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The insect vitelline envelope is the outer proteinaceous layer outside the oocyte and egg. The vitelline envelope, not being a cellular structure, is commonly referred to as a membrane. However, this is a technical misnomer as the structure is composed of protein and is not a cellular component. It varies in thickness between different insects ...
The vitelline membrane or vitelline envelope is a structure surrounding the outer surface of the plasma membrane of an ovum (the oolemma) or, in some animals (e.g., birds), the extracellular yolk and the oolemma. It is composed mostly of protein fibers, with protein receptors needed for sperm binding which, in turn, are bound to sperm plasma ...
The vitelline membrane consists of two major layers found below the ovary and the outer layer found in the oviduct. This membrane supports the yolk and separates from the albumen, or egg white. The proteins that primarily compose the vitelline membrane are the lysozyme and ovomucin foundational for membrane growth during embryonic development ...
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. Its formation, which depends on a conserved zona pellucida-like (ZP) module that mediates the polymerization of egg coat components, [2] is critical to successful fertilization. [3]
The yolk mass, together with the ovum proper (after fertilization, the embryo) are enclosed by the vitelline membrane, whose structure is different from a cell membrane. [ 2 ] [ 3 ] The yolk is mostly extracellular to the oolemma , being not accumulated inside the cytoplasm of the egg cell (as occurs in frogs ), [ 4 ] contrary to the claim that ...
The egg jelly is located immediately surrounding the vitelline envelope and consists primarily of a network of short peptides and sulfated fucan glycoproteins. [1] These short peptides diffuse into the surrounding area and stimulate respiration and movement of the sperm to the egg. [ 1 ]
For these stains, the remedy is a time-honored one — Fels-Naptha soap, which has been around since the late 1800s. The relatively high pH levels disperse oil molecules, lifting them from fabric ...
Vitelline arteries, arteries that bring blood to the yolk sac; Vitelline circulation, the system of blood flowing between an embryo and its yolk sac; Vitelline cyst, a developmental defect relating to the closure of the vitelline duct; Vitelline duct, a tube that joins the yolk sac to the midgut lumen of a human embryo