Robin Holliday 1932–2014

Robin Holliday When the founder of a field of investigation departs from our midst, there is the palpable feeling among his or her close associates that an era has come to an end. Such is the sense that the elders of the field of genetic recombination feel with the passing of Robin Holliday, whose very name is synonymous with the process. Hediedathis homeon theoutskirtsofSydney, Australia, on the 50 year anniversary of his seminal model for recombination. To be sure, his passing leaves a hole in the hearts of immediate friends and colleagues. But, as is often the case when a towering figure passes, younger investigators who quite possibly never met him nor completely appreciated the historical context from which their own field originated might not feel his loss so acutely. So, for all of his associates and investigators in the field, whatever their standing, this brief recollection is offered as a remembrance of Robin as an extraordinary figure and as a reflection on his contributions to science and his hopes for the future. Robin, the youngest of four brothers, was born in 1932 in the ancient city of Jaffa in the British Mandate of Palestine, his father having been brought in as an architect to help modernize the infrastructure after the fall of the Ottoman Empire. During his early years, the family also lived in Ceylon (now Sri Lanka), South Africa, and Gibraltar. No doubt four young boys could not have asked for a better environment for adventure and discovery. So, growing up exploring these rich and changing landscapes imprinted on him a curiosity for the natural world that was to shape his career. The family returned to England after the end of World War II, and following several years of schooling, Robin entered Cambridge University in 1952 to study natural sciences. He did not find university life particularly fulfilling and remarked that, at the time, the science taught there was neither challenging nor up to date. For example, he complained that a botany instructor specializing in taxonomy refused to believe that Mendelian genetics was important and that the textbook he used for plant physiology was published in 1894. This pessimistic outlook changed completely one day in the autumn of 1954 when he heard a lecture by Harold Whitehouse describing the Watson-Crick structure of DNA and its strong genetic implications, in particular that the pairing between homologous chromosomes atmeiosismight depend on base pairing. Although he was miffed that it took 18 months for the discoveries of Watson and Crick, who were working in Cambridge, to reach the ears of Cambridge undergraduates, this was a defining moment in his career as he decided he wanted to carry out research in genetics. To this end, Robin joined HaroldWhitehouse’s laboratory in the Botany School as a graduate student. Harold’s personal research interest was inmosses, but his approach to training was to suggest to new students that they develop the genetics of some new microorganism not previously well studied. He suggested that Robin consider investigating a species of the parasitic smut fungi of plants because, unlike other fungi under study at that time that grew in a filamentous form, smut fungi grew as a single cell in a yeast-like form. This would make experimental manipulations easier to manage. After some consideration, Robin and Harold concluded that Ustilago maydis would be the best species for study, and after they obtained dormant spores from Jonas J. Christensen’s laboratory at the University of Minnesota, Robin set out to investigate the genetics of U. maydis. He embarked on this endeavor the same year that Carl Lindegren’s discovery of gene conversion in yeast was confirmed in Neurospora by Mary B. Mitchell. These fungi have the property of producing tetrads or octads, respectively, after meiosis enabling isolation and analysis of the products of a single meiotic event. Gene conversionwas noted as a deviation (3:1, 1:3 or 6:2, 2:6, respectively) from the normal Mendelian segregation of markers (2:2 or 4:4, respectively) in tetrads or octads, the latter arising by one further mitotic division after meiosis. Subsequent studies showed that gene conversion was