A vandal has attacked a blue plaque marking a landmark DNA discovery by adding the name of a woman scientist who played a pivotal role alongside Cambridge University researchers.
Rosalind Franklin's name has been added to the sign on The Eagle pub, as the Cambridge News reported.
The plaque marks the moment in 1953 that Francis Crick and James Watson announced their discovery in the pub.
It was Franklin's X-ray photo that helped them to work out DNA structure.
The Eagle on Bene't Street in Cambridge was the "local" for scientists such as Crick and Watson, working at the university's Cavendish Laboratory.
It was there in February 1953 they announced their discovery of how DNA (deoxyribonucleic acid) carries genetic information.
The plaque was put up outside the pub in 2003 by a voluntary organisation, Cambridge Blue Plaque Scheme.
However, Crick and Watson's discovery was made possible because of the contribution of Rosalind Franklin and Maurice Wilkins, who were studying DNA using X-rays.
Franklin produced an X-ray photograph that allowed Crick and Watson to work out the 3D structure of DNA - the double helix.
In 1962 Crick and Watson, along with Wilkins, received the Nobel Prize in Physiology or Medicine for their discovery. Rosalind Franklin had died four years earlier.
Newnham College in Cambridge, where Franklin studied natural sciences in 1941, tweeted a response to news of the graffiti, saying: "Teacher: What did Watson and Crick discover? Pupil: Rosalind Frank's notes?"
An English Heritage blue plaque on her one-time home in Chelsea, London, recognises her contribution to DNA research.