Presently, only the function of a few percent of the DNA is known, the rest has been believed to be useless garbage, commonly called "Junk DNA" by molecular biologists. Increasing evidence is now indicating that this DNA is not "junk" at all. Especially, it has been found to have various regulatory roles. This means that this so-called "non-coding DNA" influences the behavior of the genes, the "coding DNA", in important ways.
However, the knowledge is still very incomplete about this DNA. And there is little knowledge about the..
relationship between non-coding DNA and the DNA of genes.
Without this knowledge it is completely impossible to foresee and control the effect of artificial insertion of foreign genes.
This is a very important reason why genetic engineering is unsuitable for commercial application. It is still at a stage of early experimentation with very incomplete understanding about its consequences. According to the ethical standards of sound science, the products of such experimentation should be strictly contained in labortories, especially as released DNA may spread indefinitely in an uncontrollable way.
Presently, only the function of a few percent of the DNA is known, the rest has been believed to be "junk". The most exhaustive knowledge is about the genes responsible for the bodily structures, the structural genes, which are the simplest part of the system. But the knowledge about the most important part of this system, the regulator genes, is incomplete. The genetic code language of these genes is only partially known.
More than 98 percent of all DNA, was called "Junk DNA" by molecular biologists, because they were unable to ascribe any function to it. They assumed that it was just "molecular garbage". If it were "junk", the sequence of the "syllables", i.e. the nucleotides in DNA should be completely random.
However it has been found that the sequence of the syllables is not random at all and has a striking resemblance with the structure of human language. Therefore, scientists now generally believe that this DNA must contain some kind of coded information. But the code and its function is yet completely unknown.
It has been reported that the sequences of this unknown DNA are inherited and that some repetitive patterns in it seem to be associated with increased risk for cancer. Also, the DNA has been found to mutate rapidly for example in response to cancer. It has been speculated that this DNA may contribute to the regulation of cellular processes. Haig H. Kazazian, Jr., chairman of genetics at the University of Pennysylvania has recently found reasons to suspect they may be a key force for the development of new species during evolution. He thinks this DNA may be essential for increasing the plasticity of the hereditary substance.
ConclusionThe idea that a major part of our DNA is "garbage" ignored the fact that a key feature of biological organisms is optimal energy expenditure. To carry enormous amounts of unnecessary molecules is contrary to this fundamental energy saving feature of biological organisms. Increasing evidence are now indicating many important functions of this DNA, including various regulatory roles.
This means that this so-called non-coding DNA influences the behavior of the genes, the "coding DNA", in important ways. Still there is very little knowledge about the relationship between non-coding DNA and the DNA of genes.
By Jaan Suurkula M.D.