Oxford grid showing the homeologous relationships which have been conserved between rainbow trout chromosome arms after the 4th Whole Genome Duplication specific to salmonids. Linkage group and chromosome arm numbers are indicated on first and second lines and rows respectively. Numbers of markers shared between duplicated regions are given. When two numbers per cell are given (i.e. 1 + 1), the second one corresponds to additional homeologies found by comparing the rainbow trout and model species linkage groups. Blue cells: previously well-characterised homeologies. Green and orange cells: homologies respectively based on a single marker or suggested in Danzmann et al.  and confirmed with additional duplicated markers in the current study. Red cells: newly identified homeologies supported by two or more markers. Grey cells: homeologies based on a single marker and not considered in this study.