Behavioral, morphometric, and gene expression effects in adult zebrafish (Danio rerio) embryonically exposed to PFOA, PFOS, and PFNA

Abstract

Perfluoroalkylated substances (PFAS) are a class of persistent anthropogenic chemicals that have been detected worldwide. PFASs consist of fluorinated carbon chains of varying length, terminal groups, and have a number of industrial uses. A previous zebrafish study from our laboratory showed that acute (3–120 h post fertilization, 0.02–2.0μM), waterborne embryonic exposure to these chemicals resulted in chemical specific alterations at 5 days post fertilization (dpf), and some effects persisted up to 14 dpf. Using a gene battery consisting of 100 transcripts identified several genes that were up or down regulated. This current study looks at the long-term impacts of PFASs in adult zebrafish using the same exposure regimen. It was hypothesized that sub-lethal exposure of perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), or perfluorooctane sulfonate (PFOA) in embryonic zebrafish (3–120 hpf) would result in permanent morphometric, gene expression, and behavioral changes in adult fish similar to those observed at 5 and 14 dpf. Zebrafish were exposed to PFOS, PFOA, and PFNA (Control 0μM, 2.0μM) for the first five days post fertilization. At six months post fertilization, no PFAS treatment resulted in a significant change in total body length or weight. In terms of behavior, PFNA males showed a reduction in total distance traveled and time of immobility, and an increase in thigmotaxis behavior, aggressive attacks, and preference for the bright section of the tank. PFOS treated males had a reduced aggression behavior, and PFOA females preferred the dark section of the tank. Gene expression of slco2b1, slco1d1, and tgfb1a were analyzed because these transcripts were previously found to be affected by PFAS exposure in 5dpf and 14 dpf zebrafish and resulted in: significant decrease in expression of slco2b1 for both sexes in PFNA and PFOS treated groups, significant decrease of slco1d1 in all treatment groups for females and PFOS and PFOA exposed males, significant increase of tgfb1a in males treated with PFOS and PFNA, and a significant increase of bdnf in all PFAS male groups. This study demonstrates that acute, embryonic exposure (5 days) to individual PFASs result in significant biochemical and behavioral changes in young adult zebrafish 6 months after exposure. These three PFASs have long term and persistent impacts following short term embryonic exposure that persists into adulthood.

β-Cyclodextrin Attenuates Perfluorooctanoic Acid Toxicity in the Zebrafish Embryo Model

“…Variability in lethal concentrations is presumably due to genetic differences of zebrafish lines used and/or other experimental conditions, and were not addressed further in the present study. Both reduced body size ( Figure 4 ) and locomotory effects ( Figure 5 ) have been, likewise, reported for PFOA-treated zebrafish embryos at sub-lethal concentrations [ 32 , 37 , 38 , 39 ]. Notably, these sub-lethal effects were observed in previous studies [ 38 , 39 ] at considerably lower (i.e., micro- to nanomolar) exposure concentrations, and, interestingly, effects extended into (following embryonic exposure) adult stages.…”

“…As such, the zebrafish embryo has been employed to look at a wide range of environmental contaminants in terms of acute and chronic toxicity [ 29 , 30 , 31 ]. Acute toxicological endpoints (e.g., embryotoxicity, teratogenicity, neurotoxicity), which are readily accessible in the zebrafish embryo model, are, furthermore, aligned with the reported health concerns associated with PFOA, and the system has, indeed, been used to evaluate toxicity of PFOA and related perfluorinated alkyl substances [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ].…”

Dynamic transcriptome landscape of Asian domestic honeybee (Apis cerana) embryonic development revealed by high-quality RNA sequencing

“…Among these phases, embryogenesis, which is precisely controlled and modulated by both environmental and intracellular signals, is the first and the most important stage. During the embryogenesis period, the rudimentary organs of the adult honeybees are gradually formed [ 12 , 13 ], and gene expression in the embryonic stage contributes greatly to the adult morphology, appearance and behavior [ 14 – 16 ].…”

The Cyclodextrin-Perfluorinated Surfactant Host-Guest Complex: Fundamental Studies for Potential Environmental Remediation and Therapeutic Applications

“…Variability in lethal concentrations is presumably due to genetic differences of zebrafish lines used and/or other experimental conditions, and were not addressed further in the present study. Both reduced body size and locomotory effects have been, likewise, reported for PFOA-treated zebrafish embryos at sub-lethal concentrations (Hagenaars et al 2011, Jantzen et al 2016a, Jantzen et al 2016b, Jantzen et al 2017. Notably, these sub-lethal effects were observed in previous studies (Jantzen et al 2016b, Jantzen et al 2017 at considerably lower (i.e., micro-to nanomolar) exposure concentrations, and effects extended into (following embryonic exposure) adult stages.…”

“…As such, the zebrafish embryo has been employed to look at a wide range of environmental contaminants in terms of acute and chronic toxicity (Hinton et al 2005, Scholz et al 2008, Sarmah and Marrs 2016. Acute toxicological endpoints (e.g., embryotoxicity, teratogenicity, neurotoxicity), which are readily accessible in the zebrafish embryo model, are aligned with the reported health concerns associated with PFOA, and the system has been used to evaluate toxicity of PFOA and related PFASs (Hagenaars et al 2011, Zheng et al 2011, Hagenaars et al 2013, Ding et al 2013, Ulhaq et al 2015, Jantzen et al 2016a, Jantzen et al 2016b, Jantzen et al 2017, Rainieri et al 2017).…”