Most cases of male infertility can not be adequately explained although some are thought to involve fertilization dysfunction. Our objective is to understand the cell and molecular biology of one of the first stages of the human fertilization process - the early association of the sperm with the egg's zona pellucida - and to determine if there is a class of male infertility resulting from dysfunction of this stage of gamete interaction. The proposed experiments will test with human gametes a model developed from animal studies which suggests sperm-zona binding is due to bonds formed between an externally exposed, plasma membrane sperm enzyme (galactosyltransferase) and terminal N-acetylglucosamine residues in the zona pellucida. In pilot experiments, we have detected galactosyltransferase on human sperm. In this project we will test the role of this enzyme in the binding of sperm to the human zona pellucida by determining: 1) the effectiveness of inhibitors of the enzyme in blocking sperm-zona binding, 2) the ability of the human zona pellucida to serve as an acceptor for sperm galactosyltransferase-catalyzed transfer of [3H]-galactose from uridinediphospho[3H]galactose and 3) the ability of uridinediphosphogalactose to cause detachment of sperm bound to the human zona pellucida. The incidence of subnormal sperm-zona binding in infertile men will be reinvestigated using an assay of increased precision, and the correlation between the sperm-zona binding and sperm galactosyltransferase activity will be determined in both fertile and infertile men, to see if subnormal sperm transferase activity can be used as an indicator of infertility. Finally, the major protein components of the human zona pellucida will be analyzed by SDS/polyacrylamide gel electrophoresis. A solubilized preparation of human zonae pellucidae will be tested for its ability to induce acrosome reactions in human sperm and to see if it contains material with properties expected of a sperm receptor.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
2R01HD019587-02
Application #
3316964
Study Section
Reproductive Biology Study Section (REB)
Project Start
1985-09-30
Project End
1988-08-31
Budget Start
1986-09-01
Budget End
1987-08-31
Support Year
2
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of California Davis
Department
Type
Schools of Medicine
DUNS #
094878337
City
Davis
State
CA
Country
United States
Zip Code
95618
Cross, N L; Moore, S (1990) Regional binding of human anti-sperm antibodies assessed by indirect immunofluorescence. Hum Reprod 5:47-51
Morales, P; Cross, N L; Overstreet, J W et al. (1989) Acrosome intact and acrosome-reacted human sperm can initiate binding to the zona pellucida. Dev Biol 133:385-92
Fukuda, M; Cross, N L; Cummings-Paulson, L et al. (1989) Correlation of acrosomal status and sperm performance in the sperm penetration assay. Fertil Steril 52:836-41
Cross, N L; Meizel, S (1989) Methods for evaluating the acrosomal status of mammalian sperm. Biol Reprod 41:635-41
Morales, P; Cross, N L (1989) A new procedure for determining acrosomal status of very small numbers of human sperm. J Histochem Cytochem 37:1291-2
Overstreet, J W; Cross, N L (1988) The biology of human sperm-zona pellucida interaction. Ann N Y Acad Sci 541:337-45
Cross, N L; Morales, P; Overstreet, J W et al. (1988) Induction of acrosome reactions by the human zona pellucida. Biol Reprod 38:235-44
Cross, N L; Overstreet, J W (1987) Glycoconjugates of the human sperm surface: distribution and alterations that accompany capacitation in vitro. Gamete Res 16:23-35
Wiley, L M; Obasaju, M F; Overstreet, J W et al. (1987) Detection of antisperm antibodies: their localization to human sperm antigens that are transferred to the surface of zona-free hamster oocytes during the sperm penetration assay. Fertil Steril 48:292-8
Cherr, G N; Cross, N L (1987) Immobilization of mammalian eggs on solid substrates by lectins for electron microscopy. J Microsc 145:341-5

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