Consulta: subjectFacets:"Ascidian"
Registros recuperados: 5
Data/hora: 06/06/2024 10:37:31

Msxb is a core component of the genetic circuitry specifying the dorsal and ventral neurogenic midlines in the ascidian embryo
Provedor de dados: 5
Autores: Roure, Agnes; Darras, Sebastien.
The tail ascidian larval peripheral nervous system is made up of epidermal sensory neurons distributed more or less regularly in ventral and dorsal midlines. Their formation occurs in two-steps: the ventral and dorsal midlines are induced as neurogenic territories by Fgf9/-16/20 and Admp respectively. The Delta2/Notch interaction,then controls the number of neurons that form. The genetic machinery acting between the inductive processes taking place before gastrulation and neuron specification at tailbud stages are largely unknown. The analysis of seven transcription factors expressed in the forming midlines revealed an unexpected complexity and dynamic of gene expression. Their systematic overexpression confirmed that these genes do not interact following...
Tipo: Text
Palavras-chave: Ascidian; Gene regulatory network; Transcription factors; Peripheral nervous system; Neurogenic.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00374/48557/48984.pdf

Trophic relationships between the farmed pearl oyster Pinctada margaritifera and its epibionts revealed by stable isotopes and feeding experiments
Provedor de dados: 5
Autores: Lacoste, Elise; Raimbault, Patrick; Harmelin-vivien, Mireille; Gaertner-mazouni, Nabila.
Bivalve cultures support a host of epibionts, mainly suspension feeders, which can compete for food resources with the cultivated bivalves. However, the magnitude of interspecific competition for food in bivalve aquaculture settings remains inconclusive, especially in tropical areas. We investigated the interactions for food between the farmed pearl oyster Pinctada margaritifera and its epibionts, using stable isotope analysis and feeding experiments. Inter-and intraspecific variations of delta C-13 and delta N-15 stable isotope ratios (SIRs) were determined for oysters in the presence or absence of epibionts. The diet of the most abundant epibionts, Herdmania momus and Didemnum sp., was specified using isotope measurements and flow cytometry during...
Tipo: Text
Palavras-chave: Ascidian; Biofouling; Trophic interactions; Stable isotope; Flow cytometry.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00664/77582/79564.pdf

Description of Sidneioides peregrinus sp. nov. (Tunicata: Ascidiacea: Polyclinidae): a possible exotic species in the Atlantic Ocean
Provedor de dados: 103
Autores: Kremer,Laura Pioli; Metri,Rafael; Rocha,Rosana Moreira da.
Three species of Sidneioides Kesteven, 1909 were known until now, all of them from the western Pacific. Sidneioides peregrinus is a new species we found in Paranaguá Bay, southern Brazil. Diagnostic characteristics of the species are: colonies with 1-5 lobes, closely clumped, and attached by the entire basal area or by a common smaller area; seven to ten thin longitudinal fiber muscles (some branched) along the anterior two thirds of the thorax; no transverse muscle fibers; more than 30 tentacles of three orders forming one circle; pharynx with 10 to 12 rows of stigmata with 13 to 15 stigmata in each half row; bilobed anus at the level of the fourth or fifth row of stigmata; posterior abdomen not very elongated, oval, and joined to the abdomen by a narrow...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ascidian; Brazil; Encrusting community; New species; Species introduction.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702011000600012

Structure and anticoagulant properties of sulfated glycosaminoglycans from primitive Chordates
Provedor de dados: 42
Autores: PAVÃO,MAURO S. G.
Dermatan sulfates and heparin, similar to the mammalian glycosaminoglycans, but with differences in the degree and position of sulfation were previously isolated from the body of the ascidian Styela plicata and Ascidia nigra. These differences produce profound effects on their anticoagulant properties. S. plicata dermatan sulfate composed by 2-O-sulfatedalpha-L-iduronic acid and 4-O-sulfated N-acetyl-beta-D-galactosamine residues is a potent anticoagulant due to a high heparin cofactor II activity. Surprisingly, it has a lower potency to prevent thrombus formation on an experimental model and a lower bleeding effect in rats than the mammalian dermatan sulfate. In contrast, A. nigra dermatan sulfate, also enriched in 2-O-sulfated alpha-L-iduronic acid, but...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ascidian; Heparin; Dermatan sulfate; Heparin cofactor II; Anticoagulant; Antithrombotic.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652002000100007

In vivo antithrombotic properties of a heparin from the oocyte test cells of the sea squirt Styela plicata(Chordata-Tunicata)
Provedor de dados: 56
Autores: Cardilo-Reis,L.; Cavalcante,M.C.M.; Silveira,C.B.M.; Pavão,M.S.G.
In the ascidian Styela plicata, the oocytes are surrounded by two types of accessory cells named follicle cells and test cells. A heparin-like substance with an anticoagulant activity equivalent to 10% of mammalian heparin and about 5% as potent as the mammalian counterpart for the inhibition of thrombin by antithrombin was isolated from the oocyte test cells. In the present study, we compared the antithrombotic and hemorrhagic effects of sea squirt oocyte test cell heparin with those of porcine heparin in rat models of venous thrombosis and blood loss. Intravenous administration of the oocyte test cell heparin to Wistar rats (both sexes, weighing ~300 g, N = 4 in each group) at a dose of 5.0 mg/kg body weight, which produced a 1.8-fold increase in plasma...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ascidian; Heparin; Experimental thrombosis; Antithrombotics; Hemorrhage.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006001100004