scholarly journals Observations on the Development and Struoture of the Vitelline Membrane of the Hen's Egg: An Eleotron Miorosoope Study

1969 ◽  
Vol 22 (3) ◽  
pp. 653 ◽  
Author(s):  
Joan M Bain ◽  
Janice M Hall
Keyword(s):  
Outer Layer ◽  
Egg Yolk ◽  
Vitelline Membrane ◽  
Secretory Cells ◽  
White Leghorn ◽  
Hen’S Egg ◽  
The Relationship

Stages in the development of the outer layer of the vitelline membrane of a hen's egg have been observed in an egg found in the infundibulum of a sacrificed White Leghorn hen. Tissue from the infundibulum and the underlying egg yolk material was taken at increasing distances from the upper end of the egg and the relationship between the secretory cells of the infundibulum and the vitelline mem-brane observed. The structure of the vitelline membrane in ova just liberated from the ovary and not yet in the oviduct and that of the vitelline membrane in new-laid eggs from other White Leghorn hens were observed for comparison.

Isolation, characterization and localization of a lectin within the vitelline membrane of the hen's egg

Development ◽  
1985 ◽  
Vol 90 (1) ◽  
pp. 389-407
Author(s):  
Geoffrey M. W. Cook ◽  
Ruth Bellairs ◽  
Nicholas G. Rutherford ◽  
Caroline A. Stafford ◽  
Thomas Alderson
Keyword(s):  
Outer Layer ◽  
Gel Electrophoresis ◽  
Immunofluorescence Microscopy ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Vitelline Membrane ◽  
Two Dimensional Gel Electrophoresis ◽  
Sulphated Polysaccharides ◽  
Hen’S Egg ◽  
Bactericidal Properties

A lectin with an affinity for certain sulphated polysaccharides, such as fucoidin and dextran sulphate, has been isolated from the vitelline membrane of hens' eggs and purified to homogeneity as assessed by two-dimensional gel electrophoresis. Polyclonal and monoclonal antibodies have been raised to the lectin and used in indirect immunofluorescence microscopy to localize the agglutinin in the outer layer of the vitelline membrane, where the lectin persists prior to the breakdown of the vitelline membrane. The quantity of lectin extracted from the two layers of the membrane, which have been separated by the method of Bellairs, Harkness & Harkness (1963), correlated well with the results of immunofluorescence microscopy. Sodium dodecyl sulphate—polyacrylamide gel electrophoresis of the two layers of the membrane indicates that each layer has a distinctive polypeptide composition, the outer layer containing in particular lysozyme and avidin. The evidence obtained in this study indicates that the lectin is not involved in adhesion of the blastoderm to the vitelline membrane; neither is it involved in the expansion of the blastoderm nor in maintaining the strength of the membrane. The possible roles in promoting transport of solutes across the membrane as well as providing bactericidal properties to the egg are discussed.

The Relations Between Yolk and White in the Hen'S Egg

1931 ◽  
Vol 8 (3) ◽  
pp. 293-311
Author(s):  
MICHAEL SMITH ◽  
JAMES SHEPHERD
Keyword(s):  
Steady State ◽  
Alternative Explanation ◽  
Water Movement ◽  
Egg Yolk ◽  
Egg White ◽  
Effect Of Temperature ◽  
Vitelline Membrane ◽  
Osmotic Concentration ◽  
Freezing Points ◽  
Hen’S Egg

1. The freezing-points of white and yolk in the hen's egg gradually approach equality when the egg is kept for long periods; and the rate of the process of equilibration is rapid at first but becomes very slow as equality is more closely approached. 2. Between 0° and 25° C. the rate of equilibration has a temperature coefficient (Q 10) of from 1.5 to 2. At 25° C. equality of freezing-points is reached after about 70 days. 3. Equilibration is achieved partly by the passage of water across the vitelline membrane from white to yolk, but partly also by more complicated changes of osmotic concentration occurring more or less independently in white and yolk. 4. The recovery of hypertony by a yolk, previously diluted by immersion in water, when it is replaced in egg-white can, be explained on the basis of a temporary heterogeneity of the diluted yolk, and this explanation is supported by experimental evidence. 5. The rate of equilibration is much greater when the separated yolk is placed in mixed egg-white than in the intact egg, but since it is also greater in thin white than in thick white, and greater again in the white dialysate, the structure and viscosity of the white are probably important factors. 6. There is evidence of an appreciable resistance to water-movement both in egg-white and in egg-yolk. 7. In hypotonic or hypertonic aqueous solutions of glucose or glycerol, or in Ringer's solution, the rate of equilibration is greater than in egg-white and many times greater than in the intact egg. Water is taken up by the yolk both from hypotonic and hypertonic solutions of Ringer, within the range δ = 0.10° to 1.20° C., at a rate which increases the further the solution is removed from the point of isotony. 8. Evidence that the apparent disequilibrium in intact eggs is not a steady state maintained by a "Lebenswirkung," is afforded by: (i) the form of the equilibration curves, which strongly suggest the slow attainment of an equilibrium by diffusion, rather than a steady state terminated by death; (ii) the temperature relations of equilibration, which are consistent with the former assumption, but which do not agree at all with the effect of temperature on the viability of fertile eggs; (iii) the absence of any tendency of the yolk to maintain its hypertony when the white is concentrated by rapid evaporation; (iv) the alternative explanation for the recovery of hypertony by diluted yolks, which was the most crucial evidence for the existence of a steady state maintained by the expenditure of energy.

scholarly journals Isolation of a novel protein from the outer layer of the vitelline membrane

1992 ◽  
Vol 286 (1) ◽  
pp. 17-22 ◽  
Author(s):  
S Kido ◽  
A Morimoto ◽  
F Kim ◽  
Y Doi
Keyword(s):  
Outer Layer ◽  
Alpha Helix ◽  
Egg Yolk ◽  
Exchange Chromatography ◽  
Equilibrium Analysis ◽  
Sedimentation Equilibrium ◽  
Vitelline Membrane ◽  
Heat Denaturation ◽  
Protein Sequence Comparison ◽  
Novel Protein

The outer layer of the vitelline membrane from hen egg yolk consists of ovomucin, vitelline membrane outer layer protein I (VMOI) and lysozyme. Here we report the occurrence of a further basic protein (pI 11.5) in the outer layer, which was designated as vitelline membrane outer layer protein II (VMOII). It was dissociated from the outer layer in a 10% (w/v) NaCl solution and purified to homogeneity by ion-exchange chromatography. VMOII is a simple protein with a molecular mass of 6000 Da, as determined by sedimentation equilibrium analysis. The amino acid composition of VMOII was characterized by the absence of Met and high contents of cystine (half) (14%) and basic amino acids (6% Arg, 6% Lys and 3% His). Analysis of carboxymethylated VMOII indicated that all cysteine residues were involved in disulphide bonding, which appears to facilitate the binding of SDS to the protein. Sequence comparison of the N-terminal 20 residues revealed no identity with other known proteins. VMOII contained a small amount of alpha-helix and was quite resistant to heat denaturation.

scholarly journals Osmotic pressures in the henʼs egg

1934 ◽  
Vol 114 (789) ◽  
pp. 436-440 ◽  
Keyword(s):  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Freezing Point ◽  
Egg Yolk ◽  
Egg White ◽  
Vitelline Membrane ◽  
Osmotic Gradient ◽  
Hen’S Egg ◽  
The Difference ◽  
The Hill

In a recent paper Howard (1932) claims to have shown, by three methods, that the "expected" osmotic equilibria exist between the yolk and white of a hen's egg. Johlin (1933) has criticized her technique of cryhydric measurement and re-asserted that the yolk and white of an egg hive different values for depression of freezing point. Although Needham (1931) and Meyerhof (1931) have considered the possibility of the outer layer of yolk having a lower osmotic pressure than the inner, Howard gives no experimental evidence indicating the existence of an osmotic gradient within the yolk. The methods she used being apparently incapable of showing the difference in osmotic pressure between the whole yolk and the whole white of an egg were presumably unable also to detect the osmotic gradient in the yolk. Grollman's (1931) criticisms of the Hill thermo-electric method for the measurement of vapour pressures when employed with viscous solutions were repeated by Howard, with no other evidence than that it gave results which disagreed with her own. In particular, Bateman's low vapour pressure depression found in mixtures of egg yolk and egg white are declared to be incompatible with high vapour pressure depressions for yolk. It is strange that in the differentiation of the properties of egg yolk and white so many authors should have considered the yolk as homogeneous. It is a well-known fact that the formation of an egg yolk occurs by daily deposits in the ovary of the hen. These extend over several days and that the integrity of the daily deposit is maintained more or less for many days is evidenced by observation of the spherical zones in the yolk of a frozen egg that has been sectioned. Also it is easy to withdraw from the centre of the yolk, using a fine pipette, white yolk which is different chemically from the surrounding yellow yolk. Since no membrane is known to separate these two kinds of yolk nor the daily deposit of yolk, the existence of this non-homogeneity within the yolk must be an indication of the slowness of equilibration inside a hen's egg. Hence, when one speaks of the difference in osmotic pressure of average egg white and average egg yolk, no conclusions can be drawn logically regarding the difference in osmotic pressure on opposite sides of the vitelline membrane. As the Hill thermoelectric method of measuring vapour pressure requires but small quantities of solution, it was of interest to use this micro method to study the difference in osmotic pressures of samples of yolk and white obtained on opposite sides of the membrane.

scholarly journals A Rapid Method for Evaluating the Strength of the Vitelline Membrane of the Hen’s Egg Yolk

1962 ◽  
Vol 41 (5) ◽  
pp. 1516-1521 ◽  
Author(s):  
Daniel Fromm ◽  
Gennard Matrone
Keyword(s):  
Rapid Method ◽  
Egg Yolk ◽  
Vitelline Membrane ◽  
Hen’S Egg

6,8-Dihydroxypurine in the Hen’s Egg Yolk

1973 ◽  
Vol 28 (7-8) ◽  
pp. 482-483
Author(s):  
S. De Boeck ◽  
T. Rymen ◽  
J. Stockx
Keyword(s):  
Egg Yolk ◽  
Hen’S Egg

Characterization of glycopeptides derived from the low-density lipoprotein of hen's egg yolk

1968 ◽  
Vol 46 (8) ◽  
pp. 983-988 ◽  
Author(s):  
J. Z. Augustyniak ◽  
W. G. Martin
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Egg Yolk ◽  
Low Density ◽  
Amide Nitrogen ◽  
Acetylneuraminic Acid ◽  
Hen’S Egg ◽  
Terminal Amino ◽  
Protein Moiety

Two glycopeptides (A and B) were isolated from pronase-digested vitellenin, the protein moiety of the low-density lipoprotein of hen's egg yolk. Aspartic acid was the only N-terminal amino acid of both glycopeptides but only A contained N-acetylneuraminic acid. A contained 55% hexose (mannose), 14% hexosamine, 12% N-acetylneuraminic acid, 0.71% amide nitrogen, and its molecular weight was 2.3 × 103. The corresponding values for B were 64, 17, 0.0, 0.75, and 2.0 × 103. Chemical analyses showed that B (and probably A) occurs in vitellenin with the heteropolysaccharide group bound N-glycosidically via the β-amide group of an asparaginyl residue. The indicated structure is R∙(NH)Asp∙Thr∙Ser∙(Ala, Gly, Val)∙Ile, where R, the heteropolysaccharide group, contains 2 hexosamine and 8 hexose residues.

scholarly journals Microscopical characterization of the salivary glands of the carnivorous cephalaspidean Philinopsis depicta (Mollusca, Opisthobranchia)

2009 ◽  
Vol 15 (S3) ◽  
pp. 39-40
Author(s):  
A. Lobo-da-Cunha ◽  
I. Ferreira ◽  
G. Calado
Keyword(s):  
Salivary Glands ◽  
Secretory Cells ◽  
Apical Region ◽  
Ciliated Cells ◽  
Transmission Electron ◽  
Herbivorous Species ◽  
Small Clusters ◽  
The Relationship ◽  
Apical Vacuole

AbstractCephalaspideans are a group of opisthobranch gastropods comprising carnivorous and herbivorous species, allowing an investigation of the relationship between these diets and the morphofunctional features of the salivary glands.In this study, the salivary glands of the carnivorous cephalaspidean Philinopsis depicta were observed by light microscopy using semithin sections and by transmission electron microscopy. A central duct runs along the length of these thin ribbon-shaped glands dividing them in two halves, each formed by a single row of tubules perpendicularly attached to the central duct. The simple epithelium of the central duct and lateral tubes contains ciliated cells and two types of secretory cells, named granular cells and cells with apical vacuole (Fig. 1). A very thin outer layer of connective tissue covers the epithelium (Fig. 1). The ciliated cells are numerous but very thin, forming small clusters between secretory cells. The nucleus, several mitochondria and a few lysosomes are located in the apical region were the cells are wider. A very thin cytoplasmic stalk reaches the base of the epithelium and contains bundles of filaments in addition to some mitochondria.

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