Epigenetic transgenerational effects of endocrine disruptors on male fertility were studied in rats. Exposure of pregnant females to vinclozolin (an antiandrogenic compound) or methoxychlor (an estrogenic compound) during critical periods of gonadal sex determination led to reduced spermatogenic capacity and increased male infertility in the F1 generation. These effects were transmitted through the male germ line to subsequent generations (F1 to F4), with over 90% of males exhibiting the phenotype. The effects correlated with altered DNA methylation patterns in the germ line, suggesting an epigenetic mechanism. The study also found that exposure during the remethylation phase of germ cell development could lead to long-term epigenetic changes. The transgenerational effects were observed in both vinclozolin and methoxychlor-treated animals, with no significant genetic mutations identified as the cause. The study highlights the potential for environmental factors to induce epigenetic changes that can be passed on through generations, affecting male fertility. The findings have implications for evolutionary biology and disease etiology, emphasizing the need for further research on the impact of endocrine disruptors on reproductive health.Epigenetic transgenerational effects of endocrine disruptors on male fertility were studied in rats. Exposure of pregnant females to vinclozolin (an antiandrogenic compound) or methoxychlor (an estrogenic compound) during critical periods of gonadal sex determination led to reduced spermatogenic capacity and increased male infertility in the F1 generation. These effects were transmitted through the male germ line to subsequent generations (F1 to F4), with over 90% of males exhibiting the phenotype. The effects correlated with altered DNA methylation patterns in the germ line, suggesting an epigenetic mechanism. The study also found that exposure during the remethylation phase of germ cell development could lead to long-term epigenetic changes. The transgenerational effects were observed in both vinclozolin and methoxychlor-treated animals, with no significant genetic mutations identified as the cause. The study highlights the potential for environmental factors to induce epigenetic changes that can be passed on through generations, affecting male fertility. The findings have implications for evolutionary biology and disease etiology, emphasizing the need for further research on the impact of endocrine disruptors on reproductive health.