Model illustrating the transgenerational effect of PM 2.5 exposure on male fertility. Our study revealed that paternal PM 2.5 exposure results in a transgenerational effect on male offspring, with F1 and F2 male offspring showing traits of male hypogonadism, while female offspring remain unaffected. Our study found the impact of PM 2.5 exposure on sRNA changes, with an abnormal increase in piRNAs levels and an increase in DNA methylation. While we did not observe piRNAs maintenance in F1 sperm, we did find that DNA methylation levels may have a lasting effect. Interestingly, piRNA molecules were found to have transgenerational and intergenerational effects through regulation of target genes. One sRNA molecule, piR016061, was found to target Lhcgr , leading to functional changes in Leydig cells and decreased testosterone production in F1 offspring. Furthermore, high levels of DNA methylation in Lhcgr and Gnas in F0 generation mice may also contribute to Leydig cell dysfunction. Additionally, we found that other piRNAs, such as piR006695 and piR033435, regulate the methylation levels of Lhcgr and Gnas in F1 male germ cells by targeting Tet1 , leading to transgenerational effects on Leydig cell function in F2 offspring. Values are presented as the mean ± SEM. For statistical analysis, P values were calculated by two-way ANOVA followed by uncorrected Fisher’s LSD test ( a – c , f , g ) or one-way ANOVA followed by Dunnett’s multiple comparisons test ( d , e ).
