DNA Day celebration, not an annual holiday. Every year from 2003 onward, annual DNA Day celebrations have been organized by the National Human Genome Research Institute (NHGRI), starting as early as April 23 in 2010, April 15 in 2011 and April 20 in 2012. April 25 has since been declared "International DNA Day" and "World DNA Day" by several groups. 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
Francis Crick the protein alpha helix a few years earlier. The Watson and Crick discovery of the DNA double helix structure was made possible by their willingness to combine theory, modelling and experimental results (albeit mostly done by others) to achieve their goal. The DNA double helix structure proposed by Watson and Crick was based upon "Watson-Crick" bonds between the four bases most frequently found in DNA (A, C, T, G) and RNA (A, C, U, G). However, later research showed that triple-stranded, quadruple-stranded and other more complex DNA molecular structures required Hoogsteen base pairing. The entire field of synthetic biology began