Independent segregation for the traits of myoclonic jerk number in [C57BL/6J × DBA/2J] F1 hybrid mice. The mean total number of myoclonic jerks preceding a generalized seizure per flurothyl trial, throughout the repeated flurothyl model, for C57BL/6J (black circles), DBA/2J (red squares), and [C57BL/6J × DBA/2J] F1 hybrid (blue open squares) mice (data from C57BL/6J and DBA/2J mice have been replotted from Figure 3 for this comparison). A significant group by trial interaction (F7,336 = 11.2, P < 0.0001), in addition to a significant between-group difference (F1,48 = 32.8, P < 0.007) and between-trial difference (F7,336 = 8.1, P < 0.0001) was noted. * denotes significantly different from DBA/2J (P < 0.03); # denotes significantly different from [C57BL/6J × DBA/2J] F1 hybrid (P < 0.05); $ denotes significantly different from [C57BL/6J × DBA/2J] F1 hybrid (P < 0.0002); @ denotes significantly different within the strain from trial 8 (P < 0.02).