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Dale R Calder
Two new species of hydroids, Eudendrium bleakneyi and Halecium praeparvum, are described from the Bay of Fundy. Fourteen others, Tubularia acadiae Petersen, 1990, Coryne pusilla Gaertner, 1774, Sarsia lovenii (M. Sars, 1846), Zanclea implexa (Alder, 1856), Corydendrium dispar Kramp, 1935, Rhizogeton fusiformis L. Agassiz, 1862, Bougainvillia muscus (Allman, 1863), Rhizorhagium roseum M. Sars, in G.O. Sars, 1874, Hydractinia symbiolongicarpus Buss & Yund, 1989, Eudendrium vaginatum Allman, 1863, Tiaropsis multicirrata (M...
April 24, 2017: Zootaxa
James M Gahan, Christine E Schnitzler, Timothy Q DuBuc, Liam B Doonan, Justyna Kanska, Sebastian G Gornik, Sofia Barreira, Kerry Thompson, Philipp Schiffer, Andreas D Baxevanis, Uri Frank
The function of Notch signaling was previously studied in two cnidarians, Hydra and Nematostella, representing the lineages Hydrozoa and Anthozoa, respectively. Using pharmacological inhibition in Hydra and a combination of pharmacological and genetic approaches in Nematostella, it was shown in both animals that Notch is required for tentacle morphogenesis and for late stages of stinging cell maturation. Surprisingly, a role for Notch in neural development, which is well documented in bilaterians, was evident in embryonic Nematostella but not in adult Hydra...
August 1, 2017: Developmental Biology
Hakima Flici, Christine E Schnitzler, R Cathriona Millane, Graham Govinden, Amy Houlihan, Stephanie D Boomkamp, Sanbing Shen, Andreas D Baxevanis, Uri Frank
SoxB transcription factors and histone deacetylases (HDACs) are each major players in the regulation of neurogenesis, but a functional link between them has not been previously demonstrated. Here, we show that SoxB2 and Hdac2 act together to regulate neurogenesis in the cnidarian Hydractinia echinata during tissue homeostasis and head regeneration. We find that misexpression of SoxB genes modifies the number of neural cells in all life stages and interferes with head regeneration. Hdac2 was co-expressed with SoxB2, and its downregulation phenocopied SoxB2 knockdown...
February 7, 2017: Cell Reports
Otto M P Oliveira, Thaís P Miranda, Enilma M Araujo, Patricia Ayón, Cristina M Cedeño-Posso, Amancay A Cepeda-Mercado, Pablo Córdova, Amanda F Cunha, Gabriel N Genzano, Maria Angélica Haddad, Hermes W Mianzan, Alvaro E Migotto, Lucília S Miranda, André C Morandini, Renato M Nagata, Karine B Nascimento, Miodeli Nogueira Júnior, Sergio Palma, Javier Quiñones, Carolina S Rodriguez, Fabrizio Scarabino, Agustín Schiariti, Sérgio N Stampar, Valquíria B Tronolone, Antonio C Marques
We have compiled available records in the literature for medusozoan cnidarians and ctenophores of South America. New records of species are also included. Each entry (i.e., identified species or still as yet not determined species referred to as "sp." in the literature) includes a synonymy list for South America, taxonomical remarks, notes on habit, and information on geographical occurrence. We have listed 800 unique determined species, in 958 morphotype entries: 5 cubozoans, 905 hydrozoans, 25 scyphozoans, 3 staurozoans, and 20 ctenophores...
November 17, 2016: Zootaxa
Anna Török, Philipp H Schiffer, Christine E Schnitzler, Kris Ford, James C Mullikin, Andreas D Baxevanis, Antony Bacic, Uri Frank, Sebastian G Gornik
BACKGROUND: Cnidarians are a group of early branching animals including corals, jellyfish and hydroids that are renowned for their high regenerative ability, growth plasticity and longevity. Because cnidarian genomes are conventional in terms of protein-coding genes, their remarkable features are likely a consequence of epigenetic regulation. To facilitate epigenetics research in cnidarians, we analysed the histone complement of the cnidarian model organism Hydractinia echinata using phylogenomics, proteomics, transcriptomics and mRNA in situ hybridisations...
2016: Epigenetics & Chromatin
Sergiu A Chicu, Ladislaus Schannen, Mihai V Putz, Georgeta-M Simu
The structure-toxicity relationships for a series of singular human stomatological pharmaceuticals preparations and in mixture with Iodoform on Hydractinia echinata were obtained and their synergism was analyzed through the Metamorphosis Reduction Concentration (MRC50) within the "Köln model". The differences manifested between the total and individual components of the samples and mixtures, associated with toxic versus non-toxic synergism, are dependent on three essential factors of synthesis (the nature, the concentration and the number) besides manifested isotoxicity of the given components...
August 31, 2016: Ecotoxicology and Environmental Safety
Stefan Siebert, Celina E Juliano
Mechanisms of sex determination vary greatly among animals. Here we survey what is known in Cnidaria, the clade that forms the sister group to Bilateria and shows a broad array of sexual strategies and sexual plasticity. This observed diversity makes Cnidaria a well-suited taxon for the study of the evolution of sex determination, as closely related species can have different mechanisms, which allows for comparative studies. In this review, we survey the extensive descriptive data on sexual systems (e.g., gonochorism and hermaphroditism) and the plasticity of sex in various cnidarian taxa...
February 2017: Molecular Reproduction and Development
James M Gahan, Brian Bradshaw, Hakima Flici, Uri Frank
Hydractinia species have been animal models in developmental biology and comparative immunology for over a century, but are having a renaissance due to the establishment of modern genetic and genomic tools by the growing community of researchers utilizing them. Hydractinia has a predictable and accessible life cycle and its stem cell system, known as interstitial- or i-cells has been a paradigm for animal stem cells since the late 1800s. In adult Hydractinia, i-cells continuously provide progenitors to sustain clonal growth, tissue homeostasis, sexual reproduction and regeneration...
October 2016: Current Opinion in Genetics & Development
Maja Rischer, Jonathan L Klassen, Thomas Wolf, Huijuan Guo, Ekaterina Shelest, Jon Clardy, Christine Beemelmanns
The assembly and annotation of the draft genome sequence of Shewanella sp. strain P1-14-1 are reported here to investigate the genes responsible for interkingdom interactions, secondary metabolite production, and microbial electrogenesis.
2016: Genome Announcements
Jonathan L Klassen, Thomas Wolf, Maja Rischer, Huijuan Guo, Ekaterina Shelest, Jon Clardy, Christine Beemelmanns
To gain a broader understanding of the importance of a surface-associated lifestyle and morphogenic capability, we have assembled and annotated the genome sequences of Pseudoalteromonas strains P1-7a, P1-9, P1-13-1a, P1-16-1b, P1-25, and P1-26, isolated from Hydractinia echinata. These genomes will allow detailed studies on bacterial factors mediating interkingdom communication.
2015: Genome Announcements
Jonathan L Klassen, Maja Rischer, Thomas Wolf, Huijuan Guo, Ekaterina Shelest, Jon Clardy, Christine Beemelmanns
The genomes of three Pseudoalteromonas strains (P1-8, P1-11, and P1-30) were sequenced and assembled. These genomes will inform future study of the genes responsible for the production of biologically active compounds responsible for these strains' antimicrobial, biofouling, and algicidal activities.
2015: Genome Announcements
Gary W Litman, Larry J Dishaw
Allorecognition in Hydractinia, a cnidarian, is governed by two different, highly polymorphic genes encoding transmembrane proteins. Using a fluorescent cell read-out system, a new study now shows that the basis for specificity involves homophilic interactions between extracellular domains.
November 2, 2015: Current Biology: CB
Uma B Karadge, Minja Gosto, Matthew L Nicotra
Sessile colonial invertebrates-animals such as sponges, corals, bryozoans, and ascidians-can distinguish between their own tissues and those of conspecifics upon contact [1]. This ability, called allorecognition, mediates spatial competition and can prevent stem cell parasitism by ensuring that colonies only fuse with self or close kin. In every taxon studied to date, allorecognition is controlled by one or more highly polymorphic genes [2-8]. However, in no case is it understood how the proteins encoded by these genes discriminate self from non-self...
November 2, 2015: Current Biology: CB
Steven M Sanders, Paulyn Cartwright
Hydrozoans are known for their complex life cycles, which can alternate between an asexually reproducing polyp stage and a sexually reproducing medusa stage. Most hydrozoan species, however, lack a free-living medusa stage and instead display a developmentally truncated form, called a medusoid or sporosac, which generally remains attached to the polyp. Although evolutionary transitions in medusa truncation and loss have been investigated phylogenetically, little is known about the genes involved in the development and loss of this life cycle stage...
August 2015: Genome Biology and Evolution
Álvaro L Peña Cantero
A number of benthic hydroid species inhabiting the Southern Ocean are insufficiently characterized. A revision of eight little-known Antarctic species of the order Anthoathecata was made, based on the study of type material. Some of the species have not been recorded since their original description a century ago. Four species (Bimeria corynopsis, Bougainvillia macloviana, ?Koellikerina belgicae and Rhizorhagium antarcticum) belong to the family Bougainvilliidae, two species (Hydractinia angusta and H. dendritica) to the family Hydractiniidae, Perarella clavata to the family Cytaeididae and, finally, Rhysia halecii to the family Rhysiidae...
June 12, 2015: Zootaxa
Brian Bradshaw, Kerry Thompson, Uri Frank
Cnidarians possess remarkable powers of regeneration, but the cellular and molecular mechanisms underlying this capability are unclear. Studying the hydrozoan Hydractinia echinata we show that a burst of stem cell proliferation occurs following decapitation, forming a blastema at the oral pole within 24 hr. This process is necessary for head regeneration. Knocking down Piwi1, Vasa, Pl10 or Ncol1 expressed by blastema cells inhibited regeneration but not blastema formation. EdU pulse-chase experiments and in vivo tracking of individual transgenic Piwi1(+) stem cells showed that the cellular source for blastema formation is migration of stem cells from a remote area...
2015: ELife
Toshio Takahashi, Noriyo Takeda
Cnidarians are the most primitive animals to possess a nervous system. This phylum is composed of the classes Scyphozoa (jellyfish), Cubozoa (box jellyfish), and Hydrozoa (e.g., Hydra, Hydractinia), which make up the subphylum Medusozoa, as well as the class Anthozoa (sea anemones and corals). Neuropeptides have an early evolutionary origin and are already abundant in cnidarians. For example, from the cnidarian Hydra, a key model system for studying the peptides involved in developmental and physiological processes, we identified a wide variety of novel neuropeptides from Hydra magnipapillata (the Hydra Peptide Project)...
2015: International Journal of Molecular Sciences
Yulia Kraus, Hakima Flici, Katrin Hensel, Günter Plickert, Thomas Leitz, Uri Frank
With the rapid increase of the quantity of molecular data, many animals joined the ranks of the so-called 'emerging models' of Evo-Devo. One of the necessary steps in converting an emerging model into an established one is gaining comprehensive knowledge of its normal embryonic development. The marine colonial hydrozoan Hydractinia echinata - an excellent model for research on stem cells, metamorphosis, and allorecognition - has been studied for decades. Yet knowledge of its embryonic development remains fragmentary and incomplete...
November 2014: Evolution & Development
Katrin Hensel, Tamar Lotan, Steve M Sanders, Paulyn Cartwright, Uri Frank
We have studied the evolution of Wnt genes in cnidarians and the expression pattern of all Wnt ligands in the hydrozoan Hydractinia echinata. Current views favor a scenario in which 12 Wnt sub-families were jointly inherited by cnidarians and bilaterians from their last common ancestor. Our phylogenetic analyses clustered all medusozoan genes in distinct, well-supported clades, but many orthologous relationships between medusozoan Wnts and anthozoan and bilaterian Wnt genes were poorly supported. Only seven anthozoan genes, Wnt2, Wnt4, Wnt5, Wnt6, Wnt 10, Wnt11, and Wnt16 were recovered with strong support with bilaterian genes and of those, only the Wnt2, Wnt5, Wnt11, and Wnt16 clades also included medusozoan genes...
September 2014: Evolution & Development
Sergiu Adrian Chicu, Melania Munteanu, Ioana Cîtu, Codruta Soica, Cristina Dehelean, Cristina Trandafirescu, Simona Funar-Timofei, Daniela Ionescu, Georgeta Maria Simu
Structure-toxicity relationships for a series of 75 azo and azo-anilide dyes and five diazonium salts were developed using Hydractinia echinata (H. echinata) as model species. In addition, based on these relationships, predictions for 58 other azo-dyes were made. The experimental results showed that the measured effectiveness Mlog(1/MRC50) does not depend on the number of azo groups or the ones corresponding to metobolites, but it is influenced by the number of anilide groups, as well as by the substituents' positions within molecules...
2014: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
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