J. Michael Bedford 1932–2018 (2018)

John Michael (Mike) Bedford was a gamete biologist who changed our understanding of how mammalian gametes interact during maturation and fertilization! For over fifty years he was an innovative and curious student of gametes and their interactions. Mike acquired his first enduring taste for fertilization research as a young scientist at the Worcester Foundation for Experimental Biology (Shrewsbury MA) in the lab of M.C. Chang, where he formed his lifelong friendship with Ryuzo Yanagimachi. After this auspicious beginning he did his PhD with the legendary Professor Amoroso in London. Mike was involved in many areas of gamete research but perhaps that with the greatest impact on fertility research direction in subsequent years was findings from his early research in the 1960s and early 70s that mammalian fertilization events differed profoundly from those in the sea urchin − the major experimental model, ‘textbook’ archetype of fertilization and source of knowledge on fertilization at the time. Mike and his colleagues were the first to describe the mammalian sperm acrosome reaction as multiple membrane fusions between the outer acrosomal membrane and overlaying plasma membrane, and most profoundly that the remaining equatorial segment of the acrosome was the site of membrane binding and fusion between the sperm and egg. Mike was also a leader, with notably Marie-Claire Orgebin-Crist, in discovering and describing the processes of sperm maturation and storage in the epididymis in the male. He was the first to uncover close relationships between sperm's fertilizing capacity and acrosome molecular remodelling and structural stabilization of sperm nucleus and tail components. He and his colleagues found that once spermatozoa mature, they do not remain viable for more than a very few days outside of the milieu of the cauda epididymis. Mike used his early training as a veterinary surgeon to devise ingenious surgical approaches to show that the lower temperature created by the evolution of scrotum significantly modifies the ionic and protein composition of secretions of the cauda epididymis that prolong sperm viability within this portion of the epididymis. Mike was also first to describe sperm capacitation as a change in the sperm plasma membrane, that the uterus and oviduct act synergistically in capacitating spermatozoa in vivo, and that sperm capacitation in vitro is not species-specific. Mike argued that sperm capacitation is evolutionally related to sperm storage in the cauda epididymis. Mike's lengthy CV includes research on gamete function and fertilization in many non-laboratory species – birds, reptiles, monotremes, marsupials, primates, and ‘primitive’ eutherian mammals the Insectivore, especially shrews. He fostered benchmark studies of sperm maturation events in the epididymis and in vivo fertilization events in marsupials. These included the first description of sperm transport and fertilization in a marsupial. This comparative research on gamete biology and function was not driven by a simple curiosity about strange or different animals. In each case the reproductive biology of the species offered potential to Mike an experimental model in which to examine fundamental aspects of gamete function with fresh eyes. Whether it be; the unusually large acrosomes of shrews; the complex post-testicular formation of the acrosome and morphological maturation of marsupial sperm in the epididymis; or the variable form and apparent function of the zona pellucida across the mammals. These were all systems in which to try to better understand the fundamental principles of sperm epididymal maturation, sperm capacitation, sperm-egg biding and zona pellucida penetration. Michael Bedford had a profound impact on our development as gamete-focused reproductive biologists. Not only through training us in techniques and research models but in ways of critical thinking. Research methods and fashions come and go but big questions remain. Given Mike's early involvement with Chang in sperm capacitation and the ground breaking work on sperm-egg fusion in eutherian mammals it is perhaps not so surprising that he continued to probe these fundamental events through out his long and highly productive career. Michael will be greatly missed not only by his colleagues but by his many friends outside of science, and his wife Rita Reinhardt Bedford and their family. Mike came late to marriage, but he enjoyed his ‘adopted’ family, especially his grandson James, till the end. John Rodger1 Peter Temple-Smith2 Ryuzo Yanagimachi3 1University of Newcastle, Newcastle, AU 2Monash University, Melbourne, AU 3University of Hawaii, Honolulu, US