Two days ago, a big meeting in Maryland of researchers into non-coding DNA (alleged “junk DNA” ) wrapped up, and people have been writing to us about the various, so-far unofficially publicized findings that friends have told them about. One researcher whose specialty is orphan genes observed that although we have similar genes to mice, the DHS regions in the DNA associated with these genes feature only 5% similarity between mice and humans.
This is all the more peculiar because the eventual development of mice is very similar to that of humans even though so many differences in regulatory pathways exist.
He was part of a research team that discovered this:
Abstract: To study the evolutionary dynamics of regulatory DNA, we mapped >1.3 million deoxyribonuclease I–hypersensitive sites (DHSs) in 45 mouse cell and tissue types, and systematically compared these with human DHS maps from orthologous compartments. We found that the mouse and human genomes have undergone extensive cis-regulatory rewiring that combines branch-specific evolutionary innovation and loss with widespread repurposing of conserved DHSs to alternative cell fates, and that this process is mediated by turnover of transcription factor (TF) recognition elements. Despite pervasive evolutionary remodeling of the location and content of individual cis-regulatory regions, within orthologous mouse and human cell types the global fraction of regulatory DNA bases encoding recognition sites for each TF has been strictly conserved. Our findings provide new insights into the evolutionary forces shaping mammalian regulatory DNA landscapes. Open access
It concludes: “widespread repurposing of conserved DHSs to alternative cell fates” Repurposing ?
Also, ENCODE 2015’s final agenda.
Oh and, anyone remember the total war against ENCODE by molecular evolutionist Dan Graur? Read it and decide for yourself. At one time, the idea that most of the human genome is junk was big among Christians for Darwin too.
Meanwhile: Rob Sheldon tries to help Darwin followers get over the ENCODE findings
New York Times science writer defends the myth of junk DNA
Junk DNA hires a PR firm
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