NORMAL MICE DEVELOP FROM OOCYTES INJECTED WITH SPERMATOZOA WITH GROSSLY MISSHAPEN HEADS

Because in the mouse some structurally abnormal spermatozoa can penetr ate oocytes, we decided to determine whether mouse oocytes fertilized by spermatozoa with grossly misshapen heads are able to develop normal ly. We injected such spermatozoa from BALB/c mice individually into ma ture oocytes of hybrid mice B6D2F1. Eighty to ninety percent of the oo cytes were activated and developed into blastocysts in vitro and, when transferred to foster mothers, some developed into apparently normal fertile adults. This finding indicates that a proportion of abnormal s permatozoa carry all the genome and organelles necessary for normal em bryonic development and growth to fertile maturity.