Adipogenesis of perfluorooctanesulfonate (pfos) on japanese medaka (oryzias latipes) embryo using ovo-nanoinjection-mRNA seq analysis

Perfluorooctanesulfonate (PFOS) is a worldwide persistent organic pollutant and suspected to have effects on animals. The present study used in ovo-nanoinjection to simulate the maternal bioaccumulation and biotransformation of PFOS from parental Japanese medaka (Oryzias latipes) to embryos, investigated and elucidated the obesogenic activity in vivo and the gene expression changes. Results showed that no significant differences on the survival of medaka embryos and larvae between control, solvent control, and three PFOS exposure groups (0.05, 0.5 and 5 ng per embryo). Hatching time of medaka embryo was significantly delayed in the 0.05 ng PFOS exposure group and significantly accelerated in the 5 ng exposure group compare with those in control. The adipocyte areas were significantly increased in 0.05 and 0.5 ng per embryo PFOS exposure groups comparing to that of the control. The mRNA sequencing analysis on the medaka larvae chromosome gene expressions showed that 24 genes had significantly changed expressions (p < 0.05, FDR < 0.05) including genes involved in the pathways of metabolism and adipogenesis, like g6pca.2 in the 'Insulin signaling pathway' and 'Adipocytokine signaling pathway'. These results suggested that ovo-nanoinjection-mRNA Seq analysis is a reliable method to evaluate and understand the maternal effect of chemicals.