Abstract: | Mount, intromission, and ejaculation number and latency were measured in male mice of the DBA/1Bg, DBA/2Bg, and DBA/2.DBA/1-YBg congenic strains. The DBA/2 and DBA/2.DBA/1-Y congenic strains differ in the source of their Y chromosome. Fifty percent of the DBA/2 and 13 percent of the DBA/2.DBA/1-Y males mounted at least once in the test of male copulatory behavior. There were no other significant differences between these two congenic strains. This finding suggests that the Y chromosome has an effect on the proportion of mice that mount in this test. |