Increased production of mouse embryos in in vitro fertilization by preincubating sperm cells with the nuclease inhibitor aurintricarboxylic acid

Exposure of spermatozoa to stress conditions causes a drastic reduction of their fertilizing ability. We report here that the decrease in fertilizatio n can be effectively antagonized by preincubating sperm cells with the nucl ease inhibitor drug aurintricarboxylic acid (ATA). Preincubation of mouse e pididymal sperm cells with ATA increased the yield of 2-cell embryos produc ed by in vitro fertilization assays. The effect of ATA was selectively exer ted via spermatozoa, since neither preincubation of eggs, nor the direct tr eatment of zygotes, modified the yield of 2-cell-stage embryos. Our results suggest that ATA does not directly improve the ability of sperm cells to p enetrate the egg cytoplasm but instead acts by preserving sperm nuclei from induced or spontaneously occurring damage and/or favors events that trigge r early embryogenesis.