It's DNA Day!

By Selina Haefeli

Today marks the 60th anniversary of the publication of the structure of DNA.

The 25th of April is not only ANZAC Day but also the day in 1953 when the world was first introduced to the “molecule of life”—deoxyribonucleic acid (DNA). Papers describing the structure of DNA were published by James Watson, Francis Crick, Maurice Wilkins and Rosalind Franklin in the journal Nature on this date. At the time, there was not actually much public interest in the mysterious molecule that these scientists wrote about in their papers. The biological importance of DNA took almost a decade to be recognised and nowadays it is seen as the vital recipe book for life.

DNA is found in the nucleus of all cells in the body. It looks like a microscopic ladder that twists very tightly around proteins called histones (the spheres in the image above). Twisted DNA strands form larger structures called chromosomes—of which human cells have 23 pairs in their nucleus. Single DNA strands would measure around two metres long if stretched out but because they form such tight coils they can fit into the nucleus of a cell, which is approximately six micrometres in diameter.

Source: [Nature]