Vitellin

Physical Properties. The egg is composed of three basic parts shell, whites (albumen), and yolk. Each of these components has its own membranes to keep the component intact and separate from the other components. The vitelline membrane surrounds the yolk, which in turn is surrounded by the chala2iferous layer of albumen, keeping the yolk in place. Egg white (albumen) consists of an outer thin layer next to the shell, an outer thick layer near the shell, an inner thin layer, and finally, an inner thick layer next to the yolk. Thick layers of albumen have a higher level of ovomucin in addition to natural proportions of all the other egg white proteins. This ovomucin breaks into shorter fibers when the egg white is blended on a high speed mixer (3), or when the egg white ages. Viscosity is gready reduced when the egg white is blended in this way. 

The yolk is separated from the white by the vitelline membrane, and is made up of layers that can be seen upon careful examination. Egg yolk is a complex mixture of water, Hpids, and proteias. Lipid components iaclude glycerides, 66.2% phosphoUpids, 29.6% and cholesterol [57-88-5] 4.2%. The phosphohpids consist of 73% lecithin [8002 3-5] 15% cephahn [3681-36-7], and 12% other phosphohpids. Of the fatty acids, 33% are saturated and 67% unsaturated, including 42% oleic acid [112-80-1] and 7% linoleic acid [60-33-3]. Fatty acids can be changed by modifying fatty acids ia the laying feed (see... 

Dotter-. yolk, vitelline, -gelb, n. egg yolk, egg yellow. -61, n. gold-of-pleasure oil, camelina (seed) oil. 

No spermatozoa are seen on the egg surface or on the vitelline coat. After 5 h of treatment with 10 M TBTCl, a few spermatozoa, with very anomalous heads, have been detected. The absence of spermatozoa on the egg surface or on the vitelline coat could be explained by the absence of the follicle cells, which, in S. plicata, primarily play an attracting function. It was previously shown that TBTCl solution, either 10 or 10 M, induces anomalies in spermatozoa, unfertilized, and fertilized eggs of Ascidia malaca. In particular, the follicle cells detach from eggs and the test cells show anomalies in their nucleus and granules. Moreover, damaged spermatozoa are observed in the vitelline coat, but never in... 

The isolated oocytes are still surrounded by the vitelline membrane, an inner glycoprotein matrix layer (Yao et al., 2000). This layer does not interfere with whole-cell recording experiments. It can be removed manually however, for patch-clamp experiments requiring the formation of high-resistance seals. 

E. Abderhalden und A. Hunter. Hydrolyse des im Eigelb des Huhnereies enthaltenen Proteins ( Vitellin"). Zeit. physiol. Chem., igo6, 48, 505-512. 

P. A. Levene and C. L. Alsberg. The Cleavage Products of Vitellin. J. Biol. Chem.,... 

At this stage, a normal yolk sac presents a robust vascular network (Fig. la). When the yolk sac is positioned to view the ventral side of the embryo, separate origins of the vitelline and umbilical vessels should be evident (Fig. lb). The score is reduced according to deviations from expected morphology. 

Aligned prism Vitelline membrane outer layer protein I, subunit A... 

Nelson, D. R. and Leopold, R. A. (2003). Composition of the surface hydrocarbons from the vitelline membranes of dipteran embryos. Comp. Biochem. Physiol. B, 136, 295-308. 

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