Figure 1. Genetic variation between the two populations. (A) Maximum-likelihood tree from genome-wide single nucleotide polymorphisms (SNPs). The samples from BY and LJX are shadowed in red and blue respectively. (B) Principal component analysis plot of the first two components. The fraction of the variance explained is 5.42% for PC1 and 5.11% for PC2. The samples from BY are clustered more compactly than those from LJX. (C) Manhattan plot of genetic differentiation between the BY and LJX population. Green dots indicate outlier regions (1% most divergent) with F ST > 0.07 (top panel) and πLJXBY > 1.64 (bottom panel). The genes encoding serine/threonine protein kinase PIM1 with complete kinase domain are highlighted by a shaded green column and the schematic representation of PIM1 domain structure is shown. (D) Volcano plot indicating the results of differential expression analysis for testis. The green dots represent the significantly upregulated genes in BY population and the overlapped gene (PIM1 ) between PSGs and DEGs is shadowed in green.