DOI: 10.5061/dryad.j4g98
title: Data from: Early life exposure to low levels of AHR agonist PCB126 (3,3’,4,4’,5-pentachlorobiphenyl) reprograms gene expression in adult brain

description: Early life exposure to environmental chemicals can have long-term
 consequences that are not always apparent until later in life. We recently
 demonstrated that developmental exposure of zebrafish to low,
 non-embryotoxic levels of 3,3’,4,4’,5-pentachlorobiphenyl (PCB126) did not
 affect larval behavior, but caused changes in adult behavior. The
 objective of this study was to investigate the underlying molecular basis
 for adult behavioral phenotypes resulting from early life exposure to
 PCB126. We exposed zebrafish embryos to PCB126 during early development
 and measured transcriptional profiles in whole embryos, larvae and adult
 male brains using RNA-sequencing. Early life exposure to 0.3 nM PCB126
 induced cyp1a transcript levels in 2-dpf embryos, but not in 5-dpf larvae,
 suggesting transient activation of aryl hydrocarbon receptor with this
 treatment. No significant induction of cyp1a was observed in the brains of
 adults exposed as embryos to PCB126. However, a total of 2209 and 1628
 genes were differentially expressed in 0.3 nM and 1.2 nM PCB126-exposed
 groups, respectively. KEGG pathway analyses of upregulated genes in the
 brain suggest enrichment of calcium signaling, MAPK and notch signaling,
 and lysine degradation pathways. Calcium is an important signaling
 molecule in the brain and altered calcium homeostasis could affect
 neurobehavior. The downregulated genes in the brain were enriched with
 oxidative phosphorylation and various metabolic pathways, suggesting that
 the metabolic capacity of the brain is impaired. Overall, our results
 suggest that PCB exposure during sensitive periods of early development
 alters normal development of the brain by reprogramming gene expression
 patterns, which may result in alterations in adult behavior.
description: GSE98741Strand-specific RNAsequencing data from zebrafish embryos, larvae and adult brain tissue developmentally exposed to two different concentrations of PCB126. Raw data files (fastq) were pre-processed, reads were mapped to the zebrafish genome (GRCz10; ensembl version 87) using STAR aligner. Read counts were obtained using HTSeq-count and differential gene expression analysis was done using edgeR.summary_statisticsThis file contains the details about the number of raw reads and the mapping statistics such as uniquely mapped reads, mapped to multiple loci and unmapped reads for all the samples.Differentially expressed genesEach spread sheet contains the list of differentially expressed genes (FDR &lt;5%) at each time point and concentration.dge.xlsxCommon genesThis is the list of genes that are common to both 0.3 nM and 1.2 nM PCB126 exposed adult whole brain samples.977-commongenes.xlsxKEGG and Geno Ontology Pathway analysis of upregulated genes in the brainThis file contains the list of genes that are represented under each enriched GO and KEGG pathway terms. These genes are differentially expressed in the adult brain samples exposed to either 0.3nM or 1.2nM PCB126.PathwayAnalysis_Up.xlsxKEGG and Gene Ontology Pathway analysis of the downregulated genes in the brainThis file contains the list of genes associated with each enriched KEGG and GO terms in the whole brain samples of 0.3nM and 1.2nM PCB126 exposed adult fish. These GO and KEGG terms are enriched in the downregulated gene set.PathwayAnalysis_Down.xlsx