UCDavis University of California

Education

• B.A., Sonoma State University, Biology, 1979
• Ph.D., University of California, Davis, Zoology, 1984

Research Interests

Dr. Cherr´s current laboratory focus is on understanding the cellular and physiological mechanisms of reproduction and development over a wide phylogenetic range. His research program has emphasized understanding how stressors, both natural and anthropogenic, impact these basic mechanisms in organisms ranging from algae to mammals. Research in the laboratory ranges from the biochemical to organismal levels. A system which has been a major focus of the laboratory in recent years has been to understand the effects of environmental factors on reproduction and development in the Pacific herring. This species represents a major fishery in the San Francisco and Bodega Bay regions and is a critical food source for salmonids in the near shore environment. This system is unique among all lower vertebrates and most invertebrates (with the exception of the horseshoe crab and some tunicates) in that the sperm, which possess flagella, are released in near-shore waters yet are immotile. These cells exhibit a unique adaptive mechanism for being capable of fertilizing eggs for up to 24 hours after their release. His work has shown that when non-motile sperm physically contact a glycoprotein bound to the egg coat, signal transduction and subsequent motility is initiated. This motility initiation event is dependent on an influx of calcium and decreased extracellular sodium (activation of reverse sodium/calcium exchange) and correlates with the fact that spawning occurs in lowered salinity sites. In addition to fertilization, embryo and larval development is also dependent on decreased salinity and thus, it is apparently the osmotic capabilities of the early life stages of herring which regulate their migration to near-shore spawning sites. In comparative and mechanistic studies, he has also been investigating the role of the PH-20 protein in mammailian sperm in intracellular signaling and increases in intracellular calcium. The lab is also actively involved in investigating adaptive mechanisms marine embryos and larvae utilize to environmental stressors. These include temperature, salinity, and a number of pollutants which are of concern in California.

Publications

• Cherr, G.N., and S. Suarez. 1989. Structure and physiology of mature sperm and egg, pp. 159-168, In: E. Meisami and P.S. Timiras (eds), Handbook of Human Growth and Developmental Biology; Vol. II, CRC Press, Boca Raton, Florida.
• Nuccitelli, R., G.N. Cherr, and W.H. Clark, Jr., eds. 1989. Mechanisms of Egg Activation, Bodega Marine Laboratory, Marine Science Series, No. 2, (J.S. Clegg, Series Ed.), Plenum Press, New York, 290 pp.
• Cherr, G.N., A.I. Yudin, and D.F. Katz. 1990. Organization of the hamster cumulus extracellular matrix: A hyaluronate-glycoprotein gel which modulates sperm access to the oocyte. Development Growth Differentiation, 32:353-365.
• Cherr, G.N., and T. Ducibella. 1990. Cortical granule distribution, exocytosis, and activation of the egg, pp. 309-330. In: Serono Symposium on Fertilization in Mammals, B.D. Bavister, J. Cummins, and E.R.S. Roldan (eds.). Serono Symposia, USA, Norwell, Massachusetts.
• Cherr, G.N., R.G. Summers, J.D. Baldwin, and J.B. Morrill. 1992. Preservation and visualization of the sea urchin blastoceolic extracellular matrix. Microscopy Research and Technique, 22:11-22.
• Cherr, G.N. and E.Z. Drobnis. 1992. Fertilization in the Golden Hamster, In: A Comparative Overview of Mammalian Fertilization. B.S. Dunbar and M.G. O'Rand, (eds.), Plenum Press, New York and London. pp. 217-243.
• Yanagimachi, R., G.N. Cherr, M.C. Pillai, and J.D. Baldwin. 1992. Evidence suggesting the presence of sperm activating and guiding factors in the micropyle area of salmonid and herring eggs. Development Growth Differentiation, 34: 447-461.
• Pillai, M.C., Shields, T.S., Yanagimachi, R. and Cherr, G.N. 1993. Isolation and partial characterization of the sperm motility initiating factor from the eggs of the Pacific herring, Clupea pallasi. Journal of Experimental Zoology. 265:336-342.
• Pillai, M.C., Yanagimachi, R. and Cherr, G.N. 1994. In vivo and in vitro initiation of sperm motility using cryopreserved gametes from the Pacific herring, Clupea pallasi. Journal of Experimental Zoology. 269:62-68.
• Griffin, F.J., C.A. Vines, M.C. Pillai, R. Yanagimachi, and G.N. Cherr. 1996. Sperm motility inititating factor (SMIF) is a minor component of the Pacific herring egg chorion. Development Growth Differentiation, 38:193-202.
• Cherr, G.N., S.A. Meyers, A.I. Yudin, C.A. VandeVoort, D. G. Myles, P. Primakoff, and J.W. Overstreet. 1996. The PH-20 protein in cynomolgus macaque spermatozoa: Identification of two different forms exhibiting hyaluronidase activity. Developmental Biology, 175:142-153.
• Meyers, S.A., A.I. Yudin, G.N. Cherr, C.A. Vandevoort, D.G. Myles, P. Primakoff, and J.W. Overstreet. 1997. Hyaluronidase activity of macaque sperm assessed by an in vitro cumulus penetration assay. Molecular Reproduction and Development, 46:392-400.
• Sabeur, K., G.N. Cherr, A.I. Yudin, P. Primakoff, M-W. Li, and J.W. Overstreet. 1997. The PH-20 protein in human spermatozoa. Journal of Andrology, 18:151-158.
• VandeVoort, C.A., G.N. Cherr, and J.W. Overstreet. 1997. Hyaluronic acid enhances the zona pellucida-induced acrosome reaction of macaque sperm. Journal of Andrology, 18:1-5.
• Garman, G.D., S.L. Anderson, and G.N. Cherr. 1997. Developmental abnormalities and DNA-protein crosslinks in sea urchin embryos exposed to three metals. Aquatic Toxicology, 39:247-265.
• Li, M-W., G.N. Cherr, A.I. Yudin, and J.W. Overstreet. 1997. Biochemical Characterization of the protein on the plasma and inner acrosomal membrane of cynomolgus macaque spermatozoa. Molecular Reproduction and Development 48:356-366.
• Griffin, F.J., M.C. Pillai, C.A. Vines, R. Yanagimachi, and G.N. Cherr. 1998. Effects of salinity on sperm motility, fertilization, and development in the Pacific herring, Clupea pallasi.. Biological Bulletin, 194:25-35.
• Yudin, A.I., G.N. Cherr, C.A. VandeVoort, and J.W. Overstreet. 1998. Sperm surface PH-20 rearrangement after exposure to anti- PH-20 antibodies or upon binding to zona pellucida. Molecular Reproduction and Development, 50:207-220.
• Sabeur, K., G.N. Cherr, A.I. Yudin, and J.W. Overstreet. 1999. Hyaluronic acid enhances induction of the acrosome reaction of human sperm through interaction with the PH-20 protein. Zygote. In Press.
• Lokeshwar, V.B., M.M. Young, G. Goudarzi, N. Lida, A.I. Yudin, G.N. Cherr, and M. Seizer. 1999. Identification of bladder tumor-derived hyaluronidase: Its similarity to Hyal-1. Cancer Research, In press.