The primary interest of Dr. Bleil's laboratory is analysis of mammalian fertilization at the molecular level, combining techniques of biochemistry and molecular genetics. Studies proposed here are designed to determine which of two identified mouse sperm proteins functions as the ZP3 recognition protein: i.e., the sperm protein responsible for primary binding of mouse sperm to the zone pellucida. In preliminary studies, a mouse sperm "56K doublet" protein having properties expected of the ZP3 recognition protein has been identified on the basis of affinity chromatography and crosslinking studies. This protein will be further characterized biochemically. It has been proposed by others that a sperm galactose-binding protein related to asialoglycoprotein receptor functions as the mouse sperm protein which recognizes ZP3. Studies described here are designed to determine whether this rat protein is related to the mouse sperm 56kD protein and, independently, whether an asialoglycoprotein receptor-related protein of mouse sperm has properties expected for the ZP3 recognition protein. The long term objectives of the proposed study are 1) to identify and characterize mammalian sperm proteins (fertilization proteins") which mediate interaction between sperm and egg at the level of the zona pellucida and 2) to determine, at the molecular level, how sperm "fertilization proteins" interact with their counterparts in the zone pellucida. %%% This work proposes to identify those molecules on sperm that are responsible for recognition of receptors on the egg surface that enable fertilization to take place. %%%
