Person Lyon; Mary Frances (1925 - 2014); geneticist Lyon Mary Frances geneticist 1925 - 2014 British Female Maternity Home, 3 Aspland Road, Norwich, England 15 May 1925 19250515 Her home, Crabtree Cottage, Crabtree Lane, Drayton, Oxfordshire, England 25 December 2014 20141225 Cremation: Oxford, England (16 January 2015).

96 St Leonard’s Road, Norwich, England (1925) Crabtree Cottage, Crabtree Lane, Drayton, Oxfordshire, England (2014)

Geneticist Biology Genetics Education; Primary school in Bradford and Norwich; King Edward VI High School, Birmingham (1936); Woking Grammar School for Girls (1939); Girton College, Cambridge (titular degree 1946); PhD (1950) Career: Awarded a Medical Research Council (MRC) grant to work in the team led by Toby Carter, studying the genetic effects of radiation in mice (1950); team relocated to MRC Radiology Unit at Harwell, Oxfordshire (1955); Head of the Genetics Section of the MRC Radiology Unit at Harwell (1962-1987); Clothworkers' visiting research fellowship at Girton College, working with Richard Gardner (1970-1971); retired but remained active in the laboratory (1990); died at home from bronchopneumonia and Parkinson’s disease. Awards/Medals: William Allan Award (1986) Wolf Prize in Medicine (1997) Parents: Clifford James Lyon (1896–1963), tax office clerk, and Louise Frances, née Kirby (1893–1986). Distinguished for many important contributions to mammalian genetics, notably on the mutagenic effects of irradiation as measured in mice, and on the building of the hypothesis that one of the two X chromosomes of the female is inactivated at an early stage of embryogenesis. The hypothesis, which is now almost universally accepted as proved, offered a solution to the long standing problem of X-dosage compensation in the female mammal, has thrown much light on the nature of sex-chromosome aneuploidy, has influenced ideas on the origin of certain tumours and of chronic granulocytic leukaemia in man, and has provided food for thought about the fundamental mechanism of switching off genes. Medals and prizes: Royal Medal 1984 Fellow 15/03/1973 47 Lyon M F, IM002838.jpg International Standard Archival Authority Record for Corporate Bodies, Persons and Families - ISAAR(CPF) - Ottawa 1996 ISBN 0-9696035-3-3 National Council on Archives, Rules for the Construction of Personal, Place and Corporate Names, 1997 https://royalsocietypublishing.org/doi/10.1098/rsbm.2024.0005 https://royalsocietypublishing.org/action/doSearch?ContribAuthorRaw=Lyon%2C+Mary+Frances 15 May 1925 - 25 Dec 2014 The past Fellows entries are under continuous revision. If you have queries or additional information to contribute, please contact Library@royalsociety.org. Content in external sources is not controlled by the Royal Society and historical sources may include content that is now unacceptable. Reviewed on 22/01/2025 as part of the Name Authority Project update. NA165 21/11/2001 Andyg Pmab 17/03/2026 RS_NET\VirginiaM Yes http://viaf.org/viaf/27731364 a41a6550-491f-4d05-a3ec-bd4fbec9d644