title: De novo transcriptome sequencing and analysis of freshwater snail (Radix balthica) to discover genes and pathways affected by exposure to oxazepam.
abstract: Pharmaceuticals are increasingly found in aquatic ecosystems due to the non-efficiency of waste water treatment plants. Therefore, aquatic organisms are frequently exposed to a broad diversity of pharmaceuticals. Freshwater snail Radix balthica has been chosen as model to study the effects of oxazepam (psychotropic drug) on developmental stages ranging from trochophore to hatching. In order to provide a global insight of these effects, a transcriptome deep sequencing has been performed on exposed embryos. Eighteen libraries were sequenced, six libraries for three conditions: control, exposed to the lowest oxazepam concentration with a phenotypic effect (delayed hatching) (TA) and exposed to oxazepam concentration found in freshwater (TB). A total of 39,759,772 filtered raw reads were assembled into 56,435 contigs having a mean length of 1579.68 bp and mean depth of 378.96 reads. 44.91% of the contigs have at least one annotation. The differential expression analysis between the control condition and the two exposure conditions revealed 146 contigs differentially expressed of which 144 for TA and two for TB. 34.0% were annotated with biological function. There were four mainly impacted processes: two cellular signalling systems (Notch and JNK) and two biosynthesis pathways (Polyamine and Catecholamine pathways). This work reports a large-scale analysis of differentially transcribed genes of R. balthica exposed to oxazepam during egg development until hatching. In addition, these results enriched the de novo database of potential ecotoxicological models.
authors.affiliation: Biochimie et Toxicologie des Substances Bioactives (BTSB), EA7417, Université de Toulouse, INU Champollion, Albi, France. jyves.maz@gmail.com.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Mazzitelli
authors.affiliation: Biochimie et Toxicologie des Substances Bioactives (BTSB), EA7417, Université de Toulouse, INU Champollion, Albi, France.
authors.forename: Elsa
authors.initials: E
authors.lastname: Bonnafe
authors.affiliation: Unité de Mathématique et Informatique Appliquées de Toulouse, UR0875, INRA Toulouse, Castanet-Tolosan, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Klopp
authors.affiliation: Unité de Mathématique et Informatique Appliquées de Toulouse, UR0875, INRA Toulouse, Castanet-Tolosan, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Escudier
authors.affiliation: Biochimie et Toxicologie des Substances Bioactives (BTSB), EA7417, Université de Toulouse, INU Champollion, Albi, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Geret
mesh_terms: D000818:Animals; D005618:Fresh Water; D015870:Gene Expression / Q000187:drug effects*; D020869:Gene Expression Profiling; D059014:High-Throughput Nucleotide Sequencing; D010076:Oxazepam / Q000633:toxicity*; D011619:Psychotropic Drugs / Q000633:toxicity*; D012908:Snails / Q000235:genetics*; D059467:Transcriptome
chemical_list: D011619:Psychotropic Drugs; D010076:Oxazepam
keywords: Differential analysis; Ecotoxicology; Pharmaceutical; RNA sequencing; Radix balthica