Massively parallel sequencing of the multitissue transcriptome of the thicklip grey labrosus , a suitable pollution sentinel

Key sentinel species are employed to monitor biological effects of pollution and assess the health of ecosystems. High throughput “omic” techniques such as expression microarrays employed in transcriptomics allow identification of single genes and/or gene pathways that could be assessed as biomarkers of exposure to specific chemical compounds. Nevertheless, ecotoxicogenomic studies have to face the problem of the lack of genetic information available for environmentally relevant species. In this sense, pyrosequencing allows obtaining deep de novo sequence information cost-effectively. We have employed the GS-FLX platform to sequence a multitissue (liver, brain, gill, gonad, muscle) normalized (Evrogen) transcriptome of the thikclip grey mullet ( Chelon labrosus ), a suitable sentinel of pollution able to survive heavily polluted marine/estuarine waters and widely distributed in southern Europe. After completing 1 full plate sequencing-run of the mullet 126 Mb of sequence information were obtained. These sequences were first filtered through Blastx analysis, matching sequences being further annotated through Blast2go. This approach allowed annotation of 15792 new gene fragments. The rest of sequences, some of them belonging to untranslated regions, were analyzed through Blastn and 2540 additional sequences were homologically identified in this way. Finally, a custom high density Agilent microarray has been generated incorporating all these sequences, and the previously known 160 gene sequences, in a 4x44K format. This microarray will be employed to study gene transcription profiles in mullets in pollution monitoring programs and in laboratory exposure experiments. Funded: Basque Government (SAIOTEK-IKERKOSTA S-PC08UN03; Special- Research-Actions AE-2008-1-1). Technical and human support provided by SGIker (UPV/EHU, MICINN, GV/EJ, AND ESF) is gratefully acknowledge, especially to E.Ogando from the IZO-SGI.

TOPIC: D12_ OMICS: from gene to ecosystem

KEY WORDS: Chelon labrosus , high-density microarray, pyrosequencing.

PRESENTATION PREFERENCE: poster presentation

(Co-)AUTHORS: Oihane Diaz de Cério . Dept.. of Zoology and Cell Biology. School of Science and Technology. University of the Basque Country, E-48080 Bilbao Val Fernández-Lanza. Dept.. of Zoology and Animal Cell Biology. School of Science and Technology. University of the Basque Country, E-48080 Bilbao Ibon Cancio. Dept. of Zoology and Animal Cell Biology. School of Science and Technology. University of the Basque Country, E-48080 Bilbao