Re-shaping marine plankton communities: effects of diatom oxylipins on copepods and beyond

Russo, Ennio; Ianora, Adrianna; Carotenuto, Ylenia

doi:10.1007/s00227-018-3456-2

Cited by 17 publications

(18 citation statements)

References 90 publications

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“…Because sea urchins are browsing animals that eat phytoplankton and organic matter in the sand or mud, they may accumulate oxylipins through feeding or be exposed to high local concentrations of these compounds that may affect growth performance, as already demonstrated for copepods exposed to PUAs [45]. Very recently, Russo et al [56] reported on oxylipin production rates in natural planktonic diatom communities in the Gulf of Naples, from which sea urchins were collected in the present study. These authors provided the first piece of evidence that the oxylipins analysed from natural phytoplankton communities derive mostly from diatoms.…”

Section: Discussionmentioning

confidence: 50%

Combined Effects of Diatom-Derived Oxylipins on the Sea Urchin Paracentrotus lividus

Esposito

Ruocco

Albarano

et al. 2020

IJMS

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Oxylipins are diatom-derived secondary metabolites, deriving from the oxidation of polyunsatured fatty acids that are released from cell membranes after cell damage or senescence of these single-celled algae. Previous results revealed harmful toxic effects of polyunsaturated aldehydes (PUAs) and hydroxyacids (HEPEs) on sea urchin Paracentrotus lividus embryonic development by testing individual compounds and mixtures of the same chemical group. Here, we investigated the combined effects of these compounds on sea urchin development at the morphological and molecular level for the first time. Our results demonstrated that oxylipin mixtures had stronger effects on sea urchin embryos compared with individual compounds, confirming that PUAs induce malformations and HEPEs cause developmental delay. This harmful effect was also confirmed by molecular analysis. Twelve new genes, involved in stress response and embryonic developmental processes, were isolated from the sea urchin P. lividus; these genes were found to be functionally interconnected with 11 genes already identified as a stress response of P. lividus embryos to single oxylipins. The expression levels of most of the analyzed genes targeted by oxylipin mixtures were involved in stress, skeletogenesis, development/differentiation, and detoxification processes. This work has important ecological implications, considering that PUAs and HEPEs represent the most abundant oxylipins in bloom-forming diatoms, opening new perspectives in understanding the molecular pathways activated by sea urchins exposed to diatom oxylipins.

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Section: Discussionmentioning

confidence: 50%

Combined Effects of Diatom-Derived Oxylipins on the Sea Urchin Paracentrotus lividus

Esposito

Ruocco

Albarano

et al. 2020

IJMS

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“…In this perspective, assessment of biotic and abiotic factors influencing copepod populations can be of primary importance to understand marine pelagic food web functioning. Phytoplankton-derived oxylipins potentially represent key factors affecting wild copepod populations [3]. These molecules are end products of well characterized enzymatic pathways activated after cell wounding, starting from lipolytic release of free fatty acids (FFAs) from complex lipids [4][5][6] and proceeding through oxygenation of FFAs by lipoxygenases (LOX) [5,[7][8][9][10][11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

“…Variations in copepod egg production, hatching success and naupliar survival in response to phytoplankton abundance and composition have been investigated in several copepod species through field surveys [3,22,[34][35][36][37][38][39][40][41][42], but information about the molecular responses of adult females from natural populations are still limited to the Northern Ariatic Sea [35].…”

Section: Introductionmentioning

confidence: 99%

RNA-Seq and differential gene expression analysis in Temora stylifera copepod females with contrasting non-feeding nauplii survival rates: an environmental transcriptomics study

et al. 2020

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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.

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“…Their broad bioactivities, based on the Michael reaction [15], confer PUA with fairly non-specific toxic properties [16]. PUA are thought to function as part of a multifaceted infochemical approach to bloom regulation through the bottom-up control of herbivore populations [17][18][19][20] and by exerting allelopathic influence over inter-and intraspecifics [21][22][23]. Published data on whether PUA are mediators of diatom-bacteria interactions within the phycosphere are equivocal, but indicate bacteriostatic properties by directly accumulating within their membranes [24], perhaps in response to infection [25].…”

Section: Introductionmentioning

confidence: 99%

“…With renewed interest in elucidating the role of PUA at sea, particularly over oceanic scales [20,27,[35][36][37][38][39], it is timely to revisit the bacteriostatic hypothesis, albeit at a laboratory scale. We used next-generation sequencing to address the biodiversity element of the bacteriostatic definition.…”

Section: Introductionmentioning

confidence: 99%

Diatom-Derived Polyunsaturated Aldehydes Are Unlikely to Influence the Microbiota Composition of Laboratory-Cultured Diatoms

Eastabrook

Whitworth

Robinson

et al. 2020

Life

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Diatom-derived oxylipins, including polyunsaturated aldehydes (PUA), are considered to have infochemical, allelochemical and bacteriostatic properties, with plausible roles as grazing deterrents and regulators of inter- and intraspecific competition. However, the extent and mechanisms of how PUA influence diatom–bacteria interactions remain unresolved. In this study, impacts on the diversity of the associated bacterial communities (microbiota) of two contrasting Skeletonema marinoi strains (a PUA and a non-PUA producer) were investigated under three nitrate conditions in batch culture. Further, the response of the culture microbiota was studied when spiked with PUA at ecologically relevant concentrations (86nM octadienal and 290nM heptadienal). Of the 741 identified OTUs, Proteobacteria was the most abundant phylum (62.10%), followed by Bacteroidetes (12.33%) and Firmicutes (6.11%). Escherichia/Shigella were the most abundant genera for all treatments. Similar communities were present in both spiked and non-spiked cultures suggesting they can tolerate PUA exposure at realistic concentrations. This study suggests that PUA are not major drivers of diatom–bacteria interactions in laboratory cultures.

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Re-shaping marine plankton communities: effects of diatom oxylipins on copepods and beyond

Cited by 17 publications

References 90 publications

Combined Effects of Diatom-Derived Oxylipins on the Sea Urchin Paracentrotus lividus

Combined Effects of Diatom-Derived Oxylipins on the Sea Urchin Paracentrotus lividus

RNA-Seq and differential gene expression analysis in Temora stylifera copepod females with contrasting non-feeding nauplii survival rates: an environmental transcriptomics study

Diatom-Derived Polyunsaturated Aldehydes Are Unlikely to Influence the Microbiota Composition of Laboratory-Cultured Diatoms

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