelminthes; Pomacea canaliculata, Aplysia kurodai, Bradybaena similaris and Achatina fulica of the Mollusca; and Gnorimosphaeroma rayi, Procambarus clarkii, Hemigrapsus sanguineus, Helice tridens and Gryllus bimaculatus of the Arthropoda; Asterina pectinifera of the Echinodermata; and Halocynthia roretzi of the Protochordata. 4. These results demonstrate that an OXT-immunoreactive substance is widely present not only in vertebrates but also in invertebrates. 5. OXT seems to have been introduced into these invertebrates at an early stage of their phylogenetic history.

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

Gill monogenean communities (Platyhelminthes, Monogenea, Dactylogyridae) of butterflyfishes from tropical Indo-West Pacific Islands.

PubMed

Reverter, Miriam; Cutmore, Scott C; Bray, Rodney; Cribb, Thomas H; Sasal, Pierre

2016-10-01

We studied the monogenean communities of 34 species of butterflyfish from the tropical Indo-West Pacific, identifying 13 dactylogyrid species (including two species that are presently undescribed). Monogenean assemblages differed significantly between host species in terms of taxonomic structure, intensity and prevalence. Parasite richness ranged from 0 (Chaetodon lunulatus) to 11 (C. auriga, C. citrinellus and C. lunula). Host specificity varied between the dactylogyrids species, being found on 2-29 of the 34 chaetodontid species examined. Sympatric butterflyfish species were typically parasitized by different combinations of dactylogyrid species, suggesting the existence of complex host-parasite interactions. We identified six clusters of butterflyfish species based on the similarities of their dactylogyrid communities. Dactylogyrid richness and diversity were not related to host size, diet specialization, depth range or phylogeny of butterflyfish species. However, there was a weak positive correlation between monogenean richness and diversity and host geographical range. Most communities of dactylogyrids were dominated by Haliotrema aurigae and H. angelopterum, indicating the importance of the genus Haliotrema in shaping monogenean communities of butterflyfishes. This study casts light on the structure of the monogenean communities of butterflyfishes, suggesting that the diversity and complexity of community structures arises from a combination of host species-specific parameters.

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

Cell renewal and apoptosis in macrostomum sp. [Lignano].

PubMed

Nimeth, K; Ladurner, P; Gschwentner, R; Salvenmoser, W; Rieger, R

2002-01-01

In platyhelminths, all cell renewal is accomplished by totipotent stem cells (neoblasts). Tissue maintenance is achieved in a balance between cell proliferation and apoptosis. It is known that in Macrostomum sp. the epidermis undergoes extensive cell renewal. Here we show that parenchymal cells also exhibit a high rate of cell turnover. We demonstrate cell renewal using continuous 5'bromo-2-deoxyuridine (BrdU) exposure. About one-third of all cells are replaced after 14 days. The high level of replacement requires an equivalent removal of cells by apoptosis. Cell death is characterized using a combination of three methods: (1). terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL), (2). specific binding of phosphatidyl-serine to fluorescent-labelled annexin V and (3). identification of apoptotic stages by ultrastructure. The number of cells observed in apoptosis is insufficient to explain the homeostasis of tissues in Macrostomum. Apoptosis-independent mechanisms may play an additional role in tissue dynamics.

Eukaryotic opportunists dominate the deep-subsurface biosphere in South Africa

PubMed Central

Borgonie, G.; Linage-Alvarez, B.; Ojo, A. O.; Mundle, S.O.C.; Freese, L B.; Van Rooyen, C.; Kuloyo, O.; Albertyn, J.; Pohl, C.; Cason, E. D.; Vermeulen, J.; Pienaar, C.; Litthauer, D.; Van Niekerk, H.; Van Eeden, J.; Lollar, B. Sherwood.; Onstott, T. C.; Van Heerden, E.

2015-01-01

Following the discovery of the first Eukarya in the deep subsurface, intense interest has developed to understand the diversity of eukaryotes living in these extreme environments. We identified that Platyhelminthes, Rotifera, Annelida and Arthropoda are thriving at 1.4 km depths in palaeometeoric fissure water up to 12,300 yr old in South African mines. Protozoa and Fungi have also been identified; however, they are present in low numbers. Characterization of the different species reveals that many are opportunistic organisms with an origin due to recharge from surface waters rather than soil leaching. This is the first known study to demonstrate the in situ distribution of biofilms on fissure rock faces using video documentation. Calculations suggest that food, not dissolved oxygen is the limiting factor for eukaryal population growth. The discovery of a group of Eukarya underground has important implications for the search for life on other planets in our solar system. PMID:26597082

Preliminary analysis of cold stress responsive proteins in Mesocestoides corti larvae.

PubMed

Canclini, Lucía; Esteves, Adriana

2007-07-01

Many parasites undergo sudden changes in environmental conditions at some stage during their life cycle. The molecular response to this variation is characterised by a rapid transcriptional activation of a specific set of genes coding for proteins generically known as stress proteins. They appear to be also involved in various biological processes including cell proliferation and differentiation. The platyhelminth parasite, Mesocestoides corti (Cestoda) presents important properties as a model organism. Under stress conditions, key molecules involved in metabolic pathways as well as in the growth and differentiation of the parasite can be identified. 2D protein expression profile of tetrathyridia of M. corti, submitted to nutritional starvation and cold stress is described, as well as the recovery pattern. A set of specifically expressed proteins was observed in each experimental condition. Quantitative and qualitative differences and stress recovery pattern are also reported. This work makes evident the high plasticity and resistance to extreme environmental conditions of these parasites at the molecular level.

Eukaryotic opportunists dominate the deep-subsurface biosphere in South Africa.

PubMed

Borgonie, G; Linage-Alvarez, B; Ojo, A O; Mundle, S O C; Freese, L B; Van Rooyen, C; Kuloyo, O; Albertyn, J; Pohl, C; Cason, E D; Vermeulen, J; Pienaar, C; Litthauer, D; Van Niekerk, H; Van Eeden, J; Sherwood Lollar, B; Onstott, T C; Van Heerden, E

2015-11-24

Following the discovery of the first Eukarya in the deep subsurface, intense interest has developed to understand the diversity of eukaryotes living in these extreme environments. We identified that Platyhelminthes, Rotifera, Annelida and Arthropoda are thriving at 1.4 km depths in palaeometeoric fissure water up to 12,300 yr old in South African mines. Protozoa and Fungi have also been identified; however, they are present in low numbers. Characterization of the different species reveals that many are opportunistic organisms with an origin due to recharge from surface waters rather than soil leaching. This is the first known study to demonstrate the in situ distribution of biofilms on fissure rock faces using video documentation. Calculations suggest that food, not dissolved oxygen is the limiting factor for eukaryal population growth. The discovery of a group of Eukarya underground has important implications for the search for life on other planets in our solar system.

FOX and ETS family transcription factors regulate the pigment cell lineage in planarians.

PubMed

He, Xinwen; Lindsay-Mosher, Nicole; Li, Yan; Molinaro, Alyssa M; Pellettieri, Jason; Pearson, Bret J

2017-12-15

Many pigment cells acquire unique structural properties and gene expression profiles during animal development. The underlying differentiation pathways have been well characterized in cells formed during embryogenesis, such as the neural crest-derived melanocyte. However, much less is known about the developmental origins of pigment cells produced in adult organisms during tissue homeostasis and repair. Here we report a lineage analysis of ommochrome- and porphyrin-producing cells in the brown, freshwater planarian Schmidtea mediterranea Using an RNA-sequencing approach, we identified two classes of markers expressed in sequential fashion when new pigment cells are generated during regeneration or in response to pigment cell ablation. We also report roles for FOXF-1 and ETS-1 transcription factors, as well as for an FGFR-like molecule, in the specification and maintenance of this cell type. Together, our results provide insights into mechanisms of adult pigment cell development in the strikingly colorful Platyhelminthes phylum. © 2017. Published by The Company of Biologists Ltd.

Ultrastructure of the spermatozoon of Dipylidium caninum (Cestoda, Cyclophyllidea, Dilepididae), an intestinal parasite of Canis familiaris.

PubMed

Miquel, J; Marchand, B

1997-01-01

We report for the first time the ultrastructure of the spermatozoon of a Dilepididae cestode. The mature spermatozoa of Dipylidium caninum is filiform and tapered at both ends and lacks mitochondria. The anterior extremity exhibits an apical cone of electron-dense material measuring about 600 nm in length and a single helicoidal crested-like body that is 150 nm thick. This single crested-like body is spiralized at an angle of about 40 degrees to the spermatozoon axis. The axoneme, showing the 9 + "l" pattern of the Platyhelminthes, lacks a periaxonemal sheath. The cortical microtubules constitute a continuous, submembranous, electron-dense material, and they are also twisted at an angle of about 40 degrees to the spermatozoon axis. Moreover, the nucleus is coiled in a helix around the axoneme, which is centrally located throughout its length. We demonstrate for the first time the presence of peripheral microtubules twisted to the spermatozoon axis up to the posterior extremity of the gamete.

Cholinergic, serotoninergic and peptidergic components of the nervous system of Discocotyle sagittata (Monogenea:Polyopisthocotylea).

PubMed

Cable, J; Marks, N J; Halton, D W; Shaw, C; Johnston, C F; Tinsley, R C; Gannicott, A M

1996-12-01

Cholinergic, serotoninergic (5-HT) and peptidergic neuronal pathways have been demonstrated in both central and peripheral nervous systems of adult Discocotyle sagittata, using enzyme histochemistry and indirect immunocytochemistry in conjunction with confocal scanning laser microscopy. Antisera to 2 native flatworm neuropeptides, neuropeptide F and the FMRFamide-related peptide (FaRP), GNFFRFamide, were employed to detect peptide immunoreactivity. The CNS is composed of paired cerebral ganglia and connecting dorsal commissure, together with several paired longitudinal nerve cords. The main longitudinal nerve cords (lateral, ventral and dorsal) are interconnected at intervals by a series of annular cross-connectives, producing a ladder-like arrangement typical of the platyhelminth nervous system. At the level of the haptor, the ventral cords provide nerve roots which innervate each of the 9 clamps. Cholinergic and peptidergic neuronal organisation was similar, but distinct from that of the serotoninergic components. The PNS and reproductive system are predominantly innervated by peptidergic neurones.

What helminth genomes have taught us about parasite evolution.

PubMed

Zarowiecki, Magdalena; Berriman, Matt

2015-02-01

The genomes of more than 20 helminths have now been sequenced. Here we perform a meta-analysis of all sequenced genomes of nematodes and Platyhelminthes, and attempt to address the question of what are the defining characteristics of helminth genomes. We find that parasitic worms lack systems for surface antigenic variation, instead maintaining infections using their surfaces as the first line of defence against the host immune system, with several expanded gene families of genes associated with the surface and tegument. Parasite excretory/secretory products evolve rapidly, and proteases even more so, with each parasite exhibiting unique modifications of its protease repertoire. Endoparasitic flatworms show striking losses of metabolic capabilities, not matched by nematodes. All helminths do however exhibit an overall reduction in auxiliary metabolism (biogenesis of co-factors and vitamins). Overall, the prevailing pattern is that there are few commonalities between the genomes of independently evolved parasitic worms, with each parasite having undergone specific adaptations for their particular niche.

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

PubMed

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

2014-01-22

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

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

PubMed

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

2007-02-01

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

Monorchiids (Platyhelminthes: Digenea) of chaetodontid fishes (Perciformes): biogeographical patterns in the tropical Indo-West Pacific.

PubMed

McNamara, M K A; Adlard, R D; Bray, R A; Sasal, P; Cribb, T H

2012-06-01

Species richness and biogeography of the monorchiid genus Hurleytrematoides was studied by the examination of 2834 individuals of 45 species of Chaetodontidae at six major sites in the tropical Indo-West Pacific: Heron Island, Lizard Island, Ningaloo (Western Australia), Palau, New Caledonia and Moorea (French Polynesia). In total, 18 species were distributed among six sites; descriptions are provided for eight new species: H. boucheti n. sp., H. combesi n. sp., H. deblocki n. sp., H. dollfusi n. sp., H. euzeti n. sp., H. kulbickii n. sp., H. pasteuri n. sp., and H. planesi n. sp. Overall richness ranged from zero to five Hurleytrematoides species per chaetodontid species. Seven Hurleytrematoides species were found at only one locality and eleven were found at multiple localities. Only one species, H. morandi, was found at all localities. Individual localities had between six (Moorea) and 10 (Heron Island) species; we attribute Moorea's depauperate parasite fauna to its isolation and distance from the Indo-Philippine centre of biological diversity. Using cluster analysis of 18 species of Hurleytrematoides and 45 species of chaetodontids sampled in the Indo-West Pacific, we show that the localities on the Great Barrier Reef (Heron Island and Lizard Island) and New Caledonia have the most similar chaetodontid and parasite fauna of any locality pairs. Cluster analysis results also show that the similarity of the chaetodontid assemblages at five of the six localities is relatively high and that Ningaloo has the most distinct fauna. Similarity values based on sharing of species of Hurleytrematoides are generally lower than those for their hosts; Moorea, Ningaloo and Palau all have low similarity to New Caledonia and Great Barrier Reef sites. We attribute these distinctions to the differential dispersal capability of the fish and their parasites. Chaetodontids have long-lived mobile pelagic larvae, the dispersal of which would be most affected by prominent biogeographical barriers, such as that between the Indian and Pacific Oceans. In contrast, monorchiids have no obvious dispersal stage, and vast distances have the capacity to act as effective barriers to dispersal. We conclude that the present distributions of species of Hurleytrematoides in the Indo-Pacific are driven by historical opportunity and capacity to disperse, and that some disjunct distributions are sculpted by stochasticity. Copyright © 2011. Published by Elsevier Ireland Ltd.

Purification and kinetic analysis of cytosolic and mitochondrial thioredoxin glutathione reductase extracted from Taenia solium cysticerci.

PubMed

Plancarte, Agustin; Nava, Gabriela

2015-02-01

Thioredoxin glutathione reductases (TGRs) (EC 1.8.1.9) were purified to homogeneity from the cytosolic (cTsTGR) and mitochondrial (mTsTGR) fractions of Taenia solium, the agent responsible for neurocysticercosis, one of the major central nervous system parasitic diseases in humans. TsTGRs had a relative molecular weight of 132,000, while the corresponding value per subunit obtained under denaturing conditions, was of 62,000. Specific activities for thioredoxin reductase and glutathione reductase substrates for both TGRs explored were in the range or lower than values obtained for other platyhelminths and mammalian TGRs. cTsTGR and mTsTGR also showed hydroperoxide reductase activity using hydroperoxide as substrate. Km(DTNB) and Kcat(DTNB) values for cTsTGR and mTsTGR (88 µM and 1.9 s(-1); 45 µM and 12.6 s(-1), respectively) and Km(GSSG) and Kcat(GSSG) values for cTsTGR and mTsTGR (6.3 µM and 0.96 s(-1); 4 µM and 1.62 s(-1), respectively) were similar to or lower than those reported for mammalian TGRs. Mass spectrometry analysis showed that 12 peptides from cTsTGR and seven from mTsTGR were a match for gi|29825896 thioredoxin glutathione reductase [Echinococcus granulosus], confirming that both enzymes are TGRs. Both T. solium TGRs were inhibited by the gold compound auranofin, a selective inhibitor of thiol-dependent flavoreductases (I₅₀ = 3.25, 2.29 nM for DTNB and GSSG substrates, respectively for cTsTGR; I₅₀ = 5.6, 25.4 nM for mTsTGR toward the same substrates in the described order). Glutathione reductase activity of cTsTGR and mTsTGR exhibited hysteretic behavior with moderate to high concentrations of GSSG; this result was not observed either with thioredoxin, DTNB or NADPH. However, the observed hysteretic kinetics was suppressed with increasing amounts of both parasitic TGRs. These data suggest the existence of an effective substitute which may account for the lack of the detoxification enzymes glutathione reductase

Role and convergent evolution of competing RNA secondary structures in mutually exclusive splicing

PubMed Central

Yue, Yuan; Hou, Shouqing; Wang, Xiu; Zhan, Leilei; Cao, Guozheng; Li, Guoli; Shi, Yang; Zhang, Peng; Hong, Weiling; Lin, Hao; Liu, Baoping; Shi, Feng; Yang, Yun; Jin, Yongfeng

2017-01-01

ABSTRACT Exon or cassette duplication is an important means of expanding protein and functional diversity through mutually exclusive splicing. However, the mechanistic basis of this process in non-arthropod species remains poorly understood. Here, we demonstrate that MRP1 genes underwent tandem exon duplication in Nematoda, Platyhelminthes, Annelida, Mollusca, Arthropoda, Echinodermata, and early-diverging Chordata but not in late-diverging vertebrates. Interestingly, these events were of independent origin in different phyla, suggesting convergent evolution of alternative splicing. Furthermore, we showed that multiple sets of clade-conserved RNA pairings evolved to guide species-specific mutually exclusive splicing in Arthropoda. Importantly, we also identified a similar structural code in MRP exon clusters of the annelid, Capitella teleta, and chordate, Branchiostoma belcheri, suggesting an evolutionarily conserved competing pairing-guided mechanism in bilaterians. Taken together, these data reveal the molecular determinants and RNA pairing-guided evolution of species-specific mutually exclusive splicing spanning more than 600 million years of bilaterian evolution. These findings have a significant impact on our understanding of the evolution of and mechanism underpinning isoform diversity and complex gene structure. PMID:28277933

Role and convergent evolution of competing RNA secondary structures in mutually exclusive splicing.

PubMed

Yue, Yuan; Hou, Shouqing; Wang, Xiu; Zhan, Leilei; Cao, Guozheng; Li, Guoli; Shi, Yang; Zhang, Peng; Hong, Weiling; Lin, Hao; Liu, Baoping; Shi, Feng; Yang, Yun; Jin, Yongfeng

2017-10-03

Exon or cassette duplication is an important means of expanding protein and functional diversity through mutually exclusive splicing. However, the mechanistic basis of this process in non-arthropod species remains poorly understood. Here, we demonstrate that MRP1 genes underwent tandem exon duplication in Nematoda, Platyhelminthes, Annelida, Mollusca, Arthropoda, Echinodermata, and early-diverging Chordata but not in late-diverging vertebrates. Interestingly, these events were of independent origin in different phyla, suggesting convergent evolution of alternative splicing. Furthermore, we showed that multiple sets of clade-conserved RNA pairings evolved to guide species-specific mutually exclusive splicing in Arthropoda. Importantly, we also identified a similar structural code in MRP exon clusters of the annelid, Capitella teleta, and chordate, Branchiostoma belcheri, suggesting an evolutionarily conserved competing pairing-guided mechanism in bilaterians. Taken together, these data reveal the molecular determinants and RNA pairing-guided evolution of species-specific mutually exclusive splicing spanning more than 600 million years of bilaterian evolution. These findings have a significant impact on our understanding of the evolution of and mechanism underpinning isoform diversity and complex gene structure.

Harnessing the Toxocara Genome to Underpin Toxocariasis Research and New Interventions.

PubMed

Gasser, Robin B; Korhonen, Pasi K; Zhu, Xing-Quan; Young, Neil D

2016-01-01

Parasitic worms, such as flatworms (platyhelminths) and roundworms (nematodes), cause substantial morbidity and mortality in animals and people globally. The ascaridoid nematode Toxocara canis is a zoonotic parasite of socioeconomic significance worldwide. In humans, this worm causes toxocariasis (disease) mainly in underprivileged communities in both the developed and developing worlds. While reasonably well studied from clinical and epidemiological perspectives, little is understood about the molecular biology of T. canis, its relationship with its hosts and the disease that it causes. However, a recent report of the draft genome and transcriptomes of T. canis should underpin many fundamental and applied research areas in the future. The present article gives a background on Toxocara and toxocariasis, a brief account of diagnostic approaches for specific identification and genetic analysis, and gives a perspective on the impact that the genome of T. canis and advanced molecular technologies could have on our understanding of the parasite and the diseases that it causes as well as the design of new and improved approaches for the diagnosis, treatment and control of toxocariasis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Discovery and molecular characterization of a Bcl-2-regulated cell death pathway in schistosomes.

PubMed

Lee, Erinna F; Clarke, Oliver B; Evangelista, Marco; Feng, Zhiping; Speed, Terence P; Tchoubrieva, Elissaveta B; Strasser, Andreas; Kalinna, Bernd H; Colman, Peter M; Fairlie, W Douglas

2011-04-26

Schistosomiasis is an infectious disease caused by parasites of the phylum platyhelminthe. Here, we describe the identification and characterization of a Bcl-2-regulated apoptosis pathway in Schistosoma japonicum and S. mansoni. Genomic, biochemical, and cell-based mechanistic studies provide evidence for a tripartite pathway, similar to that in humans including BH3-only proteins that are inhibited by prosurvival Bcl-2-like molecules, and Bax/Bak-like proteins that facilitate mitochondrial outer-membrane permeabilization. Because Bcl-2 proteins have been successfully targeted with "BH3 mimetic" drugs, particularly in the treatment of cancer, we investigated whether schistosome apoptosis pathways could provide targets for future antischistosomal drug discovery efforts. Accordingly, we showed that a schistosome prosurvival protein, sjA, binds ABT-737, a well-characterized BH3 mimetic. A crystal structure of sjA bound to a BH3 peptide provides direct evidence for the feasibility of developing BH3 mimetics to target Bcl-2 prosurvival proteins in schistosomes, suggesting an alternative application for this class of drugs beyond cancer treatment.

Discovery and molecular characterization of a Bcl-2–regulated cell death pathway in schistosomes

PubMed Central

Lee, Erinna F.; Clarke, Oliver B.; Evangelista, Marco; Feng, Zhiping; Speed, Terence P.; Tchoubrieva, Elissaveta B.; Strasser, Andreas; Kalinna, Bernd H.; Colman, Peter M.; Fairlie, W. Douglas

2011-01-01

Schistosomiasis is an infectious disease caused by parasites of the phylum platyhelminthe. Here, we describe the identification and characterization of a Bcl-2–regulated apoptosis pathway in Schistosoma japonicum and S. mansoni. Genomic, biochemical, and cell-based mechanistic studies provide evidence for a tripartite pathway, similar to that in humans including BH3-only proteins that are inhibited by prosurvival Bcl-2–like molecules, and Bax/Bak-like proteins that facilitate mitochondrial outer-membrane permeabilization. Because Bcl-2 proteins have been successfully targeted with “BH3 mimetic” drugs, particularly in the treatment of cancer, we investigated whether schistosome apoptosis pathways could provide targets for future antischistosomal drug discovery efforts. Accordingly, we showed that a schistosome prosurvival protein, sjA, binds ABT-737, a well-characterized BH3 mimetic. A crystal structure of sjA bound to a BH3 peptide provides direct evidence for the feasibility of developing BH3 mimetics to target Bcl-2 prosurvival proteins in schistosomes, suggesting an alternative application for this class of drugs beyond cancer treatment. PMID:21444803

Planarians sense simulated microgravity and hypergravity.

PubMed

Adell, Teresa; Saló, Emili; van Loon, Jack J W A; Auletta, Gennaro

2014-01-01

Planarians are flatworms, which belong to the phylum Platyhelminthes. They have been a classical subject of study due to their amazing regenerative ability, which relies on the existence of adult totipotent stem cells. Nowadays they are an emerging model system in the field of developmental, regenerative, and stem cell biology. In this study we analyze the effect of a simulated microgravity and a hypergravity environment during the process of planarian regeneration and embryogenesis. We demonstrate that simulated microgravity by means of the random positioning machine (RPM) set at a speed of 60 °/s but not at 10 °/s produces the dead of planarians. Under hypergravity of 3 g and 4 g in a large diameter centrifuge (LDC) planarians can regenerate missing tissues, although a decrease in the proliferation rate is observed. Under 8 g hypergravity small planarian fragments are not able to regenerate. Moreover, we found an effect of gravity alterations in the rate of planarian scission, which is its asexual mode of reproduction. No apparent effects of altered gravity were found during the embryonic development.

Helminth fauna of Megaleporinus obtusidens (Characiformes: Anostomidae) from Lake Guaíba: analysis of the parasite community.

PubMed

Wendt, E W; Monteiro, C M; Amato, S B

2018-06-01

Structure of the helminth community of Megaleporinus obtusidens collected in Lake Guaíba was evaluated, and the results indicated that the diversity of helminth species was probably determined by fish behavior and eating habits. The influence of sex, weight, and standard length of hosts for parasitic indices was also analyzed. Sixteen helminth species were found parasitizing M. obtusidens, including the following: platyhelminths, with the highest richness, represented by one species of Aspidobothrea; four species of Digenea; and eight species of Monogenea; the latter, presented the highest prevalence. Rhinoxenus arietinus, found in nasal cavities, had the greater abundance, and was the only species classified as core. The prevalence of Urocleidoides paradoxus was significantly influenced by the sex of the host; females had the highest values. Abundance was weakly influenced by fish weight and the body length of the hosts. Urocleidoides sp. had its abundance weakly influenced by the host weight. The other helminths were not influenced by biometric characteristics of the hosts. The total species richness was similar between male and female fish, and both had 14 helminth species of parasites.

Suppression of nemo-like kinase by miR-71 in Echinococcus multilocularis.

PubMed

Guo, Xiaola; Zhang, Xueyong; Yang, Jing; Jin, Xiaoliang; Ding, Juntao; Xiang, Haitao; Ayaz, Mazhar; Luo, Xuenong; Zheng, Yadong

2017-12-01

Echinococcus multilocularis metacestodes are a causative pathogen for alveolar echinococcosis in human beings, and have been found to express miRNAs including emu-miR-71. miR-71 is evolutionarily conserved and highly expressed across platyhelminths, but little is known about its role. Here it was shown that emu-miR-71 was differentially expressed in protoscoleces and was unlikely to be expressed in neoblasts. The results of the luciferase assay indicated that emu-miR-71 was able to bind in vitro to the 3'-UTR of emu-nlk, encoding a key regulator of cell division, causing significant downregulation of luciferase activity (p < 0.01) compared to the negative control and the construct with mutations in the binding site. Consistent with the decreased luciferase activity, transfection of emu-miR-71 mimics into protoscoleces notably repressed emu-NLK (p < 0.05). These results demonstrate the suppression of emu-nlk by emu-miR-71, potentially involved in the protoscolex development. Copyright © 2017 Elsevier Inc. All rights reserved.

Preference for different prey allows the coexistence of several land planarians in areas of the Atlantic Forest.

PubMed

Boll, Piter Kehoma; Leal-Zanchet, Ana Maria

2016-06-01

Land planarians are recognized as important predators, yet studies on their feeding habits are usually restricted to invasive species. Thus, it is difficult to determine the real ecological role of this group in ecosystems and how their communities are structured. In the present study, we analyzed the diet of six co-occurring Neotropical land planarians and their success in capturing prey, based on experiments in the laboratory, in order to determine how they share resources in the same environment. We also calculated indices of food niche breadth and food niche overlap for land planarians for the first time. The diet of Luteostriata abundans comprises only woodlice and the diets of Obama ficki and Obama ladislavii are composed only of gastropods, while Paraba multicolor and Obama anthropophila feed on both gastropods and other land planarians. An invasive species recently found in Western Europe, Obama nungara, showed the highest food niche breadth, feeding on gastropods, earthworms and planarians. We found the highest niche overlap between O. anthropophila and P. multicolor. The results suggest that land planarians are frequent predators of woodlice and land gastropods in the Neotropical ecozone and thus are important for the maintenance of native ecosystems and for the control of invasive species. The coexistence of several species in the same habitat is possible due to the use of different species as main prey, which reduces interspecific competition. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

PubMed

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

2011-12-01

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

When proglottids and scoleces conflict: phylogenetic relationships and a family-level classification of the Lecanicephalidea (Platyhelminthes: Cestoda).

PubMed

Jensen, Kirsten; Caira, Janine N; Cielocha, Joanna J; Littlewood, D Timothy J; Waeschenbach, Andrea

2016-05-01

This study presents the first comprehensive phylogenetic analysis of the interrelationships of the morphologically diverse elasmobranch-hosted tapeworm order Lecanicephalidea, based on molecular sequence data. With almost half of current generic diversity having been erected or resurrected within the last decade, an apparent conflict between scolex morphology and proglottid anatomy has hampered the assignment of many of these genera to families. Maximum likelihood and Bayesian analyses of two nuclear markers (D1-D3 of lsrDNA and complete ssrDNA) and two mitochondrial markers (partial rrnL and partial cox1) for 61 lecanicephalidean species representing 22 of the 25 valid genera were conducted; new sequence data were generated for 43 species and 11 genera, including three undescribed genera. The monophyly of the order was confirmed in all but the analyses based on cox1 data alone. Sesquipedalapex placed among species of Anteropora and was thus synonymized with the latter genus. Based on analyses of the concatenated dataset, eight major groups emerged which are herein formally recognised at the familial level. Existing family names (i.e., Lecanicephalidae, Polypocephalidae, Tetragonocephalidae, and Cephalobothriidae) are maintained for four of the eight clades, and new families are proposed for the remaining four groups (Aberrapecidae n. fam., Eniochobothriidae n. fam., Paraberrapecidae n. fam., and Zanobatocestidae n. fam.). The four new families and the Tetragonocephalidae are monogeneric, while the Cephalobothriidae, Lecanicephalidae and Polypocephalidae comprise seven, eight and four genera, respectively. As a result of their unusual morphologies, the three genera not included here (i.e., Corrugatocephalum, Healyum and Quadcuspibothrium) are considered incertae sedis within the order until their familial affinities can be examined in more detail. All eight families are newly circumscribed based on morphological features and a key to the families is provided. Aspects of morphological evolution and host associations are discussed in a phylogenetic context for each family and for the order as a whole. Lecanicephalidean genera lacking apical structures were confirmed as the earliest diverging lineages. Proglottid anatomy was determined to be much more conserved and indicative of phylogenetic affinities than scolex morphology. Collectively, the Lecanicephalidea parasitize three of the four orders of Batoidea-their almost exclusive absence from skates (Order Rajiformes) appears to be real; only a few records from sharks exist. At the family level, the breadth of host associations is correlated with taxonomic diversity of the family. The degree to which factors such as intermediate host use or host specificity at any stage in the life-cycle shape these patterns is currently unknown. Copyright © 2016 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

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

PubMed

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

2015-08-01

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

Species diversity in the marine microturbellarian Astrotorhynchus bifidus sensu lato (Platyhelminthes: Rhabdocoela) from the Northeast Pacific Ocean.

PubMed

Van Steenkiste, Niels W L; Herbert, Elizabeth R; Leander, Brian S

2018-03-01

Increasing evidence suggests that many widespread species of meiofauna are in fact regional complexes of (pseudo-)cryptic species. This knowledge has challenged the 'Everything is Everywhere' hypothesis and also partly explains the meiofauna paradox of widespread nominal species with limited dispersal abilities. Here, we investigated species diversity within the marine microturbellarian Astrotorhynchus bifidus sensu lato in the Northeast Pacific Ocean. We used a multiple-evidence approach combining multi-gene (18S, 28S, COI) phylogenetic analyses, several single-gene and multi-gene species delimitation methods, haplotype networks and conventional taxonomy to designate Primary Species Hypotheses (PSHs). This included the development of rhabdocoel-specific COI barcode primers, which also have the potential to aid in species identification and delimitation in other rhabdocoels. Secondary Species Hypotheses (SSHs) corresponding to morphospecies and pseudo-cryptic species were then proposed based on the minimum consensus of different PSHs. Our results showed that (a) there are at least five species in the A. bifidus complex in the Northeast Pacific Ocean, four of which can be diagnosed based on stylet morphology, (b) the A. bifidus complex is a mixture of sympatric and allopatric species with regional and/or subglobal distributions, (c) sympatry occurs on local (sample sites), regional (Northeastern Pacific) and subglobal (Northern Atlantic, Arctic, Northeastern Pacific) scales. Mechanisms for this co-occurrence are still poorly understood, but we hypothesize they could include habitat differentiation (spatial and/or seasonal) and life history characteristics such as sexual selection and dispersal abilities. Our results also suggest the need for improved sampling and exploration of molecular markers to accurately map gene flow and broaden our understanding of species diversity and distribution of microturbellarians in particular and meiofauna in general. Copyright © 2017 Elsevier Inc. All rights reserved.

Identification and activity of a lower eukaryotic serine proteinase inhibitor (serpin) from Cyanea capillata: analysis of a jellyfish serpin, jellypin.

PubMed

Cole, Elisabeth B; Miller, David; Rometo, David; Greenberg, Robert M; Brömme, Dieter; Cataltepe, Sule; Pak, Stephen C; Mills, David R; Silverman, Gary A; Luke, Cliff J

2004-09-21

Delineating the phylogenetic relationships among members of a protein family can provide a high degree of insight into the evolution of domain structure and function relationships. To identify an early metazoan member of the high molecular weight serine proteinase inhibitor (serpin) superfamily, we initiated a cDNA library screen of the cnidarian, Cyanea capillata. We identified one serpin cDNA encoding for a full-length serpin, jellypin. Phylogenetic analysis using the deduced amino acid sequence showed that jellypin was most similar to the platyhelminthe Echinococcus multiocularis serpin and the clade P serpins, suggesting that this serpin evolved approximately 1000 million years ago (MYA). Modeling of jellypin showed that it contained all the functional elements of an inhibitory serpin. In vitro biochemical analysis confirmed that jellypin was an inhibitor of the S1 clan SA family of serine proteinases. Analysis of the interactions between the human serine proteinases, chymotrypsin, cathepsin G, and elastase, showed that jellypin inhibited these enzymes in the classical serpin manner, forming a SDS stable enzyme/inhibitor complex. These data suggest that the coevolution of serpin structure and inhibitory function date back to at least early metazoan evolution, approximately 1000 MYA.

Germline Defects Caused by Smed-boule RNA-Interference Reveal That Egg Capsule Deposition Occurs Independently of Fertilization, Ovulation, Mating, or the Presence of Gametes in Planarian Flatworms.

PubMed

Steiner, Jessica Kathryne; Tasaki, Junichi; Rouhana, Labib

2016-05-01

Few animals are known to lay eggs in the absence of ovulation or copulation, as it is presumably energetically wasteful and subjected to negative selection. Characterization of Smed-boule, a member of the DAZ family of germline RNA-binding proteins, revealed that egg capsule (or capsule) production and deposition occurs independently of the presence of gametes in the planarian flatworm Schmidtea mediterranea. Reduction of Smed-boule expression by RNA-interference (RNAi) causes ablation of spermatogonial stem cells and the inability of ovarian germline stem cells to undergo oogenesis. Although animals subjected to Smed-boule RNAi lose their gametes and become sterile, they continue to lay egg capsules. Production of sterile capsules is even observed in virgin Smed-boule(RNAi) and control planarians maintained in complete isolation, demonstrating that egg production in S. mediterranea occurs independently of ovulation, fertilization, or mating. Evidence suggests that this is a conserved feature amongst Platyhelminthes, and therefore relevant to the pathology and dissemination of parasitic flatworms. These findings demonstrate that Smed-boule functions at different stages during male and female germline stem cell development, and also demonstrate that egg capsule production by planarian flatworms occurs independently of signals produced by mating or ova.

Dispersal of Udonella australis (Monogenea: Udonellidae) between caligid copepods Caligus rogercresseyi and Lepeophtheirus mugiloidis on Chilean rock cod.

PubMed

Marin, Sandra L; Carvajal, Juan; George-Nascimento, Mario

2007-04-01

Udonella australis is a platyhelminth that lives on the surface of the ectoparasite copepods Caligus rogercresseyi and Lepeophtheirus mugiloidis, which coexist on the Chilean rock cod Eleginops maclovinus. The absence of a planktonic oncomiracidium stage in the life cycle of udonellids may limit their dispersal ability. However, the high prevalence and intensity of U. australis on C. rogercresseyi suggest they have developed dispersal strategies to compensate for the lack of a free-living larval stage. The goals of this study were to determine the main dispersal mechanisms of U. australis in 1 copepod species and to compare the dispersal ability of U. australis between 2 different copepod species. Chilean rock cods were infected with female (without udonellids) and male (with and without udonellids) C. rogercresseyi. Other fishes were also infected with this copepod (with U. australis) and with L. mugiloidis (without U. australis). The dispersal of udonellids among copepods occurs through both intraspecific and interspecific processes. The main dispersal mechanism appears to be copepod mating; contact between same-sex individuals is less important. Intraspecific dispersal seems to be more dependent on the number of udonellids per fish than on copepod abundance, as observed for interspecific dispersal.

Flatworms have lost the right open reading frame kinase 3 gene during evolution

PubMed Central

Breugelmans, Bert; Ansell, Brendan R. E.; Young, Neil D.; Amani, Parisa; Stroehlein, Andreas J.; Sternberg, Paul W.; Jex, Aaron R.; Boag, Peter R.; Hofmann, Andreas; Gasser, Robin B.

2015-01-01

All multicellular organisms studied to date have three right open reading frame kinase genes (designated riok-1, riok-2 and riok-3). Current evidence indicates that riok-1 and riok-2 have essential roles in ribosome biosynthesis, and that the riok-3 gene assists this process. In the present study, we conducted a detailed bioinformatic analysis of the riok gene family in 25 parasitic flatworms (platyhelminths) for which extensive genomic and transcriptomic data sets are available. We found that none of the flatworms studied have a riok-3 gene, which is unprecedented for multicellular organisms. We propose that, unlike in other eukaryotes, the loss of RIOK-3 from flatworms does not result in an evolutionary disadvantage due to the unique biology and physiology of this phylum. We show that the loss of RIOK-3 coincides with a loss of particular proteins associated with essential cellular pathways linked to cell growth and apoptosis. These findings indicate multiple, key regulatory functions of RIOK-3 in other metazoan species. Taking advantage of a known partial crystal structure of human RIOK-1, molecular modelling revealed variability in nucleotide binding sites between flatworm and human RIOK proteins. PMID:25976756

Planarians Sense Simulated Microgravity and Hypergravity

PubMed Central

Adell, Teresa; Saló, Emili; van Loon, Jack J. W. A.

2014-01-01

Planarians are flatworms, which belong to the phylum Platyhelminthes. They have been a classical subject of study due to their amazing regenerative ability, which relies on the existence of adult totipotent stem cells. Nowadays they are an emerging model system in the field of developmental, regenerative, and stem cell biology. In this study we analyze the effect of a simulated microgravity and a hypergravity environment during the process of planarian regeneration and embryogenesis. We demonstrate that simulated microgravity by means of the random positioning machine (RPM) set at a speed of 60 °/s but not at 10 °/s produces the dead of planarians. Under hypergravity of 3 g and 4 g in a large diameter centrifuge (LDC) planarians can regenerate missing tissues, although a decrease in the proliferation rate is observed. Under 8 g hypergravity small planarian fragments are not able to regenerate. Moreover, we found an effect of gravity alterations in the rate of planarian scission, which is its asexual mode of reproduction. No apparent effects of altered gravity were found during the embryonic development. PMID:25309918

The inland water macro-invertebrate occurrences in Flanders, Belgium.

PubMed

Vannevel, Rudy; Brosens, Dimitri; Cooman, Ward De; Gabriels, Wim; Frank Lavens; Mertens, Joost; Vervaeke, Bart

2018-01-01

The Flanders Environment Agency (VMM) has been performing biological water quality assessments on inland waters in Flanders (Belgium) since 1989 and sediment quality assessments since 2000. The water quality monitoring network is a combined physico-chemical and biological network, the biological component focusing on macro-invertebrates. The sediment monitoring programme produces biological data to assess the sediment quality. Both monitoring programmes aim to provide index values, applying a similar conceptual methodology based on the presence of macro-invertebrates. The biological data obtained from both monitoring networks are consolidated in the VMM macro-invertebrates database and include identifications at family and genus level of the freshwater phyla Coelenterata, Platyhelminthes, Annelida, Mollusca, and Arthropoda. This paper discusses the content of this database, and the dataset published thereof: 282,309 records of 210 observed taxa from 4,140 monitoring sites located on 657 different water bodies, collected during 22,663 events. This paper provides some background information on the methodology, temporal and spatial coverage, and taxonomy, and describes the content of the dataset. The data are distributed as open data under the Creative Commons CC-BY license.

Flatworms have lost the right open reading frame kinase 3 gene during evolution.

PubMed

Breugelmans, Bert; Ansell, Brendan R E; Young, Neil D; Amani, Parisa; Stroehlein, Andreas J; Sternberg, Paul W; Jex, Aaron R; Boag, Peter R; Hofmann, Andreas; Gasser, Robin B

2015-05-15

All multicellular organisms studied to date have three right open reading frame kinase genes (designated riok-1, riok-2 and riok-3). Current evidence indicates that riok-1 and riok-2 have essential roles in ribosome biosynthesis, and that the riok-3 gene assists this process. In the present study, we conducted a detailed bioinformatic analysis of the riok gene family in 25 parasitic flatworms (platyhelminths) for which extensive genomic and transcriptomic data sets are available. We found that none of the flatworms studied have a riok-3 gene, which is unprecedented for multicellular organisms. We propose that, unlike in other eukaryotes, the loss of RIOK-3 from flatworms does not result in an evolutionary disadvantage due to the unique biology and physiology of this phylum. We show that the loss of RIOK-3 coincides with a loss of particular proteins associated with essential cellular pathways linked to cell growth and apoptosis. These findings indicate multiple, key regulatory functions of RIOK-3 in other metazoan species. Taking advantage of a known partial crystal structure of human RIOK-1, molecular modelling revealed variability in nucleotide binding sites between flatworm and human RIOK proteins.

WormBase 2016: expanding to enable helminth genomic research.

PubMed

Howe, Kevin L; Bolt, Bruce J; Cain, Scott; Chan, Juancarlos; Chen, Wen J; Davis, Paul; Done, James; Down, Thomas; Gao, Sibyl; Grove, Christian; Harris, Todd W; Kishore, Ranjana; Lee, Raymond; Lomax, Jane; Li, Yuling; Muller, Hans-Michael; Nakamura, Cecilia; Nuin, Paulo; Paulini, Michael; Raciti, Daniela; Schindelman, Gary; Stanley, Eleanor; Tuli, Mary Ann; Van Auken, Kimberly; Wang, Daniel; Wang, Xiaodong; Williams, Gary; Wright, Adam; Yook, Karen; Berriman, Matthew; Kersey, Paul; Schedl, Tim; Stein, Lincoln; Sternberg, Paul W

2016-01-04

WormBase (www.wormbase.org) is a central repository for research data on the biology, genetics and genomics of Caenorhabditis elegans and other nematodes. The project has evolved from its original remit to collect and integrate all data for a single species, and now extends to numerous nematodes, ranging from evolutionary comparators of C. elegans to parasitic species that threaten plant, animal and human health. Research activity using C. elegans as a model system is as vibrant as ever, and we have created new tools for community curation in response to the ever-increasing volume and complexity of data. To better allow users to navigate their way through these data, we have made a number of improvements to our main website, including new tools for browsing genomic features and ontology annotations. Finally, we have developed a new portal for parasitic worm genomes. WormBase ParaSite (parasite.wormbase.org) contains all publicly available nematode and platyhelminth annotated genome sequences, and is designed specifically to support helminth genomic research. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Kirkegaardia (Polychaeta, Cirratulidae), new name for Monticellina Laubier, preoccupied in the Rhabdocoela, together with new records and descriptions of eight previously known and sixteen new species from the Atlantic, Pacific, and Southern Oceans.

PubMed

Blake, James A

2016-09-13

A new name, Kirkegaardia, is proposed to replace Monticellina Laubier, 1961, a bitentaculate cirratulid polychaete genus, that is a junior homonym of the turbellarian Monticellina Westblad, 1953 (Platyhelminthes, Rhabdocoela). In addition, the opportunity is taken to complete a major revision of the genus including the redescription, revalidation, and separation of three species previously referred to synonymy with K. dorsobranchialis (Kirkegaard, 1959) and five other previously described species. In addition, 16 new species are described from the western North Atlantic, eastern and central Pacific, off western South America, and seas around Antarctica, bringing the total number of species in the genus to 38. Included are two new species of the unusual mud ball worms, first reported as Tharyx luticastellus Jumars, 1975, from southern California deep basins. A review of all 38 species reveals that three distinct species groups may be identified within the genus in addition to 5-6 species that may eventually be referred elsewhere. This review includes a discussion of the taxonomic characters and various newly defined character states that are found among species of Kirkegaardia. Several of these are unique among the Cirratulidae.

Parasites of the mangrove mussel Mytella guyanensis (Bivalvia: Mytilidae) in Camamu Bay, Bahia, Brazil.

PubMed

Ceuta, L O; Boehs, G

2012-08-01

This contribution reports the parasites found in the mangrove mussel Mytella guyanensis in Camamu Bay, Bahia, Brazil. Samples were collected monthly from September 2006 through October 2007. A total of 460 individuals were collected, fixed in Davidson's solution, and processed by standard histological techniques, and the sections were stained with Harris hematoxylin and eosin (H&E). The water temperature ranged from 23.5 to 31.6 ºC, and the salinity from 25 to 37‰. Microscopic analysis showed Rickettsia-like organisms (RLOs), Nematopsis sp. (Apicomplexa), and Platyhelminthes, including a turbellarian, sporocysts of Bucephalus sp., metacercariae, and metacestodes of Tylocephalum sp. Parasites were observed mainly in the gills, mantle, and digestive gland. The prevalence of Nematopsis sp. was 100%, and in heavily infected mussels the tissues of the labial palps were damaged. RLOs occurred in high prevalence and intensity of infection in some periods. The digenean sporocysts showed moderate prevalence but high intensity of infection, and caused parasitic castration. In general, there was no significant spatial or temporal variation (p > 0.05) of the parasites, which is probably attributable to the small variations of temperature and salinity in the region.

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.

Ultrastructure of the digestive tract of Gyliauchen nahaensis (Platyhelminthes, Digenea), an inhabitant of the hindgut of herbivorous fishes.

PubMed

Jones, M K; Hughes-Stamm, S R; East, R M; Cribb, T H

2000-12-01

Digenean parasites of vertebrates usually amplify the surface area of their gut by increasing the size of the absorptive caeca. Some members of the family Gyliauchenidae, however, have relatively small caeca but have a greatly expanded foregut. The morphology of the elongate gut of the digenean Gyliauchen nahaensis, an inhabitant of herbivorous fish of the family Siganidae, was examined by light and transmission electron microscopy. The extensive foregut, consisting of a mouth, pharynx, and esophagus, is lined with a syncytial tegument-like lining, which is connected to nucleated cell bodies sunken in the parenchyma. The apical cytoplasm in the mouth and anterior regions of the pharynx resembles that of the general body tegument, although some regional specialization is present. The lining of posterior regions of the pharynx is armed with large apical projections, which are thought to serve as filtration structures. The lining of the anterior and middle esophagus displays a peculiar form of surface amplification involving the formation of elongate flask-shaped invaginations of the apical cytoplasm. The cell bodies associated with these regions are rich in secretory vesicles and it is proposed that these regions of the esophagus are expanded to promote extracellular digestion. The posterior region of the esophagus lacks the invaginations of other esophageal regions, but displays instead large surface projections. The caeca consists of columnar cells lined by extensive apical microlamellae. The peculiar gut morphology of G. nahaensis, coupled with alterations in the arrangement of suckers, is interpreted to be an adaptation to the predominantly herbivorous diets of the definitive hosts.

WormBase ParaSite - a comprehensive resource for helminth genomics.

PubMed

Howe, Kevin L; Bolt, Bruce J; Shafie, Myriam; Kersey, Paul; Berriman, Matthew

2017-07-01

The number of publicly available parasitic worm genome sequences has increased dramatically in the past three years, and research interest in helminth functional genomics is now quickly gathering pace in response to the foundation that has been laid by these collective efforts. A systematic approach to the organisation, curation, analysis and presentation of these data is clearly vital for maximising the utility of these data to researchers. We have developed a portal called WormBase ParaSite (http://parasite.wormbase.org) for interrogating helminth genomes on a large scale. Data from over 100 nematode and platyhelminth species are integrated, adding value by way of systematic and consistent functional annotation (e.g. protein domains and Gene Ontology terms), gene expression analysis (e.g. alignment of life-stage specific transcriptome data sets), and comparative analysis (e.g. orthologues and paralogues). We provide several ways of exploring the data, including genome browsers, genome and gene summary pages, text search, sequence search, a query wizard, bulk downloads, and programmatic interfaces. In this review, we provide an overview of the back-end infrastructure and analysis behind WormBase ParaSite, and the displays and tools available to users for interrogating helminth genomic data. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

An animal model to study human muscular diseases involving mitochondrial oxidative phosphorylation.

PubMed

Lemieux, Hélène; Warren, Blair E

2012-08-01

Mitochondria are producing most of the energy needed for many cellular functions by a process named oxidative phosphorylation (OXPHOS). It is now well recognized that mitochondrial dysfunctions are involved in several pathologies or degenerative processes, including cardiovascular diseases, diabetes, and aging. Animal models are currently used to try to understand the role of mitochondria in human diseases but a major problem is that mitochondria from different species and tissues are variable in terms of regulation. Analysis of mitochondrial function in three species of planarian flatworms (Tricladia, Platyhelminthes) shows that they share a very rare characteristic with human mitochondria: a strong control of oxidative phosphorylation by the phosphorylation system. The ratio of coupled OXPHOS over maximal electron transport capacity after uncoupling (electron transport system; ETS) well below 1.0 indicates that the phosphorylation system is limiting the rate of OXPHOS. The OXPHOS/ETS ratios are 0.62 ± 0.06 in Dugesia tigrina, 0.63 ± 0.05 in D. dorotocephala and 0.62 ± 0.05 in Procotyla fluviatilis, comparable to the value measured in human muscles. To our knowledge, no other animal model displays this peculiarity. This new model offers a venue in which to test the phosphorylation system as a potential therapeutic control point within humans.

Host and ecology both play a role in shaping distribution of digenean parasites of New Zealand whelks (Gastropoda: Buccinidae: Cominella).

PubMed

Donald, Kirsten M; Spencer, Hamish G

2016-08-01

Digenean parasites infecting four Cominella whelk species (C. glandiformis, C. adspersa, C. maculosa and C. virgata), which inhabit New Zealand's intertidal zone, were analysed using molecular techniques. Mitochondrial 16S and cytochrome oxidase 1 (COI) and nuclear rDNA ITS1 sequences were used to infer phylogenetic relationships amongst digenea. Host species were parasitized by a diverse range of digenea (Platyhelminthes, Trematoda), representing seven families: Echinostomatidae, Opecoelidae, Microphallidae, Strigeidae and three, as yet, undetermined families A, B and C. Each parasite family infected between one and three host whelk species, and infection levels were typically low (average infection rates ranged from 1·4 to 3·6%). Host specificity ranged from highly species-specific amongst the echinostomes, which were only ever observed infecting C. glandiformis, to the more generalist opecoelids and strigeids, which were capable of infecting three out of four of the Cominella species analysed. Digeneans displayed a highly variable geographic range; for example, echinostomes had a large geographic range stretching the length of New Zealand, from Northland to Otago, whereas Family B parasites were restricted to fairly small areas of the North Island. Our results add to a growing body of research identifying wide ranges in both host specificity and geographic range amongst intertidal, multi-host parasite systems.

Trace Fossil Evidence of Trematode-Bivalve Parasite-Host Interactions in Deep Time.

PubMed

Huntley, John Warren; De Baets, Kenneth

2015-01-01

Parasitism is one of the most pervasive phenomena amongst modern eukaryotic life and yet, relative to other biotic interactions, almost nothing is known about its history in deep time. Digenean trematodes (Platyhelminthes) are complex life cycle parasites, which have practically no body fossil record, but induce the growth of characteristic malformations in the shells of their bivalve hosts. These malformations are readily preserved in the fossil record, but, until recently, have largely been overlooked by students of the fossil record. In this review, we present the various malformations induced by trematodes in bivalves, evaluate their distribution through deep time in the phylogenetic and ecological contexts of their bivalve hosts and explore how various taphonomic processes have likely biased our understanding of trematodes in deep time. Trematodes are known to negatively affect their bivalve hosts in a number of ways including castration, modifying growth rates, causing immobilization and, in some cases, altering host behaviour making the host more susceptible to their own predators. Digeneans are expected to be significant agents of natural selection. To that end, we discuss how bivalves may have adapted to their parasites via heterochrony and suggest a practical methodology for testing such hypotheses in deep time. Copyright © 2015 Elsevier Ltd. All rights reserved.

A checklist of helminth parasites of Elasmobranchii in Mexico

PubMed Central

Merlo-Serna, Aldo Iván; García-Prieto, Luis

2016-01-01

Abstract A comprehensive and updated summary of the literature and unpublished records contained in scientific collections on the helminth parasites of the elasmobranchs from Mexico is herein presented for the first time. At present, the helminth fauna associated with Elasmobranchii recorded in Mexico is composed of 132 (110 named species and 22 not assigned to species), which belong to 70 genera included in 27 families (plus 4 incertae sedis families of cestodes). These data represent 7.2% of the worldwide species richness. Platyhelminthes is the most widely represented, with 128 taxa: 94 of cestodes, 22 of monogeneans and 12 of trematodes; Nematoda and Annelida: Hirudinea are represented by only 2 taxa each. These records come from 54 localities, pertaining to 15 states; Baja California Sur (17 sampled localities) and Baja California (10), are the states with the highest species richness: 72 and 54 species, respectively. Up to now, 48 elasmobranch species have been recorded as hosts of helminths in Mexico; so, approximately 82% of sharks and 67% of rays distributed in Mexican waters lack helminthological studies. The present list provides the host, distribution (with geographical coordinates), site of infection, accession number in scientific collections, and references for the parasites. A host-parasite list is also provided. PMID:27047240

A checklist of helminth parasites of Elasmobranchii in Mexico.

PubMed

Merlo-Serna, Aldo Iván; García-Prieto, Luis

2016-01-01

A comprehensive and updated summary of the literature and unpublished records contained in scientific collections on the helminth parasites of the elasmobranchs from Mexico is herein presented for the first time. At present, the helminth fauna associated with Elasmobranchii recorded in Mexico is composed of 132 (110 named species and 22 not assigned to species), which belong to 70 genera included in 27 families (plus 4 incertae sedis families of cestodes). These data represent 7.2% of the worldwide species richness. Platyhelminthes is the most widely represented, with 128 taxa: 94 of cestodes, 22 of monogeneans and 12 of trematodes; Nematoda and Annelida: Hirudinea are represented by only 2 taxa each. These records come from 54 localities, pertaining to 15 states; Baja California Sur (17 sampled localities) and Baja California (10), are the states with the highest species richness: 72 and 54 species, respectively. Up to now, 48 elasmobranch species have been recorded as hosts of helminths in Mexico; so, approximately 82% of sharks and 67% of rays distributed in Mexican waters lack helminthological studies. The present list provides the host, distribution (with geographical coordinates), site of infection, accession number in scientific collections, and references for the parasites. A host-parasite list is also provided.

Germline Defects Caused by Smed-boule RNA-Interference Reveal That Egg Capsule Deposition Occurs Independently of Fertilization, Ovulation, Mating, or the Presence of Gametes in Planarian Flatworms

PubMed Central

Steiner, Jessica Kathryne; Tasaki, Junichi; Rouhana, Labib

2016-01-01

Few animals are known to lay eggs in the absence of ovulation or copulation, as it is presumably energetically wasteful and subjected to negative selection. Characterization of Smed-boule, a member of the DAZ family of germline RNA-binding proteins, revealed that egg capsule (or capsule) production and deposition occurs independently of the presence of gametes in the planarian flatworm Schmidtea mediterranea. Reduction of Smed-boule expression by RNA-interference (RNAi) causes ablation of spermatogonial stem cells and the inability of ovarian germline stem cells to undergo oogenesis. Although animals subjected to Smed-boule RNAi lose their gametes and become sterile, they continue to lay egg capsules. Production of sterile capsules is even observed in virgin Smed-boule(RNAi) and control planarians maintained in complete isolation, demonstrating that egg production in S. mediterranea occurs independently of ovulation, fertilization, or mating. Evidence suggests that this is a conserved feature amongst Platyhelminthes, and therefore relevant to the pathology and dissemination of parasitic flatworms. These findings demonstrate that Smed-boule functions at different stages during male and female germline stem cell development, and also demonstrate that egg capsule production by planarian flatworms occurs independently of signals produced by mating or ova. PMID:27149082

Quo Vadis Venomics? A Roadmap to Neglected Venomous Invertebrates

PubMed Central

von Reumont, Bjoern Marcus; Campbell, Lahcen I.; Jenner, Ronald A.

2014-01-01

Venomics research is being revolutionized by the increased use of sensitive -omics techniques to identify venom toxins and their transcripts in both well studied and neglected venomous taxa. The study of neglected venomous taxa is necessary both for understanding the full diversity of venom systems that have evolved in the animal kingdom, and to robustly answer fundamental questions about the biology and evolution of venoms without the distorting effect that can result from the current bias introduced by some heavily studied taxa. In this review we draw the outlines of a roadmap into the diversity of poorly studied and understood venomous and putatively venomous invertebrates, which together represent tens of thousands of unique venoms. The main groups we discuss are crustaceans, flies, centipedes, non-spider and non-scorpion arachnids, annelids, molluscs, platyhelminths, nemerteans, and echinoderms. We review what is known about the morphology of the venom systems in these groups, the composition of their venoms, and the bioactivities of the venoms to provide researchers with an entry into a large and scattered literature. We conclude with a short discussion of some important methodological aspects that have come to light with the recent use of new -omics techniques in the study of venoms. PMID:25533518

The complete mitochondrial genome of the onychophoran Epiperipatus biolleyi reveals a unique transfer RNA set and provides further support for the ecdysozoa hypothesis.

PubMed

Podsiadlowski, Lars; Braband, Anke; Mayer, Georg

2008-01-01

Onychophora (velvet worms) play a crucial role in current discussions on position of arthropods. The ongoing Articulata/Ecdysozoa debate is in need of additional ground pattern characters for Panarthropoda (Arthropoda, Tardigrada, and Onychophora). Hence, Onychophora is an important outgroup taxon in resolving the relationships among arthropods, irrespective of whether morphological or molecular data are used. To date, there has been a noticeable lack of mitochondrial genome data from onychophorans. Here, we present the first complete mitochondrial genome sequence of an onychophoran, Epiperipatus biolleyi (Peripatidae), which shows several characteristic features. Specifically, the gene order is considerably different from that in other arthropods and other bilaterians. In addition, there is a lack of 9 tRNA genes usually present in bilaterian mitochondrial genomes. All these missing tRNAs have anticodon sequences corresponding to 4-fold degenerate codons, whereas the persisting 13 tRNAs all have anticodons pairing with 2-fold degenerate codons. Sequence-based phylogenetic analysis of the mitochondrial protein-coding genes provides a robust support for a clade consisting of Onychophora, Priapulida, and Arthropoda, which confirms the Ecdysozoa hypothesis. However, resolution of the internal ecdysozoan relationships suffers from a cluster of long-branching taxa (including Nematoda and Platyhelminthes) and a lack of data from Tardigrada and further nemathelminth taxa in addition to nematodes and priapulids.

Effect of Donepezil, Tacrine, Galantamine and Rivastigmine on Acetylcholinesterase Inhibition in Dugesia tigrina.

PubMed

Bezerra da Silva, Cristiane; Pott, Arnildo; Elifio-Esposito, Selene; Dalarmi, Luciane; Fialho do Nascimento, Kátia; Moura Burci, Ligia; de Oliveira, Maislian; de Fátima Gaspari Dias, Josiane; Warumby Zanin, Sandra Maria; Gomes Miguel, Obdulio; Dallarmi Miguel, Marilis

2016-01-11

Dugesia tigrina is a non-parasitic platyhelminth, which has been recently utilized in pharmacological models, regarding the nervous system, as it presents a wide sensitivity to drugs. Our trials aimed to propose a model for an in vivo screening of substances with inhibitory activity of the enzyme acetylcholinesterase. Trials were performed with four drugs commercialized in Brazil: donepezil, tacrine, galantamine and rivastigmine, utilized in the control of Alzheimer's disease, to inhibit the activity of acetylcholinesterase. We tested five concentrations of the drugs, with an exposure of 24 h, and the mortality and the inhibition of acetylcholinesterase planarian seizure-like activity (pSLA) and planarian locomotor velocity (pLMV) were measured. Galantamine showed high anticholinesterasic activity when compared to the other drugs, with a reduction of 0.05 μmol·min(-1) and 63% of convulsant activity, presenting screw-like movement and hypokinesia, with pLMV of 65 crossed lines during 5 min. Our results showed for the first time the anticholinesterasic and convulsant effect, in addition to the decrease in locomotion induced by those drugs in a model of invertebrates. The experimental model proposed is simple and low cost and could be utilized in the screening of substances with anticholinesterasic action.

Protein Translation Enzyme lysyl-tRNA Synthetase Presents a New Target for Drug Development against Causative Agents of Loiasis and Schistosomiasis.

PubMed

Sharma, Arvind; Sharma, Manmohan; Yogavel, Manickam; Sharma, Amit

2016-11-01

Helminth parasites are an assemblage of two major phyla of nematodes (also known as roundworms) and platyhelminths (also called flatworms). These parasites are a major human health burden, and infections caused by helminths are considered under neglected tropical diseases (NTDs). These infections are typified by limited clinical treatment options and threat of drug resistance. Aminoacyl-tRNA synthetases (aaRSs) are vital enzymes that decode genetic information and enable protein translation. The specific inhibition of pathogen aaRSs bores well for development of next generation anti-parasitics. Here, we have identified and annotated aaRSs and accessory proteins from Loa loa (nematode) and Schistosoma mansoni (flatworm) to provide a glimpse of these protein translation enzymes within these parasites. Using purified parasitic lysyl-tRNA synthetases (KRSs), we developed series of assays that address KRS enzymatic activity, oligomeric states, crystal structure and inhibition profiles. We show that L. loa and S. mansoni KRSs are potently inhibited by the fungal metabolite cladosporin. Our co-crystal structure of Loa loa KRS-cladosporin complex reveals key interacting residues and provides a platform for structure-based drug development. This work hence provides a new direction for both novel target discovery and inhibitor development against eukaryotic pathogens that include L. loa and S. mansoni.

Protein Translation Enzyme lysyl-tRNA Synthetase Presents a New Target for Drug Development against Causative Agents of Loiasis and Schistosomiasis

PubMed Central

Yogavel, Manickam; Sharma, Amit

2016-01-01

Helminth parasites are an assemblage of two major phyla of nematodes (also known as roundworms) and platyhelminths (also called flatworms). These parasites are a major human health burden, and infections caused by helminths are considered under neglected tropical diseases (NTDs). These infections are typified by limited clinical treatment options and threat of drug resistance. Aminoacyl-tRNA synthetases (aaRSs) are vital enzymes that decode genetic information and enable protein translation. The specific inhibition of pathogen aaRSs bores well for development of next generation anti-parasitics. Here, we have identified and annotated aaRSs and accessory proteins from Loa loa (nematode) and Schistosoma mansoni (flatworm) to provide a glimpse of these protein translation enzymes within these parasites. Using purified parasitic lysyl-tRNA synthetases (KRSs), we developed series of assays that address KRS enzymatic activity, oligomeric states, crystal structure and inhibition profiles. We show that L. loa and S. mansoni KRSs are potently inhibited by the fungal metabolite cladosporin. Our co-crystal structure of Loa loa KRS-cladosporin complex reveals key interacting residues and provides a platform for structure-based drug development. This work hence provides a new direction for both novel target discovery and inhibitor development against eukaryotic pathogens that include L. loa and S. mansoni. PMID:27806050

Modelling a 3D structure for EgDf1 from shape Echinococcus granulosus: putative epitopes, phosphorylation motifs and ligand

NASA Astrophysics Data System (ADS)

Paulino, M.; Esteves, A.; Vega, M.; Tabares, G.; Ehrlich, R.; Tapia, O.

1998-07-01

EgDf1 is a developmentally regulated protein from the parasite Echinococcus granulosus related to a family of hydrophobic ligand binding proteins. This protein could play a crucial role during the parasite life cycle development since this organism is unable to synthetize most of their own lipids de novo. Furthermore, it has been shown that two related protein from other parasitic platyhelminths (Fh15 from Fasciola hepatica and Sm14 from Schistosoma mansoni) are able to confer protective inmunity against experimental infection in animal models. A three-dimensional structure would help establishing structure/function relationships on a knowledge based manner. 3D structures for EgDf1 protein were modelled by using myelin P2 (mP2) and intestine fatty acid binding protein (I-FABP) as templates. Molecular dynamics techniques were used to validate the models. Template mP2 yielded the best 3D structure for EgDf1. Palmitic and oleic acids were docked inside EgDf1. The present theoretical results suggest definite location in the secondary structure of the epitopic regions, consensus phosphorylation motifs and oleic acid as a good ligand candidate to EgDf1. This protein might well be involved in the process of supplying hydrophobic metabolites for membrane biosynthesis and for signaling pathways.

What Explains Patterns of Diversification and Richness among Animal Phyla?

PubMed Central

Jezkova, Tereza; Wiens, John J.

2016-01-01

Animal phyla vary dramatically in species richness (from 1 species to >1.2 million), but the causes of this variation remain largely unknown. Animals have also evolved striking variation in morphology and ecology, including sessile marine taxa lacking heads, eyes, limbs, and complex organs (e.g. sponges), parasitic worms (e.g. nematodes, platyhelminths), and taxa with eyes, skeletons, limbs, and complex organs that dominate terrestrial ecosystems (arthropods, chordates). Relating this remarkable variation in traits to the diversification and richness of animal phyla is a fundamental yet unresolved problem in biology. Here, we test the impacts of 18 traits (including morphology, ecology, reproduction, and development) on diversification and richness of extant animal phyla. Using phylogenetic multiple regression, the best-fitting model includes five traits that explain ~74% of the variation in diversification rates (dioecy, parasitism, eyes/photoreceptors, a skeleton, non-marine habitat). However, a model including just three (skeleton, parasitism, habitat) explains nearly as much variation (~67%). Diversification rates then largely explain richness patterns. Our results also identify many striking traits that have surprisingly little impact on diversification (e.g. head, limbs, and complex circulatory and digestive systems). Overall, our results reveal the key factors that shape large-scale patterns of diversification and richness across >80% of all extant, described species. PMID:28221832

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

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

PubMed

Baguñà, Jaume; Martinez, Pere; Paps, Jordi; Riutort, Marta

2008-04-27

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 bearing several or most features of advanced coelomate bilaterians (archicoelomate theory). We report phylogenetic analyses of bilaterian metazoans using quantitative (ribosomal, nuclear and expressed sequence tag sequences) and qualitative (HOX cluster genes and microRNA sets) markers. The phylogenetic trees obtained corroborate the position of acoel and nemertodermatid flatworms as the earliest branching extant members of the Bilateria. Moreover, some acoelomate and pseudocoelomate clades appear as early branching lophotrochozoans and deuterostomes. These results strengthen the view that stem bilaterians were small, acoelomate/pseudocoelomate, benthic organisms derived from planuloid-like organisms. Because morphological and recent gene expression data suggest that cnidarians are actually bilateral, the origin of the last common bilaterian ancestor has to be put back in time earlier than the cnidarian-bilaterian split in the form of a planuloid animal. A new systematic scheme for the Bilateria that includes the Cnidaria is suggested and its main implications discussed.

Comparative community-level associations of helminth infections and microparasite shedding in wild long-tailed macaques in Bali, Indonesia.

PubMed

Wilcox, Justin J S; Lane-Degraaf, Kelly E; Fuentes, Agustin; Hollocher, Hope

2015-03-01

Helminthes have the capacity to modulate host immunity, leading to positive interactions with coinfecting microparasites. This phenomenon has been primarily studied during coinfections with a narrow range of geo-helminthes and intracellular microparasites in human populations or under laboratory conditions. Far less is known regarding differences in coinfection dynamics between helminth types, the range of microparasites that might be affected or the overall community-level effects of helminth infections on microparasites in wild systems. Here, we analysed the presence/absence and abundance patterns of enteric parasites in long-tailed macaques (Macaca fascicularis) on the island of Bali, Indonesia, to assess whether naturally occurring helminth infections were associated with increased shedding of the most common intracellular (Cryptosporidium spp., Isospora spp.) and extracellular (Entamoeba spp., Giardia spp.) microparasites. We also comparatively assessed the statistical correlations of different helminth taxa with microparasite shedding to determine if there were consistent relationships between the specific helminth taxa and microparasites. Helminth infections were associated with increased shedding of both intracellular and extracellular microparasites. Platyhelminthes repeatedly displayed strong positive correlations with several microparasites; while nematodes did not. Our results indicate that helminthes can influence microparasite community shedding dynamics under wild conditions, but that trends may be driven by a narrow range of helminthes.

Tracing ancient evolutionary divergence in parasites.

PubMed

Tinsley, Richard C; Tinsley, Matthew C

2016-12-01

For parasitic platyhelminths that generally lack a fossil record, there is little information on the pathways of morphological change during evolution. Polystomatid monogeneans are notable for their evolutionary diversification, having originated from ancestors on fish and radiated in parallel with tetrapod vertebrates over more than 425 million years (My). This study focuses on the genus Polystomoides that occurs almost worldwide on freshwater chelonian reptiles. Morphometric data show a major divergence in structural adaptations for attachment; this correlates with a dichotomy in micro-environmental conditions in habitats within the hosts. Species infecting the urinary tract have attachment organs with large hamuli and small suckers; species in the oro-nasal tract differ fundamentally, having small hamuli and large suckers. Zoogeographical and molecular evidence supports ancient separation of these site-specific clades: a new genus is proposed - Uropolystomoides - containing urinary tract species distinct from Polystomoides sensu stricto in oro-nasal sites. Aside from differences in attachment adaptations, body plans have probably changed little over perhaps 150 My. This case contrasts markedly with polystomatids in other vertebrate groups where major morphological changes have evolved over much shorter timescales; the chelonian parasites show highly stable morphology across their global distribution over a long period of evolution, exemplifying 'living fossils'.

Cross-disciplinary approaches for measuring parasitic helminth viability and phenotype.

PubMed

Peak, Emily; Hoffmann, Karl F

2011-06-01

Parasitic worms (helminths) within the Phyla Nematoda and Platyhelminthes are responsible for some of the most debilitating and chronic infectious diseases of human and animal populations across the globe. As no subunit vaccine for any parasitic helminth is close to being developed, the frontline strategy for intervention is administration of therapeutic, anthelmintic drugs. Worryingly, and unsurprising due to co-evolutionary mechanisms, many of these worms are developing resistance to the limited compound classes currently being used. This unfortunate reality has led to a renaissance in next generation anthelmintic discovery within both academic and industrial sectors. However, a major bottleneck in this process is the lack of quantitative methods for screening large numbers of small molecules for their effects on the whole organism. Development of methodologies that can objectively and rapidly distinguish helminth viability or phenotype would be an invaluable tool in the anthelmintic discovery pipeline. Towards this end, we describe how several basic techniques currently used to assess single cell eukaryote viability have been successfully applied to parasitic helminths. We additionally demonstrate how some of these methodologies have been adopted for high-throughput use and further modified for assessing worm phenotype. Continued development in this area is aimed at increasing the rate by which novel anthelmintics are identified and subsequently translated into everyday, practical applications.

Northeast India Helminth Parasite Information Database (NEIHPID): Knowledge Base for Helminth Parasites.

PubMed

Biswal, Devendra Kumar; Debnath, Manish; Kharumnuid, Graciously; Thongnibah, Welfrank; Tandon, Veena

2016-01-01

Most metazoan parasites that invade vertebrate hosts belong to three phyla: Platyhelminthes, Nematoda and Acanthocephala. Many of the parasitic members of these phyla are collectively known as helminths and are causative agents of many debilitating, deforming and lethal diseases of humans and animals. The North-East India Helminth Parasite Information Database (NEIHPID) project aimed to document and characterise the spectrum of helminth parasites in the north-eastern region of India, providing host, geographical distribution, diagnostic characters and image data. The morphology-based taxonomic data are supplemented with information on DNA sequences of nuclear, ribosomal and mitochondrial gene marker regions that aid in parasite identification. In addition, the database contains raw next generation sequencing (NGS) data for 3 foodborne trematode parasites, with more to follow. The database will also provide study material for students interested in parasite biology. Users can search the database at various taxonomic levels (phylum, class, order, superfamily, family, genus, and species), or by host, habitat and geographical location. Specimen collection locations are noted as co-ordinates in a MySQL database and can be viewed on Google maps, using Google Maps JavaScript API v3. The NEIHPID database has been made freely available at http://nepiac.nehu.ac.in/index.php.

The Global Invertebrate Genomics Alliance (GIGA): developing community resources to study diverse invertebrate genomes.

PubMed

Bracken-Grissom, Heather; Collins, Allen G; Collins, Timothy; Crandall, Keith; Distel, Daniel; Dunn, Casey; Giribet, Gonzalo; Haddock, Steven; Knowlton, Nancy; Martindale, Mark; Medina, Mónica; Messing, Charles; O'Brien, Stephen J; Paulay, Gustav; Putnam, Nicolas; Ravasi, Timothy; Rouse, Greg W; Ryan, Joseph F; Schulze, Anja; Wörheide, Gert; Adamska, Maja; Bailly, Xavier; Breinholt, Jesse; Browne, William E; Diaz, M Christina; Evans, Nathaniel; Flot, Jean-François; Fogarty, Nicole; Johnston, Matthew; Kamel, Bishoy; Kawahara, Akito Y; Laberge, Tammy; Lavrov, Dennis; Michonneau, François; Moroz, Leonid L; Oakley, Todd; Osborne, Karen; Pomponi, Shirley A; Rhodes, Adelaide; Santos, Scott R; Satoh, Nori; Thacker, Robert W; Van de Peer, Yves; Voolstra, Christian R; Welch, David Mark; Winston, Judith; Zhou, Xin

2014-01-01

Over 95% of all metazoan (animal) species comprise the "invertebrates," but very few genomes from these organisms have been sequenced. We have, therefore, formed a "Global Invertebrate Genomics Alliance" (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site (http://giga.nova.edu) has been launched to facilitate this collaborative venture.

Intracellular Immunohistochemical Detection of Tetrodotoxin in Pleurobranchaea maculata (Gastropoda) and Stylochoplana sp. (Turbellaria)

PubMed Central

Salvitti, Lauren R.; Wood, Susanna A.; Winsor, Leigh; Cary, Stephen Craig

2015-01-01

Tetrodotoxin (TTX), is a potent neurotoxin targeting sodium channels that has been identified in multiple marine and terrestrial organisms. It was recently detected in the Opisthobranch Pleurobranchaea maculata and a Platyhelminthes Stylochoplana sp. from New Zealand. Knowledge on the distribution of TTX within these organisms is important to assist in elucidating the origin and ecological role of this toxin. Intracellular micro-distribution of TTX was investigated using a monoclonal antibody-based immunoenzymatic technique. Tetrodotoxin was strongly localized in neutral mucin cells and the basement membrane of the mantle, the oocytes and follicles of the gonad tissue, and in the digestive tissue of P. maculata. The ova and pharynx were the only two structures to contain TTX in Stylochoplana sp. Using liquid chromatography-mass spectrometry, TTX was identified in the larvae and eggs, but not the gelatinous egg cases of P. maculata. Tetrodotoxin was present in egg masses of Stylochoplana sp. These data suggest that TTX has a defensive function in adult P. maculata, who then invest this in their progeny for protection. Localization in the digestive tissue of P. maculata potentially indicates a dietary source of TTX. Stylochoplana sp. may use TTX in prey capture and for the protection of offspring. PMID:25636158

What Explains Patterns of Diversification and Richness among Animal Phyla?

PubMed

Jezkova, Tereza; Wiens, John J

2017-03-01

Animal phyla vary dramatically in species richness (from one species to >1.2 million), but the causes of this variation remain largely unknown. Animals have also evolved striking variation in morphology and ecology, including sessile marine taxa lacking heads, eyes, limbs, and complex organs (e.g., sponges), parasitic worms (e.g., nematodes, platyhelminths), and taxa with eyes, skeletons, limbs, and complex organs that dominate terrestrial ecosystems (arthropods, chordates). Relating this remarkable variation in traits to the diversification and richness of animal phyla is a fundamental yet unresolved problem in biology. Here, we test the impacts of 18 traits (including morphology, ecology, reproduction, and development) on diversification and richness of extant animal phyla. Using phylogenetic multiple regression, the best-fitting model includes five traits that explain ∼74% of the variation in diversification rates (dioecy, parasitism, eyes/photoreceptors, a skeleton, nonmarine habitat). However, a model including just three (skeleton, parasitism, habitat) explains nearly as much variation (∼67%). Diversification rates then largely explain richness patterns. Our results also identify many striking traits that have surprisingly little impact on diversification (e.g., head, limbs, and complex circulatory and digestive systems). Overall, our results reveal the key factors that shape large-scale patterns of diversification and richness across >80% of all extant, described species.

Northeast India Helminth Parasite Information Database (NEIHPID): Knowledge Base for Helminth Parasites

PubMed Central

Debnath, Manish; Kharumnuid, Graciously; Thongnibah, Welfrank; Tandon, Veena

2016-01-01

Most metazoan parasites that invade vertebrate hosts belong to three phyla: Platyhelminthes, Nematoda and Acanthocephala. Many of the parasitic members of these phyla are collectively known as helminths and are causative agents of many debilitating, deforming and lethal diseases of humans and animals. The North-East India Helminth Parasite Information Database (NEIHPID) project aimed to document and characterise the spectrum of helminth parasites in the north-eastern region of India, providing host, geographical distribution, diagnostic characters and image data. The morphology-based taxonomic data are supplemented with information on DNA sequences of nuclear, ribosomal and mitochondrial gene marker regions that aid in parasite identification. In addition, the database contains raw next generation sequencing (NGS) data for 3 foodborne trematode parasites, with more to follow. The database will also provide study material for students interested in parasite biology. Users can search the database at various taxonomic levels (phylum, class, order, superfamily, family, genus, and species), or by host, habitat and geographical location. Specimen collection locations are noted as co-ordinates in a MySQL database and can be viewed on Google maps, using Google Maps JavaScript API v3. The NEIHPID database has been made freely available at http://nepiac.nehu.ac.in/index.php PMID:27285615

Helminth.net: expansions to Nematode.net and an introduction to Trematode.net

PubMed Central

Martin, John; Rosa, Bruce A.; Ozersky, Philip; Hallsworth-Pepin, Kymberlie; Zhang, Xu; Bhonagiri-Palsikar, Veena; Tyagi, Rahul; Wang, Qi; Choi, Young-Jun; Gao, Xin; McNulty, Samantha N.; Brindley, Paul J.; Mitreva, Makedonka

2015-01-01

Helminth.net (http://www.helminth.net) is the new moniker for a collection of databases: Nematode.net and Trematode.net. Within this collection we provide services and resources for parasitic roundworms (nematodes) and flatworms (trematodes), collectively known as helminths. For over a decade we have provided resources for studying nematodes via our veteran site Nematode.net (http://nematode.net). In this article, (i) we provide an update on the expansions of Nematode.net that hosts omics data from 84 species and provides advanced search tools to the broad scientific community so that data can be mined in a useful and user-friendly manner and (ii) we introduce Trematode.net, a site dedicated to the dissemination of data from flukes, flatworm parasites of the class Trematoda, phylum Platyhelminthes. Trematode.net is an independent component of Helminth.net and currently hosts data from 16 species, with information ranging from genomic, functional genomic data, enzymatic pathway utilization to microbiome changes associated with helminth infections. The databases’ interface, with a sophisticated query engine as a backbone, is intended to allow users to search for multi-factorial combinations of species’ omics properties. This report describes updates to Nematode.net since its last description in NAR, 2012, and also introduces and presents its new sibling site, Trematode.net. PMID:25392426

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

PubMed Central

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

2017-01-01

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

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

PubMed

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

2007-12-01

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

Giant worms chez moi! Hammerhead flatworms (Platyhelminthes, Geoplanidae, Bipalium spp., Diversibipalium spp.) in metropolitan France and overseas French territories

PubMed Central

Winsor, Leigh; Gey, Delphine; Gros, Pierre; Thévenot, Jessica

2018-01-01

Background Species of the genera Bipalium and Diversibipalium, or bipaliines, are giants among land planarians (family Geoplanidae), reaching length of 1 m; they are also easily distinguished from other land flatworms by the characteristic hammer shape of their head. Bipaliines, which have their origin in warm parts of Asia, are invasive species, now widespread worldwide. However, the scientific literature is very scarce about the widespread repartition of these species, and their invasion in European countries has not been studied. Methods In this paper, on the basis of a four year survey based on citizen science, which yielded observations from 1999 to 2017 and a total of 111 records, we provide information about the five species present in Metropolitan France and French overseas territories. We also investigated the molecular variability of cytochrome-oxidase 1 (COI) sequences of specimens. Results Three species are reported from Metropolitan France: Bipalium kewense, Diversibipalium multilineatum, and an unnamed Diversibipalium ‘black’ species. We also report the presence of B. kewense from overseas territories, such as French Polynesia (Oceania), French Guiana (South America), the Caribbean French islands of Martinique, Guadeloupe, Saint Martin and Saint Barthélemy, and Montserrat (Central America), and La Réunion island (off South-East Africa). For B. vagum, observations include French Guiana, Guadeloupe, Martinique, Saint Barthélemy, Saint Martin, Montserrat, La Réunion, and Florida (USA). A probable new species, Diversibipalium sp. ‘blue,’ is reported from Mayotte Island (off South–East Africa). B. kewense, B. vagum and D. multilineatum each showed 0% variability in their COI sequences, whatever their origin, suggesting that the specimens are clonal, and that sexual reproduction is probably absent. COI barcoding was efficient in identifying species, with differences over 10% between species; this suggests that barcoding can be used in the future for identifying these invasive species. In Metropolitan south–west France, a small area located in the Department of Pyrénées-Atlantiques was found to be a hot-spot of bipaliine biodiversity and abundance for more than 20 years, probably because of the local mild weather. Discussion The present findings strongly suggest that the species present in Metropolitan France and overseas territories should be considered invasive alien species. Our numerous records in the open in Metropolitan France raise questions: as scientists, we were amazed that these long and brightly coloured worms could escape the attention of scientists and authorities in a European developed country for such a long time; improved awareness about land planarians is certainly necessary. PMID:29844951

A new species of Temnocephala (Platyhelminthes) with an unusual pharynx, including an amendment of the diagnosis of the genus.

PubMed

De leÓn, Rodrigo Ponce; Volonterio, Odile

2018-02-08

Three species of Temnocephala have been reported on Aegla from Uruguay: Temnocephala axenos, Temnocephala mertoni and Temnocephala talicei. As part of a systematic review of the Uruguayan species of Temnocephala, a fourth species was found on Aegla platensis and Aegla uruguayana. This species, new for the genus, has the following diagnostic characters: Large temnocephalan; slightly curved penial stylet (225 µm in length) with a symmetrical introvert (27 long by 18 µm in diameter) that has at least 44 spine-like projections, each bearing 7 rows of internal spines; a seminal vesicle that opens sub-polarly into the contractile vesicle; a muscular vagina with a strong asymmetrical sphincter; preequatorial nephridiopores close to the internal borders of the elongate-oval excretory syncytia; a large pharynx with anterior and posterior sphincters of about the same diameter and a narrow pharyngeal lumen with nearly uniform width. To contemplate the characters of the pharynx, an amendment of the genus Temnocephala is given. The new species resembles Temnocephala cyanoglandula, which also has a very long, slightly curved penial stylet, but differs from it by having a shorter penial stylet, a lower number of rows of spines in the introvert, a larger, different type of pharynx, a smaller contractile vesicle and a larger sucker. The new species is carnivorous and feeds on whole preys, which are mainly annelids (Stratiodrilus) and other species of Temnocephala. The new species was found to be hyperparasitised by plerocercoid and nematode larvae, but hyperparasites were not found in the other sympatric species of Temnocephala. Based on the findings presented here, it is clear that detailed histological descriptions of the pharynx should be contemplated as part of the normal work in taxonomy of temnocephalans.

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

PubMed

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

2014-08-01

Tapeworms of the order Spathebothriidea Wardle et McLeod, 1952 (Cestoda) are reviewed. Molecular data made it possible to assess, for the first time, the phylogenetic relationships of all genera and to confirm the validity of Bothrimonus Duvernoy, 1842, Diplocotyle Krabbe, 1874 and Didymobothrium Nybelin, 1922. A survey of all species considered to be valid is provided together with new data on egg and scolex morphology and surface ultrastructure (i.e. microtriches). The peculiar morphology of the members of this group, which is today represented by five effectively monotypic genera whose host associations and geographical distribution show little commonality, indicate that it is a relictual group that was once diverse and widespread. The order potentially represents the earliest branch of true tapeworms (i.e. Eucestoda) among extant forms.

Chromosome Evolution in the Free-Living Flatworms: First Evidence of Intrachromosomal Rearrangements in Karyotype Evolution of Macrostomum lignano (Platyhelminthes, Macrostomida)

PubMed Central

Zadesenets, Kira S.; Ershov, Nikita I.; Berezikov, Eugene; Rubtsov, Nikolay B.

2017-01-01

The free-living flatworm Macrostomum lignano is a hidden tetraploid. Its genome was formed by a recent whole genome duplication followed by chromosome fusions. Its karyotype (2n = 8) consists of a pair of large chromosomes (MLI1), which contain regions of all other chromosomes, and three pairs of small metacentric chromosomes. Comparison of MLI1 with metacentrics was performed by painting with microdissected DNA probes and fluorescent in situ hybridization of unique DNA fragments. Regions of MLI1 homologous to small metacentrics appeared to be contiguous. Besides the loss of DNA repeat clusters (pericentromeric and telomeric repeats and the 5S rDNA cluster) from MLI1, the difference between small metacentrics MLI2 and MLI4 and regions homologous to them in MLI1 were revealed. Abnormal karyotypes found in the inbred DV1/10 subline were analyzed, and structurally rearranged chromosomes were described with the painting technique, suggesting the mechanism of their origin. The revealed chromosomal rearrangements generate additional diversity, opening the way toward massive loss of duplicated genes from a duplicated genome. Our findings suggest that the karyotype of M. lignano is in the early stage of genome diploidization after whole genome duplication, and further studies on M. lignano and closely related species can address many questions about karyotype evolution in animals. PMID:29084138

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

PubMed Central

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

2009-01-01

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

A clustering package for nucleotide sequences using Laplacian Eigenmaps and Gaussian Mixture Model.

PubMed

Bruneau, Marine; Mottet, Thierry; Moulin, Serge; Kerbiriou, Maël; Chouly, Franz; Chretien, Stéphane; Guyeux, Christophe

2018-02-01

In this article, a new Python package for nucleotide sequences clustering is proposed. This package, freely available on-line, implements a Laplacian eigenmap embedding and a Gaussian Mixture Model for DNA clustering. It takes nucleotide sequences as input, and produces the optimal number of clusters along with a relevant visualization. Despite the fact that we did not optimise the computational speed, our method still performs reasonably well in practice. Our focus was mainly on data analytics and accuracy and as a result, our approach outperforms the state of the art, even in the case of divergent sequences. Furthermore, an a priori knowledge on the number of clusters is not required here. For the sake of illustration, this method is applied on a set of 100 DNA sequences taken from the mitochondrially encoded NADH dehydrogenase 3 (ND3) gene, extracted from a collection of Platyhelminthes and Nematoda species. The resulting clusters are tightly consistent with the phylogenetic tree computed using a maximum likelihood approach on gene alignment. They are coherent too with the NCBI taxonomy. Further test results based on synthesized data are then provided, showing that the proposed approach is better able to recover the clusters than the most widely used software, namely Cd-hit-est and BLASTClust. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Evaluation of cystic echinococcosis cases given a histopathologic diagnosis from 2002 to 2007 in Diyarbakir].

PubMed

Ozekinci, Selver; Bakir, Sule; Mizrak, Bülent

2009-01-01

Echinococcosis is a common parasitic disease manifesting as cyst formation in humans and animals, caused by the platyhelminth, Echinococcosis and it is an important health problem in our country. The aim of this study was to acquire knowledge about the topographic features, the prevalence of cystic echinococcosis and to predict its frequency in the Diyarbakir region. From 2005 to 2007, 234 patients who had been given a histopathological diagnosis of cystic echinococcosis were analysed retrospectively. Based on the pathological records age, sex and location of the parasite were evaluated, and if a patient had the parasite in more than one location, it was counted as one. Female patients constituted 60.25% of the cases, and males, 39.74%. The average age of the patients was 27.01 years (28.2 years in females and 25.3 years in males). The most frequent location of echinococcus was in the liver (44.01%), and the second in the lung (31.19%). In general the characteristics of the patients correlated with the characteristics of previous literatures results but the age of the patients when diagnosed was earlier than that previously reported in the literature. Cystic echinococcosis was found to be an important public health problem in Diyarbakir region. For the eradication of echinococcosis it is necessary to get reliable data, and to implement an appropriate eradication program.

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.

Gastrointestinal Parasites of Ecuadorian Mantled Howler Monkeys (Alouatta palliata aequatorialis) Based on Fecal Analysis.

PubMed

Helenbrook, William D; Wade, Susan E; Shields, William M; Stehman, Stephen V; Whipps, Christopher M

2015-06-01

An analysis of gastrointestinal parasites of Ecuadorian mantled howler monkeys, Alouatta palliata aequatorialis, was conducted based on examination of fecal smears, flotations, and sedimentations. At least 1 type of parasite was detected in 97% of the 96 fecal samples screened across 19 howler monkey groups using these techniques. Samples averaged 3.6 parasite species per individual (±1.4 SD). Parasites included species representing genera of 2 apicomplexans: Cyclospora sp. (18% of individual samples) and Isospora sp. (3%); 6 other protozoa: Balantidium sp. (9%), Blastocystis sp. (60%), Chilomastix sp. (4%), Dientamoeba sp. (3%), Entamoeba species (56%), Iodamoeba sp. (5%); 4 nematodes: Enterobius sp. (3%), Capillaria sp. (78%), Strongyloides spp. (88%) which included 2 morphotypes, Trypanoxyuris sp. (12%); and the platyhelminth Controrchis sp. (15%). A statistically significant positive correlation was found between group size and each of 3 different estimators of parasite species richness adjusted for sampling effort (ICE: r(2) = 0.24, P = 0.05; Chao2: r(2) = 0.25, P = 0.05, and Jackknife: r(2) = 0.31, P = 0.03). Two significant associations between co-infecting parasites were identified. Based on the prevalence data, individuals infected with Balantidium sp. were more likely to also be infected with Isospora sp. (χ(2) = 6.02, P = 0.01), while individuals harboring Chilomastix sp. were less likely to have Capillaria sp. present (χ(2) = 4.03, P = 0.04).

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

PubMed

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

2015-11-01

The Macrostomorpha-an early branching and species-rich clade of free-living flatworms-is attracting interest because it contains Macrostomum lignano, a versatile model organism increasingly used in evolutionary, developmental, and molecular biology. We elucidate the macrostomorphan molecular phylogeny inferred from both nuclear (18S and 28S rDNA) and mitochondrial (16S rDNA and COI) marker genes from 40 representatives. Although our phylogeny does not recover the Macrostomorpha as a statistically supported monophyletic grouping, it (i) confirms many taxa previously proposed based on morphological evidence, (ii) permits the first placement of many families and genera, and (iii) reveals a number of unexpected placements. Specifically, Myozona and Bradynectes are outside the three classic families (Macrostomidae, Microstomidae and Dolichomacrostomidae) and the asexually fissioning Myomacrostomum belongs to a new subfamily, the Myozonariinae nov. subfam. (Dolichomacrostomidae), rather than diverging early. While this represents the first evidence for asexuality among the Dolichomacrostomidae, we show that fissioning also occurs in another Myozonariinae, Myozonaria fissipara nov. sp. Together with the placement of the (also fissioning) Microstomidae, namely as the sister taxon of Dolichomacrostomidae, this suggests that fissioning is not basal within the Macrostomorpha, but rather restricted to the new taxon Dolichomicrostomida (Dolichomacrostomidae+Microstomidae). Furthermore, our phylogeny allows new insights into the evolution of the reproductive system, as ancestral state reconstructions reveal convergent evolution of gonads, and male and female genitalia. Finally, the convergent evolution of sperm storage organs in the female genitalia appears to be linked to the widespread occurrence of hypodermic insemination among the Macrostomorpha. Copyright © 2015 Elsevier Inc. All rights reserved.

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

Orally administered Taenia solium Calreticulin prevents experimental intestinal inflammation and is associated with a type 2 immune response

PubMed Central

Cruz-Rivera, Mayra; Diaz-Gandarilla, Jose Alfredo; Flores-Torres, Marco Antonio; Avila, Guillermina; Perfiliev, Maria; Salazar, Ana Maria; Arriaga-Pizano, Lourdes; Ostrosky-Wegman, Patricia; Flisser, Ana

2017-01-01

Intestinal helminth antigens are inducers of type 2 responses and can elicit regulatory immune responses, resulting in dampened inflammation. Several platyhelminth proteins with anti-inflammatory activity have been reported. We have identified, cloned and expressed the Taenia solium calreticulin (rTsCRT) and shown that it predominantly induces a type 2 response characterized by IgG1, IL-4 and IL-5 production in mice. Here, we report the rTsCRT anti-inflammatory activity in a well-known experimental colitis murine model. Mice were orally immunized with purified rTsCRT and colitis was induced with trinitrobenzene sulfonic acid (TNBS). Clinical signs of disease, macroscopic and microscopic tissue inflammation, cytokine production and micronuclei formation, as a marker of genotoxicity, were measured in order to assess the effect of rTsCRT immunization on experimentally induced colitis. rTsCRT administration prior to TNBS instillation significantly reduced the inflammatory parameters, including the acute phase cytokines TNF-α, IL-1β and IL-6. Dampened inflammation was associated with increased local expression of IL-13 and systemic IL-10 and TGF-β production. Genotoxic damage produced by the inflammatory response was also precluded. Our results show that oral treatment with rTsCRT prevents excessive TNBS-induced inflammation in mice and suggest that rTsCRT has immunomodulatory properties associated with the expression of type 2 and regulatory cytokines commonly observed in other helminths. PMID:29036211

Phylogeny and mitochondrial gene order variation in Lophotrochozoa in the light of new mitogenomic data from Nemertea

PubMed Central

Podsiadlowski, Lars; Braband, Anke; Struck, Torsten H; von Döhren, Jörn; Bartolomaeus, Thomas

2009-01-01

Background The new animal phylogeny established several taxa which were not identified by morphological analyses, most prominently the Ecdysozoa (arthropods, roundworms, priapulids and others) and Lophotrochozoa (molluscs, annelids, brachiopods and others). Lophotrochozoan interrelationships are under discussion, e.g. regarding the position of Nemertea (ribbon worms), which were discussed to be sister group to e.g. Mollusca, Brachiozoa or Platyhelminthes. Mitochondrial genomes contributed well with sequence data and gene order characters to the deep metazoan phylogeny debate. Results In this study we present the first complete mitochondrial genome record for a member of the Nemertea, Lineus viridis. Except two trnP and trnT, all genes are located on the same strand. While gene order is most similar to that of the brachiopod Terebratulina retusa, sequence based analyses of mitochondrial genes place nemerteans close to molluscs, phoronids and entoprocts without clear preference for one of these taxa as sister group. Conclusion Almost all recent analyses with large datasets show good support for a taxon comprising Annelida, Mollusca, Brachiopoda, Phoronida and Nemertea. But the relationships among these taxa vary between different studies. The analysis of gene order differences gives evidence for a multiple independent occurrence of a large inversion in the mitochondrial genome of Lophotrochozoa and a re-inversion of the same part in gastropods. We hypothesize that some regions of the genome have a higher chance for intramolecular recombination than others and gene order data have to be analysed carefully to detect convergent rearrangement events. PMID:19660126

An adaptable chromosome preparation methodology for use in invertebrate research organisms.

PubMed

Guo, Longhua; Accorsi, Alice; He, Shuonan; Guerrero-Hernández, Carlos; Sivagnanam, Shamilene; McKinney, Sean; Gibson, Matthew; Sánchez Alvarado, Alejandro

2018-02-26

The ability to efficiently visualize and manipulate chromosomes is fundamental to understanding the genome architecture of organisms. Conventional chromosome preparation protocols developed for mammalian cells and those relying on species-specific conditions are not suitable for many invertebrates. Hence, a simple and inexpensive chromosome preparation protocol, adaptable to multiple invertebrate species, is needed. We optimized a chromosome preparation protocol and applied it to several planarian species (phylum Platyhelminthes), the freshwater apple snail Pomacea canaliculata (phylum Mollusca), and the starlet sea anemone Nematostella vectensis (phylum Cnidaria). We demonstrated that both mitotically active adult tissues and embryos can be used as sources of metaphase chromosomes, expanding the potential use of this technique to invertebrates lacking cell lines and/or with limited access to the complete life cycle. Simple hypotonic treatment with deionized water was sufficient for karyotyping; growing cells in culture was not necessary. The obtained karyotypes allowed the identification of differences in ploidy and chromosome architecture among otherwise morphologically indistinguishable organisms, as in the case of a mixed population of planarians collected in the wild. Furthermore, we showed that in all tested organisms representing three different phyla this protocol could be effectively coupled with downstream applications, such as chromosome fluorescent in situ hybridization. Our simple and inexpensive chromosome preparation protocol can be readily adapted to new invertebrate research organisms to accelerate the discovery of novel genomic patterns across the branches of the tree of life.

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

Increased taxon sampling reveals thousands of hidden orthologs in flatworms

PubMed Central

2017-01-01

Gains and losses shape the gene complement of animal lineages and are a fundamental aspect of genomic evolution. Acquiring a comprehensive view of the evolution of gene repertoires is limited by the intrinsic limitations of common sequence similarity searches and available databases. Thus, a subset of the gene complement of an organism consists of hidden orthologs, i.e., those with no apparent homology to sequenced animal lineages—mistakenly considered new genes—but actually representing rapidly evolving orthologs or undetected paralogs. Here, we describe Leapfrog, a simple automated BLAST pipeline that leverages increased taxon sampling to overcome long evolutionary distances and identify putative hidden orthologs in large transcriptomic databases by transitive homology. As a case study, we used 35 transcriptomes of 29 flatworm lineages to recover 3427 putative hidden orthologs, some unidentified by OrthoFinder and HaMStR, two common orthogroup inference algorithms. Unexpectedly, we do not observe a correlation between the number of putative hidden orthologs in a lineage and its “average” evolutionary rate. Hidden orthologs do not show unusual sequence composition biases that might account for systematic errors in sequence similarity searches. Instead, gene duplication with divergence of one paralog and weak positive selection appear to underlie hidden orthology in Platyhelminthes. By using Leapfrog, we identify key centrosome-related genes and homeodomain classes previously reported as absent in free-living flatworms, e.g., planarians. Altogether, our findings demonstrate that hidden orthologs comprise a significant proportion of the gene repertoire in flatworms, qualifying the impact of gene losses and gains in gene complement evolution. PMID:28400424

Spiralian phylogeny informs the evolution of microscopic lineages.

PubMed

Laumer, Christopher E; Bekkouche, Nicolas; Kerbl, Alexandra; Goetz, Freya; Neves, Ricardo C; Sørensen, Martin V; Kristensen, Reinhardt M; Hejnol, Andreas; Dunn, Casey W; Giribet, Gonzalo; Worsaae, Katrine

2015-08-03

Despite rapid advances in the study of metazoan evolutionary history [1], phylogenomic analyses have so far neglected a number of microscopic lineages that possess a unique combination of characters and are thus informative for our understanding of morphological evolution. Chief among these lineages are the recently described animal groups Micrognathozoa and Loricifera, as well as the two interstitial "Problematica" Diurodrilus and Lobatocerebrum [2]. These genera show a certain resemblance to Annelida in their cuticle and gut [3, 4]; however, both lack primary annelid characters such as segmentation and chaetae [5]. Moreover, they show unique features such as an inverted body-wall musculature or a novel pharyngeal organ. This and their ciliated epidermis have led some to propose relationships with other microscopic spiralians, namely Platyhelminthes, Gastrotricha, and in the case of Diurodrilus, with Micrognathozoa [6, 7]-lineages that are grouped by some analyses into "Platyzoa," a clade whose status remains uncertain [1, 8-11]. Here, we assess the interrelationships among the meiofaunal and macrofaunal members of Spiralia using 402 orthologs mined from genome and transcriptome assemblies of 90 taxa. Lobatocerebrum and Diurodrilus are found to be deeply nested members of Annelida, and unequivocal support is found for Micrognathozoa as the sister group of Rotifera. Analyses using site-heterogeneous substitution models further recover a lophophorate clade and position Loricifera + Priapulida as sister group to the remaining Ecdysozoa. Finally, with several meiofaunal lineages branching off early in the diversification of Spiralia, the emerging concept of a microscopic, acoelomate, direct-developing ancestor of Spiralia is reviewed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Broad Phylogenetic Occurrence of the Oxygen-Binding Hemerythrins in Bilaterians

PubMed Central

Schrago, Carlos G.; Halanych, Kenneth M.

2017-01-01

Abstract Animal tissues need to be properly oxygenated for carrying out catabolic respiration and, as such, natural selection has presumably favored special molecules that can reversibly bind and transport oxygen. Hemoglobins, hemocyanins, and hemerythrins (Hrs) fulfill this role, with Hrs being the least studied. Knowledge of oxygen-binding proteins is crucial for understanding animal physiology. Hr genes are present in the three domains of life, Archaea, Bacteria, and Eukaryota; however, within Animalia, Hrs has been reported only in marine species in six phyla (Annelida, Brachiopoda, Priapulida, Bryozoa, Cnidaria, and Arthropoda). Given this observed Hr distribution, whether all metazoan Hrs share a common origin is circumspect. We investigated Hr diversity and evolution in metazoans, by employing in silico approaches to survey for Hrs from of 120 metazoan transcriptomes and genomes. We found 58 candidate Hr genes actively transcribed in 36 species distributed in 11 animal phyla, with new records in Echinodermata, Hemichordata, Mollusca, Nemertea, Phoronida, and Platyhelminthes. Moreover, we found that “Hrs” reported from Cnidaria and Arthropoda were not consistent with that of other metazoan Hrs. Contrary to previous suggestions that Hr genes were absent in deuterostomes, we find Hr genes present in deuterostomes and were likely present in early bilaterians, but not in nonbilaterian animal lineages. As expected, the Hr gene tree did not mirror metazoan phylogeny, suggesting that Hrs evolutionary history was complex and besides the oxygen carrying capacity, the drivers of Hr evolution may also consist of secondary functional specializations of the proteins, like immunological functions. PMID:29016798

Trematodes with a reproductive division of labour: heterophyids also have a soldier caste and early infections reveal how colonies become structured.

PubMed

Garcia-Vedrenne, Ana E; Quintana, Anastasia C E; DeRogatis, Andrea M; Dover, Christina M; Lopez, Maribel; Kuris, Armand M; Hechinger, Ryan F

2017-01-01

Recent findings have extended the documentation of complex sociality to the Platyhelminthes, describing the existence of a reproductive division of labour involving a soldier caste among the parthenitae of trematode parasites. However, all species examined to date occupy high positions in trematode interspecific dominance hierarchies and belong to two closely related families, the Echinostomatidae and the Philophthalmidae (Superfamily Echinostomatoidea). Further, the two species documented as lacking soldiers also belong to the Echinostomatidae. Here, we examine four species of intermediate dominance, all belonging to the family Heterophyidae (Superfamily Opisthorchioidea): Euhaplorchis californiensis, Phocitremoides ovale, Pygidiopsoides spindalis and Stictodora hancocki, all of which infect the California horn snail, Cerithideopsis californica (=Cerithidea californica). We quantify morphology, distribution and behaviour of rediae from fully developed colonies. We also provide information on colony structure for three developing heterophyid colonies to better understand colony development. We discuss the implications of our findings, particularly with respect to how they suggest alternatives to the conclusions of other researchers concerning the nature of trematode sociality. Our analyses of morphological, distributional and behavioural patterns of developed colonies indicate that these heterophyid trematodes have a non-reproductive caste whose function is defence of the colony from invading trematodes. Hence, a soldier caste occurs for species lower in dominance hierarchies than previously known, and is present in at least two superfamilies of digenean trematodes, suggesting that selection for a soldier caste may be much more common among the Trematoda than previously recognised. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

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

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

Detailed reconstruction of the nervous and muscular system of Lobatocerebridae with an evaluation of its annelid affinity.

PubMed

Kerbl, Alexandra; Bekkouche, Nicolas; Sterrer, Wolfgang; Worsaae, Katrine

2015-12-10

The microscopic worm group Lobatocerebridae has been regarded a 'problematicum', with the systematic relationship being highly debated until a recent phylogenomic study placed them within annelids (Curr Biol 25: 2000-2006, 2015). To date, a morphological comparison with other spiralian taxa lacks detailed information on the nervous and muscular system, which is here presented for Lobatocerebrum riegeri n. sp. based on immunohistochemistry and confocal laser scanning microscopy, supported by TEM and live observations. The musculature is organized as a grid of longitudinal muscles and transverse muscular ring complexes in the trunk. The rostrum is supplied by longitudinal muscles and only a few transverse muscles. The intraepidermal central nervous system consists of a big, multi-lobed brain, nine major nerve bundles extending anteriorly into the rostrum and two lateral and one median cord extending posteriorly to the anus, connected by five commissures. The glandular epidermis has at least three types of mucus secreting glands and one type of adhesive unicellular glands. No exclusive "annelid characters" could be found in the neuromuscular system of Lobatocerebridae, except for perhaps the mid-ventral nerve. However, none of the observed structures disputes its position within this group. The neuromuscular and glandular system of L. riegeri n. sp. shows similarities to those of meiofaunal annelids such as Dinophilidae and Protodrilidae, yet likewise to Gnathostomulida and catenulid Platyhelminthes, all living in the restrictive interstitial environment among sand grains. It therefore suggests an extreme evolutionary plasticity of annelid nervous and muscular architecture, previously regarded as highly conservative organ systems throughout metazoan evolution.

[Regeneration of planarians: experimental object].

PubMed

Sheĭman, 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.

Advanced stages of embryonic development and cotylocidial morphogenesis in the intrauterine eggs of Aspidogaster limacoides Diesing, 1835 (Aspidogastrea), with comments on their phylogenetic implications.

PubMed

Świderski, Zdzisław; Poddubnaya, Larisa G; Gibson, David I; Młocicki, Daniel

2012-06-01

Ultrastructural aspects of the advanced embryonic development and cotylocidial morphogenesis of the aspidogastrean Aspidogaster limacoides are described. The posterior or distal regions of the uterus are filled with eggs containing larvae at advanced stages of morphogenesis and fully-formed cotylocidia. Various stages and organs of this larva are described in detail, including the aspects of the developing and fully-differentiated cotylocidium, the body wall (tegument and musculature), glandular regions and the protonephridial excretory system. Blastomere multiplication by means of mitotic divisions takes place simultaneously with the degeneration or apoptosis of some micromeres; this frequently observed characteristic is compared and discussed in relation to corresponding reports for other neodermatans. During the advanced stages of the embryonic development of A. limacoides, the vitelline syncytium disappears and the size of the embryo increases rapidly. Evident polarization of the differentiating larva was observed; towards one pole of the egg, cytodifferentiation of the mouth, surrounded by the oral sucker and cephalic glands, takes place, whereas, towards the opposite pole, differentiation of the posterior sucker (incipient ventral disc) occurs. The oral and posterior suckers are formed from numerous embryonic cells which have differentiated into myocytes. The central part of the oral sucker undergoes invagination and forms the future pharynx and intestine. Fully-developed cotylocidia of A. limacoides have a neodermatan type of tegument, flame cells and two types of glandular structures. These results suggest a sister relationship between the Aspidogastrea and the Digenea, although the systematic position of aspidogastreans in relation to other platyhelminth taxa remains somewhat equivocal.

Molecular phylogeny of Cyclophyllidea (Cestoda: Eucestoda): an in-silico analysis based on mtCOI gene.

PubMed

Sharma, Sunil; Lyngdoh, Damanbha; Roy, Bishnupada; Tandon, Veena

2016-09-01

Order Cyclophyllidea (of cestode platyhelminths) has a rich diversity of parasites and includes many families and species that are known to cause serious medical condition in humans and domestic and wild animals. Despite various attempts to resolve phylogenetic relationships at the inter-family level, uncertainty remains. In order to add resolution to the existing phylogeny of the order, we generated partial mtCO1 sequences for some commonly occurring cyclophyllidean cestodes and combined them with available sequences from GenBank. Phylogeny was inferred taking a total 83 representative species spanning 8 families using Bayesian analysis. The phylogenetic tree revealed Dilepididae as the most basal taxon and showed early divergence in the phylogenetic tree. Paruterinidae, Taeniidae and Anoplocephalidae showed non-monophyletic assemblage; our result suggests that the family Paruterinidae may represent a polyphyletic group. The diverse family Taeniidae appeared in two separate clades; while one of them included all the members of the genus Echinococcus and also Versteria, the representatives of the genera Taenia and Hydatigera clubbed in the other clade. A close affinity of Dipylidiidae with Taenia and Hydatigera was seen, whereas existence of a close relationship between Mesocestoididae and Echinococcus (of Taeniidae) is also demonstrated. The crown group comprised the families Anoplocephalidae, Davaineidae, Hymenolepididae and Mesocestoididae, and also all species of the genus Echinococcus and Versteria mustelae; monophyly of these families (excepting Anolplocephalidae) and the genus Echinococcus as well as its sister-taxon relation with V. mustelae is also confirmed. Furthermore, non-monophyly of Anoplocephalidae is suggested to be correlated with divergence in the host selection.

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.

Expression and bioactivity of allatostatin-like neuropeptides in helminths.

PubMed

Mousley, Angela; Moffett, Christy L; Duve, Hanne; Thorpe, Alan; Halton, David W; Geary, Timothy G; Thompson, David P; Maule, Aaron G; Marks, Nikki J

2005-12-01

Allatostatins are the largest family of known arthropod neuropeptides. To date more than 150 different arthropod type-A allatostatins have been identified and are characterized by the C-terminal signature, (Y/F)XFG(L/I)amide. Using specific allatostatin antisera, positive immunoreactivity has been identified within the central and peripheral nervous systems of the flatworm (platyhelminth) Procerodes littoralis and the roundworm (nematode) Panagrellus redivivus. Comparative analyses of the allatostatin-like immunoreactivity and that of other known helminth neuropeptides (FMRFamide-like peptides [FLPs]) indicate differences in the distribution of these peptide families. Specific differences in neuropeptide distribution have been noted within the pharyngeal innervation of flatworms and in the cephalic papillary neurons of nematodes. In arthropods, type-A allatostatins have functions that include potent myoactivity. In this study, seven members of the allatostatin superfamily induced concentration-dependent contractions of flatworm muscle fibres. Pharmacological studies indicate that these peptides do not interact with muscle-based FLP receptors. The type-A allatostatins, therefore, represent the second family of neuropeptides that induce muscle contraction in flatworms. Although the majority of arthropod type-A allatostatins examined did not affect the somatic body wall muscle or the ovijector of the pig nematode, Ascaris suum, two type-A allatostatins (GDGRLYAFGLamide and DRLYSFGLamide) exhibited significant inhibitory effects on the A. suum ovijector at 10 microM. These data suggest that allatostatin-like peptides and receptors occur in helminths. Further, although arthropod type-A allatostatins display inter-phyla activities, their receptors are less compelling as potential targets for broad-spectrum parasiticides (endectocides) than FLP receptors.

Increasing diversity of land planarians (Platyhelminthes: Geoplanidae) in the Interior Atlantic Forest with the description of two new species and new records from Argentina.

PubMed

Negrete, Lisandro; Brusa, Francisco

2017-12-04

Here, we describe two new species of land planarians of the genera Pasipha and Imbira from the Atlantic Forest of Argentina: Pasipha quirogai sp. nov. and Imbira negrita sp. nov. Their external features and internal anatomy distinguish them from their congeners. Pasipha quirogai sp. nov. is about 40mm long, characterized by brown beige dorsal pigmentation with a golden yellow median band and thin graphite black para-median stripes, cylindrical pharynx, extrabulbar prostatic vesicle with paired proximal portion, male atrium with small folds in its proximal part, and female canal opening into the dorso-caudal wall of the female atrium. Imbira negrita sp. nov. is about 110mm long, with jet black dorsal pigmentation, pharynx collar-type, short female canal opening in the postero-dorsal portion of the female atrium, and epithelial lining of female atrium with stratified appearance. We also provide exhaustive descriptions of Geoplana quagga, Obama ladislavii, and Paraba multicolor, all recorded for the first time in Argentina, by analysing anatomical features of taxonomic relevance. In addition, we improve the description of G. quagga, mainly regarding the musculature, secretory cells, and the copulatory apparatus.

The systematic position and structure of the genus Leyogonimus Ginetsinskaya, 1948 (Platyhelminthes: Digenea) with comments on the taxonomy of the superfamily Microphalloidea Ward, 1901.

PubMed

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

2017-09-26

The systematic position, phylogenetic relationships and composition of the genus Leyogonimus Ginetsinskaya, 1948 have always been uncertain. In the present study, we investigate the taxonomic position and phylogenetic relationships between the type-species L. polyoon (Linstow, 1887) and L. postgonoporus (Neiland, 1951) (previously classified as Macyella), based on newly obtained partial sequences of the nuclear large ribosomal subunit DNA. To test some of the previously proposed systematic arrangements, we have also sequenced specimens of Stomylotrema vicarium Braun, 1901 and Phaneropsolus sp. Our results clearly demonstrate that both L. polyoon and L. postgonoporus belong to the family Pleurogenidae Looss, 1899 within the superfamily Microphalloidea. Thus, the Leyogonimidae Dollfus, 1951 should be recognized as a synonym of the Pleurogenidae. Leyogonimus polyoon clearly constitutes a separate, sister branch to the clade consisting of Collyricloides massanae Vaucher, 1969 and L. postgonoporus. Based on these results, we resurrect the genus Macyella Neiland, 1951 with type-species M. postgonoporus. Besides, Collyricloides Vaucher, 1968 is synonymized with Macyella resulting in new combination Macyella massanae (Vaucher, 1968) comb. nov. Molecular phylogenetic analysis has demonstrated the lack of a close phylogenetic relationships between Stomylotema vicarium and Leyogonimus previously placed by several authors into the family Stomylotrematidae Poche, 1925. The status of the Phaneropsolidae Mehra, 1935 as independent family was confirmed with the addition of the newly sequenced Phaneropsolus sp. from China.

Development and Evaluation of a Single-Step Duplex PCR for Simultaneous Detection of Fasciola hepatica and Fasciola gigantica (Family Fasciolidae, Class Trematoda, Phylum Platyhelminthes)

PubMed Central

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

2012-01-01

A single-step multiplex PCR (here referred to as a duplex PCR) has been developed for simultaneous detection and diagnosis of Fasciola hepatica and F. gigantica. These species overlap in distribution in many countries of North and East Africa and Central and Southeast Asia and are similar in egg morphology, making identification from fecal samples difficult. Based on a comparative alignment of mitochondrial DNA (mtDNA) spanning the region of cox1-trnT-rrnL, two species-specific forward primers were designed, FHF (for F. hepatica) and FGF (for F. gigantica), and a single reverse primer, FHGR (common for both species). Conventional PCR followed by sequencing was applied using species-specific primer pairs to verify the specificity of primers and the identity of Fasciola DNA templates. Duplex PCR (using three primers) was used for testing with the DNA extracted from adult worms, miracidia, and eggs, producing amplicons of 1,031 bp for F. hepatica and 615 bp for F. gigantica. The duplex PCR failed to amplify from DNA of other common liver and intestinal trematodes, including two opisthorchiids, three heterophyids, an echinostomid, another fasciolid, and a taeniid cestode. The sensitivity assay showed that the duplex PCR limit of detection for each Fasciola species was between 0.012 ng and 0.006 ng DNA. Evaluation using DNA templates from 32 Fasciola samples (28 adults and 4 eggs) and from 25 field-collected stools of ruminants and humans revealed specific bands of the correct size and the presence of Fasciola species. This novel mtDNA duplex PCR is a sensitive and fast tool for accurate identification of Fasciola species in areas of distributional and zonal overlap. PMID:22692744

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

PubMed

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

2012-08-01

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

High-intensity cardiac infections of Phthinomita heinigerae n. sp. (Digenea: Aporocotylidae) in the orangelined cardinalfish, Taeniamia fucata (Cantor), off Heron Island on the Great Barrier Reef.

PubMed

Nolan, Matthew J; Cantacessi, Cinzia; Cutmore, Scott C; Cribb, Thomas H; Miller, Terrence L

2016-10-01

We report a new species of aporocotylid trematode (Platyhelminthes: Digenea) from the heart of the orangelined cardinalfish, Taeniamia fucata (Cantor), from off Heron Island on the southern Great Barrier Reef. We used an integrated approach, analysing host distribution, morphology, and genetic data from the internal transcribed spacer 2 of the ribosomal DNA, to circumscribe Phthinomita heinigerae n. sp. This is the first species of Phthinomita Nolan & Cribb, 2006 reported from the Apogonidae; existing species and known 'types' are recorded from species of the Labridae, Mullidae, and Siganidae. The new species is distinguished from its 11 congeners in having a body 2977-3539 long and 16.5-22.4 times longer than wide, an anterior testis 6.2-8.2 times longer than wide and 8.3-13.0 times longer than the posterior testis, a posterior testis whose width is 35-56% of the body width, and an ovary positioned 11-13% of the body length from the posterior end, and is entirely anterior to the posterior margin of the anterior testis. In addition, 2-34 base differences (0.4-7.0% sequence divergence over 485 base positions) were detected among the ITS2 sequence representing P. heinigerae n. sp. and the 14 representing other Phthinomita species/molecular types. Prevalence and intensity of infection with P. heinigerae n. sp. was relatively high within the heart tissue of T. fucata, with 19 of 20 fish examined from off Heron Island infected (95%) with 7-25 adult worms (arithmetic mean 16.6). Infections by these parasites accounted for an occupation of 7-30% of the total estimated heart volume. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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

PubMed Central

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

2014-01-01

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

EGG-HATCHING MECHANISM OF HUMAN LIVER FLUKE, OPISTHORCHIS VIVERRINI: A ROLE FOR LEUCINE AMINOPEPTIDASES FROM THE SNAIL HOST, BITHYNIA SIAMENSIS GONIOMPHALOS.

PubMed

Tesana, Smarn; Khampoosa, P; Piratae, S; Prasopdee, S; Sripanidkulchai, B

2018-05-08

The human liver fluke Opisthorchis viverrini (Platyhelminthes, Trematoda, Digenea) uses snails of the genus Bithynia as first intermediate host. Peculiarly among trematodes, the eggs of O. viverrini hatch within the digestive tract of its snail host. It remains uncertain whether hatching in this species is mediated through mechanical fracture of the eggshell or by digestion with specific digestive enzymes. This study aimed to characterize enzymes with specific inhibitor and factors involved in the hatching activity of O. viverrini eggs. For measuring egg hatching in vivo, 50 O. viverrini mature eggs were fed to individual Bithynia siamensis goniomphalos snail at various temperature conditions for 24 hrs. Ex vivo, mature eggs were incubated with crude snail extract and commercial leucine aminopeptidase (LAP). Egg-hatching of O. viverrini was temperature dependent, with optimal hatching occurring at 24-28 C, with a peak of hatching of 93.54% in vivo and 30.55% ex vivo occurring at these temperatures. Ex vivo hatching rates increased to 45.87% under anaerobic conditions at 28 C. Some 22.70% and 16.21% of heat-killed eggs also hatched within the snail digestive tract and snail extract, respectively, indicating that host molecules are involved in the hatching response. Most eggs hatch in the anterior regions of the digestive tract. Hatching was completely inhibited in the presence of bestatin, an inhibitor of leucine aminopeptidase (LAP), but not in the presence of phosphatase inhibitors. Bestatin inhibition of hatching was reversible. Finally, egg hatching could be induced by addition of a porcine LAP. The results indicate that this digenean utilizes both LAP of the snail host and movement of miracidia for hatching.

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.

Broad Phylogenetic Occurrence of the Oxygen-Binding Hemerythrins in Bilaterians.

PubMed

Costa-Paiva, Elisa M; Schrago, Carlos G; Halanych, Kenneth M

2017-10-01

Animal tissues need to be properly oxygenated for carrying out catabolic respiration and, as such, natural selection has presumably favored special molecules that can reversibly bind and transport oxygen. Hemoglobins, hemocyanins, and hemerythrins (Hrs) fulfill this role, with Hrs being the least studied. Knowledge of oxygen-binding proteins is crucial for understanding animal physiology. Hr genes are present in the three domains of life, Archaea, Bacteria, and Eukaryota; however, within Animalia, Hrs has been reported only in marine species in six phyla (Annelida, Brachiopoda, Priapulida, Bryozoa, Cnidaria, and Arthropoda). Given this observed Hr distribution, whether all metazoan Hrs share a common origin is circumspect. We investigated Hr diversity and evolution in metazoans, by employing in silico approaches to survey for Hrs from of 120 metazoan transcriptomes and genomes. We found 58 candidate Hr genes actively transcribed in 36 species distributed in 11 animal phyla, with new records in Echinodermata, Hemichordata, Mollusca, Nemertea, Phoronida, and Platyhelminthes. Moreover, we found that "Hrs" reported from Cnidaria and Arthropoda were not consistent with that of other metazoan Hrs. Contrary to previous suggestions that Hr genes were absent in deuterostomes, we find Hr genes present in deuterostomes and were likely present in early bilaterians, but not in nonbilaterian animal lineages. As expected, the Hr gene tree did not mirror metazoan phylogeny, suggesting that Hrs evolutionary history was complex and besides the oxygen carrying capacity, the drivers of Hr evolution may also consist of secondary functional specializations of the proteins, like immunological functions. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

[Ultrastructure of nephridial systems in cyclophyllidean cestoda: Catenotaenia pusilla (Goeze, 1782), Hymenolepis diminuta (Rudolphi, 1819) and Inermicapsifer madagascariensis (Davaine, 1870) Baer, 1956].

PubMed

Swiderski, Z; Euzet, L; Schönenberger, N

1975-01-01

Electron microscopic study of nephridial systems in three cyclophyllidean cestodes indicates a resemblance in their ultrastructure. The walls of longitudinal, transverse and collecting ducts show a very similar pattern of organization. The surface of the anucleate epithelium lining the ducts is developed into microvilli. A relatively thick layer of fibrillar tissue underlies the basal membrane of the microvillar epithelium. The nucleated portions or "pericaryons", situated between the parenchymal cells, are directly connected with epithelium by cytoplasmic prolongations. The canalicular lumen extends through a single series of cells curved into a ring. The epithelial surface of the canalicular wall is developed into short, densly staining microvilli and the immediately underlying fibrillar tissue appears very compact. The cilia were never observed in any of the above ducts. The ultrastructure of protonephridia proper is comparable with those already described in other cestodes. There is a close association between the flame-cell and the cancalicular ending, enlarged into a nephridial funnel. A single row of nephridial rods of the flame-cell is surrounded by a row of digitiform prolongations of the nephridial funnel border. The prolongations alternate with the rods and their interlocking pattern appears clearly in cross-sections. A series of minute pores or "nephrostomes" providing a direct contact between the nephridial chamber and intercellular space of the paranchyma was shown. The problem of classification and definition between the "closed" protonephridia and open metanephridia is discussed. The structural unity of protonephridia in different groupes of Platyhelminthes is reviewed. The different number of flagella within the "flames" of different cestodes is compared and analyzed. The ultrastructural characteristics of duct-wall epithelium provides some confirmation of its high metabolic activity.

Genome-Wide Transcriptome Analysis Reveals Extensive Alternative Splicing Events in the Protoscoleces of Echinococcus granulosus and Echinococcus multilocularis

PubMed Central

Liu, Shuai; Zhou, Xiaosu; Hao, Lili; Piao, Xianyu; Hou, Nan; Chen, Qijun

2017-01-01

Alternative splicing (AS), as one of the most important topics in the post-genomic era, has been extensively studied in numerous organisms. However, little is known about the prevalence and characteristics of AS in Echinococcus species, which can cause significant health problems to humans and domestic animals. Based on high-throughput RNA-sequencing data, we performed a genome-wide survey of AS in two major pathogens of echinococcosis-Echinococcus granulosus and Echinococcus multilocularis. Our study revealed that the prevalence and characteristics of AS in protoscoleces of the two parasites were generally consistent with each other. A total of 6,826 AS events from 3,774 E. granulosus genes and 6,644 AS events from 3,611 E. multilocularis genes were identified in protoscolex transcriptomes, indicating that 33–36% of genes were subject to AS in the two parasites. Strikingly, intron retention instead of exon skipping was the predominant type of AS in Echinococcus species. Moreover, analysis of the Kyoto Encyclopedia of Genes and Genomes pathway indicated that genes that underwent AS events were significantly enriched in multiple pathways mainly related to metabolism (e.g., purine, fatty acid, galactose, and glycerolipid metabolism), signal transduction (e.g., Jak-STAT, VEGF, Notch, and GnRH signaling pathways), and genetic information processing (e.g., RNA transport and mRNA surveillance pathways). The landscape of AS obtained in this study will not only facilitate future investigations on transcriptome complexity and AS regulation during the life cycle of Echinococcus species, but also provide an invaluable resource for future functional and evolutionary studies of AS in platyhelminth parasites. PMID:28588571

RNA-Seq Reveals Infection-Induced Gene Expression Changes in the Snail Intermediate Host of the Carcinogenic Liver Fluke, Opisthorchis viverrini

PubMed Central

Prasopdee, Sattrachai; Sotillo, Javier; Tesana, Smarn; Laha, Thewarach; Kulsantiwong, Jutharat; Nolan, Matthew J.

2014-01-01

platyhelminths including schistosomes. PMID:24676090

The Unique Morgue Ubiquitination Protein Is Conserved in a Diverse but Restricted Set of Invertebrates

PubMed Central

Zhou, Ying; Carpenter, Zachary W.; Brennan, Gregory

2009-01-01

Drosophila Morgue is a unique ubiquitination protein that facilitates programmed cell death and associates with DIAP1, a critical cell death inhibitor with E3 ubiquitin ligase activity. Morgue possesses a unique combination of functional domains typically associated with distinct types of ubiquitination enzymes. This includes an F box characteristic of the substrate-binding subunit in Skp, Cullin, and F box (SCF)-type ubiquitin E3 ligase complexes and a variant ubiquitin E2 conjugase domain where the active site cysteine is replaced by a glycine. Morgue also contains a single C4-type zinc finger motif. This architecture suggests potentially novel ubiquitination activities for Morgue. In this study, we address the evolutionary origins of this distinctive protein utilizing a combination of bioinformatics and molecular biology approaches. We find that Morgue exhibits widespread but restricted phylogenetic distribution among metazoans. Morgue proteins were identified in a wide range of Protostome phyla, including Arthropoda, Annelida, Mollusca, Nematoda, and Platyhelminthes. However, with one potential exception, Morgue was not detected in Deuterostomes, including Chordates, Hemichordates, or Echinoderms. Morgue was also not found in Ctenophora, Cnidaria, Placozoa, or Porifera. Characterization of Morgue sequences within specific animal lineages suggests that gene deletion or acquisition has occurred during divergence of nematodes and that at least one arachnid expresses an atypical form of Morgue consisting only of the variant E2 conjugase domain. Analysis of the organization of several morgue genes suggests that exon-shuffling events have contributed to the evolution of the Morgue protein. These results suggest that Morgue mediates conserved and distinctive ubiquitination functions in specific cell death pathways. PMID:19602541

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

PubMed

Meini, Gianluca

2015-04-16

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

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

PubMed

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

2016-01-01

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

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

PubMed Central

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

2016-01-01

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

Real-time PCR detection and phylogenetic relationships of Neorickettsia spp. in digeneans from Egypt, Philippines, Thailand, Vietnam and the United States.

PubMed

Greiman, Stephen E; Vaughan, Jefferson A; Elmahy, Rasha; Adisakwattana, Poom; Van Ha, Nguyen; Fayton, Thomas J; Khalil, Amal I; Tkach, Vasyl V

2017-02-01

Neorickettsia (Rickettsiales, Anaplasmataceae) is a genus of obligate intracellular bacterial endosymbionts of digeneans (Platyhelminthes, Digenea). Some Neorickettsia are able to invade cells of the digenean's vertebrate host and are known to cause diseases of domestic animals, wildlife, and humans. In this study we report the results of screening digenean samples for Neorickettsia collected from bats in Egypt and Mindoro Island, Philippines, snails and fishes from Thailand, and fishes from Vietnam and the USA. Neorickettsia were detected using a real-time PCR protocol targeting a 152bp fragment of the heat shock protein coding gene, GroEL, and verified with nested PCR and sequencing of a 1853bp long region of the GroESL operon and a 1371bp long region of 16S rRNA. Eight unique genotypes of Neorickettsia were obtained from digenean samples. Neorickettsia sp. 8 obtained from Lecithodendrium sp. from Egypt; Neorickettsia sp. 9 and 10 obtained from two species of Paralecithodendrium from Mindoro, Philippines; Neorickettsia sp. 11 from Lecithodendrium sp. and Neorickettsia sp. 4 (previously identified from Saccocoelioides lizae, from China) from Thailand; Neorickettsia sp. 12 from Dicrogaster sp. Florida, USA; Neorickettsia sp. 13 and SF agent from Vietnam. Sequence comparison and phylogenetic analysis demonstrated that the forms, provisionally named Neorickettsia sp. 8-13, represent new genotypes. We have for the first time detected Neorickettsia in a digenean from Egypt (and the African continent as a whole), the Philippines, Thailand and Vietnam based on PCR and sequencing evidence. Our findings suggest that further surveys from the African continent, SE Asia, and island countries are likely to reveal new Neorickettsia lineages as well as new digenean host associations. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Genomes of Fasciola hepatica from the Americas Reveal Colonization with Neorickettsia Endobacteria Related to the Agents of Potomac Horse and Human Sennetsu Fevers.

PubMed

McNulty, Samantha N; Tort, Jose F; Rinaldi, Gabriel; Fischer, Kerstin; Rosa, Bruce A; Smircich, Pablo; Fontenla, Santiago; Choi, Young-Jun; Tyagi, Rahul; Hallsworth-Pepin, Kymberlie; Mann, Victoria H; Kammili, Lakshmi; Latham, Patricia S; Dell'Oca, Nicolas; Dominguez, Fernanda; Carmona, Carlos; Fischer, Peter U; Brindley, Paul J; Mitreva, Makedonka

2017-01-01

Food borne trematodes (FBTs) are an assemblage of platyhelminth parasites transmitted through the food chain, four of which are recognized as neglected tropical diseases (NTDs). Fascioliasis stands out among the other NTDs due to its broad and significant impact on both human and animal health, as Fasciola sp., are also considered major pathogens of domesticated ruminants. Here we present a reference genome sequence of the common liver fluke, Fasciola hepatica isolated from sheep, complementing previously reported isolate from cattle. A total of 14,642 genes were predicted from the 1.14 GB genome of the liver fluke. Comparative genomics indicated that F. hepatica Oregon and related food-borne trematodes are metabolically less constrained than schistosomes and cestodes, taking advantage of the richer millieux offered by the hepatobiliary organs. Protease families differentially expanded between diverse trematodes may facilitate migration and survival within the heterogeneous environments and niches within the mammalian host. Surprisingly, the sequencing of Oregon and Uruguay F. hepatica isolates led to the first discovery of an endobacteria in this species. Two contigs from the F. hepatica Oregon assembly were joined to complete the 859,205 bp genome of a novel Neorickettsia endobacterium (nFh) closely related to the etiological agents of human Sennetsu and Potomac horse fevers. Immunohistochemical studies targeting a Neorickettsia surface protein found nFh in specific organs and tissues of the adult trematode including the female reproductive tract, eggs, the Mehlis' gland, seminal vesicle, and oral suckers, suggesting putative routes for fluke-to-fluke and fluke-to-host transmission. The genomes of F. hepatica and nFh will serve as a resource for further exploration of the biology of F. hepatica, and specifically its newly discovered trans-kingdom interaction with nFh and the impact of both species on disease in ruminants and humans.

Genomes of Fasciola hepatica from the Americas Reveal Colonization with Neorickettsia Endobacteria Related to the Agents of Potomac Horse and Human Sennetsu Fevers

PubMed Central

McNulty, Samantha N.; Rosa, Bruce A.; Fontenla, Santiago; Choi, Young-Jun; Hallsworth-Pepin, Kymberlie; Kammili, Lakshmi; Latham, Patricia S.; Dell’Oca, Nicolas; Dominguez, Fernanda; Carmona, Carlos; Fischer, Peter U.; Mitreva, Makedonka

2017-01-01

Food borne trematodes (FBTs) are an assemblage of platyhelminth parasites transmitted through the food chain, four of which are recognized as neglected tropical diseases (NTDs). Fascioliasis stands out among the other NTDs due to its broad and significant impact on both human and animal health, as Fasciola sp., are also considered major pathogens of domesticated ruminants. Here we present a reference genome sequence of the common liver fluke, Fasciola hepatica isolated from sheep, complementing previously reported isolate from cattle. A total of 14,642 genes were predicted from the 1.14 GB genome of the liver fluke. Comparative genomics indicated that F. hepatica Oregon and related food-borne trematodes are metabolically less constrained than schistosomes and cestodes, taking advantage of the richer millieux offered by the hepatobiliary organs. Protease families differentially expanded between diverse trematodes may facilitate migration and survival within the heterogeneous environments and niches within the mammalian host. Surprisingly, the sequencing of Oregon and Uruguay F. hepatica isolates led to the first discovery of an endobacteria in this species. Two contigs from the F. hepatica Oregon assembly were joined to complete the 859,205 bp genome of a novel Neorickettsia endobacterium (nFh) closely related to the etiological agents of human Sennetsu and Potomac horse fevers. Immunohistochemical studies targeting a Neorickettsia surface protein found nFh in specific organs and tissues of the adult trematode including the female reproductive tract, eggs, the Mehlis’ gland, seminal vesicle, and oral suckers, suggesting putative routes for fluke-to-fluke and fluke-to-host transmission. The genomes of F. hepatica and nFh will serve as a resource for further exploration of the biology of F. hepatica, and specifically its newly discovered trans-kingdom interaction with nFh and the impact of both species on disease in ruminants and humans. PMID:28060841

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

Conservation and diversification of Msx protein in metazoan evolution.

PubMed

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

2008-01-01

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 position of the intron located N-terminally to the HDs was widely conserved in all the genes examined, including those of cnidarians. Amino acid (aa) sequence comparison revealed 3 new evolutionarily conserved domains, as well as very strong conservation of the HDs. Two of the three domains were associated with Groucho-like protein binding in both a vertebrate and a cnidarian Msx homolog, suggesting that the interaction between Groucho-like proteins and Msx proteins was established in eumetazoan ancestors. Pairwise comparison among the collected HDs and their C-flanking aa sequences revealed that the degree of sequence conservation varied depending on the animal taxa from which the sequences were derived. Highly conserved Msx genes were identified in the Vertebrata, Cephalochordata, Hemichordata, Echinodermata, Mollusca, Brachiopoda, and Anthozoa. The wide distribution of the conserved sequences in the animal phylogenetic tree suggested that metazoan ancestors had already acquired a set of conserved domains of the current Msx family genes. Interestingly, although strongly conserved sequences were recovered from the Vertebrata, Cephalochordata, and Anthozoa, the sequences from the Urochordata and Hydrozoa showed weak conservation. Because the Vertebrata-Cephalochordata-Urochordata and Anthozoa-Hydrozoa represent sister groups in the Chordata and Cnidaria, respectively, Msx sequence diversification may have occurred differentially in the course of evolution. We speculate that selective loss of the conserved domains in Msx family

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.

Chromosome numbers in three species groups of freshwater flatworms increase with increasing latitude.

PubMed

Lorch, Sven; Zeuss, Dirk; Brandl, Roland; Brändle, Martin

2016-03-01

Polyploidy in combination with parthenogenesis offers advantages for plasticity and the evolution of a broad ecological tolerance of species. Therefore, a positive correlation between the level of ploidy and increasing latitude as a surrogate for environmental harshness has been suggested. Such a positive correlation is well documented for plants, but examples for animals are still rare. Species of flatworms (Platyhelminthes) are widely distributed, show a remarkably wide range of chromosome numbers, and offer therefore good model systems to study the geographical distribution of chromosome numbers. We analyzed published data on counts of chromosome numbers and geographical information of three flatworm "species" (Phagocata vitta, Polycelis felina and Crenobia alpina) sampled across Europe (220 populations). We used the mean chromosome number across individuals of a population as a proxy for the level of ploidy within populations, and we tested for relationships of this variable with latitude, mode of reproduction (sexual, asexual or both) and environmental variables (annual mean temperature, mean diurnal temperature range, mean precipitation and net primary production). The mean chromosome numbers of all three species increased with latitude and decreased with mean annual temperature. For two species, chromosome number also decreased with mean precipitation and net primary production. Furthermore, high chromosome numbers within species were accompanied with a loss of sexual reproduction. The variation of chromosome numbers within individuals of two of the three species increased with latitude. Our results support the hypothesis that polyploid lineages are able to cope with harsh climatic conditions at high latitudes. Furthermore, we propose that asexual reproduction in populations with high levels of polyploidization stabilizes hybridization events. Chromosomal irregularities within individuals tend to become more frequent at the extreme environments of high

Hox genes and the parasitic flatworms: new opportunities, challenges and lessons from the free-living.

PubMed

Olson, P D

2008-03-01

Research into the roles played by Hox and related homeotic gene families in the diverse and complex developmental programmes exhibited by parasitic flatworms (Platyhelminthes) can hardly be said to have begun, and thus presents considerable opportunity for new research. Although featured in some of the earliest screens for homeotic genes outside Drosophila and mice, surveys in parasitic flatworms are few in number and almost nothing is yet known of where or when the genes are expressed during ontogeny. This contrasts sharply with a significant body of literature concerning Hox genes in free-living flatworms which have long served as models for the study of regeneration and the maintenance of omnipotent cell lines. Nevertheless, available information suggests that the complement of Hox genes and other classes of homeobox-containing genes in parasitic flatworms is typical of their free-living cousins and of other members of the Lophotrochozoa. Recent work on Schistosoma combined with information on Hox gene expression in planarians indicates that at least some disruption of the clustered genomic arrangement of the genes, as well as of the strict spatial and temporal colinear patterns of expression typical in other groups, may be characteristic of flatworms. However, available data on the genomic arrangement and expression of flatworm Hox genes is so limited at present that such generalities are highly tenuous. Moreover, a basic underlying pattern of colinearity is still observed in their spatial expression patterns making them suitable as cell or region-specific markers. I discuss a number of fundamental developmental questions and some of the challenges to addressing them in relation to each of the major parasitic lineages. In addition, I present newly characterized Hox genes from the model tapeworm Hymenolepis and analyze these by Bayesian inference together with >100 Hox and ParaHox homeodomains of flatworms and select lophotrochozoan taxa, providing a

Patterns of Diversity in Soft-Bodied Meiofauna: Dispersal Ability and Body Size Matter

PubMed Central

Curini-Galletti, Marco; Artois, Tom; Delogu, Valentina; De Smet, Willem H.; Fontaneto, Diego; Jondelius, Ulf; Leasi, Francesca; Martínez, Alejandro; Meyer-Wachsmuth, Inga; Nilsson, Karin Sara; Tongiorgi, Paolo; Worsaae, Katrine; Todaro, M. Antonio

2012-01-01

Background Biogeographical and macroecological principles are derived from patterns of distribution in large organisms, whereas microscopic ones have often been considered uninteresting, because of their supposed wide distribution. Here, after reporting the results of an intensive faunistic survey of marine microscopic animals (meiofauna) in Northern Sardinia, we test for the effect of body size, dispersal ability, and habitat features on the patterns of distribution of several groups. Methodology/Principal Findings As a dataset we use the results of a workshop held at La Maddalena (Sardinia, Italy) in September 2010, aimed at studying selected taxa of soft-bodied meiofauna (Acoela, Annelida, Gastrotricha, Nemertodermatida, Platyhelminthes and Rotifera), in conjunction with data on the same taxa obtained during a previous workshop hosted at Tjärnö (Western Sweden) in September 2007. Using linear mixed effects models and model averaging while accounting for sampling bias and potential pseudoreplication, we found evidence that: (1) meiofaunal groups with more restricted distribution are the ones with low dispersal potential; (2) meiofaunal groups with higher probability of finding new species for science are the ones with low dispersal potential; (3) the proportion of the global species pool of each meiofaunal group present in each area at the regional scale is negatively related to body size, and positively related to their occurrence in the endobenthic habitat. Conclusion/Significance Our macroecological analysis of meiofauna, in the framework of the ubiquity hypothesis for microscopic organisms, indicates that not only body size but mostly dispersal ability and also occurrence in the endobenthic habitat are important correlates of diversity for these understudied animals, with different importance at different spatial scales. Furthermore, since the Western Mediterranean is one of the best-studied areas in the world, the large number of undescribed species (37

Patterns of diversity in soft-bodied meiofauna: dispersal ability and body size matter.

PubMed

Curini-Galletti, Marco; Artois, Tom; Delogu, Valentina; De Smet, Willem H; Fontaneto, Diego; Jondelius, Ulf; Leasi, Francesca; Martínez, Alejandro; Meyer-Wachsmuth, Inga; Nilsson, Karin Sara; Tongiorgi, Paolo; Worsaae, Katrine; Todaro, M Antonio

2012-01-01

Biogeographical and macroecological principles are derived from patterns of distribution in large organisms, whereas microscopic ones have often been considered uninteresting, because of their supposed wide distribution. Here, after reporting the results of an intensive faunistic survey of marine microscopic animals (meiofauna) in Northern Sardinia, we test for the effect of body size, dispersal ability, and habitat features on the patterns of distribution of several groups. As a dataset we use the results of a workshop held at La Maddalena (Sardinia, Italy) in September 2010, aimed at studying selected taxa of soft-bodied meiofauna (Acoela, Annelida, Gastrotricha, Nemertodermatida, Platyhelminthes and Rotifera), in conjunction with data on the same taxa obtained during a previous workshop hosted at Tjärnö (Western Sweden) in September 2007. Using linear mixed effects models and model averaging while accounting for sampling bias and potential pseudoreplication, we found evidence that: (1) meiofaunal groups with more restricted distribution are the ones with low dispersal potential; (2) meiofaunal groups with higher probability of finding new species for science are the ones with low dispersal potential; (3) the proportion of the global species pool of each meiofaunal group present in each area at the regional scale is negatively related to body size, and positively related to their occurrence in the endobenthic habitat. Our macroecological analysis of meiofauna, in the framework of the ubiquity hypothesis for microscopic organisms, indicates that not only body size but mostly dispersal ability and also occurrence in the endobenthic habitat are important correlates of diversity for these understudied animals, with different importance at different spatial scales. Furthermore, since the Western Mediterranean is one of the best-studied areas in the world, the large number of undescribed species (37%) highlights that the census of marine meiofauna is still very far

Automated identification of Monogeneans using digital image processing and K-nearest neighbour approaches.

PubMed

Yousef Kalafi, Elham; Tan, Wooi Boon; Town, Christopher; Dhillon, Sarinder Kaur

2016-12-22

Monogeneans are flatworms (Platyhelminthes) that are primarily found on gills and skin of fishes. Monogenean parasites have attachment appendages at their haptoral regions that help them to move about the body surface and feed on skin and gill debris. Haptoral attachment organs consist of sclerotized hard parts such as hooks, anchors and marginal hooks. Monogenean species are differentiated based on their haptoral bars, anchors, marginal hooks, reproductive parts' (male and female copulatory organs) morphological characters and soft anatomical parts. The complex structure of these diagnostic organs and also their overlapping in microscopic digital images are impediments for developing fully automated identification system for monogeneans (LNCS 7666:256-263, 2012), (ISDA; 457-462, 2011), (J Zoolog Syst Evol Res 52(2): 95-99. 2013;). In this study images of hard parts of the haptoral organs such as bars and anchors are used to develop a fully automated identification technique for monogenean species identification by implementing image processing techniques and machine learning methods. Images of four monogenean species namely Sinodiplectanotrema malayanus, Trianchoratus pahangensis, Metahaliotrema mizellei and Metahaliotrema sp. (undescribed) were used to develop an automated technique for identification. K-nearest neighbour (KNN) was applied to classify the monogenean specimens based on the extracted features. 50% of the dataset was used for training and the other 50% was used as testing for system evaluation. Our approach demonstrated overall classification accuracy of 90%. In this study Leave One Out (LOO) cross validation is used for validation of our system and the accuracy is 91.25%. The methods presented in this study facilitate fast and accurate fully automated classification of monogeneans at the species level. In future studies more classes will be included in the model, the time to capture the monogenean images will be reduced and improvements in

Purification and characterization of two-domain glutaredoxin in the parasitic helminth Fasciola gigantica.

PubMed

Gupta, Ankita; Sripa, Banchob; Tripathi, Timir

2017-08-01

Glutaredoxins (Grxs) are small thiol-dependent proteins and key elements of redox signaling as they regulate the redox state of important cellular proteins. In the present study, the complete sequence of a glutaredoxin protein, obtained from the liver fluke Fasciola gigantica, was PCR-amplified and cloned. The 690-bp open reading frame (ORF) encodes a 230-amino acid protein with two conserved domains (FgGrxD1 and FgGrxD2) and has similarities with two monothiol Grxs of Saccharomyces cerevisiae, i.e., ScGrx3 and ScGrx4. The full-length FgGrx along with its two constituent domains were overexpressed in Escherichia coli as hexahistidyl-tagged proteins. The affinity chromatography resulted in almost pure and soluble proteins. The full-length FgGrx and the FgGrxD2 showed reddish-brown color, indicating the presence of bound iron in the second domain. In the insulin based reduction assay, both FgGrx and FgGrxD2 containing the active site motif CGFS exhibited a weak reducing activity, whereas FgGrxD1 was inactive. Additionally, FgGrx did not show any GSH-disulfide transhydrogenase activity when 2-hydroxyethyl disulfide (HED) or de-hydroascorbate (DHA) were taken as substrates. These results indicated the probable role of FgGrx in cellular iron-sulfur homeostasis. FgGrx was found to be reversibly S-glutathionylated, suggesting a potential redox regulation that is likely to take place at the active site Cys158. Since there is only one Cys in FgGrxD2, the Cys158 might be involved in FeS binding. This study is the first report on the presence of Grx in platyhelminthic parasites and provides a starting point for further characterization of the redox network in liver flukes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Molecular characterization of Fasciola gigantica from Mauritania based on mitochondrial and nuclear ribosomal DNA sequences.

PubMed

Amor, Nabil; Farjallah, Sarra; Salem, Mohamed; Lamine, Dia Mamadou; Merella, Paolo; Said, Khaled; Ben Slimane, Badreddine

2011-10-01

Fasciolosis caused by Fasciola hepatica and Fasciola gigantica (Platyhelminthes: Trematoda: Digenea) is considered the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. From Africa, F. gigantica has been previously characterized from Burkina Faso, Senegal, Kenya, Zambia and Mali, while F. hepatica has been reported from Morocco and Tunisia, and both species have been observed from Ethiopia and Egypt on the basis of morphometric differences, while the use of molecular markers is necessary to distinguish exactly between species. Samples identified morphologically as F. gigantica (n=60) from sheep and cattle from different geographical localities of Mauritania were genetically characterized by sequences of the first (ITS-1), the 5.8S, and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA) genes and the mitochondrial Cytochrome c Oxidase I (COI) gene. Comparison of the sequences of the Mauritanian samples with sequences of Fasciola spp. from GenBank confirmed that all samples belong to the species F. gigantica. The nucleotide sequencing of ITS rDNA of F. gigantica showed no nucleotide variation in the ITS-1, 5.8S, and ITS-2 rDNA sequences among all samples examined and those from Burkina Faso, Kenya, Egypt and Iran. The phylogenetic trees based on the ITS-1 and ITS-2 sequences showed a close relationship of the Mauritanian samples with isolates of F. gigantica from different localities of Africa and Asia. The COI genotypes of the Mauritanian specimens of F. gigantica had a high level of diversity, and they belonged to the F. gigantica phylogenically distinguishable clade. The present study is the first molecular characterization of F. gigantica in sheep and cattle from Mauritania, allowing a reliable approach for the genetic differentiation of Fasciola spp. and providing basis for further studies on liver flukes in the African countries. Copyright © 2011 Elsevier Inc. All

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

PwRn1, a novel Ty3/gypsy-like retrotransposon of Paragonimus westermani: molecular characters and its differentially preserved mobile potential according to host chromosomal polyploidy.

PubMed

Bae, Young-An; Ahn, Jong-Sook; Kim, Seon-Hee; Rhyu, Mun-Gan; Kong, Yoon; Cho, Seung-Yull

2008-10-14

Retrotransposons have been known to involve in the remodeling and evolution of host genome. These reverse transcribing elements, which show a complex evolutionary pathway with diverse intermediate forms, have been comprehensively analyzed from a wide range of host genomes, while the information remains limited to only a few species in the phylum Platyhelminthes. A LTR retrotransposon and its homologs with a strong phylogenetic affinity toward CsRn1 of Clonorchis sinensis were isolated from a trematode parasite Paragonimus westermani via a degenerate PCR method and from an insect species Anopheles gambiae by in silico analysis of the whole mosquito genome, respectively. These elements, designated PwRn1 and AgCR-1 - AgCR-14 conserved unique features including a t-RNATrp primer binding site and the unusual CHCC signature of Gag proteins. Their flanking LTRs displayed >97% nucleotide identities and thus, these elements were likely to have expanded recently in the trematode and insect genomes. They evolved heterogeneous expression strategies: a single fused ORF, two separate ORFs with an identical reading frame and two ORFs overlapped by -1 frameshifting. Phylogenetic analyses suggested that the elements with the separate ORFs had evolved from an ancestral form(s) with the overlapped ORFs. The mobile potential of PwRn1 was likely to be maintained differentially in association with the karyotype of host genomes, as was examined by the presence/absence of intergenomic polymorphism and mRNA transcripts. Our results on the structural diversity of CsRn1-like elements can provide a molecular tool to dissect a more detailed evolutionary episode of LTR retrotransposons. The PwRn1-associated genomic polymorphism, which is substantial in diploids, will also be informative in addressing genomic diversification following inter-/intra-specific hybridization in P. westermani populations.

Cestodes from deep-water squaliform sharks in the Azores

NASA Astrophysics Data System (ADS)

Caira, Janine N.; Pickering, Maria

2013-12-01

The majority of our knowledge on marine tapeworms (cestodes) is limited to taxa that are relatively easy to obtain (i.e., those that parasitize shallower-water species). The invitation to participate in a deep-water research survey off the Condor seamount in the Azores offered the opportunity to gain information regarding parasites of the less often studied sharks of the mesopelagic and bathypelagic zone. All tapeworms (Platyhelminthes: Cestoda) found parasitizing the spiral intestine of squaliform shark species (Elasmobranchii: Squaliformes) encountered as part of this survey, as well as some additional Azorean sampling from previous years obtained from local fishermen are reported. In total, 112 shark specimens of 12 species of squaliform sharks representing 4 different families from depths ranging between 400 and 1290 m were examined. Cestodes were found in the spiral intestines from 11 of the 12 squaliform species examined: Deania calcea, D. cf. profundorum, D. profundorum, Etmopterus princeps, E. pusillus, E. spinax, Centroscyllium fabricii, Centroscymnus coelolepis, C. cryptacanthus, C. crepidater, and Dalatias licha. No cestodes were found in the spiral intestines of Centrophorus squamosus. Light microscopy and scanning electron microscopy revealed several potentially novel trypanorhynch and biloculated tetraphyllidean species. Aporhynchid and gilquiniid trypanorhynchs dominated the adult cestode fauna of Etmopterus and Deania host species, respectively, while larval phyllobothriids were found across several host genera, including, Deania, Centroscyllium, and Centroscymnus. These results corroborate previous findings that deep-water cestode faunas are relatively depauperate and consist primarily of trypanorhynchs of the families Gilquiniidae and Aporhynchidae and larval tetraphyllideans. A subset of specimens of most cestode species was preserved in ethanol for future molecular analysis to allow more definitive determinations of the identification of the

Tracking platyhelminth parasite diversity from freshwater turtles in French Guiana: First report of Neopolystoma Price, 1939 (Monogenea: Polystomatidae) with the description of three new species.

PubMed

Du Preez, Louis H; Badets, Mathieu; Héritier, Laurent; Verneau, Olivier

2017-01-31

Polystomatid flatworms in chelonians are divided into three genera, i.e. Polystomoides Ward, 1917, Polystomoidella Price, 1939 and Neopolystoma Price, 1939, according to the number of haptoral hooks. Among the about 55 polystome species that are known to date from the 327 modern living chelonians, only four species of Polystomoides are currently recognised within the 45 South American freshwater turtles. During 2012, several sites in the vicinity of the cities Cayenne and Kaw in French Guiana were investigated for freshwater turtles. Turtles were collected at six sites and the presence of polystomatid flatworms was assessed from the presence of polystome eggs released by infected specimens. Among the three turtle species that were collected, no polystomes were found in the gibba turtle Mesoclemmys gibba (Schweigger, 1812). The spot-legged turtle Rhinoclemmys punctularia (Daudin, 1801) was infected with two species of Neopolystoma Price, 1939, one in the conjunctival sacs and the other in the urinary bladder, while the scorpion mud turtle Kinosternon scorpioides (Linnaeus, 1766) was found to be infected with a single Neopolystoma species in the conjunctival sacs. These parasites could be distinguished from known species of Neopolystoma by a combination of morphological characteristics including body size, number and length of genital spines, shape and size of the testis. They were also differentiated at the molecular level using the cox1 gene marker. Based on morphological and genetic evidences, three new species are described herein, namely Neopolystoma cayensis n. sp. and Neopolystoma guianensis n. sp. from the bladder and the conjunctival sacs of R. punctularia, respectively, and Neopolystoma scorpioides n. sp. from the conjunctival sacs of K. scorpioides. However the monophyly of Polystomoides and Neopolystoma is still questioned regarding their phylogeny based on a dataset comprising four concatenated genes, namely, 18S, 28S and 12S rRNA genes and cox1. In addition to these being the first chelonian polystomes to be reported and described from French Guiana, they represent the first polystomes from the hosts K. scorpioides and R. punctularia and the first representatives of Neopolystoma from South America. Chelonian polystomes now require an in-depth morphological study to reconcile the taxonomy of the genera with species evolution.

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

PubMed

Jensen, Kirsten; Russell, Shelbi L

2014-06-01

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

Molecular Cloning and Characterization of Taurocyamine Kinase from Clonorchis sinensis: A Candidate Chemotherapeutic Target

PubMed Central

Tokuhiro, Shinji; Nagataki, Mitsuru; Jarilla, Blanca R.; Nomura, Haruka; Kim, Tae Im; Hong, Sung-Jong; Agatsuma, Takeshi

2013-01-01

Background Adult Clonorchis sinensis lives in the bile duct and causes endemic clonorchiasis in East Asian countries. Phosphagen kinases (PK) constitute a highly conserved family of enzymes, which play a role in ATP buffering in cells, and are potential targets for chemotherapeutic agents, since variants of PK are found only in invertebrate animals, including helminthic parasites. This work is conducted to characterize a PK from C. sinensis and to address further investigation for future drug development. Methology/Principal findings A cDNA clone encoding a putative polypeptide of 717 amino acids was retrieved from a C. sinensis transcriptome. This polypeptide was homologous to taurocyamine kinase (TK) of the invertebrate animals and consisted of two contiguous domains. C. sinensis TK (CsTK) gene was reported and found consist of 13 exons intercalated with 12 introns. This suggested an evolutionary pathway originating from an arginine kinase gene group, and distinguished annelid TK from the general CK phylogenetic group. CsTK was found not to have a homologous counterpart in sequences analysis of its mammalian hosts from public databases. Individual domains of CsTK, as well as the whole two-domain enzyme, showed enzymatic activity and specificity toward taurocyamine substrate. Of the CsTK residues, R58, I60 and Y84 of domain 1, and H60, I63 and Y87 of domain 2 were found to participate in binding taurocyamine. CsTK expression was distributed in locomotive and reproductive organs of adult C. sinensis. Developmentally, CsTK was stably expressed in both the adult and metacercariae stages. Recombinant CsTK protein was found to have low sensitivity and specificity toward C. sinensis and platyhelminth-infected human sera on ELISA. Conclusion CsTK is a promising anti-C. sinensis drug target since the enzyme is found only in the C. sinensis and has a substrate specificity for taurocyamine, which is different from its mammalian counterpart, creatine. PMID:24278491

Validation of Suitable Reference Genes for Expression Normalization in Echinococcus spp. Larval Stages

PubMed Central

Espínola, Sergio Martin; Ferreira, Henrique Bunselmeyer; Zaha, Arnaldo

2014-01-01

In recent years, a significant amount of sequence data (both genomic and transcriptomic) for Echinococcus spp. has been published, thereby facilitating the analysis of genes expressed during a specific stage or involved in parasite development. To perform a suitable gene expression quantification analysis, the use of validated reference genes is strongly recommended. Thus, the aim of this work was to identify suitable reference genes to allow reliable expression normalization for genes of interest in Echinococcus granulosus sensu stricto (s.s.) (G1) and Echinococcus ortleppi upon induction of the early pre-adult development. Untreated protoscoleces (PS) and pepsin-treated protoscoleces (PSP) from E. granulosus s.s. (G1) and E. ortleppi metacestode were used. The gene expression stability of eleven candidate reference genes (βTUB, NDUFV2, RPL13, TBP, CYP-1, RPII, EF-1α, βACT-1, GAPDH, ETIF4A-III and MAPK3) was assessed using geNorm, Normfinder, and RefFinder. Our qPCR data showed a good correlation with the recently published RNA-seq data. Regarding expression stability, EF-1α and TBP were the most stable genes for both species. Interestingly, βACT-1 (the most commonly used reference gene), and GAPDH and ETIF4A-III (previously identified as housekeeping genes) did not behave stably in our assay conditions. We propose the use of EF-1α as a reference gene for studies involving gene expression analysis in both PS and PSP experimental conditions for E. granulosus s.s. and E. ortleppi. To demonstrate its applicability, EF-1α was used as a normalizer gene in the relative quantification of transcripts from genes coding for antigen B subunits. The same EF-1α reference gene may be used in studies with other Echinococcus sensu lato species. This report validates suitable reference genes for species of class Cestoda, phylum Platyhelminthes, thus providing a foundation for further validation in other epidemiologically important cestode species, such as those from the

A novel progesterone receptor membrane component (PGRMC) in the human and swine parasite Taenia solium: implications to the host-parasite relationship.

PubMed

Aguilar-Díaz, Hugo; Nava-Castro, Karen E; Escobedo, Galileo; Domínguez-Ramírez, Lenin; García-Varela, Martín; Del Río-Araiza, Víctor H; Palacios-Arreola, Margarita I; Morales-Montor, Jorge

2018-03-09

We have previously reported that progesterone (P 4 ) has a direct in vitro effect on the scolex evagination and growth of Taenia solium cysticerci. Here, we explored the hypothesis that the P 4 direct effect on T. solium might be mediated by a novel steroid-binding parasite protein. By way of using immunofluorescent confocal microscopy, flow cytometry analysis, double-dimension electrophoresis analysis, and sequencing the corresponding protein spot, we detected a novel PGRMC in T. solium. Molecular modeling studies accompanied by computer docking using the sequenced protein, together with phylogenetic analysis and sequence alignment clearly demonstrated that T. solium PGRMC is from parasite origin. Our results show that P 4 in vitro increases parasite evagination and scolex size. Using immunofluorescent confocal microscopy, we detected that parasite cells showed expression of a P 4 -binding like protein exclusively located at the cysticercus subtegumental tissue. Presence of the P 4 -binding protein in cyst cells was also confirmed by flow cytometry. Double-dimension electrophoresis analysis, followed by sequencing the corresponding protein spot, revealed a protein that was previously reported in the T. solium genome belonging to a membrane-associated progesterone receptor component (PGRMC). Molecular modeling studies accompanied by computer docking using the sequenced protein showed that PGRMC is potentially able to bind steroid hormones such as progesterone, estradiol, testosterone and dihydrodrotestosterone with different affinities. Phylogenetic analysis and sequence alignment clearly demonstrated that T. solium PGRMC is related to a steroid-binding protein of Echinoccocus granulosus, both of them being nested within a cluster including similar proteins present in platyhelminths such as Schistocephalus solidus and Schistosoma haematobium. Progesterone may directly act upon T. solium cysticerci probably by binding to PGRMC. This research has implications in the

Developmental Regulation of Genes Encoding Universal Stress Proteins in Schistosoma mansoni

PubMed Central

Isokpehi, Raphael D.; Mahmud, Ousman; Mbah, Andreas N.; Simmons, Shaneka S.; Avelar, Lívia; Rajnarayanan, Rajendram V.; Udensi, Udensi K.; Ayensu, Wellington K.; Cohly, Hari H.; Brown, Shyretha D.; Dates, Centdrika R.; Hentz, Sonya D.; Hughes, Shawntae J.; Smith-McInnis, Dominique R.; Patterson, Carvey O.; Sims, Jennifer N.; Turner, Kelisha T.; Williams, Baraka S.; Johnson, Matilda O.; Adubi, Taiwo; Mbuh, Judith V.; Anumudu, Chiaka I.; Adeoye, Grace O.; Thomas, Bolaji N.; Nashiru, Oyekanmi; Oliveira, Guilherme

2011-01-01

The draft nuclear genome sequence of the snail-transmitted, dimorphic, parasitic, platyhelminth Schistosoma mansoni revealed eight genes encoding proteins that contain the Universal Stress Protein (USP) domain. Schistosoma mansoni is a causative agent of human schistosomiasis, a severe and debilitating Neglected Tropical Disease (NTD) of poverty, which is endemic in at least 76 countries. The availability of the genome sequences of Schistosoma species presents opportunities for bioinformatics and genomics analyses of associated gene families that could be targets for understanding schistosomiasis ecology, intervention, prevention and control. Proteins with the USP domain are known to provide bacteria, archaea, fungi, protists and plants with the ability to respond to diverse environmental stresses. In this research investigation, the functional annotations of the USP genes and predicted nucleotide and protein sequences were initially verified. Subsequently, sequence clusters and distinctive features of the sequences were determined. A total of twelve ligand binding sites were predicted based on alignment to the ATP-binding universal stress protein from Methanocaldococcus jannaschii. In addition, six USP sequences showed the presence of ATP-binding motif residues indicating that they may be regulated by ATP. Public domain gene expression data and RT-PCR assays confirmed that all the S. mansoni USP genes were transcribed in at least one of the developmental life cycle stages of the helminth. Six of these genes were up-regulated in the miracidium, a free-swimming stage that is critical for transmission to the snail intermediate host. It is possible that during the intra-snail stages, S. mansoni gene transcripts for universal stress proteins are low abundant and are induced to perform specialized functions triggered by environmental stressors such as oxidative stress due to hydrogen peroxide that is present in the snail hemocytes. This report serves to catalyze the

Molecular characterization of Fasciola spp. from the endemic area of northern Iran based on nuclear ribosomal DNA sequences.

PubMed

Amor, Nabil; Halajian, Ali; Farjallah, Sarra; Merella, Paolo; Said, Khaled; Ben Slimane, Badreddine

2011-07-01

Fasciolosis caused by Fasciola spp. (Platyhelminthes: Trematoda: Digenea) is considered as the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. In the endemic regions of the North of Iran, Fasciola hepatica and Fasciola gigantica have been previously characterized on the basis of morphometric differences, but the use of molecular markers is necessary to distinguish exactly between species and intermediate forms. Samples from buffaloes and goats from different localities of northern Iran were identified morphologically and then genetically characterized by sequences of the first (ITS-1) and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the ITS of the northern Iranian samples with sequences of Fasciola spp. from GenBank showed that the examined specimens had sequences identical to those of the most frequent haplotypes of F. hepatica (n=25, 48.1%) and F. gigantica (n=20, 38.45%), which differed from each other in different variable nucleotide positions of ITS region sequences, and their intermediate forms (n=7, 13.45%), which had nucleotides overlapped between the two Fasciola species in all the positions. The ITS sequences from populations of Fasciola isolates in buffaloes and goats had experienced introgression/hybridization as previously reported in isolates from other ruminants and humans. Based on ITS-1 and ITS-2 sequences, flukes are scattered in pure F. hepatica, F. gigantica and intermediate Fasciola clades, revealing that multiple genotypes of Fasciola are able to infect goats and buffaloes in North of Iran. Furthermore, the phylogenetic trees based upon the ITS-1 and ITS-2 sequences showed a close relationship of the Iranian samples with isolates of F. hepatica and F. gigantica from different localities of Africa and Asia. In the present study, the intergenic transcribed spacers ITS-1 and ITS-2 showed to be reliable approaches for the genetic

Specific retention of the protostome-specific PsGEF may parallel with the evolution of mushroom bodies in insect and lophotrochozoan brains.

PubMed

Higuchi, Nozomu; Kohno, Keigo; Kadowaki, Tatsuhiko

2009-05-07

Gene gain and subsequent retention or loss during evolution may be one of the underlying mechanisms involved in generating the diversity of metazoan nervous systems. However, the causal relationships acting therein have not been studied extensively. We identified the gene PsGEF (protostome-specific GEF), which is present in all the sequenced genomes of insects and limpet but absent in those of sea anemones, deuterostomes, and nematodes. In Drosophila melanogaster, PsGEF encodes a short version of a protein with the C2 and PDZ domains, as well as a long version with the C2, PDZ, and RhoGEF domains through alternative splicing. Intriguingly, the exons encoding the RhoGEF domain are specifically deleted in the Daphnia pulex genome, suggesting that Daphnia PsGEF contains only the C2 and PDZ domains. Thus, the distribution of PsGEF containing the C2, PDZ, and RhoGEF domains among metazoans appears to coincide with the presence of mushroom bodies. Mushroom bodies are prominent neuropils involved in the processing of multiple sensory inputs as well as associative learning in the insect, platyhelminth, and annelid brains. In the adult Drosophila brain, PsGEF is expressed in mushroom bodies, antennal lobe, and optic lobe, where it is necessary for the correct axon branch formation of alpha/beta neurons in mushroom bodies. PsGEF genetically interacts with Rac1 but not other Rho family members, and the RhoGEF domain of PsGEF induces actin polymerization in the membrane, thus resulting in the membrane ruffling that is observed in cultured cells with activated forms of Rac. The specific acquisition of PsGEF by the last common ancestor of protostomes followed by its retention or loss in specific animal species during evolution demonstrates that there are some structural and/or functional features common between insect and lophotrochozoan nervous systems (for example, mushroom bodies), which are absent in all deuterostomes and cnidarians. PsGEF is therefore one of genes

Validation of suitable reference genes for expression normalization in Echinococcus spp. larval stages.

PubMed

Espínola, Sergio Martin; Ferreira, Henrique Bunselmeyer; Zaha, Arnaldo

2014-01-01

In recent years, a significant amount of sequence data (both genomic and transcriptomic) for Echinococcus spp. has been published, thereby facilitating the analysis of genes expressed during a specific stage or involved in parasite development. To perform a suitable gene expression quantification analysis, the use of validated reference genes is strongly recommended. Thus, the aim of this work was to identify suitable reference genes to allow reliable expression normalization for genes of interest in Echinococcus granulosus sensu stricto (s.s.) (G1) and Echinococcus ortleppi upon induction of the early pre-adult development. Untreated protoscoleces (PS) and pepsin-treated protoscoleces (PSP) from E. granulosus s.s. (G1) and E. ortleppi metacestode were used. The gene expression stability of eleven candidate reference genes (βTUB, NDUFV2, RPL13, TBP, CYP-1, RPII, EF-1α, βACT-1, GAPDH, ETIF4A-III and MAPK3) was assessed using geNorm, Normfinder, and RefFinder. Our qPCR data showed a good correlation with the recently published RNA-seq data. Regarding expression stability, EF-1α and TBP were the most stable genes for both species. Interestingly, βACT-1 (the most commonly used reference gene), and GAPDH and ETIF4A-III (previously identified as housekeeping genes) did not behave stably in our assay conditions. We propose the use of EF-1α as a reference gene for studies involving gene expression analysis in both PS and PSP experimental conditions for E. granulosus s.s. and E. ortleppi. To demonstrate its applicability, EF-1α was used as a normalizer gene in the relative quantification of transcripts from genes coding for antigen B subunits. The same EF-1α reference gene may be used in studies with other Echinococcus sensu lato species. This report validates suitable reference genes for species of class Cestoda, phylum Platyhelminthes, thus providing a foundation for further validation in other epidemiologically important cestode species, such as those from the

Elucidating the transcriptome of Fasciola hepatica - a key to fundamental and biotechnological discoveries for a neglected parasite.

PubMed

Young, Neil D; Hall, Ross S; Jex, Aaron R; Cantacessi, Cinzia; Gasser, Robin B

2010-01-01

Liver flukes of animals are parasitic flatworms (Platyhelminthes: Digenea) of major socioeconomic importance in many countries. Key representatives, such as Fasciola hepatica and F. gigantica, cause "liver fluke disease" (= fascioliasis), which is of major animal health significance worldwide. In particular, F. hepatica is a leading cause of production losses to the livestock (mainly sheep and cattle) and meat industries due to clinical disease, reduced weight gain and milk production, and deaths. This parasite is also a major food-borne pathogen of humans throughout parts of the Middle East, Asia and South America. Currently, there is a significant focus on the development of new approaches for the prevention and control of fascioliasis in livestock. Recent technological advances in genomics and bioinformatics provide unique opportunities for the identification and prevalidation of drug targets and vaccines through a better understanding of the biology of F. hepatica and related species as well as their relationship with their hosts at the molecular level. Surprisingly, despite the widespread socioeconomic impact of fascioliasis, genomic datasets for F. hepatica are scant, limiting the molecular biological research of this parasite. The present article explores specifically the transcriptome of the adult stage of F. hepatica using an integrated genomic-bioinformatic platform. The analysis of the current data reveals numerous molecules of biological relevance, some of which are inferred to be involved in key biological processes or pathways that could serve as targets for new trematocidal drugs or vaccines. Improved insights into the transcriptome of F. hepatica should pave the way for future, comparative analysis of the transcriptomes of other developmental stages of this and related parasites, such as F. gigantica, cancer-causing flatworms (Clonorchis sinensis and Opisthorchis viverrini) and blood flukes (Schistosoma mansoni and S. japonicum). Prediction of the

Evidence for Integrin - Venus Kinase Receptor 1 Alliance in the Ovary of Schistosoma mansoni Females Controlling Cell Survival.

PubMed

Gelmedin, Verena; Morel, Marion; Hahnel, Steffen; Cailliau, Katia; Dissous, Colette; Grevelding, Christoph G

2017-01-01

In metazoan integrin signaling is an important process of mediating extracellular and intracellular communication processes. This can be achieved by cooperation of integrins with growth factor receptors (GFRs). Schistosoma mansoni is a helminth parasite inducing schistosomiasis, an infectious disease of worldwide significance for humans and animals. First studies on schistosome integrins revealed their role in reproductive processes, being involved in spermatogenesis and oogenesis. With respect to the roles of eggs for maintaining the parasite´s life cycle and for inducing the pathology of schistosomiasis, elucidating reproductive processes is of high importance. Here we studied the interaction of the integrin receptor Smβ-Int1 with the venus kinase receptor SmVKR1 in S. mansoni. To this end we cloned and characterized SmILK, SmPINCH, and SmNck2, three putative bridging molecules for their role in mediating Smβ-Int1/SmVKR1 cooperation. Phylogenetic analyses showed that these molecules form clusters that are specific for parasitic platyhelminths as it was shown for integrins before. Transcripts of all genes colocalized in the ovary. In Xenopus oocytes germinal vesicle breakdown (GVBD) was only induced if all members were simultaneously expressed. Coimmunoprecipitation results suggest that a Smβ-Int1-SmILK-SmPINCH-SmNck2-SmVKR1 complex can be formed leading to the phosphorylation and activation of SmVKR1. These results indicate that SmVKR1 can be activated in a ligand-independent manner by receptor-complex interaction. RNAi and inhibitor studies to knock-down SmILK as a representative complex member concurrently revealed effects on the extracellular matrix surrounding the ovary and oocyte localization within the ovary, oocyte survival, and egg production. By TUNEL assays, confocal laser scanning microscopy (CLSM), Caspase-3 assay, and transcript profiling of the pro-apoptotic BCL-2 family members BAK/BAX we obtained first evidence for roles of this signaling

Embryonic and post-embryonic development of the polyclad flatworm Maritigrella crozieri; implications for the evolution of spiralian life history traits

PubMed Central

2010-01-01

Background Planktonic life history stages of spiralians share some muscular, nervous and ciliary system characters in common. The distribution of these characters is patchy and can be interpreted either as the result of convergent evolution, or as the retention of primitive spiralian larval features. To understand the evolution of these characters adequate taxon sampling across the Spiralia is necessary. Polyclad flatworms are the only free-living Platyhelminthes that exhibit a continuum of developmental modes, with direct development at one extreme, and indirect development via a trochophore-like larval stage at the other. Here I present embryological and larval anatomical data from the indirect developing polyclad Maritrigrella crozieri, and consider these data within a comparative spiralian context. Results After 196 h hours of embryonic development, M. crozieri hatches as a swimming, planktotrophic larva. Larval myoanatomy consists of an orthogonal grid of circular and longitudinal body wall muscles plus parenchymal muscles. Diagonal body wall muscles develop over the planktonic period. Larval neuroanatomy consists of an apical plate, neuropile, paired nerve cords, a peri-oral nerve ring, a medial nerve, a ciliary band nerve net and putative ciliary photoreceptors. Apical neural elements develop first followed by posterior perikarya and later pharyngeal neural elements. The ciliated larva is encircled by a continuous, pre-oral band of longer cilia, which follows the distal margins of the lobes; it also possesses distinct apical and caudal cilia. Conclusions Within polyclads heterochronic shifts in the development of diagonal bodywall and pharyngeal muscles are correlated with life history strategies and feeding requirements. In contrast to many spiralians, M. crozieri hatch with well developed nervous and muscular systems. Comparisons of the ciliary bands and apical organs amongst spiralian planktonic life-stages reveal differences; M. crozieri lack a distinct

Suppression of long-branch attraction artefacts in the animal phylogeny using a site-heterogeneous model

PubMed Central

Lartillot, Nicolas; Brinkmann, Henner; Philippe, Hervé

2007-01-01

Background Thanks to the large amount of signal contained in genome-wide sequence alignments, phylogenomic analyses are converging towards highly supported trees. However, high statistical support does not imply that the tree is accurate. Systematic errors, such as the Long Branch Attraction (LBA) artefact, can be misleading, in particular when the taxon sampling is poor, or the outgroup is distant. In an otherwise consistent probabilistic framework, systematic errors in genome-wide analyses can be traced back to model mis-specification problems, which suggests that better models of sequence evolution should be devised, that would be more robust to tree reconstruction artefacts, even under the most challenging conditions. Methods We focus on a well characterized LBA artefact analyzed in a previous phylogenomic study of the metazoan tree, in which two fast-evolving animal phyla, nematodes and platyhelminths, emerge either at the base of all other Bilateria, or within protostomes, depending on the outgroup. We use this artefactual result as a case study for comparing the robustness of two alternative models: a standard, site-homogeneous model, based on an empirical matrix of amino-acid replacement (WAG), and a site-heterogeneous mixture model (CAT). In parallel, we propose a posterior predictive test, allowing one to measure how well a model acknowledges sequence saturation. Results Adopting a Bayesian framework, we show that the LBA artefact observed under WAG disappears when the site-heterogeneous model CAT is used. Using cross-validation, we further demonstrate that CAT has a better statistical fit than WAG on this data set. Finally, using our statistical goodness-of-fit test, we show that CAT, but not WAG, correctly accounts for the overall level of saturation, and that this is due to a better estimation of site-specific amino-acid preferences. Conclusion The CAT model appears to be more robust than WAG against LBA artefacts, essentially because it correctly

Myxosporean hyperparasites of gill monogeneans are basal to the Multivalvulida

PubMed Central

2011-01-01

Background Myxosporeans are known from aquatic annelids but parasitism of platyhelminths by myxosporeans has not been widely reported. Hyperparasitism of gill monogeneans by Myxidium giardi has been reported from the European eel and Myxidium-like hyperparasites have also been observed during studies of gill monogeneans from Malaysia and Japan. The present study aimed to collect new hyperparasite material from Malaysia for morphological and molecular descriptions. In addition, PCR screening of host fish was undertaken to determine whether they are also hosts for the myxosporean. Results Heavy myxosporean infections were observed in monogeneans from two out of 14 fish and were detected from a further five fish using specific PCRs and pooled monogenean DNA. Positive DNA isolates were sequenced and were from a single species of myxosporean. Myxospore morphology was consistent with Myxidium with histozoic development in the parenchymal tissues of the monogenean. Simultaneous infections in the fish could not be confirmed microscopically; however, identical myxosporean DNA could be amplified from kidney, spleen and intestinal tract tissues using the specific PCR. Small subunit (SSU) rDNA for the myxosporean was amplified and was found to be most similar (92%) to that of another hyperparasitic myxosporean from a gill monogenean from Japan and to numerous multivalvulidan myxosporeans from the genus Kudoa (89-91%). Phylogenetic analyses placed the hyperparasite sequence basally to clades containing Kudoa, Unicapsula and Sphaerospora. Conclusions The myxosporean infecting the gill monogenean, Diplectanocotyla gracilis, from the Indo-Pacific tarpon, Megalops cyprinoides, is described as a new species, Myxidium incomptavermi, based on a histozoic development in the monogenean host and its phylogenetic placement. We have demonstrated for the first time that a myxosporean hyperparasite of gill monogeneans is detectable in the fish host. However, myxospores could not be isolated

Compounds Derived from the Bhutanese Daisy, Ajania nubigena, Demonstrate Dual Anthelmintic Activity against Schistosoma mansoni and Trichuris muris.

PubMed

Wangchuk, Phurpa; Pearson, Mark S; Giacomin, Paul R; Becker, Luke; Sotillo, Javier; Pickering, Darren; Smout, Michael J; Loukas, Alex

2016-08-01

Whipworms and blood flukes combined infect almost one billion people in developing countries. Only a handful of anthelmintic drugs are currently available to treat these infections effectively; there is therefore an urgent need for new generations of anthelmintic compounds. Medicinal plants have presented as a viable source of new parasiticides. Ajania nubigena, the Bhutanese daisy, has been used in Bhutanese traditional medicine for treating various diseases and our previous studies revealed that small molecules from this plant have antimalarial properties. Encouraged by these findings, we screened four major compounds isolated from A. nubigena for their anthelmintic properties. Here we studied four major compounds derived from A. nubigena for their anthelmintic properties against the nematode whipworm Trichuris muris and the platyhelminth blood fluke Schistosoma mansoni using the xWORM assay technique. Of four compounds tested, two compounds-luteolin (3) and (3R,6R)-linalool oxide acetate (1)-showed dual anthelmintic activity against S. mansoni (IC50 range = 5.8-36.9 μg/mL) and T. muris (IC50 range = 9.7-20.4 μg/mL). Using scanning electron microscopy, we determined luteolin as the most efficacious compound against both parasites and additionally was found effective against the schistosomula, the infective stage of S. mansoni (IC50 = 13.3 μg/mL). Luteolin induced tegumental damage to S. mansoni and affected the cuticle, bacillary bands and bacillary glands of T. muris. Our in vivo assessment of luteolin (3) against T. muris infection at a single oral dosing of 100 mg/kg, despite being significantly (27.6%) better than the untreated control group, was markedly weaker than mebendazole (93.1%) in reducing the worm burden in mice. Among the four compounds tested, luteolin demonstrated the best broad-spectrum activity against two different helminths-T. muris and S. mansoni-and was effective against juvenile schistosomes, the stage that is refractory to the current

Molecular and Structural Characterization of the Tegumental 20.6-kDa Protein in Clonorchis sinensis as a Potential Druggable Target.

PubMed

Kim, Yu-Jung; Yoo, Won Gi; Lee, Myoung-Ro; Kang, Jung-Mi; Na, Byoung-Kuk; Cho, Shin-Hyeong; Park, Mi-Yeoun; Ju, Jung-Won

2017-03-04

The tegument, representing the membrane-bound outer surface of platyhelminth parasites, plays an important role for the regulation of the host immune response and parasite survival. A comprehensive understanding of tegumental proteins can provide drug candidates for use against helminth-associated diseases, such as clonorchiasis caused by the liver fluke Clonorchis sinensis . However, little is known regarding the physicochemical properties of C. sinensis teguments. In this study, a novel 20.6-kDa tegumental protein of the C. sinensis adult worm (CsTegu20.6) was identified and characterized by molecular and in silico methods. The complete coding sequence of 525 bp was derived from cDNA clones and encodes a protein of 175 amino acids. Homology search using BLASTX showed CsTegu20.6 identity ranging from 29% to 39% with previously-known tegumental proteins in C. sinensis . Domain analysis indicated the presence of a calcium-binding EF-hand domain containing a basic helix-loop-helix structure and a dynein light chain domain exhibiting a ferredoxin fold. We used a modified method to obtain the accurate tertiary structure of the CsTegu20.6 protein because of the unavailability of appropriate templates. The CsTegu20.6 protein sequence was split into two domains based on the disordered region, and then, the structure of each domain was modeled using I-TASSER. A final full-length structure was obtained by combining two structures and refining the whole structure. A refined CsTegu20.6 structure was used to identify a potential CsTegu20.6 inhibitor based on protein structure-compound interaction analysis. The recombinant proteins were expressed in Escherichia coli and purified by nickel-nitrilotriacetic acid affinity chromatography. In C. sinensis , CsTegu20.6 mRNAs were abundant in adult and metacercariae, but not in the egg. Immunohistochemistry revealed that CsTegu20.6 localized to the surface of the tegument in the adult fluke. Collectively, our results contribute to a

The diterpenoid 7-keto-sempervirol, derived from Lycium chinense, displays anthelmintic activity against both Schistosoma mansoni and Fasciola hepatica.

PubMed

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

2015-03-01

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. 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 μM) 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 μM). 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. 7-keto-sempervirol negatively

Compounds Derived from the Bhutanese Daisy, Ajania nubigena, Demonstrate Dual Anthelmintic Activity against Schistosoma mansoni and Trichuris muris

PubMed Central

Pearson, Mark S.; Giacomin, Paul R.; Becker, Luke; Sotillo, Javier; Pickering, Darren

2016-01-01

Background Whipworms and blood flukes combined infect almost one billion people in developing countries. Only a handful of anthelmintic drugs are currently available to treat these infections effectively; there is therefore an urgent need for new generations of anthelmintic compounds. Medicinal plants have presented as a viable source of new parasiticides. Ajania nubigena, the Bhutanese daisy, has been used in Bhutanese traditional medicine for treating various diseases and our previous studies revealed that small molecules from this plant have antimalarial properties. Encouraged by these findings, we screened four major compounds isolated from A. nubigena for their anthelmintic properties. Methodology/Principal Findings Here we studied four major compounds derived from A. nubigena for their anthelmintic properties against the nematode whipworm Trichuris muris and the platyhelminth blood fluke Schistosoma mansoni using the xWORM assay technique. Of four compounds tested, two compounds—luteolin (3) and (3R,6R)-linalool oxide acetate (1)—showed dual anthelmintic activity against S. mansoni (IC50 range = 5.8–36.9 μg/mL) and T. muris (IC50 range = 9.7–20.4 μg/mL). Using scanning electron microscopy, we determined luteolin as the most efficacious compound against both parasites and additionally was found effective against the schistosomula, the infective stage of S. mansoni (IC50 = 13.3 μg/mL). Luteolin induced tegumental damage to S. mansoni and affected the cuticle, bacillary bands and bacillary glands of T. muris. Our in vivo assessment of luteolin (3) against T. muris infection at a single oral dosing of 100 mg/kg, despite being significantly (27.6%) better than the untreated control group, was markedly weaker than mebendazole (93.1%) in reducing the worm burden in mice. Conclusions/Significance Among the four compounds tested, luteolin demonstrated the best broad-spectrum activity against two different helminths—T. muris and S. mansoni—and was

Complete mitochondrial genomes of Taenia multiceps, T. hydatigena and T. pisiformis: additional molecular markers for a tapeworm genus of human and animal health significance.

PubMed

Jia, Wan-Zhong; Yan, Hong-Bin; Guo, Ai-Jiang; Zhu, Xing-Quan; Wang, Yu-Chao; Shi, Wan-Gui; Chen, Hao-Tai; Zhan, Fang; Zhang, Shao-Hua; Fu, Bao-Quan; Littlewood, D Timothy J; Cai, Xue-Peng

2010-07-22

Mitochondrial genomes provide a rich source of molecular variation of proven and widespread utility in molecular ecology, population genetics and evolutionary biology. The tapeworm genus Taenia includes a diversity of tapeworm parasites of significant human and veterinary importance. Here we add complete sequences of the mt genomes of T. multiceps, T. hydatigena and T. pisiformis, to a data set of 4 published mtDNAs in the same genus. Seven complete mt genomes of Taenia species are used to compare and contrast variation within and between genomes in the genus, to estimate a phylogeny for the genus, and to develop novel molecular markers as part of an extended mitochondrial toolkit. The complete circular mtDNAs of T. multiceps, T. hydatigena and T. pisiformis were 13,693, 13,492 and 13,387 bp in size respectively, comprising the usual complement of flatworm genes. Start and stop codons of protein coding genes included those found commonly amongst other platyhelminth mt genomes, but the much rarer initiation codon GTT was inferred for the gene atp6 in T. pisiformis. Phylogenetic analysis of mtDNAs offered novel estimates of the interrelationships of Taenia. Sliding window analyses showed nad6, nad5, atp6, nad3 and nad2 are amongst the most variable of genes per unit length, with the highest peaks in nucleotide diversity found in nad5. New primer pairs capable of amplifying fragments of variable DNA in nad1, rrnS and nad5 genes were designed in silico and tested as possible alternatives to existing mitochondrial markers for Taenia. With the availability of complete mtDNAs of 7 Taenia species, we have shown that analysis of amino acids provides a robust estimate of phylogeny for the genus that differs markedly from morphological estimates or those using partial genes; with implications for understanding the evolutionary radiation of important Taenia. Full alignment of the nucleotides of Taenia mtDNAs and sliding window analysis suggests numerous alternative gene

Complete mitochondrial genomes of Taenia multiceps, T. hydatigena and T. pisiformis: additional molecular markers for a tapeworm genus of human and animal health significance

PubMed Central

2010-01-01

Background Mitochondrial genomes provide a rich source of molecular variation of proven and widespread utility in molecular ecology, population genetics and evolutionary biology. The tapeworm genus Taenia includes a diversity of tapeworm parasites of significant human and veterinary importance. Here we add complete sequences of the mt genomes of T. multiceps, T. hydatigena and T. pisiformis, to a data set of 4 published mtDNAs in the same genus. Seven complete mt genomes of Taenia species are used to compare and contrast variation within and between genomes in the genus, to estimate a phylogeny for the genus, and to develop novel molecular markers as part of an extended mitochondrial toolkit. Results The complete circular mtDNAs of T. multiceps, T. hydatigena and T. pisiformis were 13,693, 13,492 and 13,387 bp in size respectively, comprising the usual complement of flatworm genes. Start and stop codons of protein coding genes included those found commonly amongst other platyhelminth mt genomes, but the much rarer initiation codon GTT was inferred for the gene atp6 in T. pisiformis. Phylogenetic analysis of mtDNAs offered novel estimates of the interrelationships of Taenia. Sliding window analyses showed nad6, nad5, atp6, nad3 and nad2 are amongst the most variable of genes per unit length, with the highest peaks in nucleotide diversity found in nad5. New primer pairs capable of amplifying fragments of variable DNA in nad1, rrnS and nad5 genes were designed in silico and tested as possible alternatives to existing mitochondrial markers for Taenia. Conclusions With the availability of complete mtDNAs of 7 Taenia species, we have shown that analysis of amino acids provides a robust estimate of phylogeny for the genus that differs markedly from morphological estimates or those using partial genes; with implications for understanding the evolutionary radiation of important Taenia. Full alignment of the nucleotides of Taenia mtDNAs and sliding window analysis suggests

Composition of abyssal macrofauna along the Vema Fracture Zone and the hadal Puerto Rico Trench, northern tropical Atlantic

NASA Astrophysics Data System (ADS)

Brandt, A.; Frutos, I.; Bober, S.; Brix, S.; Brenke, N.; Guggolz, T.; Heitland, N.; Malyutina, M.; Minzlaff, U.; Riehl, T.; Schwabe, E.; Zinkann, A.-C.; Linse, K.

2018-02-01

We analyzed composition and variations in benthic macrofaunal communities along a transect of the entire length of the Vema-Fracture Zone on board of RV Sonne (SO-237) between December 2014 and January 2015 in order to test whether the Mid-Atlantic Ridge serves as a barrier limiting benthic taxon distribution in the abyssal basins on both sides of the ridge or whether the fracture zone permits the migration of species between the western and eastern abyssal Atlantic basins. The Puerto Rico Trench, much deeper than the surrounding abyssal West Atlantic, was sampled to determine whether the biodiversity of its hadal macrofauna differs from that of the abyssal Atlantic. The composition of the macrofauna from the epibenthic sledge catches yielded a total of 21,332 invertebrates. Crustacea occurred most frequently (59%) with 12,538 individuals followed by Annelida (mostly Polychaeta) (26%) with 5491 individuals, Mollusca (7%) with 1458 individuals, Echinodermata (4%) with 778 individuals, Nematoda (2%) with 502 individuals and Chaetognatha (1%) with 152 and Porifera (1%) with 131 individuals. All other taxa occurred with overall less than ten individuals (Hemichordata, Phoronida, Priapulida, Brachiopoda, invertebrate Chordata, Echiurida, Foraminifera (here refereed to macrofaunal Komokiacea only), Chelicerata, Platyhelminthes). Within the Crustacea, Peracarida (62.6%) with 7848 individuals and Copepoda (36.1%) with 44,526 individuals were the most abundant taxa. Along the abyssal Vema-Fracture Zone macrofaunal abundances (ind./1000 m2) were generally higher on the eastern side, while the highest normalized abundance value was reported in the Puerto Rico Trench at abyssal station 14-1 2313 individuals/1000 m2. The lowest abundance was reported at station 11-4 with 120 ind./1000 m2 located at the western side of the Vema-Fracture Zone. The number of major macrofaunal taxa (phylum, class) ranged between five (stations 12-5, 13-4 and 13-5 at hadal depths in the Puerto Rico

Predicting the Potential for Natural Recovery of Atlantic Salmon (Salmo salar L.) Populations following the Introduction of Gyrodactylus salaris Malmberg, 1957 (Monogenea).

PubMed

Denholm, Scott J; Hoyle, Andrew S; Shinn, Andrew P; Paladini, Giuseppe; Taylor, Nick G H; Norman, Rachel A

2016-01-01

Gyrodactylus salaris (Monogenea, Platyhelminthes) is a notifiable freshwater pathogen responsible for causing catastrophic damage to wild Atlantic salmon stocks, most notably in Norway. In some strains of Baltic salmon (e.g., from the river Neva) however, the impact is greatly reduced due to some form of innate resistance that regulates parasite numbers, resulting in fewer host mortalities. Gyrodactylus salaris is known from 17 European states; its status in a further 35 states remains unknown; the UK, the Republic of Ireland and certain watersheds in Finland are free of the parasite. Thus, the parasite poses a serious threat if it emerges in Atlantic salmon rearing regions throughout Europe. At present, infections are generally controlled via extreme measures such as the treatment of entire river catchments with the biocide rotenone, in order to remove all hosts, before restocking with the original genetic stock. The use of rotenone in this way in EU countries is unlikely as it would be in contravention of the Water Framework Directive. Not only are such treatments economically and environmentally costly, they also eradicate the potential for any host/parasite evolutionary process to occur. Based on previous studies, UK salmon stocks have been shown to be highly susceptible to infection, analogous to Norwegian stocks. The present study investigates the impact of a G. salaris outbreak within a naïve salmon population in order to determine long-term consequences of infection and the likelihood of coexistence. Simulation of the salmon/ G. salaris system was carried out via a deterministic mathematical modelling approach to examine the dynamics of host-pathogen interactions. Results indicated that in order for highly susceptible Atlantic strains to evolve a resistance, both a moderate-strong deceleratingly costly trade-off on birth rate and a lower overall cost of the immune response are required. The present study provides insights into the potential long term

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

PubMed

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

2015-09-18

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

An integrated pipeline for next generation sequencing and annotation of the complete mitochondrial genome of the giant intestinal fluke, Fasciolopsis buski (Lankester, 1857) Looss, 1899

PubMed Central

Biswal, Devendra Kumar; Ghatani, Sudeep; Shylla, Jollin A.; Sahu, Ranjana; Mullapudi, Nandita

2013-01-01

Helminths include both parasitic nematodes (roundworms) and platyhelminths (trematode and cestode flatworms) that are abundant, and are of clinical importance. The genetic characterization of parasitic flatworms using advanced molecular tools is central to the diagnosis and control of infections. Although the nuclear genome houses suitable genetic markers (e.g., in ribosomal (r) DNA) for species identification and molecular characterization, the mitochondrial (mt) genome consistently provides a rich source of novel markers for informative systematics and epidemiological studies. In the last decade, there have been some important advances in mtDNA genomics of helminths, especially lung flukes, liver flukes and intestinal flukes. Fasciolopsis buski, often called the giant intestinal fluke, is one of the largest digenean trematodes infecting humans and found primarily in Asia, in particular the Indian subcontinent. Next-generation sequencing (NGS) technologies now provide opportunities for high throughput sequencing, assembly and annotation within a short span of time. Herein, we describe a high-throughput sequencing and bioinformatics pipeline for mt genomics for F. buski that emphasizes the utility of short read NGS platforms such as Ion Torrent and Illumina in successfully sequencing and assembling the mt genome using innovative approaches for PCR primer design as well as assembly. We took advantage of our NGS whole genome sequence data (unpublished so far) for F. buski and its comparison with available data for the Fasciola hepatica mtDNA as the reference genome for design of precise and specific primers for amplification of mt genome sequences from F. buski. A long-range PCR was carried out to create an NGS library enriched in mt DNA sequences. Two different NGS platforms were employed for complete sequencing, assembly and annotation of the F. buski mt genome. The complete mt genome sequences of the intestinal fluke comprise 14,118 bp and is thus the shortest

Matrotrophy and placentation in invertebrates: a new paradigm.

PubMed

Ostrovsky, Andrew N; Lidgard, Scott; Gordon, Dennis P; Schwaha, Thomas; Genikhovich, Grigory; Ereskovsky, Alexander V

2016-08-01

Matrotrophy, the continuous extra-vitelline supply of nutrients from the parent to the progeny during gestation, is one of the masterpieces of nature, contributing to offspring fitness and often correlated with evolutionary diversification. The most elaborate form of matrotrophy-placentotrophy-is well known for its broad occurrence among vertebrates, but the comparative distribution and structural diversity of matrotrophic expression among invertebrates is wanting. In the first comprehensive analysis of matrotrophy across the animal kingdom, we report that regardless of the degree of expression, it is established or inferred in at least 21 of 34 animal phyla, significantly exceeding previous accounts and changing the old paradigm that these phenomena are infrequent among invertebrates. In 10 phyla, matrotrophy is represented by only one or a few species, whereas in 11 it is either not uncommon or widespread and even pervasive. Among invertebrate phyla, Platyhelminthes, Arthropoda and Bryozoa dominate, with 162, 83 and 53 partly or wholly matrotrophic families, respectively. In comparison, Chordata has more than 220 families that include or consist entirely of matrotrophic species. We analysed the distribution of reproductive patterns among and within invertebrate phyla using recently published molecular phylogenies: matrotrophy has seemingly evolved at least 140 times in all major superclades: Parazoa and Eumetazoa, Radiata and Bilateria, Protostomia and Deuterostomia, Lophotrochozoa and Ecdysozoa. In Cycliophora and some Digenea, it may have evolved twice in the same life cycle. The provisioning of developing young is associated with almost all known types of incubation chambers, with matrotrophic viviparity more widespread (20 phyla) than brooding (10 phyla). In nine phyla, both matrotrophic incubation types are present. Matrotrophy is expressed in five nutritive modes, of which histotrophy and placentotrophy are most prevalent. Oophagy, embryophagy and

Construction of a medicinal leech transcriptome database and its application to the identification of leech homologs of neural and innate immune genes.

PubMed

Macagno, Eduardo R; Gaasterland, Terry; Edsall, Lee; Bafna, Vineet; Soares, Marcelo B; Scheetz, Todd; Casavant, Thomas; Da Silva, Corinne; Wincker, Patrick; Tasiemski, Aurélie; Salzet, Michel

2010-06-25

, representing all known pathways involved in these important functions. The sequences obtained for Hirudo transcripts represent the first major database of genes expressed in this important model system. Comparison of translated open reading frames (ORFs) with the other openly available leech datasets, the genome and transcriptome of Helobdella robusta, shows an average identity at the amino acid level of 58% in matched sequences. Interestingly, comparison with other available Lophotrochozoans shows similar high levels of amino acid identity, where sequences match, for example, 64% with Capitella capitata (a polychaete) and 56% with Aplysia californica (a mollusk), as well as 58% with Schistosoma mansoni (a platyhelminth). Phylogenetic comparisons of putative Hirudo innate immune response genes present within the Hirudo transcriptome database herein described show a strong resemblance to the corresponding mammalian genes, indicating that this important physiological response may have older origins than what has been previously proposed.

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

Alternaria redefined

PubMed Central

Woudenberg, J.H.C.; Groenewald, J.Z.; Binder, M.; Crous, P.W.

2013-01-01

combinations - Alternaria abundans (E.G. Simmons) Woudenb. & Crous, Alternaria alternariae (Cooke) Woudenb. & Crous, Alternaria atra (Preuss) Woudenb. & Crous, Alternaria bornmuelleri (Magnus) Woudenb. & Crous, Alternaria botrytis (Preuss) Woudenb. & Crous, Alternaria caespitosa (de Hoog & C. Rubio) Woudenb. & Crous, Alternaria cantlous (Yong Wang bis & X.G. Zhang) Woudenb. & Crous, Alternaria caricis (E.G. Simmons) Woudenb. & Crous, Alternaria cinerea (Baucom & Creamer) Woudenb. & Crous, Alternaria didymospora (Munt.-Cvetk.) Woudenb. & Crous, Alternaria fulva (Baucom & Creamer) Woudenb. & Crous, Alternaria hyacinthi (de Hoog & P.J. Mull. bis) Woudenb. & Crous, Alternaria indefessa (E.G. Simmons) Woudenberg & Crous, Alternaria leptinellae (E.G. Simmons & C.F. Hill) Woudenb. & Crous, Alternaria lolii (E.G. Simmons & C.F. Hill) Woudenb. & Crous, Alternaria multiformis (E.G. Simmons) Woudenb. & Crous, Alternaria obclavata (Crous & U. Braun) Woudenb. & Crous, Alternaria obovoidea (E.G. Simmons) Woudenb. & Crous, Alternaria oudemansii (E.G. Simmons) Woudenb. & Crous, Alternaria oxytropis (Q. Wang, Nagao & Kakish.) Woudenb. & Crous, Alternaria penicillata (Corda) Woudenb. & Crous, Alternaria planifunda (E.G. Simmons) Woudenb. & Crous, Alternaria proteae (E.G. Simmons) Woudenb. & Crous, Alternaria scirpinfestans (E.G. Simmons & D.A. Johnson) Woudenb. & Crous, Alternaria scirpivora (E.G. Simmons & D.A. Johnson) Woudenb. & Crous, Alternaria septospora (Preuss) Woudenb. & Crous, Alternaria slovaca (Svob.-Pol., L. Chmel & Bojan.) Woudenb. & Crous, Alternaria subcucurbitae (Yong Wang bis & X.G. Zhang) Woudenb. & Crous, Alternaria tellustris (E.G. Simmons) Woudenb. & Crous, Alternaria tumida (E.G. Simmons) Woudenb. & Crous, Paradendryphiella salina (G.K. Sutherl.) Woudenb. & Crous, Paradendryphiella arenariae (Nicot) Woudenb. & Crous. New names - Alternaria aspera Woudenb. & Crous, Alternaria botryospora Woudenb. & Crous, Alternaria brassicae-pekinensis Woudenb. & Crous, Alternaria