Mechanisms of Gene Duplication and Translocation and Progress towards Understanding Their Relative Contributions to Animal Genome Evolution

Figure 2

Scheme of a serial translocation via circular DNA intermediates. Two excisions create a fragment of chromosome A, delimited by genes A and E. This fragment circularizes. At reinsertion into a new genomic location, the circle is linearized by being opened between C and D and inserts between genes ∂ and β of chromosome B. The subsequent translocation involves an excision delimited by genes B and Ω. The fragment created circularizes and has sequence identity to the region on chromosome A between the C and B genes. This region of homology allows a repatriation of the segment of original genes from chromosome A, creating a duplication as well as translocating genes from chromosome B. Blue and green lines represent fragments of two different chromosomes. The capital and Greek letters represent genes within the chromosomes. The yellow capital letters denote the genes translocated from chromosome B (green line). The angled orange arrows represent excision points in the DNA. The orange cross represents a homologous recombination site. Adapted from [7].