Protective role of ascorbic acid against damage to male germ cells in rainbow trout (Oncorhynchus mykiss)

Low antioxidant levels have been implicated in damage to sperm DNP;. We use d a teleost fish to test if low paternal vitamin C status may cause mutatio ns to the sperm and birth defects. During spermatogenesis, rainbow trout (O ncorhynchus mykiss) males were fed diets with graded levels of ascorbic aci d derivative that were below and severalfold higher than those required for maximum growth. This treatment resulted in corresponding changes in levels of vitamin C in seminal plasma. We found that low levels of vitamin C in s eminal plasma of rainbow trout were associated with a high percentage of ab normal embryos in the offspring. Among abnormal embryos, 34.8% were haploid s or aneuploids, as revealed by flow cytometric measurement of DNA content. We found that UV-irradiated sperm gave rise to progeny with abnormalities similar to those resulting from sperm with low levels of antioxidants in se minal plasma. Ascorbic acid applied directly to semen did not prevent damag e due to UV irradiation. These results provide the first experimental evide nce that the lack or low levels of ascorbic acid in semen correlate with da mage to male germ cells.