Putative 4R homeologous linkage group affinities within the rainbow trout (Figure 4) and Atlantic salmon (Figure 5) genome based upon duplicated marker distributions. Acrocentric linkage groups composed of only a single ancestral arm are depicted in yellow background on the Oxford grid axes. Acrocentric linkage groups are expected to only possess a single 4R homeologous affinity while metacentric linkage groups should possess at least two 4R affinities. Several arm fusions have occurred in Atlantic salmon resulting in the expectation that metacentric chromosomes such as AS-17 possess 3 whole-arm affinities, while acrocentric chromosomes AS-2, -3, -5, -6, -8, -9, -13, -16, -22, -23, and -25 will have two whole-arm affinities. For AS-10, three whole-arm affinities are expected within this large acrocentric chromosome . Homeologies based upon only a single duplicated marker are in some instances supported by the mapping of single non-duplicated markers in alternate mapping parents to either of the putative duplicated homeologous linkage groups. Inferred homeologies based upon the comparative synteny mapping with zebrafish and medaka (Figures 1 – 3) are indicated as orange blocks in the Oxford grids.
Danzmann et al. BMC Genomics 2008 9:557 doi:10.1186/1471-2164-9-557