Fig. 1
Identification of two evolutionary strata in the sex-determining region (SDR) of S. viminalis. Chromosome positions for S. viminalis and P. trichocarpa are shown in Mb with the S. viminalis scaffold names shown on the top. The two identified strata are shown with different hues of pink and labeled above the plot. a Anchoring of S. viminalis scaffolds to the autosomal chromosome 15 of P. trichocarpa. Forward alignments are drawn in blue and reverse alignments are drawn in red. b Log2 differences of normalized SNP density between S. viminalis females and males in non-overlapping windows of 10 kb. A moving average of 25 windows is shown in the black line. The gray shaded area corresponds to the bootstrap 95% confidence interval of the autosomal data. c Log2 differences of normalized read coverage between females and males in non-overlapping windows of 10 kb. Moving average and bootstrap statistics are as in b. Values close to −1 indicate twice the coverage in males in comparison with females, thus potentially Z-linked