Data from: Developmental exposure to PCB153 (2,2’,4,4’,5,5’-hexachlorobiphenyl) alters circadian rhythms and the expression of clock and metabolic genes

Polychlorinated biphenyls (PCBs) are highly persistent and ubiquitously
distributed environmental pollutants. Based on their chemical structure,
PCBs are classified into non-ortho-substituted and ortho-substituted
congeners. Ortho-substituted PCBs are structurally similar to dioxin and
their toxic effects and mode of action are well established. In contrast,
very little is known about the effects of non-ortho-substituted PCBs,
particularly during early development. The objective of this study is to
investigate the effects of exposure to an environmentally prominent
ortho-substituted PCB (2,2’,4,4’,5,5’-hexachlorobiphenyl; PCB153) on
zebrafish embryos. We exposed zebrafish embryos to either DMSO or three
different concentrations of PCB153 starting from 4 hours
post-fertilization (hpf) to 120 hpf. We quantified gross morphological
changes, behavioral phenotypes, gene expression changes and circadian
behavior in the larvae. There were no developmental defects during the
exposure period, but starting at 7 dpf, we observed spinal deformity in
the 10 μM PCB153 treated group. A total of 633, 2227, and 3378
differentially expressed genes were observed in 0.1, 1 and 10 μM PCB153
treated embryos, respectively. Of these, 301 genes were common to all
treatment groups. KEGG pathway analysis revealed enrichment of genes
related to circadian rhythm, FoxO signaling and insulin resistance
pathways. Behavioral analysis revealed that PCB153 exposure significantly
alters circadian behavior. Disruption of circadian rhythms has been
associated with the development of metabolic and neurological diseases.
Thus, understanding the mechanisms of action on environmental chemicals in
disrupting circadian regulation of metabolism is essential for preventing
or mitigating chemical-induced metabolic disease.