Chromosomal evolution in the family Solanaceae. The actual karyotype (chromosome 1-12) of tomato, potato, eggplant, pepper and Nicotiana, and the deduced karyotype of their MRCAs are presented. Each tomato chromosome is assigned a different color, and the orthologous counterparts in the other species are painted with the corresponding color, which therefore depicts the translocations differentiating these species. Black arrows on chromosomes represent the inversions that these species have experienced subsequent to divergence from their MRCA, i.e. inversions in tomato and potato relative to ATPt, inversions in eggplant and ATPt relative to ATE, and inversions in ATE and pepper relative to ATP. Position and length of the arrows are approximate (see Additional Files 2 for details). Grey arrows on the pepper chromosomes represent inversions between pepper and ATE but it remains to be determined along which lineage these inversions occurred. White dots indicate approximate centromere location of the tomato chromosomes  and putative centromere location of the eggplant and pepper chromosomes based on their synteny with tomato [9,10]. Broken chromosomes in the ATE and ATP genomes represent unknown karyotypes, in other words, organization of these chromosome segments remains to be determined.
Wu and Tanksley BMC Genomics 2010 11:182 doi:10.1186/1471-2164-11-182