Comparison of behaviors for detection of heritable mutations

Groups of five male HA (ICR) mice were injected intraperitoneally with 60, 150, 300, or 600 mg/kg body weight of ethyl methanesulfonate (EMS) or with saline vehicle. Each male was mated to two untreated females at 2 and 5 weeks after treatment. The two successive matings utilized sperm derived from post‐ and premeiotic germ cells, respectively. Progeny were evaluated for litter size, body weight, negative geotactic response, swimming patterns, limb use while swimming, water escape time, and open‐field motor coordination activity. Body weight, geotactic response, limb use, and open‐field behavior test results demonstrated that EMS causes heritable behavior mutations in both post‐ and pre‐meiotic germ cells. Among the tests that showed inherited differences between control and treated groups, the computer‐monitored open‐field behavior test was the most definitive.