THADDEUS MANN had a long and distinguished career of scholarship, research and leadership in science in the field of reproductive biology, and made outstanding contributions to our knowledge of the biochemistry of semen and of male reproductive function. He was director of the Agricultural Research Council's Unit of Reproductive Physiology and Biochemistry at Cambridge University (1953-76) and Marshall-Walton Professor of the Physiology of Reproduction (1967-76).
Mann was born at Lwow in Poland in 1908. He studied medicine at the Johannes Casimirus University in Lwow, obtaining the degrees of Physician in 1932 and Doctor of Medicine in 1934. But it was during his student years that his lifelong interest in biochemistry was kindled, through the influence of JK Parnas, a distinguished Professor of Physiological Chemistry in the Medical School. He joined Parnas' department, where for seven years he undertook research on intermediary metabolism in muscle, blood and yeast.
A crucial turning-point was when he was awarded a Rockefeller Fellowship in 1935 and came to Cambridge to work with Professor David Keilin at the Molteno Institute. He never returned to his previous post of University Lecturer in Lwow, and remained in Cambridge for the rest of his life. Keilin was an important influence and Mann remained grateful for his paternal kindness, guidance and understanding.
Mann's early work at the Molteno Institute was on the nature and function of metalloprotein enzymes in plant and animal tissue, but he began his studies on spermatozoa and semen in 1944 on behalf of the Agricultural Research Council, interest in this area being stimulated by the recent establishment of artificial insemination in cattle breeding. This marked the start of over 30 years' extensive study on the biochemistry of semen.
He admitted that he did not take up this challenge through a specific interest in reproduction, but through the unique opportunity that it offered of correlating chemical and metabolic findings with clearly defined physiological criteria such as the motility and fertilising capacity of spermatozoa. Among his important early discoveries was the identification of fructose as the carbohydrate normally present in the semen of many mammalian species and the role of fructolysis in the metabolism of spermatozoa. There followed the identification of many other chemical constituents of semen of different animals. He showed that various components of seminal plasma were specific products of different male accessory organs and how function was influenced by hormonal, neural and other factors such as nutrition, ageing and pharmacological agents. For several years, particularly after he retired from the ARC and worked at the National Institutes for Health in Washington, his attentions were devoted to the chemical pathology of human semen. Another interest he fostered was in comparative aspects of reproduction in fish and molluscs, particularly the function of spermatophores of the Giant Octopus.
The results of his work are published in over 250 papers. His books include The Biochemistry of Semen and of the Male Reproductive Tract (1964), the most comprehensive and authoritative text on this subject. This was updated and extended in Male Reproductive Function and Semen - themes and trends in physiology, biochemistry and investigative andrology, written with his wife, Cecilia Lutwak-Mann (1981). He was revising his 1984 book on Spermatophores at the time of his death.
Thaddeus Mann's personal achievements in science were extensive, but to many people his greatest contribution was as Honorary Director of the ARC's Unit of Reproductive Physiology and Biochemistry. This was founded in 1955 at the Animal Research Station in Cambridge after the retirement of Sir John Hammond, the previous head of ARC Unit of Animal Reproduction. From a small beginning the unit grew extensively and flourished under Mann's wise leadership until by the time he retired in 1976 it had established a world-wide reputation for some of the most important recent advances in reproductive biology of farm animals and in animal breeding.
Mann provided continued encouragement and worked to get the facilities and environment for a large number of scientists, visiting workers and students to develop fundamental research on mammalian gametes, embryology and endocrinology and to apply new scientific knowledge to problems in animal breeding. Major advances included developments in the preservation of semen and artificial insemination, embryo transfer in the large domestic species, the preservation and manipulation of embryos and methods for the synchronisation of oestrous cycles. Although these were not his own direct scientific interests, he was always proud of the achievements of scientists within his unit and they owe much to his personal endeavours and quiet but efficient leadership.
Thaddeus Mann portrayed the best attributes of kindness, understanding and encouragement, particularly to younger scientists. These were coupled with the extremely good manners characteristic of his age and upbringing.