Dataset Information

Multi-omics evaluation reveals both transient and persistent adverse effects in male fathead minnows after short-term exposure to 17α-ethinylestradiol - RNA-seq part

ABSTRACT: 17α-ethynylestradiol (EE2) is a widely used estrogenic compound that is almost ubiquitous in aquatic environments across the United States and other countries. As an endocrine-disrupting chemical, EE2 can interfere with hormonal homeostasis, leading to developmental disorders, cancer, and other diseases. Exposure to EE2 is known to induce the expression of vitellogenin—a precursor protein of egg yolk typically expressed only in female fish—in male fish. However, the underlying epigenomic changes associated with vitellogenin induction and related phenotypic effects, such as feminization, remain poorly understood. This study aims to uncover the epigenetic regulatory mechanisms involved by assessing genome-wide DNA methylation changes at CpG sites using reduced representation bisulfite sequencing (RRBS). Leveraging an improved, in-house assembled fathead minnow (FHM) genome and its annotation, we selected fathead minnows as the model organism to investigate DNA methylation alterations before and after EE2 exposure. In this study, two groups of male fathead minnows (16 fish per group) were exposed to 2.5 ng/L and 10 ng/L EE2 for 48 hours. Additionally, two control groups were included: a male group as a negative control and a female group as a positive control. We utilized both RNA sequencing (RNA-seq) and RRBS data to assess EE2’s effects on gene expression and DNA methylation in liver and brain tissues.

ORGANISM(S): Pimephales promelas

PROVIDER: GSE294557 | GEO | 2026/10/01

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Rivers containing effluents from water treatment plants are complex soups of compounds, ranging from pharmaceuticals to natural hormones. Male fathead minnows (Pimephales promelas) were exposed for 3 weeks to effluent waters from the Metropolitan Wastewater Treatment Plant in St. Paul, MN. Fish were tested for their competitive nest holding behavior. Changes in vitellogenin were measured and these were correlated to changes in gene expression using a 22,000 gene microarray developed specifically for fathead minnows. Significant changes in gene expression were observed in both liver and gonad, which correlate to phenotypic changes of vitellogenin induction and reduced competitive behavior. We also compared by real-time PCR the expression changes in key genes related to steroid biosynthesis and metabolism in fish exposed to the effluent as well as in fish exposed to a model estrogen and a model androgen. While the gene expression signature from effluent-exposed fish shared some elements with estrogen and androgen signatures, overall it was different, underscoring the complexity of compounds present in sewage and their different modes of action. Fathead minnow 22,000 gene arrays were designed by EcoArray (Alachua, FL) and were purchased from Agilent. Array hybridizations were performed using a reference design, where each sample was compared to a reference sample. The reference consisted of equal amounts of RNA from control female and male tissues (liver, brain and gonad) and was prepared as a standard for several experiments. Four replicates consisting of four different individuals were analyzed for each of the tissues, liver and gonad for both the control and the effluent-exposed fish. cDNA synthesis, cRNA labeling, amplification and hybridization were performed following the manufacturerM-bM-^@M-^Ys kits and protocols (Agilent Low RNA Input Fluorescent Linear Amplification Kit and Agilent 60-mer oligo microarray processing protocol; Agilent, Palo Alto, CA). Ovarian and liver samples from the fish were labeled with Cy5 while the reference sample was labeled with Cy3.

Project description:Metformin, along with its biotransformation product guanylurea, are commonly observed in municipal wastewaters and subsequent surface waters. Previous studies in fish have identified metformin as a potential endocrine active compound but there are inconsistencies in the literature with regard to effects. To further investigate the potential reproductive toxicity of metformin and guanylurea to fish, a series of experiments were performed with reproductively mature fathead minnows (Pimephales promelas). First, explants of mature fathead minnow ovary tissue were exposed to 0.001-100 µM metformin or guanylurea to investigate whether they can directly perturb steroidogenesis. Second, spawning pairs of fathead minnows were exposed to metformin (0.41, 4.1, 41 µg/L) or guanylurea (1.0, 10, 100 µg/L) for 23 d to assess impacts on reproduction. Lastly, male fathead minnows were exposed to 41 µg/L metformin, 100 µg/L guanylurea, or a mixture of both compounds, with samples collected over a 96 h time course to investigate potential impacts to the hepatic transcriptome or metabolome. Neither metformin or guanylurea effected estradiol or testosterone by ovary tissue exposed in vitro. In the 23 d exposure, neither compound significantly impacted transcription of endocrine-related genes in male liver or gonad, circulating steroid concentrations in male or female fish, or fecundity of spawning pairs. In the 96 h time course, 100 µg guanylurea/L elicited more differential gene expression than 41 µg metformin/L , and showed the greatest impacts after 96 h. A number of DEGs up-regulated after 24 h were subsequently down-regulated after 96 h, demonstrating time-dependent impacts of guanylurea on the liver. Overall, metformin and guanylurea did not elicit effects consistent with reproductive toxicity in adult fathead minnows at environmentally relevant concentrations. Where effects were identified using ‘omics approaches, guanylurea induced greater impacts than metformin.

Dataset Information

Multi-omics evaluation reveals both transient and persistent adverse effects in male fathead minnows after short-term exposure to 17α-ethinylestradiol - RNA-seq part

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets