Moderate UVA Radiation Improves Semen Quality and Produces Endocrine and Immune Effects in Mice

UVA radiation, which makes up approximately 95% of the UV light that reaches the ground and can penetrate deep into the dermis, has a non-negligible impact on living organisms. This study aimed to investigate the potential effects of moderate UVA radiation on male mice, particularly on male germ cells. We evaluated testicular morphology and sperm quality in UVA-irradiated and control mice, and collected testes and serum from both groups of mice for transcriptomics and metabolomics analyses. The experimental results demonstrated that moderate UVA irradiation exerted no significant effects on testicular histomorphology in mice, while semen quality collected from the epididymis showed significant improvements, characterized by enhanced sperm motility and reduced abnormality rates. Our data in transcriptomics and metabolomics also identify important differentially expressed genes and differentially abundant metabolites associated with sperm. In addition, we found changes in both the endocrine system and the immune system of mice by transcriptomics and metabolomics, suggesting the complex effects of UVA radiation on mice physiology under these experimental conditions.