Figure 5From: The ancient mammalian KRAB zinc finger gene cluster on human chromosome 8q24.3 illustrates principles of C2H2 zinc finger evolution associated with unique expression profiles in human tissuesEstimation of the evolutionary selection pressure on the different domains of the ZNF genes/proteins from 8q24.3 and their orthologs. The histogram plots the average ω (= ratio between dN, the number of non-synonymous substitutions per non-synonymous site, and dS, the number of synonymous substitutions per synonymous site) for each domain, KRAB-A, KRAB-B, linker (LINK) and zinc finger array (ZNF, the consecutive sequence of all C2H2 zinc fingers of the gene/protein) of the ZNF genes/proteins. The data labeled 7AA DBD only consider the sequences -2 to 6 with respect to the a-helix of each C2H2 zinc finger for analysis, except for conserved position 4. The ω values of smaller than 1, equal to 1 or larger than 1 refer to negative purifying selection, neutral evolution or positive selection, respectively. Error bars represent the respective standard deviations. The means of the different domains were statistically compared by a T-test, the asterisks indicate the high significance (p < 0.0001).Back to article page