George L. Gerton
Perelman School of Medicine at the University of Pennsylvania
421 Curie Blvd., 1309 Biomedical Research Bldg.
Philadelphia, PA 19104-6160
Fax: 215 573-5408
BA/honors (Biochemistry/Molecular Biology)
University of California at Santa Barbara, 1975.
University of California at Davis, Dissertation: “Glycoprotein and protein changes in the envelopes from Xenopus laevis eggs.” (Advisor: Jerry L. Hedrick, Ph.D.), 1980.
Description of Research ExpertiseResearch Interests
Spermatogenesis, Fertilization, Pre-implantation Mammalian Embryo Development
Key words: Spermatogenesis, Acrosome, Spermatid, Flagellum, Acrosomal matrix, Preimplantation, Embryo, Trophoblast.
Description of Research
The Gerton laboratory uses a multidisciplinary approach to examine issues pertaining to mammalian spermatogenesis, sperm function, and preimplantation embryo development. In addition, we are carrying out clinical studies directed toward improving the diagnosis of ectopic pregnancies.
Several of the major components of the acrosome and sperm tail have been purified and their corresponding cDNAs cloned for studies of protein structure and expression. The deduced amino acid sequences of these proteins have provided new clues concerning the functions of acrosomal and flagellar proteins. One major direction of the laboratory is to study acrosomal and flagellar protein targeting and function in spermatogenic cells and transfected somatic cells using tools of molecular biology and cell biology and to extend these studies to cases of infertility in humans and other species.
Other projects in the laboratory focus upon the functions of proteins identified as components of the sperm acrosome. Acrosomal matrix protein sp56 is involved in sperm-zona pellucida interactions. These studies are leading to a re-evaluation of acrosomal exocytosis. A revised paradigm has been developed that describes acrosomal exocytosis as a continuously variable process with functional intermediates rather a two-step, acrosome-intact/acrosome-reacted, process.
We are also continuing our analysis of the roles of proteins associated with the accessory structures of sperm flagellum. These non-axonemal proteins perform novel functions in regulating sperm motility.
Regarding preimplantation embryo development in mammals, we are studying the function of progranulin, the precursor of the granulin and epithelin peptides, on mouse embryos. Our results show that acrogranin is an essential growth factor for the development of embryos to the blastocyst stage.
1. Identification of ligands bound by acrosomal matrix proteins.
2. Effect of recombinant progranulin on cultured somatic and embryonic cells.
3. Role of sp56 as a zona-binding protein (in vitro fertilization experiments).
4. Study the roles of adenine nucleotides (ATP, ADP, and AMP) in regulating sperm motility.
5. Examine the role of soluble adenylyl cyclase in enabling sperm to be capable of fertilization.
Mariano G. Buffone, Ph.D., Research Associate
Wenlei Cao, Ph.D., Senior Research Investigator
Takashi Ijiri, Ph.D., Postdoctoral Researcher
Tanya Merdiushev, Laboratory Manager
Haig Aghajanian, Research Specialist
Angel Lin, Research Specialist
Selected PublicationsCaballero-Campo Pedro, Buffone Mariano G, Benencia Fabian, Conejo-García José R, Rinaudo Paolo F, Gerton George L: A role for the chemokine receptor CCR6 in mammalian sperm motility and chemotaxis. Journal of cellular physiology 229(1): 68-78, Jan 2014.
Ijiri T W, Vadnais M L, Huang A P, Lin A M, Levin L R, Buck J, Gerton G L: Thiol changes during epididymal maturation: a link to flagellar angulation in mouse spermatozoa? Andrology Nov 2013.
Ijiri Takashi W, Vadnais Melissa L, Lin Angel M, Huang Andy P, Cao Wenlei, Merdiushev Tanya, Gerton George L: Male mice express spermatogenic cell-specific triosephosphate isomerase isozymes. Molecular reproduction and development 80(10): 862-70, Oct 2013.
Vadnais Melissa L, Aghajanian Haig K, Lin Angel, Gerton George L: Signaling in sperm: toward a molecular understanding of the acquisition of sperm motility in the mouse epididymis. Biology of reproduction 89(5): 127, 2013.
Muro Y, Buffone MG, Okabe M, Gerton GL: Function of the acrosomal matrix: zona pellucida 3 receptor (ZP3R/sp56) is not essential for mouse fertilization. Biol Reprod. 86(1):1–6, 2012.
Zhang X, Chou W, Haig-Ladewig L, Zeng W, Cao W, Gerton G, Dobrinski I, Tseng H.: BNC1 is required for maintaining mouse spermatogenesis. Genesis (New York, N.Y.: 2000) [Internet] 2012 Notes: [cited 2012 Mar 19];Available from: http://www.ncbi.nlm.nih.gov/pubmed/22266914.
Hirohashi N, Gerton GL, Buffone MG: Video imaging of the sperm acrosome reaction during in vitro fertilization. Commun Integr Biol. 4(4):471–6, 2011.
Cao W, Ijiri TW, Huang AP, Gerton GL: Characterization of a novel tektin Member, TEKT5, in mouse sperm. J Androl. 32(1):55-69, 2011.
Kim K-S, Foster JA, Kvasnicka KW, Gerton GL: Transitional states of acrosomal exocytosis and proteolytic processing of the acrosomal matrix in guinea pig sperm. Mol Reprod Dev. 78(12):930–41, 2011.
Ijiri TW, Merdiushev T, Cao W, Gerton GL: Identification and validation of mouse sperm proteins correlated with epididymal maturation. Proteomics 11(20):4047–62, 2011.