Poster: ECR 2016 / B-0631 / Comparison between CT Net enhancement and PET/CT SUV for N staging of gastric cancer by: A. A. Stabile Ianora, N. M. LUCARELLI , M. Telegrafo, A. Scardapane, A. A. Niccoli, P. Pignataro, M. Moschetta, G. Angelelli; Bari/IT
Abstract Background Copepods are fundamental components of pelagic food webs, but reports on how molecular responses link to reproductive success in natural populations are still scarce. We present a de novo transcriptome assembly and differential expression (DE) analysis in Temora stylifera females collected in the Gulf of Naples, Mediterranean Sea, where this copepod dominates the zooplankton community. High-Throughput RNA-Sequencing and DE analysis were performed from adult females collected on consecutive weeks (May 23rd and 30th 2017), because opposite naupliar survival rates were observed. We aimed at detecting key genes that may have influenced copepod reproductive potential in natural populations and whose expression was potentially affected by phytoplankton-derived oxylipins, lipoxygenase-derived products strongly impacting copepod naupliar survival. Results On the two sampling dates, temperature, salinity, pH and oxygen remained stable, while variations in phytoplankton cell concentration, oxylipin concentration and oxylipin-per-diatom-cell production were observed. T. stylifera naupliar survival was 25% on May 23rd and 93% on May 30th. De novo assembly generated 268,665 transcripts (isoforms) and 120,749 unique ‘Trinity predicted genes’ (unigenes), of which 50% were functionally annotated. Out of the 331 transcript isoforms differentially expressed between the two sampling dates, 119 sequences were functionally annotated (58 up- and 61 down-regulated). Among predicted genes (unigenes), 144 sequences were differentially expressed and 31 (6 up-regulated and 25 down-regulated) were functionally annotated. Most of the significantly down-regulated unigenes and isoforms were A5 Putative Odorant Binding Protein ( Obp ). Other differentially expressed sequences (isoforms and unigenes) related to developmental metabolic processes, protein ubiquitination, response to stress, oxidation-reduction reactions and hydrolase activities. DE analysis was validated through Real Time-quantitative PCR of 9 unigenes and 3 isoforms. Conclusions Differential expression of sequences involved in signal detection and transduction, cell differentiation and development offered a functional interpretation to the maternally-mediated low naupliar survival rates observed in samples collected on May 23rd. Down-regulation of A5 Obp along with higher quantities of oxylipins-per-litre and oxylipins-per-diatom-cell observed on May 23rd could suggest oxylipin-mediated impairment of naupliar survival in natural populations of T. stylifera . Our results may help identify biomarker genes explaining variations in copepod reproductive responses at a molecular level.
Marine organisms possess a series of cellular strategies to counteract the negative effects of toxic compounds, including the massive reorganization of gene expression networks. Here we report the modulated dose-dependent response of activated genes by diatom polyunsaturated aldehydes (PUAs) in the sea urchin Paracentrotus lividus. PUAs are secondary metabolites deriving from the oxidation of fatty acids, inducing deleterious effects on the reproduction and development of planktonic and benthic organisms that feed on these unicellular algae and with anti-cancer activity. Our previous results showed that PUAs target several genes, implicated in different functional processes in this sea urchin. Using interactomic Ingenuity Pathway Analysis we now show that the genes targeted by PUAs are correlated with four HUB genes, NF-κB, p53, δ-2-catenin and HIF1A, which have not been previously reported for P. lividus. We propose a working model describing hypothetical pathways potentially involved in toxic aldehyde stress response in sea urchins. This represents the first report on gene networks affected by PUAs, opening new perspectives in understanding the cellular mechanisms underlying the response of benthic organisms to diatom exposure.
Here, we report the draft genome sequence of a metagenome-assembled genome (MAG) of a new Alkaliphilus bacterium, NP8, of the Clostridiaceae family. This bacterium was isolated from polluted sediment collected from an abandoned industrial site located in the Gulf of Naples (Mediterranean Sea) as part of a microbial consortium.
The cover picture shows the TUNEL-stained “phantom” of a malformed and apoptotic newborn nauplius of the copepod Temora stylifera generated from mothers fed on marine diatoms. Teratogenesis and apoptosis are responsible for a drastic reduction in copepod progeny and for the detrimental impact of bloom-forming diatoms on zooplankton communities in many pelagic ecosystems of the world. In their article on p. 1810 ff., A. Fontana et al. show that the process is not neccessarily dependent on the synthesis of polyunsaturated aldehydes (PUAs), as hitherto believed. On the contrary, the toxic effects of diatoms on copepods are associated with an oxidative imbalance that follows lysis of the unicellular algae. Early activation of lypolitic and lipoxygenase enzymes causes a massive synthesis of fatty acid hydroperoxides and highly reactive oxygen species, as well as a blended mixture of undisclosed oxylipins, that explain the lethal impact of diatom diets on copepod reproduction.
Petroleum hydrocarbons (PHCs) are one of the most widespread and heterogeneous organic contaminants affecting marine ecosystems. The contamination of marine sediments or coastal areas by PHCs represents a major threat for the ecosystem and human health, calling for urgent, effective, and sustainable remediation solutions. Aside from some physical and chemical treatments that have been established over the years for marine sediment reclamation, bioremediation approaches based on the use of microorganisms are gaining increasing attention for their eco-compatibility, and lower costs. In this work, we review current knowledge concerning the bioremediation of PHCs in marine systems, presenting a synthesis of the most effective microbial taxa (i.e., bacteria, fungi, and microalgae) identified so far for hydrocarbon removal. We also discuss the challenges offered by innovative molecular approaches for the design of effective reclamation strategies based on these three microbial components of marine sediments contaminated by hydrocarbons.
The effect of several biotic and abiotic factors on the fecundity and hatching success of Calanus helgolandicus was tested during short- and long-term incubations. The results show that the variations of the reproductive responses of C.helgolandicus are time dependent and rely on the type of factor tested. When standardized over a 24 h incubation period, estimates ofin situ production and egg viability can be obtained with good accuracy.
