London, June 2 (Reuters): Junk DNA may not be so useless after all.

Scientists coined the term to describe the genetic wasteland within the human genome, or book of life, which consists of long uncharted stretches of DNA for which there is no known function.

But researchers from Harvard Medical School said today that within junk DNA in the yeast genome they have discovered a new class of gene.

Unlike other genes, the new one does not produce a protein or enzyme to carry out its function. But when it is turned on, it regulates a neighbouring gene.

“This doesn’t explain all junk DNA. It gives a potential use for some junk DNA,” Prof. Fred Winston, who headed the research team, said in an interview. “I cannot think of another regulatory gene such as this one,” he added. There are about 30,000 to 40,000 genes in the human genome. Much of the genome consists of junk DNA which scientists are trying to decipher to determine the causes and potential treatments for human diseases.

The new gene called SRG1 blocks the function of the adjacent gene in the yeast genome. Winston and his team believe other genes could work in the same way and in other organisms including humans. “We found one example of a type of regulatory gene that hasn’t been found before that might alert investigators to look for it in other cases,” Winston said.