Thaddeus Robert Rudolph Mann. 4 December 1908—27 November 1993

Abstract

Thaddeus Mann was a Polish biochemist who spent most of his scientific life in Cambridge, where he made important discoveries in male reproductive biology and semen analysis. Funded principally by the Agricultural Research Council, he provided much of the basic knowledge on the composition and origin of semen components in farm animals, relevant to storage of spermatozoa for artificial insemination and assessment of fertility. He made numerous landmark contributions. Contrary to established dogma at the time, he showed that the seminal sugar in all species was fructose, not glucose as had been assumed, and that it was secreted by the prostate and seminal vesicles under androgen control. He identified a copper-binding protein (designated haemocuprein) that was later shown to be superoxide dismutase, which helps to protect cells from the damaging effects of oxygen free radicals. Mammalian spermatozoa are especially sensitive to free radical damage as they are rich in unsaturated lipids and have a limited capacity for repair, being transcriptionally inactive. Two textbooks, published in 1954 and 1964 and outstanding for their scholarship, collated all the information on the biochemistry of mammalian spermatozoa and became the authoritative reference sources worldwide. These books were revised in 1982 with greater emphasis on diagnosis and treatment of infertility in human patients. The science of andrology and use of semen analysis in infertility clinics still depend heavily on this information. Thaddeus was awarded many honours for his research, both nationally and internationally, and leaves an important legacy in the field. Modest and generous to his staff, he is remembered with great respect and affection by colleagues around the world.