Nonreciprocal homoeologous recombination (NRHR) events mapped onto a simplified Gossypium allotetraploid phylogeny. Some contigs putatively contain multiple events. The total number of events is indicated in the upper value, while the aggregate number of affected contigs is indicated as the lower value (in bold). Values at the base of the phylogeny are those events shared by both species, which likely occurred in a common ancestor (although parallel mutation remains a possibility).
Flagel et al. BMC Genomics 2012 13:302 doi:10.1186/1471-2164-13-302