https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:48379 Saccostrea glomerata. Oysters were exposed to a “low” and a “high” mixture of (xeno) estrogens (representative of Australian and global receiving waters respectively) for 7 days and digestive gland, gill, and gonad tissue were sampled for quantification of polar metabolites by ¹H NMR spectroscopy. Exposure to both mixtures lowered body mass and altered the metabolite profile in the digestive glands. Comparatively, gills, and ovaries demonstrated lesser sensitivity to the mixtures, with significant metabolomic alterations observed only for the high mixture. The male gonad did not respond to either estrogenic exposure. In the responsive tissues, major metabolites including amino acids, carbohydrates, intermediates of the tricarboxylic acid cycle and ATP were all down-regulated and exhibited tissue-specific patterns of down-regulation with the greatest proportion of metabolites down-regulated due to estrogenic exposure in the digestive gland. Exposure to (xeno) estrogen mixtures representative of concentrations reported in receiving waters in Australia and globally can impact the metabolome and associated energy metabolism, especially in the digestive gland, translating to lower pools of available ATP energy for potential cellular homeostasis, somatic maintenance and growth, reproduction and fitness.]]> Wed 15 Mar 2023 14:50:37 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:48355 Wed 15 Mar 2023 10:59:52 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:15688 Wed 11 Apr 2018 16:09:19 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:40286 1) and lower for Pb and As (root BCFs <1). Substantial barriers for translocation from roots to stems were identified for all metal(loid)s (stem TFs; 0.07-0.68). Conversely, unrestricted flow from stems to leaves was observed for all metal(loid)s at unity or higher (leaf TFs = 1). Strong linear relationships between sediment and root for Zn and Pb were observed, indicating roots as a useful bioindicator.]]> Wed 07 Jun 2023 11:49:24 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:39440 Wed 07 Jun 2023 10:32:24 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34448 Wed 04 Sep 2019 09:56:11 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:52185 Wed 04 Oct 2023 11:03:56 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:39208 1). Further, there is significant translocation from roots to shoot for Cu, Zn and Cd (≤ 1), however, Pb is less mobile (TF = 0.65). Patterns of accumulation were similar among families, except greater Cd accumulation to roots in members of Juncaceae. Patterns of uptake to roots and translocation to leaves were broadly similar among plant type, plant form, habitat and photosynthetic mode. Zinc is lower in the leaves of salt-secreting species for some closely related taxa, suggesting some species co-excrete sodium (Na⁺) and Zn²⁺ through glands in leaf tissue. Salinity tolerance has no relationship to metal uptake and translocation. Translocation of Zn is greater at lower Zn sediment exposures, reflecting its active uptake and essentiality, but such bias does not affect outcomes of analyses when included as a covariate.]]> Wed 03 May 2023 14:02:01 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:47030 Tue 13 Dec 2022 14:08:40 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:43844 Tue 04 Oct 2022 11:53:44 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:29784 sgER) and the 5'-flanking region of the gene from the Sydney rock oyster Saccostrea glomerata. The sgER cDNA is predicted to encode a 477-amino acid protein that contains a DNA-binding domain (DBD) and a ligand-binding domain (LBD) typically conserved among both vertebrate and invertebrate ERs. A comparison of the sgER LBD sequence with those of other ligand-dependent ERs revealed that the sgER LBD is variable at several conserved residues known to be critical for ligand binding and receptor activation. Ligand binding assays using fluorescent-labelled E2 and purified sgER protein confirmed that sgER is devoid of estrogen binding. In silico analysis of the sgER 5'-flanking sequence indicated the presence of three putative estrogen responsive element (ERE) half-sites and several putative sites for ER-interacting transcription factors, suggesting that the sgER promoter may be autoregulated by its own gene product. sgER mRNA is ubiquitously expressed in adult oyster tissues, with the highest expression found in the ovary. Ovarian expression of sgER mRNA was significantly upregulated following in vitro and in vivo exposure to 17β-estradiol (E2). Notably, the activation of sgER expression by E2 in vitro was abolished by the specific ER antagonist ICI 182, 780. To determine whether sgER expression is epigenetically regulated, the in vivo DNA methylation status of the putative proximal promoter in ovarian tissues was assessed using bisulfite genomic sequencing. The results showed that the promoter is predominantly hypomethylated(with 0–3.3% methylcytosines) regardless of sgER mRNA levels. Overall, our investigations suggest thatthe estrogen responsiveness of sgER is regulated by a novel ligand-dependent receptor, presumably via a non-genomic pathway(s) of estrogen signalling.]]> Thu 14 Sep 2017 11:29:22 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34680 50's of their offspring. Zn tolerance was lost after translocation. Zn EC₅₀ values of offspring from transplanted adults bore no relation to the Zn EC₅₀'s of their location of origin. Thus the initial tolerance observed could be attributed to acclimation transferred to the F₁ generation.]]> Thu 11 Apr 2019 15:08:32 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:9606 Sat 24 Mar 2018 08:39:39 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:10574 Sat 24 Mar 2018 08:10:44 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:21764 –1) from 0–72 h postfertilization (hpf), a developmental window when steroidogenesis is unregulated by pituitary influence, resulted in the up-regulation of cyp11a, cyp17, and 3β-hsd and the down-regulation of cyp19a. Similar gene expression patterns were observed for embryos exposed to 10 mM cobalt chloride (CoCl₂, a chemical inducer of hypoxia-inducible factor 1, HIF-1), suggesting a regulatory role of HIF-1 in steroidogenesis. Testosterone (T) and estradiol (E2) concentrations in hypoxic embryos were greater and lesser, respectively, relative to the normoxic control, thus leading to an increased T/E2 ratio. Expression of the leptin-a gene (zlep-a) was up-regulated upon both hypoxia and CoCl₂ treatments. Functional assays suggested that under hypoxia, elevated zlep-a expression might activate cyp11a and 3β-hsd and inhibit cyp19a. Overall, this study indicates that hypoxia, possibly via HIF-1-induced leptin expression, modulates sex steroid synthesis by acting directly on steroidogenic gene expression.]]> Sat 24 Mar 2018 07:53:07 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27283 Sat 24 Mar 2018 07:40:21 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:24686 Sat 24 Mar 2018 07:10:54 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34744 Sarcocornia quinqueflora), across three contaminated estuaries in New South Wales, Australia. Average sediment concentrations ranged from 62 to 764 μg/g for Zn, 20–52 μg/g for Cu, 27–311 μg/g for Pb and 0.45–1.90 μg/g for Cd across estuaries. Lake Macquarie was the most contaminated estuary, with the Hunter River estuary and Sydney Olympic Park exhibiting intermediate levels of sediment metal contamination. Bioconcentration factors for metal uptake from sediment to roots were ≥ 1 (except for Cu). Translocation within the plant was low for most metals, with apparent barriers to transport identified at the root: non-photosynthetic stem interface for Zn, Cu, Pb and Cd, and at the non-photosynthetic stem: photosynthetic stem transition for Pb and Cd. All metals accumulated in roots with increasing sediment exposure, and lower soil organic matter predicted greater Pb and Cu uptake to roots. Further, increases in sediment pH predicted greater Cd root accumulation. However, transport was regulated to the non-photosynthetic stem for Zn, and to the PS stem for Zn and Pb. In terms of employing S. quinqueflora as a bioindicator, all root metals, and Pb and Cd in non-photosynthetic stem tissue exhibited relationships with sediment metal loads, though high variability made their predictive ability limited.]]> Mon 15 May 2023 11:31:26 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46223 Mon 14 Nov 2022 12:11:57 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34582 Fri 29 Mar 2019 11:40:28 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:43556 Fri 23 Sep 2022 10:33:22 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:44521 Sporobolus virginicus, across three urbanised estuaries in NSW Australia. Lake Macquarie was the most contaminated estuary, while Sydney Olympic Park, Port Jackson exhibited intermediate metal(loid) loadings and Hunter Wetlands exhibited the lowest loadings among estuaries. Essential metals (Zn and Cu) were more mobile, with sediment:root bioconcentration factors (BCFs) greater than unity and translocation among plant organs greater than, or equal to, unity. Other metal(loid)s were less mobile, with BCFs equal to unity and translocation factors among organs much reduced. Despite these barriers to translocation, all metal(loid)s were accumulated to roots with dose, and further accumulative relationships between metal(loid)s in roots and culms, and culms and leaves, were evidenced (with the exception of Cu). Along with sediment metal(loid)s, increases in sediment pH predicted Cu uptake in roots and increases in soil organic matter predicted Se uptake in roots. Although significant positive linear relationships were observed between sediment metal(loid)s and plant organ metal(loid)s(withholding Cu), the variance explained was low to intermediate for most metal(loid)s suggesting employing S. virginicus as an accumulative bioindicator would be impractical.]]> Fri 14 Oct 2022 11:18:58 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34757 Fri 05 May 2023 15:48:50 AEST ]]>