{"database":"GEO","file_versions":[{"headers":{"Content-Type":["application/json"]},"body":{"files":{"Other":["ftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE310nnn/GSE310402/"]},"type":"primary"},"statusCode":"OK","statusCodeValue":200}],"scores":null,"additional":{"omics_type":["Transcriptomics"],"species":["Danio rerio"],"gds_type":["Expression profiling by high throughput sequencing"],"full_dataset_link":["https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE310402"],"repository":["GEO"],"entry_type":["GSE"],"additional_accession":[]},"is_claimable":false,"name":"Photoperiod perturbations impact perfluorohexane sulfonate (PFHxS) induced developmental toxicity [PFHxS-5day]","description":"Perfluorohexane sulfonate (PFHxS) is a persistent perfluoroalkyl substance with increasing scrutiny due to its widespread occurrence and potential for developmental neurotoxicity. In this study, we investigated how photoperiod - a critical regulator of circadian physiology- modulates PFHxS toxicity in zebrafish embryos. Photoperiods are highly relevant in today’s context, where artificial lighting, shift work, and time-zone travel increasingly disrupt natural light-dark cycles. To evaluate this variable, embryos were raised under either a standard 14-hour light:10-hour dark (14L:10D) cycle, constant darkness (24D) or constant light (24L) and simultaneously exposed to PFHxS across a concentration range (0.0025–25 µM) from 2 to 120 hours post-fertilization. Since 24L did not elicit any significant phenotypic differences, this photoperiod was excluded from further studies. LC-MS analysis revealed comparable PFHxS uptake across 24D and 14L: 10D photoperiods, ruling out bioaccumulation-induced differences. However, behavioral assays showed photoperiod-specific phenotypes, with hyperactivity during light epochs under 24D. PFHxS elevated melatonin levels under 14L:10D but reduced them under 24D, indicating circadian endocrine disruption. Transcriptomic analysis revealed greater PFHxS-induced dysregulation under 24D, including suppressed DNA replication and cell cycle pathways and increased oxidative stress. These effects coincided with elevated ROS, increased DNA damage, and reduced proliferation. Eye-specific studies revealed reduced retinal proliferating cells and photoreceptor (cone) length under 24D, but not 14L:10D, suggesting that aberrations in eye development may be a driver of phenotypes. Collectively, our findings highlight the critical role of environmental lighting in shaping toxicological outcomes and emphasize the need to incorporate photoperiod context into risk assessments.","dates":{"publication":"2026/07/01"},"accession":"GSE310402","cross_references":{"GSM":["GSM9295473","GSM9295484","GSM9295485","GSM9295474","GSM9295482","GSM9295471","GSM9295483","GSM9295472","GSM9295488","GSM9295477","GSM9295466","GSM9295467","GSM9295478","GSM9295475","GSM9295486","GSM9295487","GSM9295465","GSM9295476","GSM9295480","GSM9295470","GSM9295481","GSM9295468","GSM9295479","GSM9295469"],"GPL":["34622"],"GSE":["310402"],"taxon":["Danio rerio"],"PMID":["[41791196]"]}}