Search results for "vitellogenin"
showing 10 items of 33 documents
Glutathionyl-biliverdin IXα, a new heme catabolite in a marine annelid: Sex and cell specific accumulation.
2011
Abstract We have isolated and characterized the green pigment accumulating in coelomic cells (eleocytes) of the common clam worm Nereis virens by means of RP-HPLC and ESI-tandem mass spectrometry. This pigment is a novel biliverdin-glutathione conjugate in which the glutathione is linked to the biliverdin-backbone via a thioether bond. The yolk precursor vitellogenin, a female-specific high-density lipoprotein ( ρ = 1179 kg/m 3 ) with a native molecular mass of ∼500 kDa and a subunit mass of ∼150 kDa, is capable of transporting this pigment as well as heme. The sex-independent large discoidal lipoprotein present in the coelomic fluid, which is sequestered by the eleocytes, could also be sh…
Physiological effects of tricyclazole on zebrafish (Danio rerio) and post-exposure recovery
2009
Short-term effects of tricyclazole on male zebrafish (Danio rerio) physiology were examined joint to the degree of recovery after exposure. Fish were exposed to 142 microg/L (1/100 LC(50)-96 h) of tricyclazole for 7 (Exp.1) and 14 days (Exp.2) and then allowed to recover for 7 or 14 more days, respectively. Whole-body triglycerides, cholesterol, glucose, lactate and total proteins were measured as well as the aspartate aminotransferase (AAT), alanine aminotransferase (AlAT), alkaline phosphatase (AP) and lactate dehydrogenase (LDH) activities as biomarkers of intermediary metabolism; gamma-glutamyl transpeptidase (gammaGT) as biomarker of oxidative detoxification processes and vitellogenin …
Vitellogenin polypeptide levels in one susceptible and one cadmium-resistant strain of Oncopeltus fasciatus (Heteroptera: Lygaeidae), and its role in…
2005
The heavy metal Cd has recently been shown to have endocrine disrupting activity in different vertebrate species. In the insect Oncopeltus fasciatus, Cd exposure delays ovarian maturation and inhibits vitellogenesis, probably through a reduction in vitellogenin (Vg) polypeptide synthesis. An O. fasciatus strain was selected in the laboratory for Cd resistance with gradually increasing Cd concentrations for 50 generations. Cd-selected (OCdR) insects were 2.7-2.3 times more resistant to chronic exposure to Cd than susceptible (OS) insects. OCdR females showed increased (up to 90%) Vg polypeptide levels in hemolymph. Vg polypeptide synthesis was equally decreased in OCdR and OS females after a…
Short-term exposure to sublethal tebuconazole induces physiological impairment in male zebrafish (Danio rerio).
2010
Abstract The aim of the present study was to assess the physiological response of male zebrafish Danio rerio to the fungicide tebuconazole and recovery in fungicide-free water. Acute toxicity tests were carried out and the median lethal concentration (LC 50 ) from 24 to 96 h was calculated. The fish were exposed to a sublethal fungicide concentration of 230 μg/L for 7 or 14 days and allowed to recover for 7 or 14 more days, respectively. Whole-body levels of vitellogenins, triglycerides, cholesterol, glucose, lactate and proteins as well as the activities γ-glutamil transpeptidase (γ-GT), alanin aminotransferase (AlAT), alkaline phosphatase (AP) and lactate dehydrogenase (LDH) were assayed;…
Vitellogenin from female and estradiol-stimulated male river lampreys (Lampetra fluviatilis L.)
2001
The influence of estradiol-17β (E2) on vitellogenesis is well documented for a number of oviparous craniates. We have examined the role that estradiol-17β plays in the induction and regulation of vitellogenin synthesis in the maturing European river lamprey, Lampetra fluviatilis. In both females and males the estradiol-17β concentrations in the plasma reached comparable maximum values in March, only a few weeks before spawning. Throughout the spawning run, the vitellogenin titer in the blood of females remains rather constant while the ovary volume increases. In contrast, we never found circulating VTG in untreated male lampreys. The synthesis and secretion of the yolk precursor molecule ca…
Regulation of vitellogenesis in Nereis virens (Annelida: Polychaeta): effect of estradiol-17beta on eleocytes.
2005
Abstract In the marine polychaete Nereis virens , the yolk protein precursor vitellogenin (Vg) is synthesized in specialized coelomic cells (eleocytes) during oogenesis. This process was visualized by immunohistochemistry using antibodies raised against the yolk protein. Transversal sections from male and female worms confirmed that eleocytes from females but not from males produce Vg. In order to investigate the hormonal regulation of Vg synthesis, eleocytes were incubated in vitro with estradiol-17β (E 2 ) at a concentration of 1 μg/l for up to three days. A strong increase in Vg secretion was detected by ELISA in culture media of treated eleocytes from vitellogenic females. In contrast, …
Honey Bee Suppresses the Parasitic Mite Vitellogenin by Antimicrobial Peptide
2020
AbstractThe negative effects of honey bee parasitic mites and deformed wing virus (DWV) on honey bee and colony health have been well characterized. However, the relationship between DWV and mites, particularly viral replication inside the mites, remains unclear. Furthermore, the physiological outcomes of honey bee immune responses stimulated by DWV and the mite to the host (honey bee) and perhaps the pathogen/parasite (DWV/mite) are not yet understood. To answer these questions, we studied the tripartite interactions between the honey bee,Tropilaelaps mercedesae, and DWV as the model.T. mercedesaefunctioned as a vector for DWV without supporting active viral replication. Thus, DWV negligib…
Expression of the Vitellogenin Gene in the Liver of Juvenile Whitefish (Coregonus lavaretus L. s.l.) Exposed to Effluents from Pulp and Paper Mills
1999
Juvenile whitefish (Coregonus lavaretus L. s.l.) were exposed by caging in the field to diluted effluents from three operating pulp, paper, and paperboard mills in Southern Lake Saimaa, Finland. The expression of the vitellogenin gene, used as a biomarker of estrogenic contamination of effluents, was measured using a Northern blotting method. Increased mRNA levels, the most specific and reliable evidence for estrogen receptor-mediated actions in vivo, were found in fish caged in the vicinity of one of three mills studied. This mill was found to discharge wood-derived compounds, such as sterols and resin acids, into Lake Saimaa in amounts considerably exceeding those from the other two mills…
Reproductive, biochemical, physiological, and population responses in perch (Perca fluviatilisL.) and roach (Rutilus rutilusL.) downstream of two ele…
2001
Perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) populations in a state of late vitellogenesis were studied downstream of two pulp and paper mills and at upstream references in southern Lake Saimaa, Finland. The mills used elemental chlorine-free bleaching and activated sludge effluent treatment technologies. The exposure of fish to pulp mill effluents, as measured by concentrations of chlorophenolics in the bile and liver ethoxyresorufin-O-deethylase (EROD) activity, was low and almost similar to the references. Nevertheless, bile resin acid concentrations in exposed perch and roach (260-320 micrograms/ml) and bile beta-sitosterol concentrations in exposed roach (1.5-3.5 microgr…
Sialotranscriptomics of the argasid tick ornithodoros moubata along the trophogonic cycle
2021
32 páginas, 8 tablas, 6 figuras