Comparison of waterborne and in ovo nanoinjection exposures to assess effects of PFOS on zebrafish embryos

Abstract

Since perfluorooctane sulfonate (PFOS) had been detected in eggs of seabirds and fish, toxicity of waterborne PFOS to embryonic development of zebrafish (Danio rerio) was investigated. However, because assessment of effects by use of dietary exposure of adults is time-consuming and expensive, a study was conducted to compare effects on embryos via nanoinjection and waterborne exposure. Nanoinjection, in which small amounts of chemicals are injected into developing eggs, was used to incorporate PFOS into the yolk sac of embryos of zebrafish. Effects of PFOS during the period of development of the embryo were assessed within 96 h post-fertilization (hpf). PFOS significantly retarded development of embryos of zebrafish and resulted in abnormalities as well as lethality of developing embryos. Both methods of exposure, waterborne and nanoinjection, resulted in similar dose-dependent effects. Some sublethal effects, such as edema at 48 hpf, delayed hatching, and curvature of the spine was observed after 72 hpf. In ovo, nanoinjection was deemed to be an accurate method of exposure for controlling the actual internal dose for study of adverse effects, which closely mimicked responses to waterborne exposure of zebrafish embryo to PFOS.

Zebrafish as a Model for Toxicological Perturbation of Yolk and Nutrition in the Early Embryo

“…Compounds including TCDD classically induce “blue sac syndrome,” a pathology characterized by yolk sac and pericardial edema [61]. However, a wide array of toxicants including polycyclic aromatic hydrocarbons [63, 64], polychlorinated biphenyls [65, 66], polybrominated flame retardants [67], poly- and perfluorinated compounds [68, 69] (unpublished data), organophosphates [70–73], herbicides [74–76], and nanoparticles [67, 77–79] among others have been demonstrated to cause yolk sac edema in zebrafish embryos. The wide range of chemical properties demonstrated by these chemicals suggests that yolk sac edema is an especially sensitive toxicological outcome for embryonic evaluation.…”

Survival rate of eukaryotic cells following electrophoretic nanoinjection

“…Injection-based single-cell methods offer a valid alternative to stochastic delivery methods. A large number of injection methods have been developed, ranging from charged lance injectors11 over AFM-based injection methods12 to classic microinjection with injection volumes in the nanoliter regime1314. Microinjection is widely used in biological research for a variety of experiments and different samples from single cells to small organisms have successfully been utilized with this technique15161718.…”

Advancing the Zebrafish embryo test for endocrine disruptor screening using micro‐injection: Ethinyl estradiol as a case study

“…Neither canola oil nor DMSO affected any of the toxicity endpoints. Dimethylsulfoxide has already been used for the injection of zebrafish embryos in previous studies (Maes et al ; Schubert et al ; Li et al ), but triolein is the more commonly used solvent in injection studies with fish embryos (Edmunds et al ; Hano et al ; Nassef et al ; Schubert et al ; Xiao et al ). Our results, however, showed that the use of triolein can lead to effects on survival and heart rate.…”

“…Out of these 2 potential solvents, DMSO was selected as the optimal solvent for the present study because the high viscosity of canola oil caused practical problems. In addition, DMSO has already been used in similar micro-injection studies with zebrafish (Maes et al 2012;Schubert et al 2014;Li et al 2015). The variation among 3 different injection needles and within a single injection needle (3 replicates) is shown in Figure 2B.…”

“…From 2000 onward, a medaka fertilized egg nanoinjection assay has been in use to assess the toxicity of a variety of compounds, often with the aim of mimicking deposition in eggs through maternal transfer (Edmunds et al 1999;Villalobos et al 2000;Colman and Ramsdell 2003;Nassef et al 2010). More recently, studies have been published that applied micro-injection in zebrafish embryos to determine the toxicity of diethyl phthalate (DEP), perfluorooctanoic acid (PFOS), and triphenyltin (among other chemicals; Liu et al 2012;Schubert et al 2014;Kim et al 2015;Li et al 2015;Xiao et al 2017).…”