Effects of Zinc Deficiency on Sperm Viability and Morphology in Mice

Abstract

To elucidate the effects of zinc deficiency on male reproduction, we examined sperm viability and morphology in young maturing mice maintained on a zinc-deficient diet (<0.5ppm). Male mice were killed after 6 weeks of feeding. The number of sperm from the cauda epididymides was determined by a standard hematocytometric procedure, and live and dead sperm were differentiated by vital staining with eosin-aniline blue. For morphological evaluation, sperm smears were stained with eosin Y. In the zinc-deficient group, the number of epididymal sperm per testis was reduced (25.7×10⁶/g vs. 51.6×10⁶/g) and the percentage of live sperm was low (41.5%vs. 54.5%). There was a positive correlation between sperm viability and body weight gain during the 6-week experimental period. In addition, the incidence of sperm abnormalities was high, ranging from 13.0% to 44.0% in the zinc-deficient mice, whereas in the control group it ranged from only 5.4% to 22.8%. The most commonly occurring abnormalities were in the sperm head and midpiece region of the tail. These findings suggest that zinc per se is essential for late spermatogenesis in mice.