Effects of desalinated seawater with excessive boron on reproductive health of male rats

To investigate the effects of desalinated seawater with excessive boron on reproduction of male rats exposed to desalinated seawater (DSW), equivalent boron (B) water, and deionized water (control group) in a 90-day experiment. We explored sperm toxicity, testicular toxicity, and differential gene expression by detecting sperm quality, testicular enzyme activity, and transcriptome, and finally conducted fertility experiments. Results showed the sperm activity-motility (MOT) decreased and follicle-stimulating hormone (FSH) increased in both DSW and B groups at 30 days. As testicular enzymes, malate dehydrogenase (MDH) and lactate dehydrogenase isoenzyme-X (LDH-X) increased in DSW group, and 3-phosphoglyceraldehyde dehydrogenase (GAPD) increased in both DSW and B groups at 30 days. alpha-glycerol phosphate dehydrogenase (alpha-GDPH), sorbitol dehydrogenase (SDH), glucose-6-phosphate dehydrogenase (G6PDH), MDH and LDH-X in DSW and B groups decreased at 90 days. Transcriptome analysis revealing the downregulated genes (Dazl, Spef2 and Strbp) and upregulated genes (Catsper3, Gapdhs, Hils1, Odf2, Spata20, Spata24, Spata32 and Spem1) associated with male reproductive processes in 90day DSW group. Our findings suggest that energy metabolism involved in MOT induced by 30 days' (short-term) exposure to DSW, while FSH and GAPD might be sensitive early biomarkers. 90 days' (long-term) and low-dose exposure to DSW may cause spermatogenesis-related genetic changes.