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

Abstract

Low antioxidant levels have been implicated in damage to sperm DNA. We used a teleost fish to test if low paternal vitamin C status may cause mutations to the sperm and birth defects. During spermatogenesis, rainbow trout (Oncorhynchus mykiss) males were fed diets with graded levels of ascorbic acid 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 seminal plasma of rainbow trout were associated with a high percentage of abnormal embryos in the offspring. Among abnormal embryos, 34.8% were haploids 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 seminal plasma. Ascorbic acid applied directly to semen did not prevent damage due to UV irradiation. These results provide the first experimental evidence that the lack or low levels of ascorbic acid in semen correlate with damage to male germ cells.