Figure 2.

Pedigree structure of the 28 individuals. (a) A neighbor-joining phylogenetic tree of the 28 individuals. The branches with green, blue, red, and purple colors represent the casper, roy, wt-heter, and wt-homo groups, respectively. (b) Pedigree structure of the 28 individuals. The x-axis shows the subgroup membership, and the y-axis exhibits the corresponding individuals from the phylogenetic tree. (c) Principal component analysis (PCA) of the 28 individuals, using the entire homozygous SNPs. Four groups were identified as follows: casper in green, roy in blue, wt-heter in red, and wt-homo in purple. (d) PCA of the 28 individuals using homozygous SNPs from the linkage disequilibrium (LD) block in chr20. It appears that all the individuals of both casper and roy strains were merged into one group.