Parental transfer of perfluorooctane sulfonate and ZnO nanoparticles chronic co-exposure and inhibition of growth in F1 offspring

Abstract

Perfluorooctane sulfonate (PFOS) and ZnO nanoparticles (Nano-ZnO) are two kinds of environmental contaminants that have been frequently detected in natural waters. The potential joint toxicity of PFOS and nano-ZnO remains to be fully elucidated. The objective of this study was to evaluate co-exposure effects of PFOS and nano-ZnO on growth in initial generation (F0) zebrafish after chronic exposure and to examine possible parental transfer of PFOS and nano-ZnO transgenerational effects on the growth of first generation (F1) larvae. When zebrafish (2 h after incubation) were exposed to single- and co-exposure groups for 120 days, bioconcentration resulted in significantly less growth as measured by body length and body weight, higher mortality, and less spawning in the F0 generation. These effects were possibly due to the down-regulation of the expression of Vtg1 genes along with a sex hormone (T/E2) involved in the hypothalamus-pituitary-gonad (HPG) axis. Furthermore, after long-term exposure, less fertilization, less hatching, greater mortality and more malformation were found in the F1 generation. The down-regulation of genes and hormones might be responsible for transgenerational toxicity. This study suggested that chronic exposure to PFOS and nano-ZnO adversely impacts development, reproduction in the F0 generation, and offspring embryonic growth.

Keywords: F1 generation; HPG axis; Nano-ZnO; PFOS; Parental transfer.