Search results for " ascidian"

The Ciona intestinalis immune-related galectin genes (CiLgals-a and CiLgals-b) are expressed by the gastric epithelium.

2017

The transcription of two Ciona intestinalis galectin genes (CiLgals-a and CiLgalseb) is uparegulated by LPS in the pharynxis (hemocytes, vessel epithelium, endostilar zones) which is retained the main organ of the immunity. In this ascidian, for the first time we show, by immunohistochemistry and in situ hybridization methods, that these two immune-related genes are expressed in the gastric epithelium of naïve ascidians, whereas the galectins appear to be only contained in the intestine columnar epithelium. In addition, according to previous results on the pharynx, the genes are also expressed and galectins produced by hemocytes scattered in the connective tissue surrounding the gut. The ge…

Inflammatory responses of the ascidian Ciona intestinalis.

2008

«Correlation between granulocytes and tunic cuticle of Ciona intestinalis (Tunicata, Ascidiacea) as evaluated by microscopy»

2012

The tunic is a peculiar integumentary tissue covering the epidermis of ascidians and other tunicates. It is an extracellular matrix whose outermost surface is revealed to be a continuos layer called tunic cuticle, composed of electron dense fibrous materials. Mechanisms occurring during the growth of the animal after metamorphosis, must assure the maintenance of the thin tunic cuticle density and integrity as it represents the primary body surface barrier preventing the mechanical and microbial assaults. Investigations by optical and electron microscopy on tunic samples from young Ciona intestinalis, allowed us to study morphological relationship between the tunic cuticle architecture and g…

Routes in Innate Immunity Evolution: Galectins and Rhamnose-binding Lectins in Ascidians

2013

Inducible lectins with galectin properties and human IL1alpha epitopes opsonize yeast during the inflammatory response of the ascidian Ciona intestin…

2007

Studies on inducible ascidian lectins may shed light on the evolutionary emergence of cytokine functions. Here, we show that the levels of opsonins, with IL1alpha-epitopes, increase in Ciona intestinalis hemolymph as a response to an inflammatory stimulus and, in particular, to intratunic injection of lipopolysaccharide (LPS). The inflammatory agent promptly (within 4 h) enhances Ca(2+)-independent serum hemagglutinating and opsonizing activities, which are both inhibited by D-galactose and D-galactosides (alpha-lactose, N-acetyl-D-lactosamine, thio-digalactoside), suggesting that anti-rabbit erythrocyte lectins with galectin properties are involved as opsonins. Inducible galectin molecules…

CiC3-1a-Mediated Chemotaxis in the Deuterostome Invertebrate Ciona intestinalis (Urochordata)

2003

Abstract Deuterostome invertebrates possess complement genes, and in limited instances complement-mediated functions have been reported in these organisms. However, the organization of the complement pathway(s), as well as the functions exerted by the cloned gene products, are largely unknown. To address the issue of the presence of an inflammatory pathway in ascidians, we expressed in Escherichia coli the fragment of Ciona intestinalis C3-1 corresponding to mammalian complement C3a (rCiC3-1a) and assessed its chemotactic activity on C. intestinalis hemocytes. We found that the migration of C. intestinalis hemocytes toward rCiC3-1a was dose dependent, peaking at 500 nM, and was specific for…

Characterization and metal-induced gene transcription of two new copper zinc superoxide dismutases in the solitary ascidian Ciona intestinalis

2013

Antioxidant enzymes are known to protect living organisms against the oxidative stress risk, also induced by metals. In the present study, we describe the purification and molecular characterization of two Cu,Zn superoxide dismutases (SODs), referred to as Ci-SODa and Ci-SODb, from Ciona intestinalis, a basal chordate widely distributed in temperate shallow seawater. The putative amino acid sequences were compared with Cu,Zn SODs from other metazoans and phylogenetic analyses indicate that the two putative Ci-SODs are more related to invertebrate SODs than vertebrate ones. Both phylogenetic and preliminary homology modeling analyses suggest that Ci-SODa and Ci-SODb are extracellular and int…

Influence of cadmium on the morphology and functionality of haemocytes in the compound ascidian Botryllus schlosseri

2013

In order to get insights into the effects of cadmium (Cd) on cell morphology and functions, we exposed haemocytes of the colonial ascidian Botryllus schlosseri to sub-lethal concentrations of CdCl(2). Results indicate that Cd hampers haemocyte spreading and phagocytosis in a dose-dependent way, through the alteration of the actin cytoskeleton. In addition, the metal decreases the stability of the internal membranes, as revealed by the Neutral Red assay. The fraction of cells showing positivity for the lysosomal enzyme acid phosphatase is also reduced in the presence of Cd, whereas the number of cells responsive to the Annexin-V assay and showing chromatin condensation increases, suggesting …

Microscopic features of the tunic in young Styela canopus (Tunicata, Styelidae)

The tunic is a unique tissue in metazoans covering the epidermis of ascidians and other tunicates. The tunic is a multifunctional tissue that provides support, mechanical rigidity, and protection against infection and predation. The outermost surface of it is covered by a thin continuous layer called tunic cuticle. The tunic cuticle density and integrity must be maintained during the growth of the animal after metamorphosis, as it represents the primary body surface barrier preventing the mechanical damage. Using transmission electronic microscopy we attempted to characterize the cuticle morphology of young Styela canopus, a solitary ascidian (Styelidae), in comparison with the cuticle arch…

Characterization and transcription studies of a phytochelatin synthase gene from the solitary tunicate Ciona intestinalis exposed to cadmium.

2014

The major thiol-containing molecules involved in controlling the level of intracellular ROS in eukaryotes, acting as a nonenzymatic detoxification system, are metallothioneins (MTs), glutathione (GSH) and phytochelatins (PCs). Both MTs and GSH are well-known in the animal kingdom. PC was considered a prerogative of the plant kingdom but, in 2001, a phytochelatin synthase (PCS) gene was described in the nematode Caenorhabditis elegans; additional genes encoding this enzyme were later described in the earthworm Eisenia fetida and in the parasitic nematode Schistosoma mansoni but scanty data are available, up to now, for Deuterostomes. Here, we describe the molecular characteristics and transc…