title: First Morphological and Molecular Evidence of the Negative Impact of Diatom-Derived Hydroxyacids on the Sea Urchin Paracentrotus lividus.
abstract: Oxylipins (including polyunsaturated aldehydes [PUAs], hydoxyacids, and epoxyalcohols) are the end-products of a lipoxygenase/hydroperoxide lyase metabolic pathway in diatoms. To date, very little information is available on oxylipins other than PUAs, even though they represent the most common oxylipins produced by diatoms. Here, we report, for the first time, on the effects of 2 hydroxyacids, 5- and 15-HEPE, which have never been tested before, using the sea urchin Paracentrotus lividus as a model organism. We show that HEPEs do induce developmental malformations but at concentrations higher when compared with PUAs. Interestingly, HEPEs also induced a marked developmental delay in sea urchin embryos, which has not hitherto been reported for PUAs. Recovery experiments revealed that embryos do not recover following treatment with HEPEs. Finally, we report the expression levels of 35 genes (involved in stress, development, differentiation, skeletogenesis, and detoxification processes) to identify the molecular targets affected by HEPEs. We show that the 2 HEPEs have very few common molecular targets, specifically affecting different classes of genes and at different times of development. In particular, 15-HEPE switched on fewer genes than 5-HEPE, upregulating mainly stress-related genes at a later pluteus stage of development. 5-HEPE was stronger than 15-HEPE, targeting 24 genes, mainly at the earliest stages of embryo development (at the blastula and swimming blastula stages). These findings highlight the differences between HEPEs and PUAs and also have important ecological implications because many diatom species do not produce PUAs, but rather these other chemicals are derived from the oxidation of fatty acids.
authors.affiliation: *Department of Biology and Evolution of Marine Organisms.
authors.forename: Stefano
authors.initials: S
authors.lastname: Varrella
authors.affiliation: Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Napoli, 80121, Italy;
authors.forename: Giovanna
authors.initials: G
authors.lastname: Romano
authors.affiliation: *Department of Biology and Evolution of Marine Organisms.
authors.forename: Nadia
authors.initials: N
authors.lastname: Ruocco
authors.affiliation: Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Napoli, 80121, Italy;
authors.forename: Adrianna
authors.initials: A
authors.lastname: Ianora
authors.affiliation: Faculty of Science and Technology, Bournemouth University, Dorset, BH12 5BB, United Kingdom.
authors.forename: Matt G
authors.initials: MG
authors.lastname: Bentley
authors.affiliation: *Department of Biology and Evolution of Marine Organisms maria.costantini@szn.it.
authors.forename: Maria
authors.initials: M
authors.lastname: Costantini
mesh_terms: D000818:Animals; D017377:Diatoms / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015118:Eicosapentaenoic Acid / Q000031:analogs & derivatives* / Q000378:metabolism / Q000633:toxicity; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D047328:Paracentrotus / Q000187:drug effects* / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; C058722:5-hydroxy-6,8,11,14,17-eicosapentaenoic acid; C059164:15-hydroxy-5,8,11,13,17-eicosapentaenoic acid; D015118:Eicosapentaenoic Acid
keywords: development; diatoms; genes.; hydroxyacids; sea urchin