Distribution of significant genes between all the chromosomes.

<p>χ² tests were performed in the available mutants under the null hypothesis of random distribution: Random, equal proportion; Norm.1, proportion normalized by chromosome length; Norm.2, normalized by number of genes in each chromosome (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001303#s4" target="_blank">Materials and Methods</a>): *, p<0.1; **, p<0.05; ***, p<0.01; ****, p<0.001. Percentages are the contribution of the chromosome for each ablated gene to the deviation from each random distribution and were calculated as proportion of the χ² values. If a chromosome other than that encoding the knock-out gene had more contribution is stated in “Other chrom”. Total genes are the number of the retrieved significant genes.