Obesogenic and developmental effects of TBT on the gene expression of juvenile Japanese medaka (Oryzias latipes).

Abstract

The widely used antifoulant tributyltin chloride (TBT) is highly toxic to aquatic organisms. In the present study, four-week-old Japanese medaka (Oryzias latipes) juveniles were orally exposed to TBT at 1 and 10ng/g bw/d for 1, 2, and 4 weeks, respectively. Half of the tested medaka juveniles showed bone morphology alterations in both 1 and 10ng/g bw/d TBT 4-week exposure groups. Nile Red (NR) staining showed that the juveniles exposed to 1ng/g bw/d TBT for 2 and 4 weeks had significantly enlarged adipocyte areas. The mRNA-Seq analysis indicated that 1ng/g bw/d TBT exposure for 2 weeks affected bone morphology through developmental processes. The GO and KEGG analyses suggested that the adipogenic effect of TBT observed in this study may be induced by metabolic processes, oxidative phosphorylation, and fatty acid degradation and metabolism pathways. Therefore, both morphological observation and mRNA-Seq analysis showed obesogenic effects and developmental toxicity of TBT to juvenile Japanese medaka.