"A structural view of egg coat architecture and function in fertilization". "Mammalian zona pellucida glycoproteins: structure and function during fertilization". "The ZP domain is a conserved module for polymerization of extracellular proteins". ^ Jovine L, Qi H, Williams Z, Litscher E, de Sanctis D, Wassarman PM (2002)."Cracking the egg: Increased complexity in the zona pellucida". Lefièvre, L Hughes, DC Barratt, CL (2005). "Analysis of fish ZP1/ZPB homologous genes-evidence for both genome duplication and species-specific amplification models of evolution". ZP3 allows species-specific sperm bindingĭata with native human protein are not currently available.Successful fertilization depends on the ability of sperm to penetrate the extracellular matrix of the zona pellucida that surrounds the egg. They bind to capacitated spermatozoa and induce the acrosome reaction. The four major sperm-binding proteins, or sperm-receptors, are ZP1, ZP2, ZP3, and ZP4. The major glycoproteins of the egg coat responsible, are known as sperm-binding proteins. Also allows correct embryo development and size. ![]() The thick membrane of the zona pellucida functions to only allow species-specific fertilization to prevent polyspermy, and enable the acrosome reaction for the successful adhesion and penetration by the sperm cell. In non-mammals it is called the vitelline membrane or vitelline envelope. Its formation, which depends on a conserved Zona pellucida-like (ZP) module that mediates the polymerization of egg coat components, is critical to successful fertilization. The zona pellucida is a translucent matrix of cross-linked glycoprotein filaments that surrounds the mammalian oocyte and is 6.5–20 μm thick depending on the species. The zona pellucida is essential for oocyte growth and fertilization. In humans, five days after the fertilization, the blastocyst performs zona hatching the zona pellucida degenerates and decomposes, to be replaced by the underlying layer of trophoblastic cells. The exact characterisation of what occurs in other species has become more complicated as further zona proteins have been identified. ZP3 is then involved in the induction of the acrosome reaction, whereby a spermatozoon releases the contents of the acrosomal vesicle. In the mouse (the best characterised mammalian system), the zona glycoprotein, ZP3, is responsible for sperm binding, adhering to proteins on the sperm plasma membrane. This structure binds spermatozoa, and is required to initiate the acrosome reaction. The corona is composed of cells that care for the egg when it is emitted from the ovary. The zona pellucida is surrounded by the corona radiata. It is secreted by both the oocyte and the ovarian follicles. The zona pellucida first appears in unilaminar primary oocytes. It is a vital constitutive part of the oocyte. Ideal Uses: As a protective coating on aluminum wheels, chrome bumpers, marine railings, chrome or aluminum covers, grills, handles, ornaments, lights, etc.The zona pellucida (plural zonae pellucidae, also egg coat or pellucid zone) is a specialized extracellular matrix that surrounds the plasma membrane of mammalian oocytes. Note: When applying over polished metals (aluminum, chrome, brass, copper etc) you must use AP120 metal prep according to instructions. To remove moisture from walls, this Glisten PC is highly recommended. ![]() It will never crack, chip, peel or yellow, and is very flexible as well. Like many other coatings, Glisten PC is a Moisture-cured coating, which means it is strengthened by exposure to moisture. Accidental contact could damage the surface before full cure has taken place. Avoid touching it for several days until it becomes hard and tough. When Glisten PC is first dry to the touch, it will appear to be very soft. Glisten PC will not leave brush marks, and will dry in less than one hour, but will take 3-4 days to reach maximum hardness. Glisten PC is a high gloss, rock hard, water-clear topcoat designed for spray or brush application over all metal surfaces, including highly polished aluminum and chrome surfaces.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |