mRNA-Seq of Daphnia magna exposed to different concentrations of sucralose against untreated control groups
The experiment investigates how the artificial sweetener sucralose affects behavior and gene expression in the freshwater invertebrate Daphnia magna in order to derive mechanistic information relevant for environmental risk assessment. Juvenile D. magna were first subjected to a behavioral swimming activity test based on the acute immobilization test (OECD Guideline 202). As no swimming activity alteration or acute effect was observed, the main test including transcriptomics, was conducted with 10 µg/L and 100 mg/L as test concentrations. Swimming activity was quantified in a 24-well plate setup using automated video tracking. In the main test, pooled animals from each exposure group and corresponding controls were sampled after 48 hours for whole-animal RNA extraction, and poly(A)-enriched RNA was sequenced (paired-end, 150 bp) on an Illumina NovaSeq platform, followed by alignment to the Daphnia magna reference genome and differential expression analysis using a DESeq2-based workflow with independent hypothesis weighting, data-driven log2 fold-change thresholds, and multiple-testing correction to define robust sets of differentially expressed genes per substance and concentration. Overrepresentation analysis of Gene Ontology terms using a common detected-gene background then mapped these gene-level changes to biological processes.
The experiment investigates how the artificial sweetener sucralose affects behavior and gene expression in the freshwater invertebrate Daphnia magna in order to derive mechanistic information relevant for environmental risk assessment. Juvenile D. magna were first subjected to a behavioral swimming activity test based on the acute immobilization test (OECD Guideline 202). As no swimming activity alteration or acute effect was observed, the main test including transcriptomics, was conducted with 10 µg/L and 100 mg/L as test concentrations. Swimming activity was quantified in a 24-well plate setup using automated video tracking. In the main test, pooled animals from each exposure group and corresponding controls were sampled after 48 hours for whole-animal RNA extraction, and poly(A)-enriched RNA was sequenced (paired-end, 150 bp) on an Illumina NovaSeq platform, followed by alignment to the Daphnia magna reference genome and differential expression analysis using a DESeq2-based workflow with independent hypothesis weighting, data-driven log2 fold-change thresholds, and multiple-testing correction to define robust sets of differentially expressed genes per substance and concentration. Overrepresentation analysis of Gene Ontology terms using a common detected-gene background then mapped these gene-level changes to biological processes.
European Bioinformatics Institute