Multi- and Transgenerational Effects of Developmental Exposure to Environmental Levels of PFAS and PFAS Mixture in Zebrafish (Danio rerio)

Abstract

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous in the environment and are tied to myriad health effects. Despite the phasing out of the manufacturing of two types of PFASs (perfluorosulfonic acid (PFOS) and perfluorooctanoic acid (PFOA)), chemical composition renders them effectively indestructible by ambient environmental processes, where they thus remain in water. Exposure via water can affect both human and aquatic wildlife. PFASs easily cross the placenta, exposing the fetus at critical windows of development. Little is known about the effects of low-level exposure during this period; even less is known about the potential for multi- and transgenerational effects. We examined the effects of ultra-low, very low, and low-level PFAS exposure (7, 70, and 700 ng/L PFOA; 24, 240, 2400 ng/L PFOS; and stepwise mixtures) from 0–5 days post-fertilization (dpf) on larval zebrafish (Danio rerio) mortality, morphology, behavior and gene expression and fecundity in adult F0 and F1 fish. As expected, environmentally relevant PFAS levels did not affect survival. Morphological abnormalities were not observed until the F1 and F2 generations. Behavior was affected differentially by each chemical and generation. Gene expression was increasingly perturbed in each generation but consistently showed lipid pathway disruption across all generations. Dysregulation of behavior and gene expression is heritable, even in larvae with no direct or indirect exposure. This is the first report of the transgenerational effects of PFOA, PFOS, and their mixture in terms of zebrafish behavior and untargeted gene expression.

Empirical Characterization of False Discovery Rates of Differentially Expressed Genes and Transcriptomic Benchmark Concentrations in Zebrafish Embryos

“…Indeed, a variety of study designs have been employed in transcriptomic experiments using embryonic zebrafish models, tailored to specific study objectives (Table S1). − ,− Generally, these studies have used pools of 1–20 embryos with n = 3–8 samples per dose group and 3–8 concentration groups. Within these studies, there is a tendency toward larger pool sizes (>10) and more concentration groups (≥4).…”

Assessment of unique behavioral, morphological, and molecular alterations in the comparative developmental toxicity profiles of PFOA, PFHxA, and PFBA using the zebrafish model system

“…These results align with epidemiological studies that link PFOA to immunological diseases and the consideration that PFOA is an immune hazard due to its roles in suppression of the antibody response and increased hypersensitivity ( NTP, 2016 ). Interestingly, an additional study also found that exposure of zebrafish embryos to PFOA resulted in multigenerational effects on immune system development ( Haimbaugh et al, 2022 ). Haimbaugh et al showed that parental exposure to 7 ng/L PFOA lead to down regulation of the innate immunity-related c3a.2 in 7 day old F1 offspring.…”

“…Haimbaugh et al showed that parental exposure to 7 ng/L PFOA lead to down regulation of the innate immunity-related c3a.2 in 7 day old F1 offspring. In addition, zebrafish embryos exposed to 7 or 70 ng/L PFOA through 5 days had changes in genes involved in immune cell function and trafficking in the 7 day-old F2 generation offspring ( Haimbaugh et al, 2022 ).…”

Survival, Growth, and Reproduction Responses in a Three‐Generation Exposure of the Zebrafish (Danio rerio) to Perfluorooctane Sulfonate

“…For example, a recent study by Christou et al (2021) exposed zebrafish during early development (0.25-5 dpf) to PFOS at 300 and 2060 μg/L (nominal), and no significant effects on survival were observed at 120 or 456 dpf. Similarly, Haimbaugh et al (2022) administered PFOS at low concentrations of 0.024, 0.240, and 2.4 µg/L (nominal) to P-generation zebrafish in early developmental exposures (0.25-5 dpf) and identified no statistically significant effects in the P generation or subsequent unexposed generations (F1 and F2). Keiter et al (2012) reported no significant zebrafish mortality in the P, F1, or F2 generations in 0.734 and 106.9 µg/L (measured) PFOS exposures.…”