DNA Day DNA Day National DNA Day is a holiday celebrated on April 25. It commemorates the day in 1953 when James Watson, Francis Crick, Maurice Wilkins, Rosalind Franklin and colleagues published papers in the journal Nature on the structure of DNA. Furthermore, on that day in 2003 it was declared that the Human Genome Project was very close to complete, and "the remaining tiny gaps [we]re considered too costly to fill." In the United States, DNA Day was first celebrated on April 25, 2003 by proclamation of both the Senate and the House of Representatives. However, they only declared a one-time
Non-helical models of DNA structure Non-helical models of DNA structure In the history of molecular biology, non-helical or "side-by-side" models of DNA were proposed in the 1970s as a challenge to the standard double-helical model. The non-helical models attempted to solve problems relating to the topology of circular DNA chromosomes during replication. These theories were briefly considered seriously as a minority viewpoint, but they were later largely rejected due to X-ray crystallography of DNA duplexes and later the nucleosome core particle, as well as the discovery of topoisomerases, and these non-double-helical models are not currently accepted by the mainstream scientific community. The strands of a