Never-Seen-Before Secret DNA Code And An 'Unusual Meaning'-Scientists Find

Scientists have found a second code cloaked within DNA, and the findings are leading to speculation that it could forever change how doctors uncover, diagnose and treat various diseases.

Scientists at the University of Washington conducted the research as a part of the Encyclopedia of DNA Elements Project, or ENCODE, according to a news release. The project's objective is to determine how and where directions for biological functions are stored in the human genome. 

Since the genetic code was understood in the 1960s, researchers have believed that it was utilized solely for writing information about proteins. The researchers were surprised to find that genomes utilize the genetic code to write two separate languages: one specifies how proteins are constructed and the other teaches the cell about how genes are managed. One language is written on top of the other, which is why the second language stayed unseen for so long.

Published in the journal Science, researchers explain how Genomes use genetic code not only to write information about proteins, but also to write in two separate languages.

"For over 40 years we have assumed that DNA changes affecting the genetic code solely impact how proteins are made," said study lead researcher Dr. John Stamatoyannopoulos.

"Now we know that this basic assumption about reading the human genome missed half of the picture. These new findings highlight that DNA is an incredibly powerful information storage device, which nature has fully exploited in unexpected ways."

The genetic code is similar for all organisms and is stored in one of the two DNA strands as non-overlapping, linear sequence of nitrogenous bases Adenine (A), Guanine (G), Cytosine (C) and Thymine (T). These four letters are the 'alphabet' of the genetic code and are used to write code words.

The code consists of three-letter words (also called triplets or codons). There are 64 codons, which the research team now named "duons" for their second meaning. Both the first and second meanings seem to work together, with one controlling proteins and the other stabilizing certain regulations to benefit the proteins.

About 15 percent of codons could act as duons and that these bilingual genetic codes have shaped protein evolution, the team said.

"The fact that the genetic code can simultaneously write two kinds of information means that many DNA changes that appear to alter protein sequences may actually cause disease by disrupting gene control programs or even both mechanisms simultaneously," said Stamatoyannopoulos.

Duons, responsible for controlling how cells created in the body control human genes, should help scientists and physicians interpret a patient's genome allowing for more precise and efficient disease diagnoses and treatment.

The National Human Genome Research Institute funded the UW team's multiyear study.