Figure 1. Proposed Mechanisms of Terminal Reassortment.

ORPHETs containing the appropriate regulatory and secretion signals may evolve independently or be derived from another effector. ORPHETs can be mobilized and integrated randomly into the genome, capturing either an existing gene or a non-coding region and thereby instantaneously creating a new chimeric effector. Alternatively, deletions downstream of an N-terminal secretion signal may also result in the formation of a new fusion protein.