Fig 4.

Introgression by integration of circular episome. (A) A segment of chromosome for the donor species forms a self-replicating circular episome that, after transfer to another yeast, may amplify and eventually integrate at various locations within the chromosomes of the recipient species, resulting in circular permutations. This panel was inspired by previous references (17, 55). (B) Schematic representation of a possible transfer of a circular episome from one nucleus to the other during the transient heterokaryotic phase of an abortive hybridization.