Gene expression and genome heterogeneity. (A) Principal Component Analysis on genes located on atypical chromosome 2. Atypical genes from the first half of the chromosome are plotted in red, typical genes from the second part are plotted in black. The first and second components shown on the x and y axis, represent 42% and 24.8% of total variation respectively, very similar to the other chromosomes. (B) Hierarchical clustering (HCl) of gene expression on atypical Chr2 compared to Chr1. Expression of genes is also represented according to the physical localisation along chromosomes (PC). Top correspond to 0 position of the Chromosome.