junk DNA

Referred to by her team as ‘array capture re-sequencing’, the procedure uses regions of human exons (lengths of DNA that code for proteins) to probe for (or fish out) the Neanderthal eons from contaminated DNA samples. Through the technique they were able to identify 88 differences (in a total of only 83 proteins) between human and Neandertal protein sequences. Amazing! The majority of our DNA does not code for protein or RNA and does not seem to regulate how the information is used. Sometimes referred to as “junk” DNA, these regions make up about 98.5 % of our genome. Is this DNA really junk? Scientists have recently identified a section of “junk” DNA that can regain function and cause disease. The section of DNA is made of repeat regions of the same sequence. They found that individuals who have 1-10 repeats on the end of chromosome 4 can develop one of the most common forms of muscular dystrophy, FSHD. The goal now is to identify a way to turn off this once non-functioning gene. One of the important insights from the resurrection of this gene is that although some diseases can be easily explained, others result from very complicated cellular interactions. What other information will our “junk”DNA reveal in the future? With the completion of the Neandertal genome by the team of Dr. Svante Paabo and a closer look at their proteins by Gregory Hannon’s team at CSHL, scientists reveal incredible similarities between Neandertals and humans.Neandertals, the extinct species of what are most likely our closest relatives, lived on earth at the same time as our human ancestors but died out about 30,000 years ago. With the sequence of their genome now complete, we can compare the DNA to humans and chimpanzees to learn more about what makes humans unique as a species.The discovery of fossils is an exciting link to our past. Although the fossil bones do contain DNA, much of it is contaminated. Dr. Emily Hodges at the Cold Spring Harbor Laboratory developed a technique to quickly identify and amplify specific portions of contaminated DNA accurately.