Bruce Macintosh Cattanach. 5 November 1932—8 April 2020

Bruce Macintosh Cattanach (5 November 1932–8 April 2020) was a pioneer of classical mouse genetics, who started and developed the field of chemical mutagenesis in mice and went on to discover autosomal imprinting in mammals. Furthermore, his work laid the foundations for deciphering mammalian sex determination. His discovery of the ‘flecked’ mouse during his PhD studies enabled progress in understanding X chromosome inactivation. He was a deep and incisive thinker, a meticulous experimentalist and an exceptionally good observer with a keen eye for detecting phenotypic abnormalities in mice and recognizing their biological significance. He considered his research his ‘paid hobby’, but also made significant achievements in his ‘unpaid hobby’, the breeding and showing of pedigree Boxer dogs.