Figure 8

The correlation between the promoter divergence of paralogs and paralog co-expression was robust in respect to the breadth of expression of target genes. This figure consists of twelve parts identified as ( a ) - ( l ). Four sets of paralog pairs were considered: ( a-b-c ) both paralogs were tissue-specific with the breadth of expression ≤ 0.33, ( d-e-f ) both genes were intermediate, ( g-h-i ) both genes were housekeeping with the breadth of expression > 0.66, and ( j-k-l ) one of the paralogs was tissue-specific and the other housekeeping. Pearson’s ( a-d-g-j ), the Kendall rank correlation coefficient ( b-e-h-k ) and Spearman's rank correlation coefficient ( c-f-i-l ) correlations were plotted. The correlation between the Jaccard index and paralog co-expression was robust under all these conditions. Paralog promoter divergence was measured using Jaccard index (JI). Paralog expression divergence was measured using Pearson correlation. The red line signified the linear model for the smoother line, while the blue line signified the non-linear model. Numbers of tags in FANTOM5 were normalized to tags per million (TPM). The TPM value of ten was chosen as a standard cutoff for a gene to be “on”, and the breadth of expression was defined as the fraction of FANTOM5 human tissue samples in which a transcript was “on”.