Figure 4. Distribution in the F2 generation of the three most pertinent PVM-susceptibility traits: (a) ΔBW^d0–d7, the body weight loss at day 7 pi (g), (b) ΔEB^d6–d7, the expiratory balance loss from day 6 to day 7 (%) and (c) LVL^d7, the lung viral load on day 7 (log₁₀ PFU/g).