New Research Highlights Transgenerational Effects of TCDD on Zebrafish Ovaries
A new open-access study published in the International Journal of Molecular Sciences reveals that early-life exposure to the toxic chemical TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) causes long-lasting reproductive effects in zebrafish ovaries across multiple generations.
Researchers at the University of Florida and Wayne State University found that a single developmental exposure to TCDD increased ovarian follicle atresia (cell death) in both exposed female zebrafish (F0) and their immediate offspring (F1), but not in the unexposed third generation (F2). Interestingly, the F2 generation showed the greatest changes in gene expression, particularly in pathways related to epigenetics and cell signaling, suggesting inherited molecular disruptions despite no direct exposure.
The study also observed altered hormone levels and identified key genetic markers and signaling pathways—including Rho GTPase and epigenetic regulators—impacted by the ancestral exposure.
These findings deepen our understanding of how environmental toxins like TCDD can cause hidden, long-term reproductive risks and highlight the importance of regulating persistent pollutants.
Read article here: Multi- and Transgenerational Histological and Transcriptomic Outcomes of Developmental TCDD Exposure in Zebrafish (Danio rerio) Ovary
Boxplots of whole-body mean hormone level changes following exposure in the F0 generation. Welch’s t-test. T: testosterone. T4: thyroxine. T3: triiodothyronine. 11-KT: 11-ketotestosterone. E2: 17β-estradiol. Vtg: vitellogenin.
Toxic Exposure, Lasting Legacy
A new study shows that a single early-life exposure to TCDD — a persistent environmental pollutant — causes ovarian damage and gene expression changes across three generations of zebrafish.
While only the first two generations showed visible reproductive damage, the third had the most molecular disruption, hinting at long-term, inherited effects of toxic exposure.
Read Article here Sublethal juvenile dioxin (TCDD) exposure alters sperm motility and whole-body vitellogenin parameters in adult male zebrafish (Danio rerio) – ScienceDirect
. Definitions of kinematic parameters as measured by the SCA® CASA system for sperm travelling from point A to point B. Curvilinear velocity (VCL, µm/s), straight-line velocity (VSL, µm/s), average pathway velocity (VAP, µm/s), linearity (LIN, %), straightness (STR, %), wobble (WOB, %), amplitude of lateral head displacement (ALH, µm), and beat cross frequency (BCF, Hz).