Extreme human–rodent CNSs with no conservation in fish identify enhancers at e11.5–12.5 only in certain genomic regions. Upper and lower plots: human–rodent (blue) and human–mouse–fish (scaled by a factor of 5, red) CNS density on the p (upper) and q (lower) arms of human chromosome 16. We tested 24 human–rodent CNSs with P-value < 1e-40 and no conservation in fish (locations marked by vertical lines) for enhancer activity at embryonic day 11.5–12.5. The five enhancers thus identified were located exclusively in two of the four loci with the highest human–mouse–fish CNS density on the chromosome (yellow bands). These loci contain developmentally regulated genes, all but one of which are transcription factors.
