Dr. Charles Philippe Leblond, O.C, M.D., Ph.D, D.Sc., CC, GOQ, F.R.S., F.R.S.C., was a world renowned Canadian anatomist and cell biologist. He is most notable for developing autoradiography and his research showing how cells continuously renew themselves, regardless of age. Professor George Palade, a Nobel Laureate, said “Charles Leblond’s discoveries are so fundamental that they are taught in schools and colleges throughout the world”. He passed away on April 10, 2007 at the age of 97.
Dr. Leblond was born in Lille, France on February 5, 1910; his father, a building contractor, died when Leblond was 10 years old, leaving his mother to raise four boys. A highly talented student, Leblond thought he would like to be film producer, an architect or a scientist. He decided to be a scientist and enrolled in the Faculty of Medicine at the University of Paris. He was attracted irresistibly by his course in histology. When he was 20 years old, he told his fellow students that he was going to train to be a histologist when he graduated from the medical school. His class mates tried to dissuade him, saying “Histology is a dead horse; the future is in biochemistry”. Despite their views, he chose histology anyway.
Leblond obtained a M.D. from the University of Paris in 1934. His doctoral thesis described the histochemical localizion of ascorbic acid, which he found to be prominent in steroid-secreting cells. In 1935, he received a Rockefeller Postdoctoral Fellowship, and was invited to do research at the endocrinology-orientated Department of Anatomy at Yale University. He carried out studies on extra hormonal factors influencing maternal behavior. It was at Yale where he met his future wife, Gertrude Sternschus; they were married for 64 years.
In 1937, Leblond joined the Laboratoire de Synthese Atomique in Paris, where he prepared radioactive isotopes for investigating the fate of various molecules in biological processes. With the guidance of Antoine Lacassagne, he injected radioiodine-128 into rats and found the label accumulated in the thyroid gland, presumably incorporated into the thyroid hormone precursor thyroglobulin.
In 1941, Lablond joined the Department of Anatomy at McGill University in Montreal, Que., as a Lecturer in Histology. He received a Ph.D in 1942 from the University of Montreal, and was promoted to Assistant Professor in 1943. His early career at McGill was interrupted by World War II; he served in the Free French Forces (1944-45), first in Rio de Janeiro and later in London, England. He conducted medical examinations of would-be soldiers in the Free French Army. In 1945, Lablond received a D.Sc. from the Sorbonne, Paris. He returned to McGill University in 1945 and was promoted to Associate Professor in 1946.
In collaboration with Dr. Leonard Belanger, Lablond developed the technique of radioautography for locating radiolabeled molecules in tissues and cells. They found when they poured liquid photographic emulsion on a histological section containing a radio-element; the emulsion was eventually activated by the radio-element. When routine photographic development and fixation was applied to the emulsion-covered section, black silver grains appeared in the emulsion wherever it overlay sites containing a radio-element. This technique is still used today and has been improved by molecular biologists to detect RNA molecules, and for the localization of genes and DNA sequences. Subsequently, Leblond and his colleagues developed a technique in which the histology slides were dipped directly into liquid emulsion. The use of thinner sections and emulsion coats led to further advances in resolution, and the introduction of tritium was great advance. Leblond also used radioautography to study the renewal and fate of cells, as well as the localization and pathways followed by radiolabeled precursors. He demonstrated that most cells and tissues in the adult body undergo continued renewal, and that they synthesize different types of macromolecules. Lebond and his colleagues refined the autoradiography and its application to electron microscopy. Lebond was appointed a full Professor in 1948.
In 1955, Lebond and Yves Clermont studied the seminiferous epithelium of humans and other mammals. They deciphered how spermatogonia gave rise to spermatocytes, and then differentiated into mature sperm cells in a specific cycle. To maintain the population of spermatagonia, the seminiferous epithelium was shown to contain a population of stem cells, which divided to produce differentiated cells, as well as to maintain their own number. Leblond stated, “The reappearance at each cycle of a new dormant cell which acts as the stem cell of spermatocytes is described as the “Stem Cell Renewal Theory”. This paper was the first one in which nests of cells dividing in an adult organ was designated as “stem cells”.
Lebond was appointed Chairman of the Department of Anatomy and Cell Biology in 1957; he was Chairman for over 25 years. His department was recognized as one of the best international research centers in histology and cell biology. In 1962 -63, he was President of the American Association of Anatomists. Instead of retiring in1974 at the age of 65, Lebond continued his research with a NIH Fogarty Scholarship at the National Institute of Dental Research. After learning more about immunohistochemistry, he began his 20 year research on molecular exploration, which resulted in his concept of the basement membrane as an integrated polymer, rather than as layers of separated macromolecules layers. Leblond published 430 scientific papers. He attended all weekly departmental seminars until he was well into his 90’s, and continued to publish in peer-reviewed journals until 2006.
Betty Hay with Charles LeBlond in 1985
Honorary Degrees of Doctor of Sciences
Acadia University, 1972; McGill University, 1982; University of Montreal, 1985; York University, 1986; Sherbrooke University, 1988.
Prix Saintour, French Academy, 1935; Gairdner Foundation International Award,1965; Isaac Sc Award, International Association for Dental Research,1974; Henry Gray Award, American Association of Anatomists, 1978; J.C.B. Grant Award, Canadian Association of Anatomists, 1979; E-B Wilson Award, American Society for Cell Biology, 1982; Duncan Graham Award, Royal College of Physicians and Surgeons of Canada, 1986; Centennial Award, American Association of Anatomists, 1979; Prix Marie-Victorin, Quebec Province, 1992.
Flavelle Medal, Royal Society of Canada, 1961; Medal Leo-Pariseau, <Assoc. Canadienne Francaise pour l’Avancement des Sciences>, 1962; McLaughlin Medal, Royal Society of Canada, 1983; George Gomori Medal, Histochemical Society, 1988.
Fellow of the Royal Society of Canada, 1951; Fellow of the Royal Society, London, UK, 1965; American Academy of Arts and Sciences, 1970; Royal Microscopical Society, UK, 1988; Canadian Medical Hall of Fame, 1995; Companion, Order of Canada, 2000; Grand Officer, National Order of Quebec, 2001.
Written by Keith L. Moore, Professor Emeritus, Division of Anatomy, Department of Surgery, Faculty of Medicine, University of Toronto, Canada.