Search results for " hemocytes"
showing 10 items of 15 documents
Cellular encapsulation in the eastern subterranean termite, Reticulitermes flavipes (Isoptera), against infection by the entomopathogenic fungus Meta…
2009
Reticulitermes flavipes workers were topically inoculated with approximately 10,000 conidia of the entomopathogenic fungus Metarhizium anisopliae. After being kept in groups of 20 individuals for 1-9 d, histopathological examination showed that termites had an individual immune reaction. The nodule formation at the point of entrance of the fungal hyphae was identified as a cellular encapsulation and the different steps in the nodule formation are described. The relative number of hemocytes per termite increased 24h after fungal exposure and remained high in the hemolymph for at least 3 d before decreasing back to pre-exposure levels. The role of an individual immune cellular reaction in soc…
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…
The ascidian Styela plicata hemocytes as a potential biomarker of marine pollution: In vitro effects of seawater and organic mercury.
2017
Toxic metals, such as mercury, contribute substantially to anthropogenic pollution in many estuarine environments. Animals living in those environments, particularly invertebrate filter feeders like tunicates, can be used as bioindicators. In an attempt to identify cellular markers for revealing pollution, this study examined in vitro the effects of different concentrations of methyl mercury on Styela plicata hemocytes. The harvested hemocytes from S. plicata that were exposed to the metal had a significant mortality, cellular count and morphometric alterations. These findings provided evidence of MeHg immunotoxic effects on S. plicata, resulting in hemocyte death and morphological changes …
Effetti tossici del metilmercurio sulle risposte immunitarie dell'ascidia Styela plicata
2008
Morphological characterization and acetylcholinesterase activity in Ciona intestinalis hemocytes
2008
An Attempt to re-examine the immune role of Ciona intestinalis hemocytes
2009
Enhanced expression of a cloned and sequenced Ciona intestinalis TNFa-like (CiTNFa) gene during the LPS-induced inflammatory response.
2008
A tumor necrosis factor-alpha (TNFalpha)-like gene from Ciona intestinalis (CiTNF alpha-like) body wall challenged with bacterial lipopolysaccharide (LPS) was cloned and sequenced 4 h after LPS inoculation. An open reading frame of 936 bp encoding a propeptide of 312 amino acids (35.4 kDa) displaying a transmembrane domain from positions 7 to 29, a TACE cleavage site, and a mature peptide domain of 185 amino acids (20.9 kDa), was determined with a predicted isoelectric point of 9.4. The phylogenetic tree based on deduced amino acid sequences of invertebrate TNF-like protein and vertebrate TNFs supported the divergence between the ascidian and vertebrate TNF families, whereas D. melanogaster…
METHYLMERCURY EFFECTS ON Mytilus galloprovincialis HAEMOCYTES ACTIVITY
2021
Bivalves, filter-feeding organisms, due to their wide distri-bution, are used by many countries in biomonitoring, particu-larly in the assessment of xenobiotics in the marine ecosystem.These sentinel organisms are able to accumulate trace metalsand other substances in their tissues. Haemocytes are effectorsof cellular immunity in bivalves and are capable of respond-ing to stressors through activities such as phagocytosis or cyto-toxicity. In order to identify cellular markers to investigate pol-lution, the effect of different concentrations of organic mercury(CH3HgCl) on the morphology and responses of Mytilus gal-loprovincialishaemocytes was studied in this work. Sublethalconcentrations of…
The conservation and diversity of ascidian cells and molecules involved in the inflammatory reaction: The Ciona robusta model
2021
Ascidians are marine invertebrate chordates belonging to the earliest branch (Tunicata) in the chordate phylum, therefore, they are of interest for studying the evolution of immune systems. Due to the known genome, the non-colonial Ciona robusta, previously considered to be C. intestinalis type A, is a model species for the study of inflammatory response. The internal defense of ascidians mainly relies on hemocytes circulating in the hemolymph and pharynx. Hemocytes can be in vivo challenged by LPS injection and various granulocyte and vacuolated cell populations differentiated to produce and release inflammatory factors. Molecular biology and gene expression studies revealed complex defens…
Effect of Bacillus thuringiensis as vegetative form on hemocytes of Rhynchophorous ferrugineus (Coleoptera Curculionidae) larvae
2010
The bacterium Bacillus thuringiensis (Bt) is a pathogen of many insect species and is actively used in biocontrol. The vegetative form as been reported to be involved in insect septicemia process. Bt during the vegetative stage of growth, is known to secern a new family of insecticidal proteins. Moreover recently evidence has been provided, that B. thuringiensis can establish itself in replicative and vegetative form on the leaf surface. Little is known on the interaction of pathogens with the defense responses of phytophagous insects. Insect circulating hemocytes are primarily responsible for the immune defense against parasites and pathogens. We use as model Rhynchophorous ferrugineus Oli…