Figure 7.

The transformations of the P1 shell on maturation with the dashed curve showing a conceptional energy profile along the expansion coordinate. The procapsid readily converts to the first expansion intermediate by various triggering events such as heat, acid, salt, or the packaging of the s segment. Packaging the m segment then leads to further slight expansion to the second intermediate, followed by packaging the l segment. Only then is the genome replicated to produce the full dsRNA complement.