Search results for "Ascidia"

Effects of tributyltin(IV) chloride on fertilization of Styela plicata (Ascidiacea: Tunicata): II. Scanning and transmission electron microscopy stud…

2003

The morphological aspects of Styela plicata fertilization after treatment with tributyltin(IV) chloride are described by means of scanning and transmission electron microscopy investigations. Alterations have been shown both on female and male gametes; spermatozoa, all the egg envelopes and the mitochondria of the egg cortical cytoplasm are modified in relation to incubation time. As a consequence, the damage to gametes blocks sperm-egg interaction and fertilization does not occur. Copyright © 2003 John Wiley & Sons, Ltd.

The Inflammatory Response of Urochordata: The Basic Process of the Ascidians’ Innate Immunity

2018

Ascidians form a widespread marine invertebrate group and are heterogeneous in terms of the taxonomic groups’ evolutionary lineages. The ascidian genomes lack significant homologies for rearranging genes of the vertebrate adoptive immunity. Genome analysis, gene sequencing, and transcriptional profiling have allowed us to disclose upregulation of innate immunity genes and cell labeling with riboprobes and antibodies has identified hemocyte types in tunic and pharynx inflammatory responses. Lymphocyte-like cells are stem cells and their immunocompetence has been proposed. Granulocyte types (compartment/morula cells) and hemocytes with large granules/vacuoles (compartment/morula cells) are ma…

Ciona intestinalis interleukin 17-like genes expression is upregulated by LPS challenge

2015

In humans, IL-17 is a proinflammatory cytokine that plays a key role in the clearance of extracellular bacteria promoting cell infiltration and production of several cytokines and chemokines. Here, we report on three Ciona intestinalis IL-17 homologues (CiIL17-1, CiIL17-2, CiIL17-3). The gene organisation, phylogenetic tree and modelling supported the close relationship with the mammalian IL-17A and IL-17F suggesting that the C. intestinalis IL-17 genes share a common ancestor in the chordate lineages. Real time PCR analysis showed a prompt expression induced by LPS inoculation suggesting that they are involved in the first phase of inflammatory response. In situ hybridization assays disclo…

Upregulated transcription of phenoloxidase genes in the pharynx and endostyle of Ciona intestinalis in response to LPS

2015

We investigated the role of phenoloxidases (POs) in ascidians inflammatory reaction, a components of a copper-containing protein family involved in invertebrate immune system. In Ciona intestinalis two phenoloxidases (CinPO-1, CinPO-2) have been sequenced. In the present study, real time PCR analysis showed that both CinPO-1 and CinPO-2 genes were modulated by LPS inoculation suggesting that they are inducible and highly expressed in the inflamed pharynx. In situ hybridization disclosed CinPO-1 and CinPO-2 transcripts in pharynx hemocytes (granulocytes) and, mainly, in unilocular refractile granulocytes (URG) which mainly populated the inflamed tunic matrix. Interestingly, the genes are als…

Acetylcholinesterase activity in juvenileCiona intestinalis(Ascidiacea, Urochordata) after exposure to tributyltin

2012

The acetylcholinesterase (AChE) activity has been studied in 4-day post-fertilization juveniles of Ciona intestinalis exposed to tributyltin (TBT) at 10-5 M using the histochemical method of Karnovsky and Roots. Relative to vertebrate tissues and organs, the development of adult form of ascidians is interesting, because the analysis of many nuclear genes indicated that the ascidians are the closest living relatives of the vertebrates. Therefore, toxicity research using different approaches could provide data for comparative studies with vertebrates. AChE is over-expressed under chemical stress and in some diseases of vertebrates. Therefore, AChE is considered a biomarker of environmental co…

COMPARATIVE ULTRASTRUCTURAL INVESTIGATION ON THE ADHESIVE PAPILLAE OF THE SWIMMING LARVAE OF THREE ASCIDIAE SPECIES

2008

Ascidian swimming larvae bear three peculiar organs of ectodermic origin, named “palps” or adhesive papillae, located in the anterior region of cephalenteron. Term “adhesive” is correlated to one of the function of these structure based on secretion of an adhesive substance which enables swimming larvae to adhere to a substratum. Recently a sensory function has also been described in some Phlebobranchia papillae with a simple morpho-functional organization. There are few ultrastructural investigations in literature, sometimes disputed, able to make clear papillae cells functions. To clarify this problem, a comparative investigation has been carried out, just in this work, about ultrastructu…

Inflammatory responses of the ascidian Ciona intestinalis.

2008

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 …

Bisphenol A (BPA) and atrazine inhibit the embryonic development ofCiona intestinalis(Ascidiacea, Urochordata)

2013

The toxicities of bisphenol A (BPA) and atrazine in Ciona intestinalis development were examined in two separate series of experiments. The fertilized eggs were exposed to BPA or atrazine at concen...

Inflammatory Response of the Ascidian Ciona intestinalis

2016

Abstract The Ciona intestinalis inflammatory response to several irritants appears to be composed of a complex reaction set. The cellular reactions in the tunic involve hemocyte infiltration, hemocyte and epidermis activities, vacuolization, and cell disruption, while cell products can contribute to form capsule components and/or cause a tunic wound. In this response, the involvement of the pharynx, as the main immune-competent organ, has been disclosed by a lipopolysaccharide challenge that upregulates innate immunity genes and transcription activation genes. The pharynx responds through hemocyte recruitment into the pharynx vessels, enhancement of galectin-like lectins in the serum hemoly…