Figure 7From: Regular heartbeat rhythm at the heartbeat initiation stage is essential for normal cardiogenesis at low temperatureBlood regurgitation at 15°C in medaka species. Genetic analysis in the Hd-rR (n = 210) and ODT (n = 205) strains. F1 were generated both via the Hd-rR female × ODT male combination (n = 215) and ODT female × Hd-rR male combination (n = 206). F2 (n = 213) were generated by intercrossing F1 progeny. Gray columns, moderate regurgitation; black columns, severe regurgitation.Back to article page