Can colinearity be exploited across the monocot/dicot divide?
Several studies have been performed to define the extent to which colinearity is retained between monocotyledonous and dicotyledonous plants and to find out whether knowledge accumulating on Arabidopsis thaliana can be used to support gene isolation in grasses. An early predictive model suggested that colinearity between sorghum and A. thaliana chromosomal segments could be expected within a distance < 3 cM (Paterson et al., 1996). Sequence comparison of the Adh1 and Sh2/A1 regions of maize and sorghum with the arabidopsis genome showed that adjacent genes in grasses are generally not colinear with Arabidopsis (Bennetzen et al., 1998; Tikhonov et al., 1999). Comparative analysis was also performed between A. thaliana and rice, the two model species for dicots and monocots, respectively. In one study, a conserved framework of genes (i.e. conserved colinearity for five genes interspersed by a number of non-conserved genes) was identified between both species in a region spanning 2.1 cM i
