title: Transcriptomic profiling of male European eel (Anguilla anguilla) livers at sexual maturity.
abstract: The European eel Anguilla anguilla has a complex life cycle that includes freshwater, seawater and morphologically distinct stages as well as two extreme long distance migrations. Eels do not feed as they migrate across the Atlantic to the Sargasso Sea but nevertheless reach sexual maturity before spawning. It is not yet clear how existing energy stores are used to reach the appropriate developmental state for reproduction. Since the liver is involved in energy metabolism, protein biosynthesis and endocrine regulation it is expected to play a key role in the regulation of reproductive development. We therefore used microarrays to identify genes that may be involved in this process. Using this approach, we identified 231 genes that were expressed at higher and 111 genes that were expressed at lower levels in sexually mature compared with immature males. The up-regulated set includes genes involved in lipid metabolism, fatty acid synthesis and transport, mitochondrial function, steroid transport and bile acid metabolism. Several genes with putative enzyme functions were also expressed at higher levels at sexual maturity while genes involved in immune system processes and protein biosynthesis tended to be down-regulated at this stage. By using a high-throughput approach, we have identified a subset of genes that may be linked with the mobilization of energy stores for sexual maturation and migration. These results contribute to an improved understanding of eel reproductive biology and provide insight into the role of the liver in other teleosts with a long distance spawning migrations.
authors.affiliation: CCMAR-Centre for Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal. Electronic address: amchurch@uvic.ca.
authors.forename: Allison M
authors.initials: AM
authors.lastname: Churcher
authors.affiliation: Department of Bioscience, Aarhus University, 8000, Denmark.
authors.forename: Jose Martin
authors.initials: JM
authors.lastname: Pujolar
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Milan
authors.affiliation: CCMAR-Centre for Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal; Department of Fisheries and Wildlife, Michigan State University, 48824 East Lansing, USA.
authors.forename: Mar
authors.initials: M
authors.lastname: Huertas
authors.affiliation: CCMAR-Centre for Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Hubbard
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bargelloni
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
authors.forename: Tomaso
authors.initials: T
authors.lastname: Patarnello
authors.affiliation: Department of Biology, University of Padova, Via G. Colombo 3, 35131 Padova, PD, Italy.
authors.forename: Ilaria A M
authors.initials: IA
authors.lastname: Marino
authors.affiliation: Department of Biology, University of Padova, Via G. Colombo 3, 35131 Padova, PD, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Zane
authors.affiliation: CCMAR-Centre for Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: Adelino V M
authors.initials: AV
authors.lastname: Canário
mesh_terms: D000811:Anguilla / Q000235:genetics* / Q000254:growth & development*; D000818:Animals; D018507:Gene Expression Regulation, Developmental; D008099:Liver / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D008297:Male; D012741:Sexual Maturation; D059467:Transcriptome
keywords: European eel; Gene expression; Liver; Reproduction; Sexual maturation