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University of Hawai'i |
(808) 956-8856 Telephone |
For Immediate Release: |
July 22, 1998 |
Contact: Noonan/Russo Communications, 212 696-4455, Ernie.knewitz@noonanrusso.com University of Hawaii, Cheryl Ernst, (808) 956-5941 |
Trio of University of Hawaii Scientists Key to First Reproducible Mammalian Cloning from Adult Cells
Ryuzo Yanagimachi Ryuzo Yanagimachi is a professor of anatomy and reproductive biology in the John A. Burns School of Medicine at the University of Hawai'i at Manoa. His work, which spans three decades, has advanced the understanding of reproduction in mammals and established the basic science understanding that led to successful in vitro fertilization in humans and animals. He is the author of more than 200 papers and chapters, including his encyclopedic review of mammalian fertilization in The Physiology of Reproduction (Raven Press, 1994). More than 70 of the key researchers working in reproductive biology around the world have spent time in his laboratory. Dr. Yanagimachi received his bachelor and doctor of science degrees from Hokkaido University in Japan and did postdoctoral training at the Worcester Foundation for Experimental Biology in Shrewsbury, Mass., before joining the fledgling University of Hawai'i School of Medicine in 1964, soon after Achieving in vitro capacitation of sperm-a series of cellular changes that normally occur within the female tract and are essential to fertilization-for the first time. The work, published in Nature in 1963, was fundamental to the first successful in vitro fertilization by Edwards and Steptoe, as well as development of in vitro fertilization methods used with cattle, sheep and goats. Since then, his laboratory has · Demonstrated for the first time, in 1970, that only acrosome-reacted mammalian sperm can fuse with the egg plasma membrane and later concluding that the acrosome reaction must modify the sperm to allow fusion with the egg. The acrosome reaction is a fusion and vesiculation of sperm head membranes. · Observed that mammalian sperm undergo a motility change during capacitation. This hyperactivation is viewed as essential to sperm transport and penetration of the egg. · Discovered in 1976 that removal of a glycoprotein egg coat from a hamster egg allowed it to fuse with sperm from many species. A resulting clinical test, sperm penetration assay, or SPA, helps in determining the fertility potential of male patients as well as analyzing chromosome constitutions of spermatozoa of various species, including humans. · Developed a microinjection technique, called intracytoplasmic sperm injection, or ICSI, in which a single sperm is injected directly into an ovum. Subsequent work in other labs has resulted in the birth of normal, live offspring in rabbits, cows and humans, suggesting a possible replacement for in vitro fertilization as a treatment for human male infertility. · Produced normal mice from oocytes injected with freeze-dried spermatozoa. Dr. Yanagimachi has received National Institutes of Health funding for the past 30 years and has brought well over $3 million in extramural funding to the University of Hawai'i since 1984.
Teruhiko Wakayama Dr. Teruhiko Wakayama received his undergraduate education at Ibaraki University and completed his doctorate in veterinary anatomy, Faculty of Agriculture at the University of Tokyo, becoming involved with collaborative research at the National Institute of Animal Health. During this time, he developed his interest in embryo development.
In 1996, he was awarded a fellowship from the Japanese Association for the Promotion of Science to continue and develop his ideas in the laboratory of Professor Ryuzo Yanagimachi at the University of Hawaii. Since arriving, his studies have utilized microinjection techniques to analyze the biology of fertilization. His work has included studies of the ability of polar bodies, dead (frozen and freeze-dried) sperm and adult somatic cell nuclei to support full embryonic development to term. He has succeeded in demonstrating that the answer in each case is Yes, and is now concentrating in his efforts on further describing the mechanisms by which each works, and improving the efficacy of each technique.
Tony Perry Dr. Tony Perry received his undergraduate education at the University of Bristol and completed his doctorate in molecular microbiology three years later at the University of Liverpool. He then returned to Bristol to study the molecular genetics of mammalian spermatozoa. Dr. Perry sought to develop his ideas on the biology of this system and in 1996 was awarded a European Molecular Biology Organization Long Term Travel Fellowship to leave England and work with Professor Ryuzo Yanagimachi on the mechanics of oocyte activation. This work addresses the conditions required within a newly-fertilized
egg for a successful developmental outcome and is thus closely related to
work on parthenogenesis and cloning from adult somatic cells. On completing
his fellowship with Professor Yanagimachi, Dr. Perry has secured a senior
Babraham research fellowship to establish a group and continue his work
in Cambridge, England. |
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