DNA unknown

In between the well-structured genes are large sections of DNA for which no function has yet been identified. These areas have been called ‘junk DNA’ or 'non-coding DNA' and make up a large proportion of the genomes of both plants and animals.

But is it junk at all?

We don’t really know. This DNA appears to act as a filler in between genes and a number of ideas are starting to emerge about what role it plays. This is a mystery to be solved in the next couple of decades.

Some of the ideas are:
o it is where defective genes, or pseudogenes, are dumped
o it is the accumulated DNA of viruses that have infected the body and failed to take over the cell
o it acts as a protective buffer against genetic damage and harmful mutations, because the area is irrelevant to the metabolic and developmental processes (if a random change occurs in the sequence, there is no effect on the body)
o it acts as a reservoir of sequences from which potentially advantageous new genes can emerge

Researchers believe that this unknown DNA probably plays some role in regulating the 'coding DNA' and therefore cellular processes. But there is currently very little knowledge about the relationship between non-coding DNA and the DNA of genes.