This past week, the ENCODE (Encyclopedia of DNA Elements) project, which was started in September 2003, released the results of its efforts to identify and map the functional elements in the human genome. The main message that came out of the consortium of research studies was this: Junk DNA is not really junk DNA. The ENCODE project has found so far that about 80% of the human genome has a biochemical function.
“Junk DNA” is the term often used to refer to regions of DNA that does not contain instructions for building proteins (a.k.a. non-coding DNA, or “genes”). It is estimated that about 98% of human DNA is non-coding DNA. However, many studies have shown that these seemingly “empty” DNA regions actually play a significant role in other ways–for example, controlling gene function, providing structural support, and serving as attachment points for enzymes, proteins, and others.
Short tandem repeats (STRs), an example of non-coding DNA, are short repeating sequences of DNA that are used in paternity and human identity testing. Most of the STRs used in identity testing are not found in genes and were counted among the “junk DNA.” For more on the science of paternity testing, visit our Paternity and Family Relationship Testing science page.
For more information on the ENCODE project, visit the following resources:
Nature ENCODE website contains an interactive map of all the studies related to the project, as well as some history and general information.
ENCODE Project at UCSC offers a searchable database ENCODE data for scientists.’s ENCODE page provides the project history and other resources.