Yanagimachi, Ryuzo

▪ 2000

      An ingenious scientist dedicated to research in the field of reproductive biology, Ryuzo Yanagimachi happily spent more than 30 years quietly working in his laboratory at the University of Hawaii, attracting the interest of fellow scientists but few others. In the past two years, however, he made headlines worldwide and appeared in front of almost as many reporters and photographers as he had test tubes and petri dishes. The attention began in 1998 when Team Yana—as Yanagimachi and his loyal group of researchers were known—produced not just a single cloned mouse, the world's first, but more than 50 mouse clones, including clones of the original clone. In 1999 they topped that achievement by creating the first clone of an adult male mammal, a male mouse, and by developing a new method using freeze-dried or detergent-treated sperm to deliver genes from one type of animal to another. Yanagimachi was not stopping there, however. The university was providing him with a new, bigger research facility, where he planned to supervise five units specializing in cloning, gene manipulation, cell differentiation, sperm and egg fertilization, and infertility. Among other projects, he hoped to develop a method for cloning cells from a human patient and redirecting them to grow into another type of cell necessary for the patient's treatment, for example, new brain cells for someone suffering from Parkinson's disease or new skin for a person needing a graft.

      Yanagimachi was born on Aug. 27, 1928, in Sapporo, Japan. He attended Hokkaido (Sapporo) University, earning his undergraduate degree in zoology in 1953 and his doctorate in animal embryology in 1960. Unable to find a research position in Japan, he applied for and received a four-year postdoctoral fellowship at the Worcester Foundation for Experimental Biology in Shrewsbury, Mass. There, his experiments provided the groundwork for the in vitro fertilization of human eggs, which was finally accomplished in 1969. Yanagimachi returned to Japan to teach at Hokkaido University for two years, but in 1966 he returned to the U.S. as an assistant professor at the University of Hawaii's John A. Burns School of Medicine and was appointed professor of anatomy and reproductive biology there in 1973. He has since honoured his adopted home by naming the innovative procedure used for cloning adult mice the Honolulu technique (distinguishing it from the less-efficient method used to produce Dolly the sheep, the first clone of an adult mammal); in addition, the new method for genetically modifying animals using treated sperm was known as Honolulu transgenesis.

      Yanagimachi's work earned him numerous awards, including the 1996 International Prize for Biology, Japan's highest scientific award, and the 1999 Carl G. Hartman Award, the Society for the Study of Reproduction's greatest honour.

Amy R. Tao

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