Scientists have discovered over 4 million gene switches, formerly known as “junk” (a scientific shorthand for “we don’t know what this means”), in the human genome. From the New York Times article Bits of Mystery DNA, Far From ‘Junk,’ Play Crucial Role (GINA KOLATA):
…The human genome is packed with at least four million gene switches that reside in bits of DNA that once were dismissed as “junk” but that turn out to play critical roles in controlling how cells, organs and other tissues behave. The discovery, considered a major medical and scientific breakthrough, has enormous implications for human health because many complex diseases appear to be caused by tiny changes in hundreds of gene switches.
The findings, which are the fruit of an immense federal project involving 440 scientists from 32 laboratories around the world, will have immediate applications for understanding how alterations in the non-gene parts of DNA contribute to human diseases, which may in turn lead to new drugs. They can also help explain how the environment can affect disease risk. In the case of identical twins, small changes in environmental exposure can slightly alter gene switches, with the result that one twin gets a disease and the other does not.
As scientists delved into the “junk” — parts of the DNA that are not actual genes containing instructions for proteins — they discovered a complex system that controls genes. At least 80 percent of this DNA is active and needed. The result of the work is an annotated road map of much of this DNA, noting what it is doing and how. It includes the system of switches that, acting like dimmer switches for lights, control which genes are used in a cell and when they are used, and determine, for instance, whether a cell becomes a liver cell or a neuron.
Reminds me of the discovery that glial cells aren’t packing material to support neurons. We were missing about half the human brain by size.
While I find both discoveries exciting, I am also mindful that we are not getting any closer to complete knowledge.
Rather opening up opportunities to correct prior mistakes and at some future time, to discover present ones.
PS: As you probably suspect, relationships between gene switches are extremely complex. New graph databases/algorithms anyone?