Search results for "Ascidia"
showing 3 items of 63 documents
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…
The effect of L-thyroxine on the metamorphosis of Ascidia malaca
1981
Larvae of Ascidia malaca, both before and after hatching, were treated with L-thyroxine solutions. The effect of the thyroid hormone was to induce the onset of metamorphosis and then to cause the rate at which body reorganization occurred to increase. In treated larvae the resorption of the tail occurred only few hours after hatching, and a beating heart appeared form 10 to 15 h earlier than in the control larvae. These results are discussed in the context of a probable relationship between the occurrence of a hormonal metamorphic factor and the button cells of the trunk.
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…