Max Perutz the onset of Huntington disease is related to the number of glutamine repeats as they bind to form what he called a polar zipper. During the early 1950s, while Watson and Crick were determining the structure of deoxyribonucleic acid (DNA), they made use of unpublished X-ray diffraction images taken by Rosalind Franklin, shown at meetings and shared with them by Maurice Wilkins, and of Franklin's preliminary account of her detailed analysis of the X-ray images included in an unpublished 1952 progress report for the King's College laboratory of Sir John Randall. Randall and others eventually criticised the manner in which
James Watson and the bases pointing outwards. Her identification of the space group for DNA crystals revealed to Crick that the two DNA strands were antiparallel. The X-ray diffraction images collected by Gosling and Franklin provided the best evidence for the helical nature of DNA. Franklin's experimental work thus proved crucial in Watson and Crick's discovery. Watson and Crick had three sources for Franklin's unpublished data: Prior to publication of the double helix structure, Watson and Crick had little interaction with Franklin. Crick and Watson felt that they had benefited from collaborating with Wilkins. They offered him a co-authorship on the article