The molecular weight of aspermatogenic antigen as determined by equilibrium ultracentrifugation.

The extraction of antigen from testis and sperm is described. This antigen, when administered in microgram amounts in a single injection, induces aspermatogenesis in 100% of guinea pigs so treated. The deletion of the seminiferous cell line is specific (no cross-reactions) and provides a tool for investigating inhibition of cell replication as well as reproductive control.

ACCEPTANCE OR REJECTION OF MALE SKIN BY ISOLOGOUS FEMALE MICE: EFFECT OF INJECTION OF SPERM.

Female C57B1/6J mice given one intraperitoneal injection of 1 to 8 million isologous epididymal sperm cells may exhibit either delayed or accelerated rejection of isologous male skin, depending on both the number of sperm cells injected and the time of application of the graft. A long time interval or a large dose of sperm cells results in maintenance of the male graft or delayed rejection, while a small dose and short time interval produces an accelerated rejection phenomenon.