GUIDO PONTECORVO PhD (Edin), LLD (Glas), ForAssUSNAS, FRS Guido Pontecorvo was born on 29 November 1907 in Pisa and died in Switzerland on 25 September 1999. His parents, Masimo and Maria Pontecorvo, were prosperous members of the Jewish community in Pisa and had eight children, all of whom were successful - three of them at international level: Guido, Bruno (a nuclear physicist) and Gillo (a film director). Guido was the eldest child and he used to tell colleagues that it was his task to boil the water for the midwife whenever a new baby was expected in the family. He initially studied at the Universities of Pisa (where he took a degree in agriculture in 1928) and Milan, subsequently specialising in the reproduction of silkworms and later of dairy cattle, and finally heading the animal breeding department of the Department of Agriculture in Tuscany. However, in 1938, sensing how the political situation in Europe was developing and in particular Mussolini’s behaviour towards Jews in Italy, he accepted a post in South America concerned with cattle breeding. Fortunately for many hundreds of students and for the science of genetics, before he crossed the Atlantic he visited Edinburgh to attend an International Genetics Congress. Here, he was fortunate enough to meet up with and impress both Nobel Laureate Hermann Muller and C. H. Waddington (who headed the Department of Genetics there for many years), eventually giving up his future in animal breeding as such, to enrol for a PhD with Muller. The latter instilled in Guido his ideas about the nature of the gene and launched his career in genetics. In 1941, Guido Pontecorvo moved to Glasgow University with support from the Carnegie Trust and the Rockefeller Foundation. After another year (1943-44) lecturing at the University of Edinburgh, he moved back to a secure Lectureship in Glasgow in 1945 - as one of the founder members of the new Department of Genetics there - and was promoted to Reader in 1952. The year of 1955 was a successful one for Guido for he was appointed to the newly- created Chair in Genetics at Glasgow and elected a Fellow of the Royal Society of London. He had previously (1946) been elected a Fellow of the Royal Society of Edinburgh and he served on the Council from 1958-61. Pontecorvo (or Ponte, as he was affectionately known by his colleagues and many students) ran a very successful Department of Genetics at Glasgow until 1968 and during that period (1956-57) the author was privileged to be one of his students. He was a brilliant lecturer and so engrossing were his talks that many students gave up taking detailed notes and sat back to enjoy the stimulation of his delivery. His laboratory classes were equally enthralling and the successful experiments with Aspergillus and Drosophila supported his theories about how genes worked. As well as being an inspirational lecturer, Pontecorvo was happy to take his beliefs (and his classes) onto the streets. In the 1950s he was running campaigns against the dangers from x-ray machines in shoe shops and luminous paint on watches and clocks. He and his assistant would personally go round shoe shops in Glasgow and spell out the dangers of the machines they were using. On one occasion, he took the whole genetics class (which included the author) to the Kelvin Hall to see the Pet Show there and demonstrate some aspects of animal genetics. Much to the enjoyment of his students he got into a fierce argument with an elderly rabbit breeder about one rabbit - Ponte insisting it was 'agouti' (coat colour), the rabbit expert, infuriated, insisting it was a Flemish Giant (breed)! His teaching success was, at least in part, due to the fact that much of the theory and the research on which it was based was his own. His early tests with various organisms lead to the use of the fungus Aspergillus nidulans as an ideal genetic organism and soon it was possible, using Aspergillus, to prove that Muller had been correct about the fine structure of the gene. This fungus became popular with geneticists as a model and ‘Glasgow’ strains are used across the world by researchers. His PhD research lead on to studies of hybrid sterility in the fruit fly Drosophila and subsequently to the idea that genetic analysis without sex was feasible, using ordinary somatic cells. This, in turn, proved to be an entry to the genetics of Penicillium, with the objective of eventually providing a scientific basis for the development of higher yielding strains providing more penicillin. In the 1950s, the Department of Genetics at the University of Glasgow was a stimulating place to be and the scientific atmosphere and sense of purpose was appreciated both by staff and students. It was undoubtedly a “centre of excellence” at the time, and regular visits by international figures such as J. Watson (only a week after the publication of his celebrated paper with Francis Crick describing the double helix structure of DNA) to give seminars served to highlight this. In 1968, he accepted an offer from Michael Stoker, a former colleague at the University of Glasgow (who subsequently described Pontecorvo as “the godfather of genetics”), to move to London to join the staff there from 1968-75 (and latterly as Honorary Consultant Geneticist, from 1975-80) at the laboratory of the Imperial Cancer Research Fund. Here, he influenced his colleagues (and cancer research in general) and made several major contributions to research - most notably in proving that (as had already been shown for plants) by adding polyethylene glycol to animal (including human) tissue cultures, the cells fuse, thus providing a first important step in parasexual cycle genetics and a key step towards mapping the human genome. Professor Pontecorvo was awarded many distinctions during his lifetime. After he left the University of Glasgow he was not only awarded an honorary degree there, but also had a building named after him - since 1995 the Genetics Institute has been housed in the Pontecorvo Building, an acknowledgement of the great distinction lent to the University by his time there. He was involved with the Genetical Society of Great Britain for many years and served as Secretary and President. He was a Council member and Leeuwenhoek Lecturer of the Royal Society of London, presented the Jessup and Messenger Lectures at the Universities of Columbia and Cornell and took part in several British Council and other lecture tours abroad - to many countries in Europe as well as both North and South America. He was awarded several Visiting Professorships and numerous distinctions, both at home and abroad, including the Hansen Prize for Microbiology and the Darwin Medal of the Royal Society of London. Guido Pontecorvo had many interests outside academia. In 1939 he married Leonore (Leni) Freyenmuth, a Swiss art historian, who died in 1986. They had one child, a daughter, Lisa. He had a deep interest in alpine plants and spent many hours photographing them - in his own collection, in his friends’ gardens and in the wild on various expeditions around Scotland. For many years he was a member, and eventually President, of the Scottish Rock Garden Club. He had a passion for Scottish country dancing and made many friends at Glasgow University through this interest. Guido and Leni had a small chalet built in the Swiss Valais and in his later years he spent much time there, studying the local flora and entertaining friends. Even after his wife’s death he spent most summers and sometimes parts of winters there and it was here, during a mushroom collecting expedition along one of the steep slopes, that he slipped and suffered a bad fall which eventually lead to his death. Guido Pontecorvo will be remembered by all his colleagues and hundreds of former students as a warm, exciting and inspirational figure and by scientists around the world as one of the founders of modern genetics.

PETER S. MAITLAND