Slashdot Mirror
New Code Discovered in DNA?
anthemaniac writes "The NY Times is reporting that scientists have found a second code in DNA that goes beyond the genes. The code is superimposed genetic information and 'sets the placement of the nucleosomes, miniature protein spools around which the DNA is looped. The spools both protect and control access to the DNA itself. The discovery, if confirmed, could open new insights into the higher order control of the genes, like the critical but still mysterious process by which each type of human cell is allowed to activate the genes it needs but cannot access the genes used by other types of cell.'"
FTA: "Biologists have suspected for years that some positions on the DNA, notably those where it bends most easily, might be more favorable for nucleosomes than others, but no overall pattern was apparent. Drs. Segal and Widom analyzed the sequence at some 200 sites in the yeast genome where nucleosomes are known to bind, and discovered that there is indeed a hidden pattern."
Honestly, many of us biologists are kind of giggling at how the NYT (and I guess Slashdot) have been hoodwinked by hot headlines. We have known for decades that histones bind DNA and organize it (into nucleosomes), periodically, all along its length. Now, this group has identified some concensus sequences where the nucleosomes are most likely to form. Turns out, yeah, it's what we thought, with the little twist that precise positioning of nucleosomes could help regulate gene expression (also heavily predicted and fully expected). There are new articles about DNA organization weekly. I think the NYT just picked one and labeled it as a "code beyond genetics", which is absurd, since the organization of DNA is controlled ultimately by DNA sequences. Also, if you want to talk about codes beyond genetics, there is a whole field of study called "epigenetics", which is "the study of reversible heritable changes in gene function that occur without a change in the sequence of nuclear DNA".