By Prarthana Mitra
Latest discoveries in the field of molecular biology have proved the existence of a different form of DNA which does not resemble the double helix structure we have come to know so well from our high school biology. According to a paper published recently in the Natural Chemistry journal, the twisted-ladder structure first discovered in 1953 is not the only kind of genetic code embedded inside our bodies.
Here’s what happened
Garvan Institute researchers have identified the existence of a new DNA structure in certain regions of the genome, that they have tentatively named the i-motif because it looks more like a twisted, four-stranded knot than the double helix.
To provide some context into how DNA structures are constituted, base pairs in quintessential human DNA are stacked on top of one another, with two strands of a sugar-phosphate backbone twisting around them to form an elegant, spiralling ladder. For the purpose of the latest study, scientists developed an antibody to detect and identify i-motifs in the genome with an immunofluorescent glow. This not only allowed researchers to see how frequently and where these knots of DNA occur, they also found that the i-motifs depending on the acidity of their surroundings could fold and unfold.
Why you should care
The latest findings shed crucial light on how the role of DNA is perceived, understood and studied. They have opened up new vistas in the study of protein synthesis. Furthermore, scientists involved in the research found the codes embedded in areas of the genome which are known to decide whether or not a certain gene gets expressed. This is a potentially groundbreaking discovery because it may reveal the i-motif as some kind of a switch that is capable of regulating gene expression.
Although earlier studies dating as a far back as the 1900’s had written about the existence of DNA in this tangled form, it had only occurred under acidic conditions that were never detected in living cells outside the laboratory before.
Researchers at the Garvan Institute of Medical Research in Australia have made a breakthrough discovery which not only certifies that the structure exists but is also abundantly found in living human cells. This may be instrumental in unravelling more mysteries about the human genetic code and puts the i-motif DNA structure on its course to becoming an important building block of modern molecular biology.