title: New oxylipins produced at the end of a diatom bloom and their effects on copepod reproductive success and gene expression levels.
abstract: Diatoms are dominant photosynthetic organisms in the world's oceans and are considered essential in the transfer of energy to higher trophic levels. However, these unicellular organisms produce secondary metabolites deriving from the oxidation of fatty acids, collectively termed oxylipins, with negative effects on predators, such as copepods, that feed on them (e.g. reduction in survival, egg production and hatching success) and, indirectly, on higher trophic levels. Here, a multidisciplinary study (oxylipin measurements, copepod fitness, gene expression analyses, chlorophyll distribution, phytoplankton composition, physico-chemical characteristics) was carried out at the end of the spring diatom bloom in April 2011 in the Northern Adriatic Sea (Mediterranean Sea) in order to deeply investigate copepod-diatom interactions, chemical communication and response pathways. The results show that the transect with the lowest phytoplankton abundance had the lowest copepod egg production and hatching success, but the highest oxylipin concentrations. In addition, copepods in both the analyzed transects showed increased expression levels of key stress-related genes (e.g. heat-shock proteins, catalase, glutathione S-transferase, aldehyde dehydrogenase) compared to control laboratory conditions where copepods were fed with the dinoflagellate Prorocentrum minimum which does not produce any oxylipins. New oxylipins that have never been reported before for microalgae are described for the first time, giving new insights into the complex nature of plant-animal signaling and communication pathways at sea. This is also the first study providing insights on the copepod response during a diatom bloom at the molecular level.
authors.affiliation: Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy. Electronic address: chiara.lauritano@szn.it.
authors.forename: Chiara
authors.initials: C
authors.lastname: Lauritano
authors.affiliation: Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Romano
authors.affiliation: Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawaii at Manoa, 1993 East-West Road, Honolulu, HI 96822, USA.
authors.forename: Vittoria
authors.initials: V
authors.lastname: Roncalli
authors.affiliation: Dipartimento di Scienze Chimiche, Università degli Studi di Napoli, Monte Sant'Angelo, 80126 Napoli, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Amoresano
authors.affiliation: Dipartimento di Scienze Chimiche, Università degli Studi di Napoli, Monte Sant'Angelo, 80126 Napoli, Italy.
authors.forename: Carolina
authors.initials: C
authors.lastname: Fontanarosa
authors.affiliation: Istituto di Scienze Marine CNR, Castello 2737/f, I30122 Venice, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Bastianini
authors.affiliation: Istituto di Scienze Marine CNR, Castello 2737/f, I30122 Venice, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Braga
authors.affiliation: Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
authors.forename: Ylenia
authors.initials: Y
authors.lastname: Carotenuto
authors.affiliation: Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
authors.forename: Adrianna
authors.initials: A
authors.lastname: Ianora
mesh_terms: D000818:Animals; D033342:Copepoda / Q000187:drug effects* / Q000235:genetics; D017377:Diatoms / Q000737:chemistry*; D005786:Gene Expression Regulation / Q000187:drug effects; D008522:Mediterranean Sea; D054883:Oxylipins / Q000302:isolation & purification / Q000494:pharmacology*; D010839:Phytoplankton / Q000737:chemistry; D012098:Reproduction / Q000187:drug effects
chemical_list: D054883:Oxylipins
keywords: Bloom; Copepods; Diatoms; Gene expression; Oxylipins; Secondary metabolites