Louis Siminovitch
Dr. Louis Siminovitch left an indelible mark on research at the University of Toronto and hospitals in the city, including UHN, SickKids and Mount Sinai. (Photo: Ontario Ministry of Citizenship and Immigration)

Dr. Louis Siminovitch, widely known as Canada's "founding father of genetics," is being remembered for his remarkable legacy of science and enormous contribution to biomedical research.

Dr. Siminovitch, who in 1956 joined the Ontario Cancer Institute (OCI), the research institute of the Princess Margaret Hospital, left an indelible mark on research at the University of Toronto and other hospitals, including SickKids and Mount Sinai. He passed away this week just shy of his 101st birthday.

"He had a profound impact on so many aspects of the medical research world," said Dr. Christopher Paige, Senior Scientist at the Princess Margaret Cancer Centre and former UHN EVP of Science and Research. "That includes his own ground-breaking work in medical genetics, his international and national leadership, and his incredible contributions to the rise of Toronto as a leading science city through the creation of new university academic departments and hospital centres and institutes.

"Lou Siminovitch had an ability to inspire generations of scientists young and old, and was always driven by the mantra of excellence and the joy of discovery."

Dr. Siminovitch, who was inducted into the Canadian Medical Hall of Fame in 1997 and was awarded the UHN Global Impact Award in 2018, was born in Montreal in 1920 and earned his PhD in chemistry at McGill University in 1944. He went on to the Pasteur Institute in Paris where, under the mentorship of Jacques Monod and Andre Lwoff, he contributed to Nobel Prize-winning work in molecular genetics.

At OCI, he pioneered a method for obtaining mutants in mammalian cells in tissue culture, which laid substantial groundwork into the genetic roots of diseases such as cancer and the discovery of the genes for muscular dystrophy and cystic fibrosis by generations of his trainees and colleagues. That resulted in more than 200 manuscripts in peer-reviewed journals in the fields of virology, stem cell differentiation and haematopoiesis.

Mentorship and leadership came naturally to Dr. Siminovitch as well. He taught many as a professor at the U of T and influenced and trained two generations of Canadian biomedical researchers. He later served as a Chairman and led the development of the U of T's Medical Genetics Department.

"He left a remarkable legacy; a legacy of science," said Dr. John Dick, Senior Scientist at the Princess Margaret, who was mentored by Dr. Siminovitch and last year spoke at his 100th birthday celebration.

"He gave birth to what is now several generations of molecular genetic research in Canada, spawning a new school. This has contributed to Canadian science punching far above its weight class on the international stage."

Dr. Dick added that Dr. Siminovitch also left "a legacy of how to do science.

"To conduct science only at the top level-never settle for anything less; to focus on the big questions rather than the fads; to set a standard for rigor and resistance for sloppy thinking."

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