The effect of sperm and egg genotype on the incidence of chromosomal anomalies in mouse embryos fertilized in vitro.

Analysis of the chromosomes of 1-cell mouse embryos fertilized in vitro showed that the incidence of polyploidy is independent of both sperm and egg genotype. No significant differences were detected between groups of eggs from 5 strains of mice fertilized by spermatozoa from a single strain, TO, or between groups of (C57BL/10 X CBA) F1 eggs fertilized by spermatozoa from 2 strains, CBA/H-T6 and TO, although there was significant heterogeneity between individual males in the latter set of experiments. While the majority of polyploids were triploids resulting from dispermic fertilization, some derived from diploid spermatozoa were also found.