Saturday, 12 May 2018

“Junk” DNA Holds Our Genome Together

The fruit fly (Drosophila melanogaster) plays a key role in a recent study on non-coding DNA. Image courtesy of Sanjay Acharya, CC BY-SA 4.0.

Joel Kontinen

If you thought satellite DNA was junk, you might need to think again. Science Daily suggests that it “plays a crucial role in holding the genome together.”

Researchers are increasingly finding use for non-coding DNA.

Professor Yukiko Yamashita and colleagues published a paper in the journal eLife, disclosing their findings.

They suggest that pericentromeric satellite DNA, once dismissed as junk, “performs the vital function of ensuring that chromosomes bundle correctly inside the cell's nucleus, which is necessary for cell survival.”

The researchers noticed that if they cut off a protein called DI from the cells of fruit flies (Drosophila melanogaster), germ cells would die and the banana munchers would thus have no offspring.

This protein is known to bind to satellite DNA.

While Prof. Yamashita thinks that we can credit evolution for preserving pericentromeric satellite DNA, which “consists of a very simple, highly repetitive sequence of genetic code,” intelligent design is a far better explanation.

Several recent studies have found important functions for “genetic junk”. (See examples here, here and here.)


University of Michigan. 2018. Scientists discover a role for 'junk' DNA. Science Daily. (11 April).