The Silent Legacy: Paternal and Maternal Exposure to Microplastics and Differential DNA Methylation in Human Oocytes and Zygotes
DOI:
https://doi.org/10.54536/ajpehs.v3i2.6381Keywords:
Assisted Reproductive Technology, DNA Methylation, Endocrine-Disrupting Chemicals, Epigenetics, Microplastics, ZygoteAbstract
The alarming pervasiveness of microplastics in our environment, along with the endocrine-disrupting chemicals (EDCs) they often carry such as phthalates and Bisphenol A BPA) represents a growing and insidious threat to human reproductive health. While epidemiological studies have linked these compounds to negative reproductive outcomes, we still lack aclear picture of their direct molecular impact. Specifically, how does parental exposure shape the epigenetic landscape of the very first stage of human life, the pre-implantation embryo? This study seeks to bridge this gap by investigating whether quantifiable exposure to microplastic-related EDCs in parents correlates with altered DNA methylation patterns in human zygotes. We designed a prospective observational cohort study involving couples undergoing IVF/ICSI treatments. We will measure concentrations of specific EDCs (BPA, phthalates, PFAS) in follicular fluid and seminal plasma using the highly sensitive technique of liquid chromatography-tandem mass spectrometry (LC-MS/MS). On non-viable or supernumerary zygotes (at the 2-Pronuclear stage), we will perform single-cell whole-genome bisulfite sequencing (scWGBS) to map the entire epigenetic landscape. Our analysis will then identify differentially methylated regions (DMRs) by comparing embryo from parents with high versus low EDC exposure, while statistically controlling for potential confounding factors. We anticipate detecting EDCs in a large proportion of the biological samples. Our primary expected outcome is the identification of specific genomic regions in the zygotes where DNA methylation is significantly associated with parental EDC levels. We hypothesize a trend towards hypomethylation a reduction in methylation in the promoter regions of genes critical for development (e.g., HOXA10, DNMT1), with EDC concentration acting as a key predictor. This research aims to provide the first direct human evidence that parental exposure to microplastics and EDCs can leave a targeted epigenetic “signature” on the zygote. We propose this “silent legacy” mechanism, where environmental toxins alter the embryonic epigenome, could fundamentally compromise implantation success and long-term developmental health. These findings would carry profound implications for the fields of assisted reproduction and public health policy.
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Copyright (c) 2025 Aqsa Akram
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