Search results for "Ciona intestinali"
showing 10 items of 113 documents
Organometallic complexes with biological molecules. XV. Effects of tributyltin(IV)chloride on enzyme activity, Ca2+, and biomolecule and synthesis in…
2001
Considerable attention has been given in recent years to the possibility that xenobiotics in the environment may affect reproduction in animals. In this study, the relative impact of tributyltin(IV) (TBT) chloride, one of the most toxic environmental pollutants, was investigated using Ciona intestinalis ovary as a model system. The pleiotropic effects of TBT exposure are concentration dependent and include a decrease of ATP levels, lipid content and nucleic acid content and synthesis. In contrast, a marked increase in calcium (Ca2+) and glucose content is observed. Furthermore, TBT alters enzymatic activity, inhibiting creatine kinase and stimulating alkaline phosphatase and cholinesterase …
cytokines in the inflammatory response of the ascidian ciona intestinalis
2015
The Ciona intestinalis inflammatory response to several irritants have been demonstrated to be composed of a complex set reaction. The cellular reactions involve hemocyte infiltration, hemocyte and epidermis activities, vacuolization, cell disruption, while cell products can contribute to form capsule components and/or cause a wound. In this response the involvement of the pharynx, as the main immune-competent organ, has been disclosed by lipopolysaccharide (LPS) challenge that upregulates innate immunity genes. In vertebrate cytokines modulate the balance between humoral and cell-based immune responses, and they regulate the maturation, growth, and responsiveness of cell populations that h…
Primo ricerche sulla ultrastruttura dell'uovo delle Ascidie
1959
Summary The cytoplasmic constituents of the unfertilized eggs of Ciona intestinalis were separated by centrifugation and studied at the electron microscope, with the following results. Lipid droplets collect at the centripetal pole; they are boundered by a thin membrane. The yolk granules are homogeneous in appearance; a few have a granular structure. Mitochondria contain numerous cristae; they accumulate in two different layers centripetally and centrifugally to the yolk granules layer respectively. Basophilic material collects at both poles of the egg in two hyaline caps: a centripetal one constituted by small Vesicles and a centrifugal represented by dense clumps. The latter, as well as …
Inflammatory hemocytes in Ciona intestinalis innate immune response
2009
In the present paper an attempt is carried out to revise Ciona intestinalis inflammatory hemocytes according to their morphology as formerly observed by light and electron microscopy, and taking in account recent reports on innate immunity gene expression. We also examine hemocyte morphofunctional aspects as derived from previous papers that refer to the tunic and body wall inflammatory responses challenged by corpusculate or soluble agents. LPS inoculation into the body wall or treating hemocytes in vitro with LPS have also been taken in account. LPS inoculation stimulated the expression of CiTNF alpha, CiFACIT- alpha chain collagen, CiC3a, CiCD94 and enhanced phenoloxidase activity. These…
Nuovi dati sull'attivazione della profenolossidasi di Ciona intestinalis nel processo infiammatorio
2009
Focusing on Ciona intestinalis (Tunicata) innate immune system. Evolutionary implications
2009
Phylogenetic analyses based on molecular data provide compelling evidence that ascidians are of critical importance for studying chordate immune system evolution. The Ciona intestinalis draft genome sequence allows searches for phylogenetic relationships, gene cloning and expression of immunorelevant molecules. Acidians lack of the pivotal components of the vertebrate recombinatory adaptive immunity, i.e., MHC, TCRs and dimeric immunoglobulins. However, bioinformatic sequence analyses recognized genic elements indicating the essential features of the Ig superfamily and ancestor proto-MHC genes, suggesting a primitive pre-duplication and pre-recombination status. C. intestinalis genes for in…
Ciona intestinalis integriinin α2I-domeenin geenin kokoaminen ja proteiinin tuottaminen
2006
Presence of thyroid hormones in ascidian larvae and their involvement in metamorphosis
2001
In this study we investigated the presence and localization of thyroxine in Ciona intestinalis larvae and its involvement in metamorphosis. To date, the mechanisms regulating the metamorphosis of ascidians remain largely unknown. In vivo treatment of swimming larvae with exogenous L-thyroxine and thiourea, and in vitro experiments utilizing high performance liquid chromatography, radioimmunoassay, and immunoperoxidase staining demonstrate the presence of thyroxine at the larval stage. This suggests that this hormone may participate in the control of metamorphosis and thus play a different role from that observed in adults.